Citation Nr: 21012457 Decision Date: 03/04/21 Archive Date: 03/04/21 DOCKET NO. 16-15 094A DATE: March 4, 2021 ORDER Entitlement to an initial rating in excess of 10 percent for service-connected left knee degenerative changes and patellofemoral pain syndrome with associated borderline patella alta (left knee disability) is denied. From February 25, 2010, to September 3, 2020, the criteria for a separate 10 percent disability rating, but no higher, for left knee instability is granted, subject to the laws and regulations governing the payment of monetary benefits. From September 4, 2020, the criteria for a 20 percent disability rating, but no higher, for left knee instability is granted, subject to the laws and regulations governing the payment of monetary benefits. Entitlement to an initial rating in excess of 10 percent for service-connected right knee degenerative joint disease (right knee disability) is denied. From December 1, 2010, to September 3, 2020, the criteria for a separate 10 percent disability rating, but no higher, for right knee instability is granted, subject to the laws and regulations governing the payment of monetary benefits. From September 4, 2020, the criteria for a 20 percent disability rating, but no higher, for right knee instability is granted, subject to the laws and regulations governing the payment of monetary benefits. Entitlement to an initial rating in excess of 10 percent prior to May 15, 2014, and in excess of 20 percent thereafter, for service-connected right foot achilles tendonitis is denied. Entitlement to an initial rating in excess of 10 percent prior to February 26, 2014, and in excess of 20 percent thereafter, for service-connected left heel achilles tendonitis is denied. Effective December 1, 2010, entitlement to a total disability rating based on individual unemployability (TDIU) due to service-connected disabilities is granted, subject to the laws and regulations governing the payment of monetary benefits. REMANDED Entitlement to a TDIU due to service-connected disabilities on an extraschedular basis prior to December 1, 2010, is remanded. FINDINGS OF FACT 1. Throughout the appeal period, the preponderance of the evidence demonstrates that the Veteran’s service-connected left knee disability was not manifested by ankylosis; flexion limited to 30 degrees; or extension limited to 15 degrees. 2. Resolving all reasonable doubt in his favor, from February 25, 2010, to September 3, 2020, the Veteran’s left knee disability was manifested by mild instability, but no more. 3. Resolving all reasonable doubt in his favor, since September 4, 2020, the Veteran’s left knee disability was manifested by moderate instability, but no more. 4. Throughout the appeal period, the preponderance of the evidence demonstrates that the Veteran’s service-connected right knee disability was not manifested by ankylosis; flexion limited to 30 degrees; or extension limited to 15 degrees. 5. Resolving all reasonable doubt in his favor, from December 1, 2010, to September 3, 2020, the Veteran’s right knee disability was manifested by mild instability, but no more. 6. Resolving all reasonable doubt in his favor, since September 4, 2020, the Veteran’s right knee disability was manifested by moderate instability, but no more. 7. Prior to May 15, 2014, the Veteran’s service-connected right foot achilles tendonitis was not manifested by marked limitation of motion, marked deformity (pronation, abduction, etc.), or ankylosis; and from May 15, 2014, the Veteran’s service-connected right foot achilles tendonitis was not manifested by marked pronation, marked inward displacement and severe spasms of the tendo achillis on manipulation, not improved by orthopedic shoes or appliances, or ankylosis. 8. Prior to February 26, 2014, the Veteran’s service-connected left heel achilles tendonitis was not manifested by marked limitation of motion, marked deformity (pronation, abduction, etc.), or ankylosis; and from February 26, 2014, the Veteran’s service-connected left foot achilles tendonitis was not manifested by marked pronation, marked inward displacement and severe spasms of the tendo achillis on manipulation, not improved by orthopedic shoes or appliances, or ankylosis. 9. Resolving all reasonable doubt in the Veteran’s favor, he was unable to secure or follow a substantially gainful occupation as a result of the combined effects his service-connected disabilities, effective December 1, 2010. CONCLUSIONS OF LAW 1. The criteria for an initial rating in excess of 10 percent for service-connected left knee disability based on limitation of flexion are not met. 38 U.S.C. §§ 1155, 5107 (2018); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5260 (2020). 2. The criteria for a separate 10 percent disability rating, but no higher, for service-connected left knee disability based on lateral instability are met from February 25, 2010, to September 3, 2020. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257 (2020). 3. The criteria for a 20 percent disability rating, but no higher, for service-connected left knee disability based on lateral instability are met from September 4, 2020. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257. 4. The criteria for an initial rating in excess of 10 percent for service-connected right knee disability based on limitation of flexion are not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5260. 5. The criteria for a separate 10 percent disability rating, but no higher, for service-connected right knee disability based on lateral instability are met from December 1, 2010, to September 3, 2020. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257. 6. The criteria for a 20 percent disability rating, but no higher, for service-connected right knee disability based on lateral instability are met from September 4, 2020. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257. 7. The criteria for an initial rating in excess of 10 percent prior to May 15, 2014, and in excess of 20 percent thereafter, for service-connected right foot achilles tendonitis are not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Codes 5271, 5276 (2020). 8. The criteria for an initial rating in excess of 10 percent prior to February 26, 2014, and in excess of 20 percent thereafter, for service-connected left heel achilles tendonitis are not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Codes 5271, 5276. 9. The criteria for an award of a TDIU are met, effective December 1, 2010. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.340, 3.341, 4.16 (2020). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from September 1976 to August 1985. I. Increased Ratings A. Background By way of background, a July 2010 rating decision granted service connection for the Veteran’s service-connected left knee disability and assigned an initial 10 percent disability rating under Diagnostic Code 5260-5010, effective February 25, 2010. In doing so, the AOJ noted that the 10 percent rating was being assigned pursuant to Diagnostic Code 5003 for the painful or limited motion of a major joint. In an August 2011 rating decision, the agency of original jurisdiction (AOJ) awarded service connection for the Veteran right knee disability and assigned an initial 10 percent disability rating under Diagnostic Code 5257-5003, effective December 1, 2010. In doing so, the AOJ cited 38 C.F.R. § 4.59 and noted that the 10 percent rating was being assigned based on evidence of painful motion. The AOJ also awarded service connection for left heel Achilles tendinitis and assigned a 10 percent disability rating under Diagnostic Code 5099-5024, effective December 1, 2010. In doing so, the AOJ noted that the 10 percent rating was being assigned for the painful or limited motion of a major joint. In a September 2012 rating decision, the AOJ awarded service connection for right heel Achilles tendinitis and assigned a 10 percent disability rating under Diagnostic Code 5099-5024, effective December 3, 2010. In doing so, the AOJ noted that the 10 percent rating was being assigned for painful motion pursuant to 38 C.F.R. § 4.59. In a March 2016 rating decision, the AOJ awarded an increased rating of 20 percent for the Veteran’s left heel Achilles tendinitis under Diagnostic Code 5099-5276, effective February 26, 2014. In a March 2017 rating decision, the AOJ awarded an increased rating of 20 percent for the Veteran’s right heel Achilles tendinitis under Diagnostic Code 5099-5276, effective May 15, 2014. It also awarded a separate 10 percent disability rating for the Veteran’s left knee instability under Diagnostic Code 5257 from May 9, 2011, to May 14, 2014. A noncompensable rating was assigned from May 15, 2014. In a September 2020 rating decision, the AOJ awarded separate 10 percent disability ratings to the Veteran’s bilateral knee disability based on instability under Diagnostic Code 5257, effective September 4, 2020. In a December 2020 rating decision, the AOJ award an earlier effective date of December 1, 2010, to the Veteran’s right heel Achilles tendinitis. B. Pertinent Rules and Regulations Disability evaluations are determined by evaluating the extent to which a veteran’s service-connected disability adversely affects his ability to function under the ordinary conditions of daily life, including employment, by comparing his symptomatology with the criteria set forth in the Schedule for Rating Disabilities (Rating Schedule). 