Citation Nr: 21068058 Decision Date: 11/09/21 Archive Date: 11/09/21 DOCKET NO. 20-01 624 DATE: November 9, 2021 ORDER 1. Entitlement to service connection for a bilateral hearing loss disability is denied. 2. Entitlement to service connection for migraine headaches, to include as secondary to the cervical spine disability and/or PTSD, is denied. 3. Entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the left knee is denied. 4. Entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the right knee is denied. 5. Entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the left knee is denied. 6. Entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the right knee is denied. 7. Entitlement to an initial rating in excess of 10 percent for diarrhea is denied. REMANDED 8. Entitlement to service connection for obstructive sleep apnea, to include as secondary to posttraumatic stress disorder (PTSD) and/or as intermediately caused by obesity, is remanded. 9. Entitlement to service connection for hypertension, to include as secondary to PTSD, medication taken for the Veteran's service-connected disabilities, and/or as intermediately caused by obesity, is remanded. 10. Entitlement to service connection for degenerative arthritis of the lumbar spine, to include as secondary to service-connected degenerative arthritis of the cervical spine, cervical radiculopathy of the bilateral upper extremities, bilateral knee disabilities, and/or as intermediately caused by obesity, is remanded. 11. Entitlement to service connection for numbness and tingling of the left foot, to include as secondary to a lumbar spine disability, cervical spine disability, bilateral knee disability, and/or as intermediately caused by obesity, is remanded. 12. Entitlement to service connection for numbness and tingling of the right foot, to include as secondary to a lumbar spine disability, cervical spine disability, bilateral knee disability, and/or as intermediately caused by obesity, is remanded. FINDINGS OF FACT 1. The preponderance of the evidence is against finding that the Veteran's bilateral hearing loss meets the requirements for a current bilateral hearing loss disability for VA purposes under 38 C.F.R. § 3.385. 2. The preponderance of the evidence is against finding that migraine headaches had an onset in service, manifested within one year of service discharge, are secondary to service-connected PTSD and/or cervical spine disability, or are otherwise related to service. 3. The preponderance of the evidence is against finding that painful motion due to degenerative arthritis of the left knee cause manifested with flexion limited to 30 degrees. 4. The preponderance of the evidence is against finding that painful motion due to degenerative arthritis of the right knee cause manifested with flexion limited to 30 degrees. 5. The preponderance of the evidence is against finding that extension in the left knee was limited to 10 degrees. 6. The preponderance of the evidence is against finding that extension in the right knee was limited to 10 degrees. 7. The preponderance of the evidence is against finding that diarrhea manifests as a moderately severe disability with frequent exacerbations. CONCLUSIONS OF LAW 1. The criteria for entitlement to service connection for a bilateral hearing loss disability have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137, 5107 (2012); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309 (2020). 2. The criteria for entitlement to service connection for migraine headaches, to include as secondary to the cervical spine disability and/or PTSD have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137, 5107 (2012); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309, 3.310 (2020). 3. The criteria for entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the left knee have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5260 (2020). 4. The criteria for entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the right knee have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5260 (2020). 5. The criteria for entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the left knee have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5260 (2020). 6. The criteria for entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the right knee have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5261 (2020). 7. The criteria for entitlement to an initial rating in excess of 10 percent for diarrhea have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.114, Diagnostic Code 7323 (2020). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from July 1980 to March 1984 and from February 1987 to December 1988. The Board remanded these matters in February 2021 and May 2021 for additional development. In consideration of the appeal, the Board is satisfied there was substantial compliance with the remand directives as to the issues decided herein and will proceed with review. Stegall v. West, 11 Vet. App. 268 (1998). Service Connection Service connection may be granted for a disability resulting from a disease or injury incurred in or aggravated by service. See 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a veteran must show: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service. Service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). Service connection is also warranted for a disability which is proximately due to or the result of a service-connected disease or injury. 38 C.F.R. § 3.310(a). Such secondary service connection is warranted for any increase in severity of a nonservice-connected disability that is proximately due to or the result of a service-connected disability. 38 C.F.R. § 3.310(b). Additionally, where a veteran served 90 days or more of active service, and certain chronic diseases become manifest to a degree of 10 percent or more within one year after the date of separation from such service, such disease shall be presumed to have been incurred in service, even though there is no evidence of such disease during the period of service. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.307, 3.309(a). 1. Entitlement to service connection for a bilateral hearing loss disability The Veteran contends that he has a bilateral hearing loss disability that he attributes to exposure to acoustic trauma during service. The Veteran served as a mechanic, and he reported noise exposure from artillery fire, generators, heavy equipment, and weapons fire during his active service. For the purpose of applying the laws administered by VA, impaired hearing will be considered to be a disability when the auditory threshold in any of the frequencies 500, 1000, 2000, 3000, or 4000 Hertz (Hz) is 40 decibels or greater; or when the auditory thresholds for at least three of these frequencies are 26 decibels or greater; or when speech recognition scores using the Maryland CNC Test are less than 94 percent. 