Citation Nr: 21066356 Decision Date: 10/29/21 Archive Date: 10/29/21 DOCKET NO. 14-40 462 DATE: October 29, 2021 ORDER Entitlement to service connection for diabetes mellitus is denied. Entitlement to service connection for diabetic peripheral neuropathy is denied. Entitlement to service connection for a right shoulder disability is denied. Entitlement to service connection for a left shoulder disability, to include as secondary to a right shoulder disability, is denied. Entitlement to a disability rating in excess of 40 percent from September 30, 2020 for service-connected chronic low back strain with degenerative arthritis (a low back disability) is denied. REMANDED Entitlement to a disability rating in excess of 20 percent prior to September 30, 2020 for a service-connected low back disability is remanded. Entitlement to a total disability rating based on individual unemployability (TDIU) prior to October 4, 2018 is remanded. FINDINGS OF FACT 1. The evidence is against a finding that the Veteran's diabetes mellitus began during active service, or is otherwise related to an in-service event, injury, or disease, to include exposure to herbicide agents while stationed in Thailand or Korea. 2. The evidence is against a finding that the Veteran's diabetic peripheral neuropathy is secondary to a service-connected disability, or is otherwise related to an in-service event, injury, or disease. 3. The evidence is against a finding that the Veteran has a right shoulder disability that began during active service, or is otherwise related to an in-service event, injury, or disease. 4. The evidence is against a finding that the Veteran has a left shoulder disability that is secondary to a service-connected right shoulder disability or is otherwise related to an in-service injury or disease. 5. From September 30, 2020, the evidence is against a finding that the Veteran's low back disability was manifested by unfavorable ankylosis of the entire thoracolumbar spine. CONCLUSIONS OF LAW 1. The criteria for service connection for diabetes mellitus have not been satisfied. 38 U.S.C. §§ 1110, 1112, 1116, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 2. The criteria for service connection for diabetic peripheral neuropathy have not been satisfied. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 3. The criteria for service connection for a right shoulder disability have not been satisfied. 38 U.S.C. §§ 1110, 1112, 1116, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 4. The criteria for service connection for a left shoulder disability have not been satisfied. 38 U.S.C. §§ 1110, 1112, 1116, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309, 3.310. 5. The criteria for a disability rating in excess of 40 percent from September 30, 2020 for a service-connected low back disability have not been satisfied. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. § 4.71a, Diagnostic Code 5237. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from August 1971 to May 1974, to include service in Korea. This matter comes before the Board of Veterans' Appeals (Board) from a December 2010 rating decision of the Department of Veterans Affairs (VA) Regional Office (RO). The issues were previously before the Board in April 2018, where they were remanded for additional development. While on remand, the RO awarded an increased, 40 percent rating for the Veteran's low back disability effective September 30, 2020 and granted entitlement to a TDIU effective October 4, 2018. As higher ratings are still available for the Veteran's low back disability during the entirety of the appeal period, and as entitlement to a TDIU prior to October 4, 2018 may still be warranted, these claims remain on appeal. The Veteran testified at a hearing before the undersigned Veterans Law Judge in October 2018. A transcript of the hearing is of record. Neither the Veteran nor his representative has raised any issues with the duty to notify or duty to assist. Service Connection Generally, to establish service connection, a claimant must show: (1) a present disability; (2) an 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, the so-called "nexus" requirement. See 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303; see also Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). A disability that is proximately due to, the result of, or aggravated by a service-connected disease or injury shall be service connected. 38 C.F.R. § 3.310. VA has established certain rules and presumptions for chronic diseases, such as diabetes mellitus and arthritis. See 38 C.F.R. §§ 3.303(b), 3.307, 3.309(a); Walker v. Shinseki, 708 F.3d 1331, 1338 (Fed. Cir. 2013). With chronic diseases shown as such in service so as to permit a finding of service connection, subsequent manifestations of the same chronic disease at any later date, however remote, are service connected, unless attributable to intercurrent causes. 38 C.F.R. § 3.303(b). If chronicity in service is not established, a showing of continuity of symptoms after discharge may support the claim. 38 C.F.R. § 3.303(b). In addition, for veterans who have served 90 days or more of active service during a war period or after December 31, 1946, chronic diseases are presumed to have been incurred in service if they manifested to a compensable degree within one year of separation from service. 