38 U.S.C. § 1155; 38 C.F.R. §§ 4.1, 4.2, 4.10. Where there is a question as to which of two evaluations shall be applied, the higher evaluation will be assigned if the disability picture more nearly approximates the criteria for that rating. Otherwise the lower rating will be assigned. 38 C.F.R. § 4.7. Reasonable doubt will be resolved in the Veteran’s favor. 38 C.F.R. § 4.3. A veteran’s entire history is to be considered when making disability evaluations. See generally 38 C.F.R. § 4.1; Schafrath v. Derwinski, 1 Vet. App. 589 (1995). Where an increase in the level of a service-connected disability is at issue, the primary concern is the present level of disability. Francisco v. Brown, 7 Vet. App. 55 (1994). However, where the question for consideration is entitlement to a higher initial rating assigned following the grant of service connection, evaluation of the medical evidence since the effective date of the grant of service connection and consideration of the appropriateness of “staged rating” (assignment of different ratings for distinct periods of time, based on the facts found) is required. Fenderson v. West, 12 Vet. App. 119, 126 (1999). Pyramiding, that is the evaluation of the same disability, or the same manifestation of a disability, under different diagnostic codes, is to be avoided when evaluating a veteran’s service-connected disability. 38 C.F.R. § 4.14 (2020). However, it is possible for a veteran to have separate and distinct manifestations from the same injury which would permit rating under several diagnostic codes; the critical element in permitting the assignment of several evaluations under various diagnostic codes is that none of the symptomatology for any one of the conditions is duplicative or overlapping with the symptomatology of the other condition. See Esteban v. Brown, 6 Vet. App. 259, 261-62 (1994). Hyphenated diagnostic codes are used when a rating under one diagnostic code requires use of an additional diagnostic code to identify the basis for the evaluation assigned; the additional code is shown after the hyphen. 38 C.F.R. § 4.27 (2020). Disability of the musculoskeletal system is primarily the inability, due to damage or infection in parts of the system, to perform the normal working movements of the body with normal excursion, strength, speed, coordination and endurance. Functional loss may be due to the absence or deformity of structures or other pathology, or it may be due to pain, supported by adequate pathology and evidenced by the visible behavior in undertaking the motion. Weakness is as important as limitation of motion, and a part that becomes painful on use must be regarded as seriously disabled. 38 C.F.R. § 4.40. In Mitchell v. Shinseki, 25 Vet. App. 32 (2011), the Court held that, although pain may cause a functional loss, “pain itself does not rise to the level of functional loss as contemplated by VA regulations applicable to the musculoskeletal system.” Rather, pain may result in functional loss, but only if it limits the ability “to perform the normal working movements of the body with normal excursion, strength, speed, coordination, or endurance.” Id., quoting 38 C.F.R. § 4.40. With respect to joints, in particular, the factors of disability reside in reductions of normal excursion of movements in different planes. Inquiry will be directed to more or less than normal movement, weakened movement, excess fatigability, incoordination, pain on movement, swelling, deformity or atrophy of disuse. 38 C.F.R. § 4.45. The intent of the Rating Schedule is to recognize actually painful, unstable or malaligned joints, due to healed injury, as entitled to at least the minimum compensable rating for the joint. 38 C.F.R. § 4.59. In Burton v. Shinseki, 25 Vet. App. 1, 5 (2011), the Court found that, when 38 C.F.R. § 4.59 is raised by the claimant or reasonably raised by the record, even in non-arthritis contexts, the Board should address its applicability. The Board notes that, during the pendency of the appeal, VA revised the rating criteria for Diagnostic Code 5257, effective February 7, 2021. See 85 Fed. Reg. 76453 (November 30, 2020). When the regulations concerning entitlement to a higher rating are changed during the course of an appeal, the veteran may be entitled to resolution of his claim under the criteria that are to his advantage. The former rating criteria may be applied throughout the period of the appeal, if they are more favorable to him. The revised rating criteria may be applied only prospectively, however, from the effective date of the change forward unless the regulatory change specifically permits retroactive application. 38 U.S.C. § 5110(g); VAOPGCPREC 7-03; VAOPGCPREC 3-00; Kuzma v. Principi, 341 F.3d 1327 (Fed. Cir. 2003). Under the former rating criteria, a 10 percent disability rating is warranted for slight recurrent subluxation or lateral instability of the knee; a 20 percent rating is warranted for moderate recurrent subluxation or lateral instability of the knee; and a 30 percent rating is warranted for severe recurrent subluxation or lateral instability of the knee. 38 C.F.R. § 4.71a. Effective February 7, 2021, Diagnostic Code 5257 was revised. Under the revised rating criteria, a 30 percent disability rating is warranted for unrepaired or failed repair of a complete ligament tear causing persistent instability, and a medical provider prescribed both an assistive device (e.g., cane(s), crutch(es), walker). Alternatively, a 30 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for a brace and either a cane or a walker. 38 C.F.R. § 4.71a, Diagnostic Code 5257 (effective February 7, 2021). Note(1) to Diagnostic Code 5257 notes that, for patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note (2) to Diagnostic Code 5257 notes that a surgical procedure that does not involve repair of one or more patellofemoral components that contribute to the underlying instability shall not qualify as surgical repair for patellar instability (including, but not limited to, arthroscopy to remove loose bodies and joint aspiration). Under Diagnostic Code 5260, a 10 percent disability rating is warranted for flexion of the knee limited to 45 degrees; a 20 percent rating is warranted for flexion of the knee limited to 30 degrees; and a 30 percent rating is warranted for flexion of the knee limited to 15 degrees. Id. Under Diagnostic Code 5261, a 10 percent rating is warranted for extension of the knee limited to 10 degrees; a 20 percent rating is warranted for extension of the knee limited to 15 degrees; a 30 percent rating is warranted for extension of the knee limited to 20 degrees; a 40 percent for extension of the knee limited to 30 degrees, and 50 percent for extension of the knee limited to 45 degrees. Id. Under Diagnostic Code 5271 limitation of motion of an ankle warrants a 10 percent rating when moderate and 20 percent when marked. Id. Full dorsiflexion is to 20 degrees and full plantar flexion is to 45 degrees. See id., Plate II. Under Diagnostic Code 5276, a 10 percent rating is assigned for moderate symptoms of bilateral pes planus, manifested by the weight-bearing line over or medial to the great toe, inward bowing of the tendo achillis, and pain on manipulation and use of the feet. A 30 percent rating is assigned for severe unilateral pes planus, manifested by objective evidence of marked deformity (pronation, abduction, etc.), pain on manipulation and use accentuated, an indication of swelling on use, and characteristic callosities. A maximum 50 percent rating is assigned for pronounced unilateral pes planus, manifested by marked pronation, extreme tenderness of plantar surfaces of the feet, marked inward displacement and severe spasm of the tendo achillis on manipulation, and the disability is not improved by orthopedic shoes or appliances. Id. The criteria in Diagnostic Code 5276 are conjunctive. See Melson v. Derwinski, 1 Vet. App. 334 (1991) (use of the conjunctive “and” in a statutory provision meant that all of the conditions listed in the provision must be met); compare Johnson v. Brown, 7 Vet. App. 9 (1994) (only one disjunctive “or” requirement must be met in order for an increased rating to be assigned); see also Tatum v. Shinseki, 23 Vet. App. 152 (2009) (holding that 38 C.F.R. § 4.7 is not applicable when the ratings criteria are successive and not variable). The Board observes that the words “mild,” “moderate,” “marked,” and “severe” are not defined in the Rating Schedule. Rather than applying a mechanical formula, the Board must evaluate all of the evidence to the degree that its decisions are “equitable and just.” See 38 C.F.R. § 4.6. It should also be noted that use of descriptive terminology such as “mild” by medical examiners, although an element of evidence to be considered by the Board, is not dispositive of an issue. All evidence must be evaluated in arriving at a decision regarding an increased rating. 