38 C.F.R. § 3.385. The Board finds the Veteran's bilateral hearing loss does not meet the requirements for a current bilateral hearing loss disability. On the authorized VA audiological evaluation in November 2015, pure tone thresholds, in decibels, for the ears were as follows: HERTZ 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz RIGHT 25 20 30 25 25 LEFT 20 20 25 25 30 The speech recognition scores were 92 percent in both the right ear and left ear. In May 2021, the Board remanded this claim to obtain an opinion to assess the discrepancy between the pure tone thresholds, which did not meet the requirements for a hearing loss disability, and the scores from the Maryland CNC test, which met the criteria for bilateral a hearing loss disability. Another VA examination was provided in June 2021. Pure tone thresholds, in decibels, for the ears were as follows: HERTZ 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz RIGHT 15 15 20 20 15 LEFT 15 15 20 25 25 The examiner was unable to test speech discrimination at this examination. The examiner noted that this was not an appropriate test for this Veteran due to language difficulties, cognitive problems, and inconsistent speech discrimination scores. The examiner documented that the Veteran had normal hearing with no permanent thresholds shifts despite the reported noise exposure in service. The Board acknowledges that the November 2015 VA examiner documented 92 percent speech recognition scores. However, the Board finds the notations by the July 2021 VA examiner that the Veteran had normal hearing and that the Maryland CNC was not an appropriate test for this Veteran to be the more probative as to whether speech discrimination established a current bilateral hearing loss disability, as it is most consistent with the evidence and medical treatment records in the claims file. The pure tone threshold testing consistently documents normal hearing in both ears on both VA examinations, conducted six years apart. Furthermore, despite the Veteran's reports related to this claim and to VA examiners, the Veteran, as documented in December 2016 VA treatment records, denied having hearing loss or difficulty hearing. Furthermore, VA treatment records from July 2015 and December 2016 document examiners describing that the Veteran's hearing was intact to conversation. The Board finds this to be highly probative evidence against a current bilateral hearing loss disability. The Veteran's allegation of hearing loss being due to in-service noise exposure is outweighed by the findings at both the November 2015 and June 2021 VA examinations, despite the Veteran's credible reports of noise exposure in service. Absent a finding that the Veteran has bilateral hearing loss disability that meets the regulatory requirements, service connection cannot be granted. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, that doctrine is not applicable where, as here, there is not an approximate balance of positive and negative evidence. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 5356 (1990). Thus, the claim for service connection for bilateral hearing loss disability is denied. 2. Entitlement to service connection for migraine headaches, to include as secondary to the cervical spine disability and/or PTSD The Veteran, in a March 2015 statement, reported that he hit his head on the steering wheel during the documented March 1987 motor vehicle accident. He reported that he remembered the car going off the road but believed he blacked out or had a concussion as he did not remember anything else until he got to the hospital. When the Veteran filed this claim in June 2017 and at his July 2017 VA examination, he reported that he believed his headaches were coming from his spine and his nerve damage, and in August 2018 he reported that pain flare ups in his cervical spine triggered his headaches. In November 2018, the Veteran asserted that he had been experiencing headaches since his motor vehicle accident in service as well as from his cervical spine, and in VA treatment records throughout 2019, he reported that he experienced headaches when he moved his neck. The Veteran's spouse has reported that the Veteran experiences repeated headaches. The Board has carefully reviewed the evidence of record and finds that the preponderance of the evidence is against the claim for service connection for headaches. The reasons follow. As to evidence of a current disability, a June 2021 VA examination report shows that the Veteran was diagnosed with migraines, including migraine variants. Therefore, the facts establish that the first element of a service connection claim is met. As to evidence of a disease or injury in service, the service treatment records (STRs) do not show that the Veteran sustained a disease or injury suggestive of or causing an onset of migraine headaches during service. One of the Veteran's current contentions is that he hit his head and blacked out or had a concussion related to his March 1987 motor vehicle accident. Later, the Veteran asserted that he has been experiencing headaches since that accident. However, a review of the STRs from the motor vehicle accident do not document that the Veteran reported that he hit his head during the accident, nor do they document that he was admitted while blacked out or after having a concussion or that he reported blacking out or having a concussion to providers at that time. These records appear to be complete, as they document that he hit his left hand on the steering wheel and reported lower leg pain immediately following the accident. These records also document that he fractured his hand, but his cervical spine was normal. These records clearly document the injuries sustained by the Veteran following the motor vehicle accident, and the Board finds it unlikely that the Veteran was admitted following a black out or concussion as those symptoms were not documented in the records. Furthermore, the records clearly document that the Veteran reported hitting his hand on the steering wheel and his leg injury. Given that the Veteran reported these injuries at the time of the accident, the Board finds it unlikely that the Veteran would have failed to report hitting his head or experiencing a black out or concussion. Thus, the Board finds the Veteran's statements, made over 20 years after the 1987 accident, to be less probative than the contemporaneous medical records, in part because they are inconsistent with the contemporaneous records, which the Board reiterates appear to be complete and thorough, but also because the Veteran himself was inconsistent as to his reporting of his injuries in this accident. The Veteran first reported that he hit his head during the accident in March 2015, 28 years after the motor vehicle accident. Additionally, in March 2015, he reported that he believed he blacked out or had a concussion after the accident, but he notably did not report that he had been experiencing headaches since the motor vehicle accident. Further, in July 2015 records, after again reporting that he hit his head during the 1987 motor vehicle accident, the Veteran specifically reported that he was not experiencing current headaches. Additionally, at the July 2017 VA examination the Veteran specifically reported that he did not have any residual headache symptoms after the motor vehicle accident and that his current headaches had an onset two to three years prior to the examination. It is not until after his claim for service connection for headaches is filed with the contention that his pain from his cervical spine were causing his headaches and his claim was denied that the Veteran reported to the June 2021 VA examiner, in contradiction to his previous statements and the contemporaneous medical records, that he has experienced headaches since his 1987 motor vehicle accident in service. Finally, the Board notes that the remainder of the STRs refute the Veteran's allegation of experiencing headaches following his 1987 motor vehicle accident. For example, within the December 1988 Report of Medical Examination, the examiner documented