38 C.F.R. §§ 3.307(a)(3), 3.309(a). 1. Service connection for diabetes mellitus 2. Service connection for diabetic peripheral neuropathy The record verifies that the Veteran currently has diabetes mellitus, type II. See February 2, 2021 VA Diabetes Mellitus Disability Benefits Questionnaire. Thus, the remaining question is whether the current diabetes is related to service. The Veteran's service treatment records show no complaints, diagnosis, or treatment related to diabetes. The earliest recorded evidence of a history of diabetes is his August 2007 diagnosis. There is no competent evidence suggesting that the Veteran developed diabetes during service, within the year after separation, or as a result of an in-service event, injury, or disease. Therefore, direct service connection cannot be established. The Veteran's main contention, however, is not that his diabetes started during service, but that he was exposed to herbicide agents in service, and that VA should presume he developed diabetes mellitus as a result of that exposure. See 38 C.F.R. § 3.309(e). As an initial matter, the Board notes that the Veteran asserted in a July 2013 statement that he had service in the Republic of Vietnam in January 1972. He asserted that he had approximately six days of service in the Republic of Vietnam prior to his official duties in Korea. Veterans who served specifically in the Republic of Vietnam between January 9, 1962, and May 7, 1975, shall also be presumed to have been exposed to an herbicide agent. 38 U.S.C. § 1116(f); 38 C.F.R. §§ 3.307(a)(6)(iii), 3.309(e). However, during his October 2018 Board hearing, the Veteran clarified that there was confusion in the record, and that he was only in Thailand and Korea. As such, further inquiry as to any service in the Republic of Vietnam is not necessary. As to the Veteran's service in Korea, a veteran who served in or near the Korean Demilitarized Zone (DMZ) during the period beginning on September 1, 1967 and ending on August 31, 1971 is presumed to have been exposed to herbicides. 38 U.S.C. § 1116B. "Near" is not defined in the statute or the corresponding regulation. Id.; see also 38 C.F.R. § 3.307(a)(6)(iv). The Board understands "near" to mean "[t]o, at, or within a short distance or interval in space or time." WEBSTER'S II NEW COLLEGE DICTIONARY 730 (1999). The Veteran's service records show that while in Korea he served in the 6th Battalion, 37th Artillery (6th Bn, 37th Arty). While the Joint Services Records Research Center (JSRRC) responded in March 2020 that the 6th Bn, 37th Arty is on the list of units identified by VA as having operated in an area on or near the DMZ, the Board notes that the Veteran's tour dates in Korea fall outside of the required date range for presumptive service connection purposes. Thus, the Veteran cannot be presumed to have been exposed to herbicide agents as a result of his service in Korea. Further, the JSRRC reported that it reviewed the operational Reports Lessons Learned (OR-LLs) submitted by the 2nd Infantry Division covering the periods between November 1971 to April 1972 and from August 1972 to October 1972, as well as the 1972 chronology submitted by the Eight United States Army. These records, according to the JSRRC, do not document the use, storage, spraying, or transporting of tactical herbicide agents. In addition, the records do not mention or document any specific duties performed by the 6th Bn, 37th Arty on or near the DMZ during the Veteran's period of deployment in Korea. While the Veteran is certainly capable of identifying dead vegetation, as a lay person he is not competent to identify an actual chemical compound or to offer an opinion as to how far a chemical compound could travel or how long a chemical would last after exposure to the elements. Simply put, the Veteran is not competent to establish that he was exposed specifically to Agent Orange or any other herbicide agent in order to establish exposure for direct service connection purposes. Moreover, JSRRC research could not document the use, storage, spraying, or transportation of herbicides in the Veteran's vicinity while he served in Korea. As such, the Board finds the preponderance of the evidence is against a finding that the Veteran was exposed to herbicide agents in Korea. As to the Veteran's service in Thailand, VA has adopted a procedure for verifying exposure to herbicides in Thailand during the Vietnam era. In governing manuals and procedures, VA has determined that there was significant use of herbicides on the fenced-in perimeters of military bases in Thailand. VA has acknowledged that the herbicide used on the Thailand base perimeters may have been tactical or a commercial variant of much greater strength and with the characteristics of tactical herbicides. Special consideration of herbicide exposure on a facts-found or direct basis should be extended to those veterans whose duties placed them on or near the perimeters of Thailand military bases. This allows for presumptive service connection of the diseases associated with herbicide exposure. For veterans who served in Thailand during the Vietnam era who were stationed at the Royal Thai