38 U.S.C. § 7104(a); 38 C.F.R. §§ 4.2, 4.6. C. Facts Although all the evidence has been reviewed, only the most relevant and salient evidence is discussed below. See Gonzales v. West, 218 F.3d 1378 (Fed. Cir. 2000) (holding that the Board must review the entire record but does not have to discuss each piece of evidence). In March 2010, the Veteran underwent a VA general medical examination, and he reported intermittent pain in his left knee over the years, as well as swelling. The examiner noted that the Veteran limped due to the pain, and that he used a cane to ambulate. He reported increased pain when climbing and descending stairs, as well as after prolonged standing, sitting, walking, and squatting. It was noted that he was unable to perform jogging exercises. The examiner noted that degenerative arthritis was demonstrated on X-rays. Examination revealed evidence of tenderness, but there was no evidence of ankylosis. In March 2010, the Veteran also underwent a VA knee examination, and his reported symptoms included instability, pain, decreased speed of motion, and crepitus. There were no episodes of dislocation or subluxation or locking episodes. The Veteran reported repeated episodes of effusion, as well as tenderness. He also reported flare-ups that were described as moderate, occurring two to three times per year, and lasting for hours at a time. Flare-ups were precipitated by bending, and he reported an inability to walk moderate to prolonged distances. There were no constitutional symptoms and/or incapacitating episodes of arthritis. The Veteran reported that he was only able to stand for fifteen to thirty minutes at a time, and he was able to walk only a quarter mile. Upon examination, his gait was antalgic, and there was evidence of left knee tenderness, pain at rest, and abnormal motion. There was evidence of crepitation, grinding, and subpatellar tenderness; however, there was no evidence of instability or a meniscus abnormality. The Veteran’s range of motion in the left knee was zero to 110 degrees with objective evidence of pain with active motion. His range of motion in the right knee was zero to 128 degrees without objective evidence of pain with active motion. There was also objective evidence of pain with repetitive motion, but the Veteran’s range of motion stayed the same. The examiner noted that ankylosis was not present, and that joint stability testing, including anterior/posterior drawer testing and stress valgus/varus testing was negative. The examiner noted that he was currently unemployed from being a water company mechanic, and that the reason for his unemployment was his low back condition. The examiner also noted that the Veteran’s left knee disability would cause decreased mobility, decreased strength, and pain, and that he would likely have to be assigned different duties. The examiner also noted that his left knee disability would prevent exercise and sports; that it would cause severe problems with chores, shopping, and traveling; and that it would cause moderate problems with recreation, bathing, dressing, toileting, grooming, and driving. A May 2010 Social Security Administration (SSA) evaluation noted that the Veteran displayed an unstable gait with knee pain. Upon examination, it was noted that the Veteran’s left knee resulted in a very instable gait. A September 2010 VA treatment record noted the presence of moderative degenerative changes and small bilateral knee effusions. Another noted that there was no ligamentous instability in the left knee, although there was moderate swelling and tenderness. A November 2010 VA treatment record noted the Veteran’s history of a left knee arthroscopy with meniscal tear. Examination revealed full extension and flexion to 100 degrees. A January 2011 VA treatment record noted that the Veteran displayed full range of motion in his left knee with mild effusion, no pain, and no instability. An April 2011 VA examination noted that the Veteran was currently unemployed, and that he last worked in 2007. The examiner noted his claim that he was unemployable due to his service-connected left knee disability, but the examiner opined that his left knee disability did not limit his ability to do some types of jobs. The examiner stated that the Veteran would be limited with movement such as walking, running, or walking up and down stairs. The examiner stated that he could not perform hard physically demanding jobs, that he had limitations with shopping, recreation, traveling, and house chores, and he could not perform hard physical activities like exercise and sporting. The examiner concluded that the Veteran could engage in employment that did not require strenuous activities, such as desk jobs, sedentary jobs, or passive jobs. In May 2011, the Veteran underwent another VA knee examination. He stated that the condition of his bilateral knee disabilities had progressively worsened. His reported symptoms included giving way, instability, pain, stiffness, decreased speed of motion, locking episodes, repeated episodes of effusions, swelling, and tenderness. The Veteran also reported flare-ups precipitated by prolonged standing and ambulation that he described as moderate and occurring weekly. There were no constitutional symptoms and/or incapacitating episodes of arthritis. The Veteran reported that he was only able to stand for one hour at a time, and he was unable to walk more than a few yards. Upon examination, his gait was antalgic with evidence of abnormal weight bearing in his shoe wear. There was evidence of crepitus, tenderness, pain at rest, guarding of movement, and grinding; however, there was no evidence of instability or a meniscus abnormality. His range of motion in the left knee was zero to 110 degrees with objective evidence of pain with active motion. His range of motion in the right knee was zero to 125 degrees with objective evidence of pain with active motion. There was also objective evidence of pain with repetitive motion, but the Veteran’s range of motion stayed the same. The examiner noted that ankylosis was not present. X-rays revealed moderate degenerative changes of the knee with small bilateral knee effusions. The examiner noted that he was currently unemployed from the water company, and that the reason for his unemployment was his lumbar pain and knee pain. The Veteran was ultimately diagnosed with left knee patellar dislocation with residual osteoarthritis; right knee degenerative joint disease; and left knee instability. The examiner also noted that the Veteran’s bilateral knee disabilities would cause decreased mobility, problems with lifting and carrying, decreased strength, and pain, and that he would likely have to be assigned different duties. The examiner also noted that his bilateral knee disabilities would prevent exercise and sports; and that it would cause mild problems with chores, shopping, recreation, traveling, and driving. The examiner ultimately opined that his left knee disability did not preclude employment given that he worked for several years after his initial injury, and that he retired due to his back pain. The examiner also noted that the Veteran experienced left knee instability that, in turn, caused him to put excessive weight on his right knee, leading to the development of his current right knee disability. In May 2011, the Veteran also underwent a VA feet examination which noted his report of heel pain since service. His reported symptoms included pain while standing and walking, fatigability while standing and walking, and a lack of endurance while standing and walking. The location of the pain was in his Achilles’ tendons, and he was only able to stand for fifteen to thirty minutes at a time, and he was unable to walk more than a few yards. Upon examination, there was evidence of painful motion, tenderness, and abnormal weight bearing. He was ultimately diagnosed with bilateral heel Achilles tendonitis. The examiner concluded that the Veteran’s bilateral feet disabilities would not preclude sedentary employment. An