that clinical evaluations of the Veteran's head and neurological system were normal. More importantly, in the December 1988 Report of Medical History, the Veteran specifically denied a history of frequent or severe headache, head injury, and periods of unconsciousness. This is strong evidence that the Veteran did not experience a head injury during service, did not experience frequent or severe headaches, and did not experience loss of consciousness during service. These denials in December 1988 refute the Veteran's current allegations. The Board finds the facts documented within this record are highly probative, as the Veteran completed this document contemporaneously with his service, which statements tend to be highly reliable. For the aforementioned reasons, the Board finds that the Veteran is not credible as to his reports that he injured his head in the 1987 motor vehicle accident and has experienced headaches since that in-service accident. Thus, the preponderance of the evidence is against the second element of a service-connection claim being met. Despite not meeting the requirements of service connection on a direct basis, the Board will still address the Veteran's secondary claims. The Veteran has asserted that his cervical spine disability and/or PTSD. However, the Board finds that the preponderance of the evidence of record is against finding that the cervical spine disability and/or PTSD caused or aggravated the diagnosed migraine headaches. The Veteran was provided a VA examination in June 2021. The examiner opined that the Veteran's cervical spine arthritis and PTSD were not at least as likely as not causing or aggravating the diagnosed migraines. As a rationale, the examiner noted that migraines are thought to be caused by a combination of brain neurotransmitter and vascular abnormalities and noted that arthritis is not a known cause of migraines. The examiner also noted that PTSD is a separate condition from migraines and is not known to cause migraines. The examiner acknowledged that migraines have many causes and triggers, which may include sleeping wrong, head injuries, lack of sleep, stress, and neck pain. However, the examiner opined that while the Veteran's cervical spine or PTSD may trigger some of his migraines, the claims file does not document that the migraines are aggravated beyond their natural progression by either of these possible triggers. Finally, to the extent the record documents that the Veteran seems to have asserted a distinction between his cervical spine disability, arthritis, causing his headaches and his nerve pain, presumably related to his upper extremity radiculopathy, the Board finds that the Veteran has not provided any other evidence to substantiate this claim, and the Veteran's representative, in arguments supporting the Veteran's claim did not differentiate between arthritis pain and nerve pain. Rather, the Veteran's representative asserted only that the degenerative arthritis of the cervical spine disability caused or aggravated the Veteran's migraines. The Board must analyze the credibility and probative value of the evidence, account for the evidence it finds persuasive or unpersuasive, and provide the reasons for its rejection of any material evidence favorable to the Veteran. Kahana v. Shinseki, 24 Vet. App. 428, 433 (2011). This includes weighing the credibility and probative value of lay evidence against the remaining evidence of record. See King v. Shinseki, 700 F.3d 1339 (Fed. Cir. 2012); Kahana, 24 Vet. App. at 43334. A lay person is competent to report to the onset and continuity of his symptomatology. Id. at 438. Moreover, lay evidence may be competent and sufficient evidence of a diagnosis or nexus if (1) the particular condition at issue is the type of condition that is within the competence or common knowledge of a lay person, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. Jandreau v. Nicholson, 492 F.3d 1372, 137677 (Fed. Cir. 2007). The Board must determine on a case-by-case basis whether a particular condition is the type of condition that is within the competence of a lay person. See Kahana, 24 Vet. App. at 433, n. 4. A veteran bears the evidentiary burden to establish all elements of a service connection claim, including the nexus requirement. Fagan v. Shinseki, 573 F.3d 1282, 1287 (Fed. Cir. 2009); see also Walker v. Shinseki, 708 F.3d 1331, 1334 (Fed. Cir. 2013). In making its ultimate determination, the Board must give a Veteran the benefit of the doubt on any issue material to the claim when there is an approximate balance of positive and negative evidence. Fagan, 573 F.3d at 1287 (quoting 38 U.S.C. § 5107(b)). The Board finds that the June 2021 VA medical opinions as to whether the migraine headaches are caused or aggravated by the service-connected cervical spine disability and/or PTSD are highly probative, as the examiner reviewed the file, listened to the Veteran's report of history, physically examined the Veteran, and provided a rationale for the opinion that relied on the specific facts of the case, which facts are accurate, and medical principles. This is evidence against a nexus between the current disability and the service-connected cervical spine disability and/or PTSD. There is no competent evidence to weigh against these medical opinions. Thus, the Board finds that the preponderance of the evidence is against finding a nexus between the Veteran's current migraine headaches and the service-connected cervical spine disability and/or PTSD. While the Veteran is competent to report symptoms that he has experienced, he is not competent to directly link the current migraine disability to his cervical spine disability and/or PTSD, as medical expertise is required. In this regard, the question of causation involves a medical subject concerning an internal physical process extending beyond an immediately observable cause-and-effect relationship. As such, the question of etiology in this case may not be competently addressed by lay evidence, and the Veteran's own opinion is nonprobative evidence. Jandreau v. Nicholson, 492 F.3d 1372, 137677 (Fed. Cir. 2007). The Veteran's representative submitted two articles that cite medical studies suggesting a relationship between PTSD and headaches and localized pain points and arthritis. However, these articles are not related to this Veteran's specific case. Furthermore, the Board notes that the VA examiner conceded that PTSD symptoms such as stress and lack of sleep and pain may be a trigger to a migraine headache, among many other potential triggers, but opined that to the extent that these symptoms may be triggering at least some of the Veteran's migraines, the examiner opined that they were not at least as likely as not aggravating the migraines beyond their natural progression. Despite not meeting the requirements for service connection on a direct and secondary basis, the Board notes that migraines are a chronic disease under 38 C.F.R. § 3.309, which allows for service connection on a presumptive basis if the chronic disease is manifested to a compensable degree within one year of discharge from service. However, in this case the preponderance of the evidence is against finding that the migraines had an onset within one year of discharge from service. Rather, the evidence of record suggests that the Veteran's headaches did not have an onset until approximately 2014 or 2015, which is over 25 years after the Veteran's discharge from active service. The Board has found the Veteran not credible as to his reported history of headaches since his 1987 motor vehicle accident, and the probative evidence of record, specifically the VA treatment records, document that the Veteran did not begin reporting headaches until 2017, when he reported that he had been experiencing headaches two to three years prior to his July 2017 VA examination. Thus, service connection on a presumptive basis due to the onset of a chronic disability within a year of discharge from service is also not warranted. In reaching the above conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, that doctrine is not applicable where, as here, there is not an approximate balance of positive and negative evidence. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. Thus, the claim for service connection for migraine headaches, to include as being secondary the service-connected cervical spine disability and/or PTSD, is denied. Increased Rating Disability evaluations are determined by the application of the facts presented to VA's Schedule for Rating Disabilities (Rating Schedule) at 38 C.F.R. Part 4. The percentage ratings contained in the Rating Schedule represent, as far as can be practicably determined, the average impairment in earning capacity resulting from diseases and injuries incurred or aggravated during military service and the residual conditions in civilian occupations. 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Reasonable doubt as to the degree of the disability will be resolved in the veteran's favor. 38 C.F.R. § 4.3. Where the appeal arises from the original assignment of a disability evaluation following an award of service connection, the severity of the disability at issue is to be considered during the entire appeal period from the initial assignment of the disability rating to the present time. See Fenderson v. West, 12 Vet. App. 119 (1999). 3. Entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the left knee 4. Entitlement to an initial rating in excess of 10 percent for painful motion due to degenerative arthritis of the right knee 5. Entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the left knee 6. Entitlement to an initial compensable rating for limited extension due to degenerative arthritis of the right knee The Veteran is currently in receipt of a 10 percent rating under Diagnostic Code 5003-5260 for painful motion of the knee joint and 38 C.F.R. § 4.59 and a diagnosis of degenerative arthritis in both the left and right knee and a noncompensable rating under Diagnostic Code 5003-5261 for limitation of extension of both the right and left knee. Hyphenated diagnostic codes signify that the rating for a service-connected disability is based upon how another disability would be rated. 38 C.F.R. § 4.27. The diagnostic code for the service-connected disability is after the hyphen. After a thorough review of the evidence of record, the Board finds initial ratings in excess of 10 percent for painful motion due to degenerative arthritis and a compensable rating based on limitation of extension for the right and left knees are denied. The reasons follow. The Veteran was provided a VA examination in November 2015. The Veteran was diagnosed with degenerative arthritis of the bilateral knee. The Veteran reported a constant, dull pain in his bilateral knee joint for which he uses a knee brace or ace wrap regularly. He also reported that he used ice therapy to treat swelling in his knees if he is on his feet all day. The Veteran denied flare-ups. Flexion was measured to 90 degrees in both knees and extension was measured to five degrees in both knees. The examiner documented no additional loss of range of motion after repetitive use, noting that this was not medically consistent or inconsistent with the Veteran's statements but a more detailed response would be speculative without direct observation. The examiner noted no tenderness or pain on palpation but documented pain on weightbearing and crepitus. Muscle strength testing was documented to be normal, and the examiner documented no muscle atrophy, ankylosis, recurrent subluxation, lateral instability, effusion, recurrent patellar dislocations, or meniscal conditions. Joint stability testing was negative. The examiner documented that the Veteran reported having missed some work due to pain in his knees as stiffness and throbbing caused by prolonged sitting required him to take frequent breaks. January 2017 VA treatment records show the Veteran reported a loss of balance, noting that his knees buckled, though he denied falling, as he was able to catch himself. VA treatment records from January 2019 document that the Veteran's gait was normal with good stability and coordination. He was documented to be able to stand on each leg without difficulty. In August 2019, the Veteran reported to VA treatment providers that he was unable to go up and down stairs due to his back and knee pain. Another VA examination was conducted in June 2021. The Veteran reported constant, throbbing pain of six to seven out of 10. He reported that his knees "puff up" if he walks or stands for 25 to 30 minutes and that he had a limited ability to do activities that involve going up and down stairs, crouching, kneeling, and crawling. The Veteran denied instability or recurrent subluxation as well as flare-ups, though he endorsed frequent effusion if he stands for more than 30 minutes at a time. Range of motion testing documented flexion to 90 degrees and normal extension in the right knee and flexion to 80 degrees and normal extension in the left knee. Pain was documented on weightbearing and on active and passive motion, but there was no additional loss of range of motion after repetitive use. The examiner documented the knees had no crepitus, localized tenderness, or pain on palpation of the joint. The examiner also documented no muscle atrophy, ankylosis, recurrent subluxation, ligament tears, recurrent patellar instability, tibial or fibular impairment, meniscal conditions, or surgeries. The Veteran reported using a brace regularly on both knees. On February 7, 2021, Diagnostic Code 5003 was amended to change the title of the diagnostic code to degenerative arthritis, other than posttraumatic, rather than arthritis (hypertrophic or osteoarthritis). This amendment is not a substantive change, but rather, was an amendment to accurately describe the disability covered by the rating code. Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76473 (Nov. 30, 2020) (to be codified at 38 C.F.R. § 4.71a). When evaluating musculoskeletal disabilities based on limitation of motion, 38 C.F.R. § 4.40 requires consideration of functional loss caused by pain or other factors listed in that section that could occur during flare-ups or after repeated use and, therefore, not be reflected on range-of-motion testing. 38 C.F.R. § 4.45 requires consideration also be given to less movement than normal, more movement than normal, weakened movement, excess fatigability, incoordination, and pain on movement. See DeLuca v. Brown, 8 Vet. App. 202 (1995); see also Mitchell v. Shinseki, 25 Vet. App. 32, 44 (2011). Nonetheless, even when the background factors listed in § 4.40 or 4.45 are relevant when evaluating a disability, the rating is assigned based on the extent to which motion is limited, pursuant to 38 C.F.R. § 4.71a (musculoskeletal system) or § 4.73 (muscle injury); a separate or higher rating under § 4.40 or 4.45 itself is not appropriate. See Thompson v. McDonald, 815 F.3d 781, 785 (Fed. Cir. 2016) ("[I]t is clear that the guidance of § 4.40 is intended to be used in understanding the nature of the veteran's disability, after which a rating is determined based on the § 4.71a [or 4.73] criteria."). Degenerative and/or traumatic arthritis, as shown by x-ray studies, are rated based on limitation of motion of the affected joint. 