Air Force Bases (RTAFB) of U-Tapao, Ubon, Nakhon Phanom, Udorn, Takhli, Korat, or Don Muang, and served as an Air Force security policeman, security patrol dog handler, member of a security police squadron, or otherwise was near the air base perimeter as shown by evidence of daily work duties, performance evaluation reports, or other credible evidence, herbicide should be acknowledged on a facts-found or direct basis. For Army veterans who served on RTAFBs in Thailand, herbicide exposure may be conceded on a facts-found basis if the veteran provides a statement that he was involved in perimeter security duty, and there is additional credible evidence supporting this statement. These provisions apply only during the Vietnam era. The Board must also consider lay statements and other evidence when determining whether a veteran had exposure to herbicide agents in Thailand. See Parseeya-Picchione v. McDonald, 28 Vet. App. 171, 176 (2016). In this case, the Veteran did not serve at one of the aforementioned RTAFBs. Instead, VA issued a formal finding in March 2020 that review of the Veteran's official military personnel file revealed that he was stationed at Camp Essayons for a period of 15 days on or around June 6, 1972. Pursuant to the Board's remand, VA asked the Veteran in December 2019 for a statement that provides greater detail regarding his asserted herbicide exposure in Thailand. To date, the Veteran has not responded to this request. As such, VA is unable to corroborate any exposure to herbicide agents during the Veteran's short time in country. The Board thus finds the preponderance of the evidence is against a finding that the Veteran was exposed to herbicide agents in Thailand. In sum, without competent evidence showing treatment for or a diagnosis of diabetes while on active duty, findings that it manifested to a compensable degree within a year following discharge from active duty, or affirmative evidence of the Veteran's personal exposure to herbicide agents during service, entitlement to service-connection for diabetes cannot be established. The claim for service connection for diabetes mellitus must, therefore, be denied. As the Board is denying the Veteran's claim for service connection for diabetes mellitus, the separate claim for service connection for diabetic peripheral neuropathy on a secondary basis must also be denied as a matter of law. See 38 C.F.R. § 3.310; Sabonis v. Brown, 6 Vet. App. 426 (1994). 3. Service connection for a right shoulder disability 4. Service connection for a left shoulder disability, to include as secondary to a right shoulder disability During his October 2018 Board hearing, the Veteran asserted that he injured his right shoulder during training, when he was sleeping on the top bunk and fell out of bed. He reported that while his in-service treatment related to the fall was mostly focused on his low back, he sought treatment, was given physical therapy, could not continue training for ten days, and was given light duty. He asserted that he has experienced trouble with his right shoulder ever since service, and that such put more strain on his left shoulder. He also asserted that, while he has had a post-service left shoulder injury, he also had an in-service left shoulder injury when he fell in a rabbit hole, with the full weight of his body, during field exercises. The Veteran has current shoulder disabilities, diagnosed during a February 2021 VA examination as a right shoulder rotator cuff tear and bilateral shoulder impingement. A private treatment record in October 2016 also indicates mild acromioclavicular osteoarthritis with accompanying subacromial-subdeltoid bursitis. The Board notes that while the Veteran has also described subjective neurological symptoms in the right upper extremity, a February 2021 VA peripheral nerves examination did not diagnose any neurological disability in the right shoulder other than diabetic peripheral neuropathy, which the Board has denied above. Thus, the remaining question is whether a current shoulder disability other than diabetic peripheral neuropathy is related to service or a service-connected disability. The Veteran's service treatment records (STRs) show no complaints, diagnosis, or treatment related specifically to a shoulder disability. As the Veteran reported other ailments during service, including recurrent back pain and left lower extremity radicular symptoms related to his confirmed fall from bed, and as shoulder problems are the type that a reasonable person would report while in the military with access to healthcare, if the Veteran was experiencing problems with his shoulders during service the Board would expect that he would have reported these problems to medical professionals. During his 1974 separation examination, evaluation of the upper extremities was normal. The examination report notes only a history of back pain after a November 1971 incident where the Veteran fell from his bunk. The Board acknowledges, however, that it is the Veteran's contention that his shoulder(s) were injured during this same incident. Nevertheless, STR's related to this incident note the Veteran falling flat on his back, with no complaints related to the shoulders or, for the purposes of any neurological