October 2011 VA treatment record noted the Veteran’s report of progressively worsening bilateral ankle pain at the Achilles’ tendon insertion in both ankles, as well as increased swelling. Upon examination, he ambulated without assistive devices with a normal gait and station. There was mild swelling of the right Achilles’ tendon on the right, normal bilateral range of motion, tenderness of the bilateral Achilles tendon’ insertion, and normal ankle strength. The treatment provider also noted that he displayed normal knee range of motion, and the anterior drawer sign was negative bilaterally. In April 2012, the Veteran underwent another VA feet examination, and the examiner noted his report of Achilles tendonitis dating back to 1977 that caused pain with swelling. His reported symptoms included pain while standing, walking and at rest; swelling while standing, walking and at rest; redness; stiffness while standing, walking and at rest; fatigability while standing, walking and at rest; weakness while standing, walking and at rest; and a lack of endurance while standing, walking and at rest. The location of the pain was in his Achilles’ tendons, and he was only able to stand for a few minutes, and he was unable to walk more than a quarter mile. Upon examination, there was evidence of swelling, tenderness, and abnormal weight bearing. He was ultimately diagnosed with bilateral heel Achilles tendonitis, and the examiner concluded that such would have a significant effect on the Veteran’s general occupational, and that it would cause decreased mobility, problems with lifting and carrying, lack of stamina, weakness or fatigue, decreased strength, and lower extremity pain. The examiner also noted that his bilateral heel Achilles tendonitis would prevent exercise and sports; that it would cause severe problems with chores, shopping, and traveling; that it would cause moderate problems with recreation, bathing, dressing, and driving; and that it would cause mild problems with toileting and grooming. In April 2012, the Veteran underwent another VA knee examination, as well as an ankle examination. His reported bilateral knee symptoms included giving way, pain, stiffness, decreased speed of motion, swelling, and tenderness. His reported right ankle symptoms included pain, swelling, and tenderness. He denied flare-ups associated with either his knees or his right ankle. There were no constitutional symptoms and/or incapacitating episodes of arthritis. The Veteran reported that he was only able to stand for few minutes, and he was unable to walk more than a quarter mile. Upon examination, he displayed poor propulsion with evidence of abnormal weight bearing, including callus formation on his right heel and hallux. There was also evidence of abnormal weight bearing in his shoe wear pattern. With regard to his right knee, there was evidence of crepitus, effusion, tenderness, abnormal motion, and guarding of movement; however, there was no evidence of instability. With regard to his left knee, there was evidence of crepitus, tenderness, abnormal motion, and guarding of movement; however, there was no evidence of instability. With regard to his right ankle, there was evidence of severe swelling and tenderness of the Achilles’ tendon; however, there was no evidence of instability. The Veteran’s range of motion in the left knee was 10 degrees to 120 degrees with objective evidence of pain with active motion. His range of motion in the right knee was 10 degrees to 105 degrees with objective evidence of pain with active motion. There was also objective evidence of pain with repetitive motion, but the Veteran’s range of motion stayed the same. His range of motion in the left ankle was zero to 20 degrees dorsiflexion, and zero to 40 degrees plantar flexion; and his range of motion in the right ankle was zero to 20 degrees dorsiflexion, and zero to 40 degrees plantar flexion. Objective evidence of pain with active motion was not shown, there was no objective evidence of pain with repetitive motion, and the Veteran’s range of motion stayed the same. The examiner also noted that ankylosis was not demonstrated in any joint. The examiner noted that he was currently unemployed from as a water plant operator, and that the reason for his unemployment was his lumbar pain. The examiner also noted that the Veteran’s bilateral knee disabilities would cause decreased mobility, problems with lifting and carrying, weakness or fatigue, decreased strength, and pain, and that he would likely have to be assigned different work duties. The examiner also noted that his bilateral knee disabilities would prevent exercise and sports; that it would cause moderate problems with chores, shopping, recreation, traveling, bathing, dressing, grooming, and driving; and that it would cause mild problems with toileting. As for the Veteran’s right Achilles’ tendonitis, the examiner noted that such would cause decreased mobility, problems with lifting and carrying, weakness or fatigue, decreased strength, and pain, and that he would likely have to be assigned different work duties. The examiner also noted that his right Achilles’ tendonitis would prevent exercise and sports; that it would cause severe problems with chores and shopping; that it would cause moderate problems with recreation, traveling, bathing, dressing, grooming, and driving; and that it would cause mild problems with toileting. Finally, the examiner noted that left knee instability was not demonstrated during the examination. In May 2014, the Veteran underwent another VA feet examination, and the examiner noted his diagnoses of bilateral Achilles tendonitis dating back to 1977 that caused pain described as stabbing burning. He also reported flare-ups with prolonged ambulation or standing. The examiner noted that the Veteran had pain on use that was accentuated with manipulation. There was no indication of swelling, characteristic calluses, and extreme tenderness of the plantar surfaces was not shown. There was no evidence of a decreased longitudinal arch, deformity, or pronation. The weight bearing lines did not fall over or medial to the great toe, there was no lower extremity causing alteration of the weight-bearing line, and there was no inward bowing, marked inward displacement, and/or severe spasms of the Achilles’ tendons. The examiner noted that there was evidence of pain, but that it did not contribute to functional loss. The contributing factors of his disability included pain on movement and pain on non-weight bearing. Pain, weakness, fatigability, or incoordination did not significantly limit his functional ability during flare-ups or following repetitive use. The examiner concluded that the Veteran’s bilateral Achilles tendonitis would cause limitations for standing and walking, but that it would not preclude a sedentary job such as clerical work. In May 2014, the Veteran also underwent another VA knee examination and the examiner noted his diagnoses of degenerative joint disease in both knees. The Veteran reported pain upon kneeling, prolonged standing, and walking. He also reported flare-ups. Upon examination, his right knee range of motion was zero to 135 degrees with evidence of painful motion at 5 degrees, and his left knee range of motion was zero to 130 degrees with evidence of painful motion at 5 degrees. Following repetitive-use testing, his range of motion remained consistent, but the examiner noted that pain on movement contributed to the Veteran’s functional loss. There was tenderness and/or pain on palpation, muscle strength testing was normal, and joint stability testing was normal. There was no evidence of history of recurrent patellar subluxation/dislocation. The examiner noted his history of a meniscal tear and his associated symptom of pain. As for the impact that the Veteran’s bilateral knee disabilities have on his ability to work, the examiner noted that the Veteran is limited in his tolerance for ambulation and standing, but that it would not preclude a sedentary job such as clerical work. In March 2019, the Veteran underwent another VA foot conditions examination, and the examiner noted his diagnosis of bilateral Achilles tendonitis, and he reported worsening bilateral heel pain that worsened with prolonged standing and walking. Overall, the examiner determined that his disabilities represented a mild impairment in the right heel and a moderate impairment in the left heel. The examiner noted that the Veteran’s bilateral feet disabilities did not compromise weight bearing, that it did not require arch supports, inserts, or shoe modifications, and that they did not require surgical. Pain was noted on movement and on weight bearing, but he was still able to walk and perform activities of daily living and self-care. The examiner concluded