38 C.F.R. § 4.71a, Diagnostic Codes 5003, 5010 (2016). When, however, the limitation of motion is noncompensable under the appropriate diagnostic codes, a rating of 10 percent may be applied to each such major joint or group of minor joints affected by limitation of motion. Id., Diagnostic Codes 5003, 5010. The limitation of motion must be objectively confirmed by findings such as swelling, muscle spasm, or satisfactory evidence of painful motion. Id. In the absence of limitation of motion, x-ray evidence of arthritis involving two or more major joints or two or more minor joint groups, will warrant a rating of 10 percent; in the absence of limitation of motion, x-ray evidence of arthritis involving two or more major joint groups with occasional incapacitating exacerbations will warrant a 20 percent rating. Id. The above ratings are to be combined, not added under Diagnostic Code 5003. Id., note 1. With any form of arthritis, painful motion is an important factor of disability, the facial expression, wincing, etc., on pressure or manipulation, should be carefully noted and definitely related to affected joints. Muscle spasm will greatly assist the identification. The intent of the schedule is to recognize painful motion with joint or periarticular pathology as productive of disability. It is the intention to recognize actually painful, unstable, or malaligned joints, due to healed injury, as entitled to at least the minimum compensable rating for the joint. Crepitation either in the soft tissues such as the tendons or ligaments, or crepitation within the joint structures should be noted carefully as points of contact which are diseased. Flexion elicits such manifestations. The joints involved should be tested for pain on both active and passive motion, in weightbearing and non-weightbearing and, if possible, with the range of the opposite undamaged joint. 38 C.F.R. § 4.59. As the Veteran is currently assigned a 10 percent rating under Diagnostic Code 5003-5260 based on the diagnosis of arthritis and noncompensable painful motion in the joint, the Board will first address whether a higher rating is warranted under this diagnostic code. The Board finds a higher rating under Diagnostic Code 5003 is not warranted as the record documents that, though the Veteran is limited in his ability to sit and stand for extended periods of time, he does not have incapacitating episodes related to his bilateral knee. Thus, a rating in excess of 10 percent under Diagnostic Code 5003 is not warranted for either knee. Despite not meeting the requirements for a higher rating under Diagnostic Code 5003, the Board will also address whether a higher and/or separate compensable rating is available under any of the other diagnostic codes for the knees. The claims file does not support a finding that the bilateral knee disability manifests with symptoms of ankylosis, dislocated or removed semilunar cartilage, impairment of the tibia or fibula, or genu recurvatum, Diagnostic Codes 5256, 5258, 5259, 5262, and 5263 do not apply in this case. Under Diagnostic Code 5261, a noncompensable evaluation is assigned for extension limited to 5 degrees, and a 10 percent disability evaluation is contemplated for extension limited to 10 degrees. When there is limitation of extension to 15 degrees, a 20 percent evaluation is warranted. A 30 percent rating will be assigned for extension limited to 20 degrees, and a 40 percent rating is contemplated for limitation of extension to 30 degrees. A 50 percent disability evaluation is warranted for extension limited to 45 degrees. The regulations provide that a normal range of motion of the knee is 0 degrees on extension. 38 C.F.R. § 4.71, Plate II. The Board finds that a compensable rating is not warranted for the Veteran's limitation of extension, as extension in both knees was documented to be limited to 5 degrees, and more recently at the June 2021 VA examination, the extension was documented to be normal at 0 degrees. As extension was not limited to 10 degrees, a separate, compensable rating is not warranted under Diagnostic Code 5261. Under Diagnostic Code 5260, a noncompensable evaluation is warranted when flexion is limited to 60 degrees, a 10 percent disability evaluation when flexion is limited to 45 degrees, a 20 percent disability evaluation when flexion is limited to 30 degrees, and a 30 percent disability rating when flexion is limited to 15 degrees. While the Veteran has some limitation of flexion in his bilateral knee, at worst, flexion was documented to be limited to 80 degrees and 90 degrees in the left and right knee respectively. As flexion is not documented to be limited to 45 degrees or less in either knee, a separate compensable rating is not available under Diagnostic Code 5260 in this case. Diagnostic Code 5257 contemplates "other impairment" of the knee including recurrent subluxation or lateral instability. Prior to February 7, 2021, under Diagnostic Code 5257, where impairment is severe, moderate, or slight, disability evaluations of 30, 20, and 10 percent are assigned, respectively. 38 C.F.R. § 4.71a. The words "slight," "moderate," "severe," and "marked" as used in the various diagnostic codes are not defined in the VA Rating Schedule. Rather than applying a mechanical formula, the Board must evaluate all of the evidence for "equitable and just" decisions. 38 C.F.R. § 4.6. From February 7, 2021, Diagnostic Code 5257 was amended to separate recurrent subluxation or lateral instability from patellar instability. With recurrent subluxation or lateral instability, a 10 percent rating is assigned for a sprain incomplete ligament tear, or complete ligament tear (repaired, unrepaired, or failed repair) causing persistent instability, without a prescription from a medical provider for an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A 20 percent rating is warranted for one or more of the following: (a) a sprain, incomplete ligament tear, or repaired complete ligament tear causing persistent instability, and a medical provider prescribes a brace and/or assistive device (e.g. cane(s), crutch(es), walker) for ambulation or (b) an unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider prescribes either an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A 30 percent rating is warranted for unrepaired or failed repair of a complete ligament tear causing persistent instability, and a medical provider prescribes both an assistive device (e.g., cane(s), crutch(es), walker) and bracing for ambulation. With patellar instability, a 10 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability (with or without history of surgical repair that does not require a prescription from a medical provider for a brace, cane, or walker. A 20 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 with one of the following: a brace, cane, or walker. 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. Note 1 clarifies that for patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note 2 clarifies 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). Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76473 (Nov. 30, 2020) (to be codified at 38 C.F.R. § 4.71a). The Veteran reported loss of balance and buckling in his knees requiring him to catch himself to VA treatment providers in January 2017. The file does not regularly document such symptomatology. As a layperson, the Veteran is competent to testify to factual matters of which he has first-hand knowledge such as experiencing pain, perceiving instability in a joint, or witnessing actually observed symptoms such as swelling. See Washington v. Nicholson, 19 Vet. App. 362, 368 (discussing competence to report experienced or witnessed symptoms versus incompetent to offer render a medical diagnosis or identify the etiology of disease or injury that require medical knowledge). When considering whether lay evidence is competent, the Board must determine on a case-by-case basis whether a veteran's particular disability is the type of disability for which lay evidence may be competent. Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). Here, the Board finds the Veteran is competent to describe many symptoms of his bilateral knee disability, such as buckling. See Jandreau, 492 F.3d at 1376 (lay witness capable of diagnosing dislocated shoulder); Falzone v. Brown, 8 Vet. App. 398, 403 (1995) (lay person competent to testify to pain and visible flatness of his feet); Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (unlike varicose veins or a dislocated shoulder, rheumatic fever is not a condition capable of lay diagnosis). The Board also finds his statements regarding perceived bilateral knee instability generally credible. To the extent, however, that VA medical personnel used specific clinical tests to assess the stability of the right and left knees, the Board finds the clinical findings by medical professionals is more probative than the lay evidence on the issue of instability because the clinical assessment of knee instability made by performing particular joint stability tests falls outside the realm of common knowledge of laypersons. Here, throughout the appeal period, competent medical evidence has consistently documented that the bilateral knee joint was stable to multiple forms of stability testing. In Jandreau, the United States Court of Appeals for the Federal Circuit (Federal Circuit) held that "[l]ay evidence can be competent and sufficient to establish a diagnosis of a condition when . . . lay testimony describing symptoms at the time supports a later diagnosis by a medical professional." Jandreau, 492 F.3d at 1977. The issue of whether the perceived symptom of bilateral knee instability is competent and sufficient to establish that he has actual instability of the knees sufficient to warrant separate disability ratings under Diagnostic Code 5257 is analogous to the situation described here in Jandreau. In this case, the Veteran has described his perception of bilateral knee instability on one occasion as buckling and loss of balance. However, medical professionals have tested his knees for instability during the pendency of his appeal and none has found even slight instability on anterior, posterior, medial, or lateral stability testing. Because the perceived symptom of bilateral knee instability has repeatedly not been demonstrated or confirmed on clinical testing by independent medical professionals, his lay testimony is insufficient to establish the presence of anterior, posterior, medial, or lateral instability sufficient to warrant separate disability rating for either knee. Furthermore, the evidence does not document recurrent subluxation. In English v. Wilkie, 30 Vet. App. 347 (2018), the U.S. Court of Appeals for Veterans Claims (Court) held that the Board cannot find objective medical evidence categorically more probative than lay evidence without explaining why that is the case. To be clear, the Board finds the objective medical evidence more probative than the reports of perceived bilateral knee instability for two reasons. First, the clinical findings by the November 2015 and June 2021 VA examiners involved at least two to three forms of stability testing, and neither examination demonstrated bilateral knee instability. The thorough, repeated stability testing, which did not reveal instability, supports the conclusion that the perceived knee instability is not due to anterior, posterior, medial, or lateral knee joint instability, nor does it show recurrent subluxation. Second, the two examinations conducted between November 2015 and June 2021a six-year periodwere performed by two, different medical professionals. Each performed joint stability testing for the right and left knees, and each documented the knees were stable to stability testing. The internal consistency among the two independent examiners bolsters the conclusion that their findings of no bilateral knee joint instability were accurate. The knees were documented to not have instability six years apart. It is for these reasons that the Board finds the clinical findings by medical professionals outweigh the assertion of bilateral knee instability, and the preponderance of the evidence is against finding that the Veteran has instability in either knee to warrant a separate rating under Diagnostic Code 5257 for instability of the knees under either the former or the amended criteria. Given the aforementioned, the Board finds that the preponderance of the evidence is against a rating in excess of 10 percent based on painful motion and a diagnosis of a degenerative arthritis and against a compensable rating based on limitation of extension in the bilateral knee. The claims for higher ratings for the bilateral knee disability are denied. 7. Entitlement to an initial rating in excess of 10 percent for diarrhea The Veteran is currently in receipt of a 10 percent rating under Diagnostic Code 7323, which provides ratings for ulcerative colitis. After a thorough review of the evidence, the Board finds a rating in excess of 10 percent is not warranted. The reasons follow. At a VA examination conducted in November 2015, the Veteran was diagnosed with diarrhea. The Veteran reported severe diarrhea after eating and after taking his medications at bedtime. He reported that he had to miss some work, noting that he occasionally left early due to the severity of his diarrhea. The Veteran does not take medications and has not had surgical treatment. The examiner also documented that there were no episodes of bowel disturbance with abdominal distress, exacerbations or attacks of the intestinal conditions, weight loss, malnutrition, serious complications, or general health effects. In December 2020, the Veteran reported to the emergency room with diarrhea. He returned five days later and was diagnosed with Covid-19. Another VA examination was conducted in June 2021. The Veteran reported that his diarrhea has become worse. He reported that he had to be near a bathroom and bring a change of clothes with him wherever he goes. He reported three bowel movements per day, many of which were runny or soft. The Veteran continued to deny treatment, surgery, or continuous medication. The examiner also documented no weight loss related to his intestinal condition, no malnutrition, no benign or malignant neoplasms or metastases, and no other pertinent physical findings. Diagnostic code 7323 provides for a 10 percent rating with moderate, infrequent exacerbations. A 30 percent rating is assigned for moderately severe ulcerative colitis, with frequent exacerbations. A 60 percent rating is assigned for severe ulcerative colitis, with numerous attacks a year and malnutrition, the health only fair during remission. A 100 percent rating is assigned for pronounced ulcerative colitis resulting in marked malnutrition, anemia, and general debility, or with serious complication as liver abcess. 