symptoms, the neck. A shoulder disability is not shown by medical evidence until approximately September 2006 where the Veteran reported to VA treatment providers that right shoulder pain began 8 hours prior after a fall, despite his assertions more recently that his shoulder pain has progressed since service. During a VA examination for the Veteran's back disability provided in March 2006, the Veteran reported no shoulder issues associated with the in-service for which his back is service-connected. In March 2007, the Veteran reported an onset of right shoulder pain in the late 1990s after a separate fall. As a chronic shoulder disability is not shown to have been present during service or in the first year after separation of service, and continuity of symptomatology leading to a diagnosis of such is not shown, in-service incurrence of a chronic shoulder disability cannot be presumed. See 38 C.F.R. §§ 3.307, 3.309(a). To the extent the Veteran asserts a continuity of symptomatology beginning during service, the Board finds these statements to lack credibility as they are in direct conflict with both the Veteran's STRs where he failed to report any shoulder pain at the time, and VA treatment records in 2006 and 2007 when he reported a later onset of shoulder pain. The Board finds these earlier records to be more reliable than more recent assertions. Pursuant to the Board's remand, a VA shoulder and arms conditions examination was provided in February 2021, at which time he was interviewed by the examiner who also reviewed the pertinent medical history and performed an examination. The examiner opined that it was less likely than not that any of the Veteran's shoulder disabilities is related to service, explaining that there is no documented chronic shoulder condition that started while he was active duty, to include during separation examination. According to a March 2006 VA examination, the examiner continued, the Veteran's his occupation since leaving military service has for the most part involved heavy labor as a stone and concrete mason as well as working for landscape company, and the record at that time only a back injury after the claimed in-service fall. It is much more likely, the examiner concluded, that his shoulder pain occurred during his career after the military, as any symptoms or pathology of an injury from a fall would certainly not initially present decades after the injury itself. The Board finds this opinion highly probative as it was made by a medical professional with consideration of the specific facts in this case and after examination of the Veteran. The opinion is also supported by other evidence of record, to include the lack of any documented shoulder pain until decades after service despite more recent assertions that his right shoulder pain has persisted since his military service. There is also no medical opinion or competent and credible evidence in significant conflict with the VA medical opinion. The Board has considered the Veteran's statements, to include his assertions that his shoulder disabilities are related to his military service. As the Veteran is not shown to have medical education or experience, he is a lay person and is competent to report (1) symptoms that are observable to a layperson, e.g., shoulder pain; (2) symptoms at the time supporting a later diagnosis by a medical professional; or (3) a contemporaneous medical diagnosis. See Davidson v. Shinseki, 581 F.3d 1313 (2009). The Veteran is not competent to independently render a medical diagnosis or opine as to the specific etiology of a condition as these are medically complex issues. Thus, his lay assertions do not constitute evidence upon which service connection can be granted. In any event, the Board assigns greater probative weight to the medical evidence of record, to include the opinion rendered by a trained medical professional based on appropriate diagnostic testing and reasonably drawn conclusions with supportive rationale. For the above reasons, the preponderance of the evidence is against the claim and service connection for right and left shoulder disabilities on a direct service connection must be denied. 38 C.F.R. § 3.303. As the Board is denying service connection for a right shoulder disability, any left shoulder disability claimed as secondary to a right shoulder disability must be denied as a matter of law. 38 C.F.R. § 3.310; Sabonis v. Brown, 6 Vet. App. 426 (1994) (noting that when the law is dispositive of the claim, then the claim must, as a matter of law, be denied because of the absence of legal merit or lack of entitlement under the law). In reaching the above conclusions, the Board has considered the applicability of the benefit of the doubt doctrine. However, as the preponderance of the evidence is against the Veteran's claims, that doctrine is not applicable in this case. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). Increased Ratings Disability ratings are determined by evaluating the extent to which a Veteran's service-connected disability adversely affects his or her ability to function under the ordinary conditions of daily life, including employment, by comparing his or her symptomatology with the criteria set forth in the Schedule for Rating Disabilities (Rating Schedule). See 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Different ratings may be assigned for different periods of time for the same disorder if the facts show distinct time periods with different levels of disability. Fenderson v. West, 12 Vet. App. 119 (1999); Hart v. Mansfield, 21 Vet. App. 505 (2007). If two ratings are potentially applicable, the higher rating will be assigned if the disability more nearly approximates the criteria required for that rating; otherwise, the lower rating will be assigned. See 38 C.F.R. § 4.7. Any reasonable doubt regarding the degree of disability will be resolved in favor of the Veteran. See 38 C.F.R. § 4.3. 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."). 5. A rating in excess of 40 percent from September 30, 2020 for a low back disability Regulations specify that disabilities of the spine should be evaluated under the General Rating Formula for Diseases and Injuries of the Spine (Spinal Formula). 38 C.F.R. § 4.71a, Diagnostic Codes 5235 to 5243. When intervertebral disc syndrome (IVDS) is present, it is to be evaluated under the Spinal Formula unless it is more favorable to rate under the Formula for Rating IVDS Based on Incapacitating Episodes (IVDS Formula). Ratings under the Spinal Formula are made with or without symptoms such as pain (whether or not it radiates), stiffness, or aching in the area of the spine affected by residuals of injury or disease. As relevant to the thoracolumbar spine, the Spinal Formula provides for a 40 percent disability rating is assigned for forward flexion of the thoracolumbar spine to 30 degrees or less, or with favorable ankylosis of the entire thoracolumbar spine. A 50 percent disability rating is assigned for unfavorable ankylosis of the entire thoracolumbar spine and a 100 percent rating is assigned with unfavorable ankylosis of the entire spine. 38 C.F.R. § 4.71a, Spinal Formula. Associated objective neurologic abnormalities should be rated separately under an appropriate diagnostic code. Id., Note (1). Ankylosis is stiffening or fixation of a joint as the result of a disease process, with fibrous or bony union across the joint. Dinsay v. Brown, 9 Vet. App. 79, 81 (1996). Ankylosis is also defined as "immobility and consolidation of a joint due to disease, injury, or surgical procedure." DORLAND'S ILLUSTRATED MEDICAL DICTIONARY 93 (30th ed. 2003). Alternatively, the IVDS Formula provides for rating based on the total duration of incapacitating episodes. 38 C.F.R. § 4.71a, IVDS Formula. Incapacitating episodes are defined as a period of acute signs and symptoms due to IVDS that requires bed rest prescribed by a physician and treatment by a physician. Id., Note (1). A 20 percent disability rating is assigned with incapacitating episodes having a total duration of at least 2 weeks. Higher ratings are available with incapacitating episodes of greater duration during a 12-month period. In this case, IVDS has not been diagnosed. Turning to the evidence, the Veteran currently receives a 40 percent evaluation, which contemplates favorable ankylosis. The Board finds that the record does not reflect that the Veteran's low back disability results in unfavorable ankylosis of the thoracolumbar spine, which is necessary for the next higher, 50 percent rating. Pursuant to the Board's previous remand, the Veteran was provided a new VA back examination in September 2020. Range of motion testing was performed and showed, at worst, 55 degrees of flexion. Additionally, the Veteran was asked about pain, flare-ups, and functional limitations, and relevant testing was performed by the examiners, to include testing for pain and testing to reveal any additional functional limitations in certain circumstances, such as after repetitive use. The Veteran reported flare-ups consisting of increased pain and weakness with repetitive use, bending, and lifting, and the examiner estimated that range of motion during both a flare-up and after repetitive use over time would be, at worst, decreased further to 30 degrees of flexion. Ankylosis, however, was not diagnosed. The Board acknowledges that the United States Court of Appeals for Veterans Claims (Court) recently has held that, while in the past the focus of applying the factors contained in 38 C.F.R. §§ 4.40 and 4.45 were limited to that of range of motion, nothing "suggests that those factors should not apply in the context of ankylosis, particularly as ankylosis is, in essence, a complete limitation of motion." Chavis v. McDonough, 34 Vet. App. 1, 20 (2021). Thus, the application of §§ 4.40 and 4.45 permits consideration under the General Rating Formula of an evaluation based on ankylosis if a claimant's functional loss amounts to the functional equivalent of ankylosis. Here, however, the Board finds that the Veteran's disability does not. VA has defined unfavorable ankylosis as a condition in which the entire cervical spine, the entire thoracolumbar spine, or the entire spine is fixed in flexion or extension, and the ankylosis results in one or more of the following: difficulty walking because of a limited line of vision; restricted opening of the mouth and chewing; breathing limited to diaphragmatic respiration; gastrointestinal symptoms due to pressure of the costal margin on the abdomen; dyspnea or dysphagia; atlantoaxial or cervical subluxation or dislocation; or neurologic symptoms due to nerve root stretching. 