that the Veteran had to avoid prolonged standing and walking activities, but that he could perform sedentary work. In March 2019, the Veteran underwent another VA knee examination and the examiner noted his diagnoses of degenerative joint disease in both knees, as well as patellofemoral pain syndrome with associated borderline patella alta in the left knee. The Veteran reported increased bilateral knee pain with prolonged walking, kneeling, and standing. He also reported flare-ups. Upon examination, his right knee range of motion was zero to 130 degrees with evidence of painful motion, and his left knee range of motion was zero to 120 degrees with evidence of painful motion. Following repetitive-use testing, his range of motion remained consistent, but the examiner noted that pain would significantly limit his functional ability following repetitive use or during flare ups. Muscle strength testing was normal, there was no evidence of ankylosis, and joint stability testing was normal. There was no evidence of history of recurrent patellar subluxation/dislocation. The examiner noted the Veteran’s history of a meniscal tear and his associated symptom of frequent episodes of pain. As for the impact that the Veteran’s bilateral knee disabilities have on his ability to work, the examiner concluded that the Veteran had to avoid prolonged standing and walking activities, but that he could perform sedentary work. In September 2020, the Veteran underwent a VA ankle conditions examination, and the examiner noted his diagnoses of bilateral Achilles tendonitis stemming from 1977 and 2011, as well as his diagnoses of bilateral degenerative joint disease; right medial malleolus calcification, chronic; and left flexor digitorum longus tendonitis. His reported symptoms included pain and occasional swelling. He also reported flare-ups described as a stabbing pain preventing him from walking far. He also reported difficulty traversing stairs. The Veteran’s right ankle range of motion was zero to 20 degrees dorsiflexion and zero to 40 degrees plantar flexion, and pain was noted during examination and it caused functional loss. The examiner also noted mild-moderate tenderness in the right Achilles’ tendon. There was also evidence of pain with weight bearing. The Veteran’s left ankle range of motion was zero to 10 degrees dorsiflexion and zero to 40 degrees plantar flexion, and pain was noted during examination and it caused functional loss. The examiner also noted moderate tenderness in the left Achilles’ tendon. There was also evidence of pain with weight bearing and crepitus. Following repetitive use, his range of motion stayed consistent. The examiner then noted that pain would significantly limit his functional ability with repeated use and during flare-ups, but that his range of motion would likely stay the same. Additional factors contributing to the Veteran’s disability include intermittent swelling. Muscle strength testing was normal, and there was no evidence of muscle atrophy, ankylosis, or ankle instability. As for the functional impact of the Veteran’s bilateral Achilles tendonitis, the examiner noted that the Veteran would be limited in prolonged standing and walking. In September 2020, the Veteran underwent another VA foot conditions examination, and the examiner noted his diagnosis of bilateral Achilles tendonitis, as well as the Veteran report of worsening heel pain and swelling. The Veteran described his pain as a stabbing pain, and he indicated that he could not walk far, that he could only stand for about fifteen minutes, and that it was difficult to go up and down stairs. Upon examination, the examiner noted that the Veteran’s pain was accentuated on use and manipulation, but there was no evidence of swelling on use or characteristic calluses. It was noted that the Veteran did not use arch supports, built-up shoes, or orthotics. There was extreme tenderness of the plantar surfaces on both feet and there was inward bowing of the bilateral Achilles’ tendons, but there was no decreased longitudinal arch height on weight-bearing, there was no evidence of a marked deformity or marked pronation, and there was no evidence of marked displacement and severe spasm of the Achilles’ tendon. Overall, the examiner determined that the Veteran’s disabilities represented a moderate impairment in both heels, that they compromised weight bearing, that they did not require arch supports, inserts, or shoe modifications, and that they did not require surgical intervention. Pain was noted on weight bearing, as was swelling and interference with standing. The examiner noted that his bilateral Achilles tendonitis limited his ability to engage in prolonged standing and weight bearing, and that there was occasional swelling. The examiner concluded that the Veteran was limited in standing for long periods, that he could not walk far or fast, and that traversing stairs was difficult. In September 2020, the Veteran underwent another VA knee examination and the examiner noted his diagnoses of a right knee meniscal tear in 2014, a left knee meniscal tear in 2011, bilateral knee osteoarthritis, bilateral knee instability, left knee patellar dislocation, and left knee patellofemoral pain syndrome. The Veteran reported bilateral knee pain with difficulty standing and instability. He also reported flare-ups, and he indicated that he could not stand or walk for long periods of time, and he could not squat. Upon examination, his right knee range of motion was zero to 130 degrees with evidence of painful motion, and his left knee range of motion was zero to 115 degrees with evidence of painful motion. The examiner also noted moderate tenderness in the right knee and moderately-severe tenderness in the left knee. There was also evidence of pain with weight bearing and crepitus bilaterally. Following repetitive-use testing, his range of motion remained consistent. The examiner then noted that pain would significantly limit his functional ability with repeated use and during flare-ups, but that his range of motion would likely stay the same. Additional factors contributing to the Veteran’s disability include intermittent swelling. Muscle strength testing showed active movement against some resistance normal, and there was no evidence of ankylosis. The examiner noted that there was a history of moderate lateral instability, as well as a history of recurrent effusions. Joint stability testing was performing and, in the right knee the Veteran displayed 2+ medial instability (5-10 millimeters) in the right knee, and 2+ medial instability and 2+ lateral instability in the left knee. Other stability testing was normal. The examiner then noted his history of bilateral meniscal tears and his associated symptoms of frequent episodes of pain and frequent episodes of joint effusion. The Veteran was noted to regularly use a cane for bilateral knee instability and, as for the impact that his bilateral knee disabilities have on his ability to work, the examiner noted that the Veteran would be limited in prolonged standing and walking, that it prevented running, and that it limited going up and down stairs. D. Analysis 1. Bilateral Knee Disabilities With regard to the Veteran’s bilateral knee disabilities, based on the evidence of record, and after resolving all reasonable doubt in his favor, the Board finds that separate 10 percent disability ratings are warranted under Diagnostic Code 5257 for mild lateral instability of the bilateral knees, effective the date of the award of service connection (February 25, 2010, for the left knee, and December 1, 2010, for the right knee). The Board notes that the Veteran has consistently reported bilateral instability throughout the appeal period, including during the March 2010 VA examination. Furthermore, the May 2010 SSA evaluation noted that the Veteran displayed an unstable gait, and the May 2011 VA examiner identified instability in the left knee. Furthermore, effective September 4, 2020, the Board finds that increased 20 percent disability ratings are warranted under Diagnostic Code 5257 for moderate lateral instability of the bilateral knees. Indeed, during the September 2020 VA examination, the examiner noted that there was a history of moderate lateral instability and that joint stability testing revealed 2+ medial instability (5-10 millimeters) in the right knee, and 2+ medial instability and 2+ lateral instability in the left knee. However, the Board finds that the Veteran is not entitled to higher ratings under any pertinent diagnostic code at any other point during the appeal period. Initially, the Board notes that higher ratings could be assigned to the Veteran’s service-connected bilateral knee disabilities under Diagnostic Code 5256 for ankylosis of the knee; however, there