38 C.F.R. § 4.114, Diagnostic Code 7323. The Board finds that the current 10 percent rating accurately describes the Veteran's diarrhea symptoms. Initially, the Board notes that a 30 percent rating requires frequent exacerbations. Both the November 2015 and June 2021 VA examiners documented that the Veteran did not have episodes of bowel disturbance with abdominal distress or exacerbations or attacks of the intestinal condition. Furthermore, the Board finds the symptoms reported by the Veteran do not rise to the level of a moderately severe disability. At the most recent June 2021 VA examination, the Veteran reported only three bowel movements per day. Though the Veteran has to be near a bathroom and carry a spare change of clothes, an average of three bowel movements per day is not indicative of a moderately severe disability. Additionally, on two examinations, which the Board notes were conducted six years apart, both the November 2015 and June 2021 VA examiners documented the Veteran did not have weight loss due to his intestinal condition, did not require continuous medication or surgical treatment, and did not exhibit malnutrition, serious complications, or general health defects related to his diagnosed diarrhea. The Board acknowledges that some accommodations were necessary at work and that on a few occasions the Veteran has had to leave work early due to his diarrhea, but overall, given the total disability picture, the Board finds the symptoms of the bowel disability documented above more closely approximate a moderate disability rather than a moderately severe disability. Thus, the preponderance of the evidence is against a 30 percent rating for diarrhea. REASONS FOR REMAND In August 2015, the Veteran asserted that his hypertension was caused by weight gain that was caused by his service-connected disabilities, and in a May 2021 letter submitted by the Veteran's representative, the representative notes that the Veteran asserts that his weight gain causes his disabilities and asserts that the Veteran's weight gain was likely caused by his PTSD. The Veteran is service connected for PTSD, a bilateral knee disability, diarrhea, a cervical spine disability, bilateral cervical radiculopathy, tinnitus, residuals of a left hand fracture, left hamstring strain, and erectile dysfunction. Under current legal authority, obesity is not a disability for VA compensation purposes. Marcelino v. Shulkin, 29 Vet. App. 155 (2018); see also VAOGCPREC 1-2017. Although obesity may be considered in certain cases as an intermediate step in secondary service connection, obesity itself is not considered a disease or injury for which direct or secondary service connection may be granted. See VAOGCPREC 1-2017. While obesity cannot be service connected on a direct basis, as noted above, and obesity cannot qualify as an in-service event for service connection purposes, obesity may serve as an intermediate step between a service-connected disability and a current disability that may be service connected on a secondary basis under 38 C.F.R. § 3.310(a). VAOGCPREC 1-2017. In such case, that evidence would need to reflect (1) a service-connected disability or disabilities caused the veteran to become obese; (2) the obesity was a substantial factor in causing another disability; and (3) the disability would not have occurred but for the obesity caused by the veteran's service-connected disability or disabilities. Id. In the Veteran's case, the DD Form 214 from the February 1987 to December 1988 period of active service documents that the Veteran was discharged for "failure to conform to weight standards" following his March 1987 motor vehicle accident. The Veteran weighed 178 pounds at his entrance examination, conducted in October 1979. At a December 1986 examination prior to the motor vehicle accident and his entrance into his second period of active duty, the Veteran weighed 193 pounds. Following the March 1987 motor vehicle accident, December 1987 STRs document the Veteran was 18 pounds overweight and April 1988 STRs document the Veteran weighed 210 pounds. At his separation examination, the Veteran's weight was down to 197.8 pounds. Previous VA examinations do not include opinions as to whether or not the service-connected disabilities caused the Veteran to become obese, and, if so, whether the obesity was a substantial factor in causing the claimed disability and whether the claimed disability would not have occurred but for the obesity. Thus, the Board finds an addendum opinion is necessary as to all of the remanded claims. 8. Entitlement to service connection for obstructive sleep apnea, to include as secondary to PTSD and/or to include as intermediately caused by obesity The May 2021 Board remand directed the AOJ to obtain an opinion as to whether or not obstructive sleep apnea was aggravated by the service-connected PTSD. The June 2021 VA examiner did not provide an adequate opinion as to whether or not obstructive sleep apnea was aggravated by the service-connected PTSD. The examiner opined that PTSD is not known to cause or contribute to obstructive sleep apnea. However, the examiner did not provide a rationale for this opinion, nor did the examiner address the article submitted by the Veteran in June 2015 titled, "Post-Traumatic Stress Disorder Severity Linked to Sleep Apnea," which asserts that the risk of sleep apnea rose with the severity of the PTSD symptoms. Thus, the Board finds an addendum opinion is necessary to reconcile this article with the opinion that PTSD did not at least as likely as not aggravate the obstructive sleep apnea and to provide a rationale for the opinion. 9. Entitlement to service connection for hypertension, to include as secondary to PTSD, as secondary to medication taken for the Veteran's service-connected disabilities, and/or as intermediately caused by obesity A thorough review of the claims file notes that the Veteran had elevated blood pressure readings during his periods of active service. For example, a March 1984 examination showed the Veteran's blood pressure was 120/90. A December 1986 examination documented blood pressure was 122/82. The separation examination conducted in December 1988 documented blood pressure was 140/86. See VBMS entry with document type, "Military Personnel Record," receipt date 12/18/2014, with "#1" in the subject field, pp. 73, 75; VBMS entry with document type, "Military Personnel Record," receipt date 03/13/2015, with "#1" in the subject field, p. 13. The June 2021 VA examiner documented that the Veteran reported he had high blood pressure readings in service, but noted he was not started on medication until 2013. However, the examiner did not specifically address that the Veteran had elevated blood pressure readings in service, nor did the examiner provide an opinion with a thorough rationale as to whether or not these elevated blood pressure readings were suggestive of an onset of hypertension in service or whether or not the currently diagnosed hypertension was at least as likely as not related to the Veteran's active service. Thus, an addendum opinion is necessary to obtain this opinion. While the Veteran has asserted that the medications he takes for his various service-connected disabilities caused or aggravated his hypertension, he has not provided evidence to support this allegation, and his allegation alone is insufficient to establish entitlement to a medical opinion. 