38 C.F.R. § 4.71a, Diagnostic Codes 5235-5242 at Note (5). While the Veteran may experience some periods of immobility, the Board does not find that these periods are the functional equivalent of the Veteran's thoracolumbar spine being in a fixed position with the additional, debilitating symptoms that are required to accompany unfavorable ankylosis as contemplated by the rating criteria. Indeed, it is emphasized that the Veteran's now-current 40 percent rating already contemplates favorable ankylosis, and the Board finds that his symptoms more closely approximate that condition. As such, a rating in excess of 40 percent is not warranted. The Board is sympathetic to the Veteran's lay statements that his low back disability is worse than currently evaluated during this particular period on appeal and those statements have been considered. The Veteran is competent to report symptoms because this requires only personal knowledge as it comes to him through his senses. Layno v. Brown, 6 Vet. App. 465 (1994). He is not, however, competent to identify a specific level of disability according to the appropriate diagnostic codes. Such competent evidence concerning the nature and extent of the Veteran's disability have been provided by the medical personnel who have examined him during the current appeal and who have rendered pertinent opinions in conjunction with the evaluations. The medical findings (as provided in the examination reports and the clinical records) directly address the criteria under which the disability is evaluated. The medical and lay evidence has been assessed by the Board in determining the overall disability rating. Neither the Veteran nor his representative has raised any other issues, nor have any other issues been reasonably raised by the record. REASONS FOR REMAND While the Board regrets further delay, the Veteran's claims for entitlement to a disability rating in excess of 20 percent prior to September 30, 2020 and entitlement to a TDIU prior to October 4, 2018 must be remanded. For the period on appeal prior to the Veteran's award of a 40 percent disability rating for his low back disability, VA examinations were afforded in April 2010, March 2016, and February 2018, and range of motion testing showed forward flexion to 40 degrees during each examination. While an additional VA examination dated in December 2009 is also of record, range of motion was not provided. Further, while Veteran did not report flare-ups in March 2010, he did report flare-ups of increased back pain during the December 2009 VA examination and again in March 2016 and February 2018. None of these examinations, however, contains estimated additional functional loss during a flareup or after repetitive use over time, with the examiners simply stating in these instances that they would be resorting to speculation as the Veteran was not being observed during a flare or after repetitive use over time. Thus, the matter must be remanded for the RO to obtain a retrospective opinion as to severity of the Veteran's service-connected low back disability from the period on appeal beginning February 19, 2009 (one year prior to the Veteran's February 2010 claim for an increased rating) through September 29, 2020. Specific instructions are below. See DeLuca v. Brown, 8 Vet. App. 202 (1995); Mitchell v. Shinseki, 25 Vet. App. 32, 44 (2011). The issue of entitlement to TDIU prior to October 4, 2018 is inextricably intertwined with the rating assigned for the Veteran's service-connected low back disability. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991). The matters are therefore REMANDED for the following actions: Obtain a retrospective medical opinion providing an estimate of any additional loss of range of motion of the thoracolumbar spine during a flare-up or with repeated use over time during the period on appeal prior to September 30, 2020, including based on the findings of VA examination reports in December 2009, March 2010, March 2016, and February 2018. The examiner need not provide an exact degree of range of limitation, but should estimate, if possible, whether forward flexion of the thoracolumbar spine would be limited to 30 degrees or less or resulted in the equivalent of unfavorable ankylosis. See 38 C.F.R. § 4.71a, Diagnostic Code 5237; Chavis v. McDonough, 34 Vet. App. 1, 20 (2021). If the examiner finds that the severity changed during this period and can be separately estimated during different times, this should be explained. If the examiner is unable to provide such an estimate, the examiner must explain why the available information, including the Veteran's statements, medical history, and the examination findings, is not sufficient for that purpose. Such a discussion should note whether the inability to provide an opinion without resorting to speculation reflects the limitation of knowledge in the medical community at large or a limitation of the individual examiner (e.g., lack of expertise). P.M. DILORENZO Veterans Law Judge Board of Veterans' Appeals Attorney for the Board R. Scarduzio, 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.