is no evidence of record demonstrating ankylosis. To the contrary, the March 2010, May 2011, April 2012, March 2019, and September 2020 VA examiners each noted that ankylosis was not present in his bilateral knees upon examination. As for Diagnostic Code 5260, concerning limitation of flexion, the Board notes that the Veteran’s range of motion has never met the criteria for a compensable rating under that code, let alone the criteria warranted for a higher rating. In fact, the Veteran’s flexion has consistently been found to be greater than 45 degrees (the criteria for a 10 percent rating under Diagnostic Code 5260). Nevertheless, as noted above, the July 2010 rating decision assigned a 10 percent disability rating under Diagnostic Code 5003 for the painful or limited motion of a major joint, and the August 2011 rating decision cited 38 C.F.R. § 4.59 when it awarded the 10 percent rating based on evidence of painful motion. As for Diagnostic Code 5261, concerning limitation of extension, the Board notes that the Veteran’s bilateral knee range of motion met the criteria for a 10 percent rating under that diagnostic code during the April 2012 VA examination. However, the Board finds that separate 10 percent disability ratings are not warranted for limitation of extension. As noted above, the separate 10 percent disability ratings were assigned pursuant to Diagnostic Code 5003 and 38 C.F.R. § 4.59 for painful motion. Under Diagnostic Code 5003, a 10 percent disability rating is assigned when limitation of motion of the specific joint is noncompensable under the appropriate diagnostic code, and 38 C.F.R. § 4.59 allows for the assignment of the minimum compensable rating for painful joints when such are otherwise noncompensable under the applicable diagnostic codes. Thus, the assignment of 10 percent disability ratings under Diagnostic Code 5261 would require the discontinuance of the ratings assigned under Diagnostic Code 5003 and 38 C.F.R. § 4.59. Furthermore, the assignment of separate compensable ratings under Diagnostic Code 5261 at any other point during the appeal period would constitute pyramiding, as it would be compensating the Veteran twice for the same symptoms, painful/limited motion in his bilateral knees. See 38 C.F.R. § 4.14. With regard to giving proper consideration to the effects of pain in assigning a disability rating, as well as the provisions of 38 C.F.R. § 4.45 and the holdings in DeLuca and Mitchell, the VA examination reports reflect consideration of these principles. However, the April 2012 and September 2020 VA examiners specifically noted that the Veteran’s range of motion was the same after repetitive-use testing, despite objective evidence of pain following repetitive motion. Furthermore, although the September 2020 VA examiner indicated that the Veteran experienced flare-ups, the examiner estimated that his range of motion following repetitive use or during flare-ups would be consistent with the range of motion displayed during the examination. Thus, the evidence does not show that the Veteran’s functional loss following repetitive use or during a flare-up would be of such frequency or severity to warrant higher ratings for either knee at any point during the appeal period. As for Diagnostic Code 5257 and the prior rating criteria, the Board has considered whether higher ratings are warranted for the Veteran’s bilateral knees at any point during the appeal period; however, as will be explained, the Board finds ratings other than those currently assigned are not warranted. As for the period prior to September 4, 2020, despite the Veteran’s report of bilateral knee instability, the May 2010 SSA evaluation, and the May 2011 VA examination report, joint stability testing has consistently been negative, including during the March 2010, May 2011, April 2012, May 2014, and March 2019. Likewise, the September 2010 VA treatment record noted that there was no ligamentous instability in the left knee, and the January 2011 VA treatment record noted that there was no instability. These test results, coupled with the Veteran’s described symptoms, most closely approximate ratings of 10 percent for mild instability of the bilateral knees prior to September 4, 2020, to the present. As for the period from September 4, 2020, the Board finds that the most probative evidence of record demonstrates that the Veteran’s bilateral knee instability was no more than moderate. Indeed, as noted above, the September 2020 VA examiner noted that there was a history of only moderate lateral instability and that joint stability testing revealed 2+ medial instability (5-10 millimeters) in the right knee, and 2+ medial instability and 2+ lateral instability in the left knee. These test results, coupled with the Veteran’s described symptoms, most closely approximate ratings of 20 percent for moderate instability of the bilateral knees from September 4, 2020, to the present. As for the new rating criteria, the evidence of record fails to demonstrate an unrepaired or failed repair of a complete ligament tear causing persistent instability, and a medical provider prescribed both an assistive device (e.g., cane(s), crutch(es), walker); or a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for a brace and either a cane or a walker. Thus, higher ratings are not warranted under Diagnostic Code 5257 at any point prior to, or after September 4, 2020. As noted above, the VA examinations note that the Veteran suffered tears in the bilateral meniscus; however, the Board finds that higher ratings are not warranted under Diagnostic Codes 5258 and/or 5259. See 38 C.F.R. § 4.71. Indeed, although the evidence indicates that the Veteran experienced frequent pain and effusions, there is nothing, including his lay statements, to indicate that he experienced frequent episodes of locking into the joint during the appeal period. Furthermore, although the evidence indicates that the Veteran underwent a partial meniscectomy in the left knee in November 2014, there is there is nothing to indicate that he experiences symptoms other than those for which he is already compensated. See 38 C.F.R. § 4.14. 2. Bilateral Heel Disabilities Based on the evidence of record, the Board finds that the Veteran is not entitled to higher ratings under any pertinent diagnostic code at any point during the appeal period for his service-connected bilateral heel disabilities. Initially, the Board notes that higher ratings could be assigned to the Veteran’s service-connected bilateral ankle disabilities under Diagnostic Code 5270 for ankylosis of the ankle; however, there is no evidence of record demonstrating ankylosis. To the contrary, the April 2012, March 2019, and September 2020 VA examiners each noted that ankylosis was not present in his bilateral ankles upon examination. As for Diagnostic Code 5271 concerning limitation of motion of the ankle, the Board notes that the Veteran has displayed full range of motion throughout the appeal period (dorsiflexion zero to 20 degrees, and plantar flexion zero to 40 degrees). Nevertheless, as noted above, the August 2011 and September 2012 rating decisions assigned 10 percent disability rating for the painful, but noncompensable range of motion. With regard to giving proper consideration to the effects of pain in assigning a disability rating, as well as the provisions of 38 C.F.R. § 4.45 and the holdings in DeLuca and Mitchell, the VA examination reports reflects consideration of these principles. However, the March 2010, May 2011, April 2012, May 2014, March 2019, and September 2020 VA examiners specifically noted that the Veteran’s range of motion was the same after repetitive-use testing, despite objective evidence of pain following repetitive motion. Furthermore, although the September 2020 VA examiner indicated that the Veteran experienced flare-ups, the examiner estimated that his range of motion following repetitive use or during flare-ups would be consistent with the range of motion displayed during the examination. Thus, the evidence does not show that the Veteran’s functional loss following repetitive use or during a flare-up would be of such frequency or severity to warrant higher ratings for either knee at any point during the appeal period. With regard to Diagnostic Code 5276, as noted above, the criteria are conjunctive, see Melson, supra, and there is no evidence suggesting that the Veteran’s service-connected bilateral heel disabilities were manifested by objective evidence of marked deformity (pronation, abduction, etc.) in either foot at any point during which he was assigned a 10 percent disability rating (February 26, 2014, for right foot achilles tendonitis and May 15, 2014, for left foot achilles tendonitis). Thus, ratings in excess of 10 percent are not warranted under