10. Entitlement to service connection for degenerative arthritis of the lumbar spine, to include as secondary to service-connected degenerative arthritis of the cervical spine, cervical radiculopathy of the bilateral upper extremities, bilateral knee disabilities, and/or as intermediately caused by obesity 11. Entitlement to service connection for numbness and tingling of the left foot, to include as secondary to a lumbar spine disability, cervical spine disability, bilateral knee disability, and/or as intermediately caused by obesity 12. Entitlement to service connection for numbness and tingling of the right foot, to include as secondary to a lumbar spine disability, cervical spine disability, bilateral knee disability, and/or as intermediately caused by obesity Beyond the need for an opinion as to whether or not obesity is an intermediate cause of the lumbar spine disability and/or the numbness and tingling of the bilateral foot, the claim for service connection for numbness and tingling of the bilateral foot is inextricably intertwined with the claim for service connection for a lumbar spine disability. Thus, these claims must be remanded as well. The matters are REMANDED for the following action: 1. Obtain an addendum opinion from an appropriate clinician regarding whether the Veteran's service-connected disabilities caused obesity, and if so, whether the obesity was an intermediate cause of the Veteran's claimed disabilities. If the clinician finds that an in-person examination is warranted to provide an informed opinion, an examination should be scheduled. The examiner should be provided a copy of the below facts. The examiner is informed of the following facts: The Veteran is service connected for posttraumatic stress disorder (PTSD), a bilateral knee disability, diarrhea, a cervical spine disability, bilateral cervical radiculopathy, tinnitus, residuals of a left hand fracture, left hamstring strain, and erectile dysfunction. The examiner is asked to provide the following opinions: (a) Did any single service-connected disability or combination of the Veteran's service-connected disabilities cause the Veteran to become obese? (b) If the answer to (a) is positive, is the obesity a substantial factor in causing the Veteran's diagnosed obstructive sleep apnea, hypertension, degenerative arthritis of the lumbar spine, or any diagnosed lower extremity radiculopathy. (c) If the answers to (a) and (b) are positive, would obstructive sleep apnea, hypertension, degenerative arthritis of the lumbar spine, and/or any diagnosed lower extremity radiculopathy not have occurred but for the obesity caused by any combination of the service-connected disabilities? (d) If the answer to either (b) or (c) is negative as to obstructive sleep apnea, the examiner is asked to specifically comment on the opinion provided by the July 2021 VA examiner, which noted that the Veteran's high BMI was at least as likely as not a major cause of the diagnosis of obstructive sleep apnea. See VBMS entry with document type, "C&P Exam," receipt date 07/15/2021 with "DBQ Medical Opinion" in the subject field, p. 2. (e) If the answer to either (b) or (c) is negative as to hypertension, the examiner is asked to specifically comment on the opinion provided by the June 2021 VA examiner, which noted that there is a well-documented association between BMI and hypertension and was the most likely contributor to the Veteran's hypertension. See VBMS entry with document type, "C&P Exam," receipt date 06/24/2021, with "DBQ Medical Opinion" in the subject field, p. 4. The examiner is asked to provide a rationale for each opinion given, including providing the medical principles and evidence relied upon for each opinion. If the examiner is unable to provide an opinion without resorting to speculation, he or she should explain why this is so and what, if any, additional evidence would be necessary before an opinion could be rendered. 2. Obtain an addendum opinion from an appropriate clinician regarding whether the service-connected PTSD aggravates the diagnosed obstructive sleep apnea. If the clinician finds that an in-person examination is warranted to provide an informed opinion, an examination should be scheduled. The examiner is asked to opine as to the following questions: a. Whether it is it at least as likely as not (50 percent probability or greater) that the obstructive sleep apnea is aggravated by the Veteran's service-connected PTSD? Aggravation is different from causation in that it did not cause the disability but that it caused an increase in severity that is not due to the natural progress of the disability. b. If the examiner finds that PTSD aggravates the obstructive sleep apnea, the examiner is asked to state whether there is medical evidence created prior to the aggravation or at any time between the time of aggravation and the current level of disability that shows a baseline for the obstructive sleep apnea prior to aggravation. If the examiner is unable to establish a baseline for the obstructive sleep apnea prior to the aggravation, he or she should state such and explain why a baseline cannot be determined. In providing this opinion, the examiner is asked to specifically comment on the article submitted by the Veteran entitled "Post-Traumatic Stress Disorder Severity Linked to Sleep Apnea." See VBMS entry with document type, "Correspondence," receipt date 06/11/2015. The examiner is asked to provide a rationale for each opinion given, including providing the medical principles and evidence relied upon for each opinion. If the examiner is unable to provide an opinion without resorting to speculation, he or she should explain why this is so and what, if any, additional evidence would be necessary before an opinion could be rendered. 3. Obtain an addendum opinion from an appropriate clinician regarding whether hypertension at least as likely as not had an onset in service or is related to service. If the clinician finds that an in-person examination is warranted to provide an informed opinion, an examination should be scheduled. The examiner is asked to opine: Is the Veteran's diagnosed hypertension at least as likely as not (50 percent probability or greater) had its onset during a period of active duty, which periods were from July 1980 to March 1984 and from February 1987 to December 1988 or is hypertension otherwise related to service? In providing the opinion, the examiner should explicitly address the notations of elevated blood pressure documented in the Veteran's STRs. See VBMS entry with document type, "Military Personnel Record," receipt date 12/18/2014, with "#1" in the subject field, pp. 74 (12/12/1986, BP: 122/820), 76 (3/27/1984, BP: 120/90); VBMS entry with document type, "Military Personnel Record," receipt date 03/13/2015, with "#1" in the subject field, p. 13 (12/8/1988, BP: 140/86). The examiner is asked to provide a rationale for each opinion given, including providing the medical principles and evidence relied upon for each opinion. If the examiner is unable to provide an opinion without resorting to speculation, he or she should explain why this is so and what, if any, additional evidence would be necessary before an opinion could be rendered. A. P. SIMPSON Veterans Law Judge Board of Veterans' Appeals Attorney for the Board A. Keninger, 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.