Diagnostic Code 5276 prior to February 26, 2014, and May 15, 2014, respectively. For the periods beginning February 26, 2014, and May 15, 2014, there is no evidence suggesting that the Veteran’s service-connected bilateral heel disabilities were manifested by marked pronation, marked inward displacement and severe spasms of the tendo achillis on manipulation, not improved by orthopedic shoes or appliances, the criteria for higher ratings under Diagnostic Code 5276. Moreover, as noted above, 20 percent is the maximum assignable rating under Diagnostic Code 5271. Thus, ratings in excess of the 20 percent ratings currently assigned are not warranted under Diagnostic Code 5276 or Diagnostic Code 5271 for the periods beginning February 26, 2014, and May 15, 2014, respectively. The Board has carefully reviewed and considered the Veteran’s statements regarding the severity of each of his service-connected disabilities, including the functional impairment associated with those disabilities, as he is competent to report observable symptoms. Layno v. Brown, 6 Vet. App. 465 (1994). Indeed, in assigning the separate 10 percent disability ratings under Diagnostic Code 5257, for bilateral knee instability, the Board has relied upon his competent lay statements concerning the symptoms associated with his service-connected bilateral knee disabilities, in additional to the competent medical evidence of record. However, with respect to the requirements for higher ratings, the Board finds that the medical evidence is more probative, as it offers detailed, specific, specialized determinations pertinent to the rating criteria, and it is the most probative with regard to evaluating the pertinent symptoms for the disabilities on appeal; the medical evidence also largely contemplates the Veteran’s descriptions of symptoms. The lay statements have been considered together with the probative medical evidence clinically evaluating the severity of the pertinent disability symptoms. In summation, after resolving all reasonable doubt in the Veteran’s favor, the Board finds that a separate 10 percent disability rating is warranted for left knee instability from February 25, 2010, to September 3, 2020; and a separate 10 percent disability rating is warranted for right knee instability from December 1, 2010, to September 3, 2020, under Diagnostic Code 5257. Additionally, a 20 percent disability rating, but no higher, for bilateral knee instability is warranted from September 4, 2020. However, the preponderance of the evidence is against any higher ratings for the Veteran’s bilateral knee disabilities and his bilateral heel Achilles tendonitis. Because the preponderance of the evidence is against higher ratings at any point during the appeal, the benefit-of-the-doubt doctrine is not applicable. See 38 U.S.C. §§ 5107(b); 38 C.F.R. §§ 3.102, 4.3; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). II. TDIU Total disability ratings for compensation may be assigned, in circumstances where the schedular rating is less than total, when the disabled person is, in the judgment of the rating agency, unable to secure or follow a substantially gainful occupation as a result of service-connected disabilities provided that, if there is only one such disability, this disability shall be ratable at 60 percent or more, and that, if there are two or more disabilities, there shall be at least one disability ratable at 40 percent or more with sufficient additional disability to bring the combined rating to 70 percent or more. See 38 C.F.R. § 4.16 (a). Although the Veteran’s formal claim for a TDIU was received on April 4, 2011, pursuant to Rice v. Shinseki, 22 Vet. App. 447 (2009), because his claim was raised in connection with claims for increased ratings for his service-connected disabilities, and because the appeal period for some of those disabilities (such as his left knee disability) stretches back to February 25, 2010, the question before the Board is whether the Veteran is entitled to a TDIU from February 25, 2010, to the present. As will be explained below, the Board finds that entitlement to a TDIU is warranted for the period from December 1, 2010. Insofar as the Veteran seeks a TDIU prior to that date, such will be addressed in the remand below. From December 1, 2010, to February 5, 2013, the Veteran was awarded service connection for the following disabilities: lumbar strain, rated as 10 percent disabling; left heel achilles tendinitis rated as 10 percent disabling; right heel achilles tendinitis rated as 10 percent disabling; left knee disability rated as 10 percent disabling; left knee instability rated as 10 percent disabling; right knee disability rated as 10 percent disabling; right knee instability rated as 10 percent disabling; and left knee scar rated as noncompensable. His overall combined disability rating for the period from December 1, 2010, to February 5, 2013, was 60 percent when considering the bilateral factor. See 38 C.F.R. § 4.26 (2020). Because each of the compensable disability ratings affect a single disability system, the Veteran’s orthopedic system, the Board notes that his combined 60 percent disability maybe considered as one disability for the purpose of establishing the schedular criteria under 38 C.F.R. § 4.16. From February 6, 2013, to February 25, 2014, the Veteran was awarded service connection for the following disabilities: lumbar strain, rated as 40 percent disabling; left heel achilles tendinitis rated as 10 percent disabling; right heel achilles tendinitis rated as 10 percent disabling; left knee disability rated as 10 percent disabling; left knee instability rated as 10 percent disabling; right knee disability rated as 10 percent disabling; right knee instability rated as 10 percent disabling; and left knee scar rated as noncompensable. His overall combined disability rating for the period from February 6, 2013, to February 25, 2014, was 70 percent when considering the bilateral factor. See 38 C.F.R. § 4.26. From February 26, 2014, to May 14, 2014, the Veteran was awarded service connection for the following disabilities: lumbar strain, rated as 40 percent disabling; left heel achilles tendinitis rated as 20 percent disabling; right heel achilles tendinitis rated as 10 percent disabling; left knee disability rated as 10 percent disabling; left knee instability rated as 10 percent disabling; right knee disability rated as 10 percent disabling; right knee instability rated as 10 percent disabling; and left knee scar rated as noncompensable. His overall combined disability rating for the period from February 26, 2014, to May 14, 2014, was 80 percent when considering the bilateral factor. See id. From May 15, 2014, to September 3, 2020, the Veteran was awarded service connection for the following disabilities: lumbar strain, rated as 40 percent disabling; left heel achilles tendinitis rated as 20 percent disabling; right heel achilles tendinitis rated as 20 percent disabling; left knee disability rated as 10 percent disabling; left knee instability rated as 10 percent disabling; right knee disability rated as 10 percent disabling; right knee instability rated as 10 percent disabling; and left knee scar rated as noncompensable. His overall combined disability rating for the period from May 15, 2014, to September 3, 2020, was 80 percent when considering the bilateral factor. See id. From September 4, 2020, the Veteran was awarded service connection for the following disabilities: lumbar strain, rated as 40 percent disabling; left heel achilles tendinitis rated as 20 percent disabling; right heel achilles tendinitis rated as 20 percent disabling; left knee instability rated as 20 percent disabling; right knee instability rated as 20 percent disabling; left knee disability rated as 10 percent disabling; right knee disability rated as 10 percent disabling; and left knee scar rated as noncompensable. His overall combined disability rating for the period from September 4, 2020, was 80 percent when considering the bilateral factor. See id. Therefore, the Board finds that the Veteran has met the schedular criteria for a TDIU, effective December 1, 2010, and the remaining inquiry is whether he was unable to secure or follow substantially gainful employment due solely to his service-connected disabilities at any point from December 1, 2010. In reaching such a determination, the central inquiry is “whether the veteran’s service-connected disabilities alone are of sufficient severity to produce unemployability.” Hatlestad v. Brown, 5 Vet. App. 524, 529 (1993). Consideration may be given to the veteran’s level of education, special training, and previous work experience in arriving at a conclusion, but not to his age or to the impairment caused by non-service-connected disabilities. See 38 C.F.R. §§ 3.341, 4.16, 4.19 (2006); Van Hoose v. Brown, 4 Vet. App. 361 (1993). An August 2010 decision by the Social Security Administration (SSA) determined that the Veteran was disabled as a result of osteoarthritis and allied disorder, and that his disability began in August 2007. Hypertension was listed as a secondary diagnosis. However, the mere fact that the SSA has deemed him unemployable does not dictate the outcome in this matter; although they are relevant and to be considered, SSA disability determinations are not binding on VA. See Murincsak v. Derwinski, 2 Vet. App. 363, 370 (1992). The Board incorporates by reference all of the evidence discussed above in connection with the Veteran’s claims for increased ratings for his service-connected bilateral knee disabilities and bilateral heel Achilles tendonitis. In his April 2011 VA Form 21-8940, Veteran’s Application for Increased Compensation Based on Unemployability, the Veteran indicated that he last worked for the water company in 2007, and that he had to stop working as a result of his service-connected left knee disability and lumbar spine disability. The Veteran noted that he was a technician, and that his last responsibility was as a plant operator. He noted that he had two years of college experience in electrical training. A May 2011 VA examination report noted that, due to the Veteran’s lumbar spine flare-ups, he would be limited in his ability to stoop and lift heavy objects, and that standing or walking for prolonged periods aggravated his pain. After noting that the Veteran last worked in 2007 and that he stopped working due to his lumbar pain and bilateral knee pain, the examiner noted that employment would not be precluded due to his lumbar spine disability so long as special accommodations were met so that he could avoid heavy lifting, stooping, prolonged standing, and prolonged walking. The examiner also stated that he could work in a sedentary job. A November 2013 VA examination report noted that the Veteran’s lumbar spine disability would likely limit his employment prospects to only sedentary jobs. A May 2014 VA examination report noted that the Veteran’s lumbar spine disability would limit his ability to stand, walk, and lift, that his seating tolerance would be limited, and that he would have trouble lifting objects from the floor. The examiner also noted that his actual condition precluded the Veteran from gainful employment due to his limited range of motion and his limited ambulation, and that his limited seating and standing tolerance caused a big hardship on his ability to perform sedentary employment. In his July 2014 VA Form 21-8940, the Veteran indicated that he last worked for the water company in 2007, and that he had to stop working as a result of his service-connected lumbar spine disability. The Veteran noted that he was a machine operator. He noted that he had two years of college experience in electrical training. An August 2017 VA examination report noted that the Veteran’s lumbar spine disability would limit his ability to stay seated for more than thirty minutes, that he could lift no more than fifteen pounds, that he could stand for no more than ten minutes, that he was limited in climbing ladders and stairs, and that he could only drive small distances. Based on the evidence of record, and after resolving all reasonable doubt in the Veteran’s favor, the evidence is in relative equipoise as to whether the combined functional impairment associated with his service-connected disabilities rendered him unable to secure and maintain gainful employment throughout the appeal period, and that entitlement to a TDIU is warranted from December 1, 2010. Significantly, weighing in favor of the Veteran’s claim is the medical evidence of record, starting with the May 2010 VA examination report in which the examiner noted that his left knee disability would cause decreased mobility, decreased strength, and pain; and that he would likely have to be assigned different duties. The April 2011 VA examiner noted that the Veteran’s left knee disability rendered him unable to perform hard physically demanding jobs. The May 2011 VA examiner noted that his bilateral knee disabilities would cause decreased mobility, problems with lifting and carrying, decreased strength, and pain, and that he would likely have to be assigned different duties. The April 2012 VA examiner concluded that the Veteran’s bilateral heel Achilles tendonitis and bilateral knee disabilities would have a significant effect on his general occupational, and that it would cause decreased mobility, problems with lifting and carrying, lack of stamina, weakness or fatigue, decreased strength, and lower extremity pain, and that he would likely have to be assigned different duties. The May 2014 VA examiner noted that his bilateral Achilles tendonitis and bilateral knee disabilities would cause limitations for standing and walking, but that they would not preclude a sedentary job such as clerical work. Finally, the March 2019 and September 2020 VA examiners concluded that the Veteran would have to avoid prolonged standing and walking activities due to his bilateral Achilles tendonitis and bilateral knee disabilities. Insofar as the VA examiners having indicated that the Veteran’s service-connected disabilities would not preclude sedentary employment, given his employment and educational history, specifically the fact that he only has two years of college education in electrical work and that his work history only involves manual labor, the Board finds that it is unlikely that he would be able to obtain and sustain gainful sedentary employment. Additionally, the August 2017 VA examiner indicated that the Veteran would likely be unable to sit for more than thirty minutes due to his service-connected lumbar strain. In view of the foregoing, the Board finds that entitlement to a TDIU based on the combined effects of his service-connected disabilities is warranted, effective December 1, 2010, the day he met the schedular criteria for a TDIU. The Board has considered the benefit-of-the-doubt rule in granting this benefit. 38 U.S.C. § 5107(b); 38 C.F.R. § 4.3; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). REASONS FOR REMAND Prior to December 1, 2010, the Veteran’s service-connected disabilities included his left knee disability rated as 10 percent disabling; and his left knee instability rated as 10 percent disabling. His overall combined disability rating is 20 percent, effective February 25, 2010. Therefore, prior to December 1, 2010, the Veteran did not meet the schedular criteria for a TDIU. Where the percentage requirements for a TDIU are not met, a total disability rating may nevertheless be assigned on an extraschedular basis when the veteran is unable to secure or follow a substantially gainful occupation as a result of his or her service-connected disability or disabilities. 38 C.F.R. § 4.16(b). In cases where entitlement to a TDIU is warranted on an extraschedular basis, the claim must be submitted to the Director of Compensation Service for initial adjudication. Id. As noted above, the evidence of record indicates that the Veteran stopped working as a mechanic at the water company in 2007, and the March 2010 VA examiner noted that the Veteran’s left knee disability caused decreased mobility, decreased strength, and pain, and that he would likely have to be assigned different employment duties. The examiner also noted that his left knee disability would prevent exercise and sports; that it would cause severe problems with chores, shopping, and traveling; and that it would cause moderate problems with recreation, bathing, dressing, toileting, grooming, and driving. Furthermore, the Veteran’s educational history includes only two years of college education in electrical work, and his employment history only involves manual labor. The Board finds that this evidence suggests that the Veteran’s service-connected disabilities rendered him unemployable prior to December 1, 2010. As a result, the Board finds that his claim for a TDIU should be referred to the Director of Compensation Service to determine whether entitlement to a TDIU is warranted on an extraschedular basis pursuant to 38 C.F.R. § 4.16(b) prior to December 1, 2010. The matters are REMANDED for the following action: 1. Refer the matter of entitlement to a TDIU on an extraschedular basis to the Director, Compensation Service for a determination as to whether the Veteran is entitled to an assignment of a TDIU under the provisions of 38 C.F.R. § 4.16(b) prior to December 1, 2010. 2. Thereafter, readjudicate the appeal. B. G. LeMoine Acting Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board James R. Springer, Counsel The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.