Back or Neck Strain Secondary to Knee Limitation of Flexion Claim Guide

We analyzed the Board's published decisions and found back or neck strain (DC 5237) claimed as secondary to knee limitation of flexion (DC 5260) is one of the larger secondary claim pools at the Board that comes down close to a coin flip once it reaches a merits decision.

How those 2,605 issues came out

The ICD-10 diagnosis codes most commonly used for DC 5237, Back or Neck Strain (the kind on your medical records, decision letter, or C&P exam report). VA rates the disability and its residuals, not the diagnosis itself, so coding can vary.

See the full diagnostic-code page →

Under 38 CFR 3.310 a secondary claim turns on three elements:

• A current diagnosis: a medical diagnosis of back or neck strain (the secondary).
• A service-connected primary: Knee Limitation of Flexion, already service-connected (the primary). A 0% primary still counts.
• A medical nexus: a medical opinion linking the back or neck strain to the knee limitation of flexion, showing the primary caused or aggravated it.

See the Secondary Claim guide for the caused-versus-aggravated split, and the Nexus Letter guide for what makes the medical opinion strong.

A secondary claim says back or neck strain flows from a service-connected knee limitation of flexion. Whether the medical link exists in any one case is a medical question decided on that case's own evidence (the nexus). See the Secondary Claim guide.

The outcome split above counts whole issues. This section goes one layer deeper. Under 38 CFR § 3.310 a secondary claim can be won two ways: the knee limitation of flexion caused the back or neck strain (§ 3.310(a)), or it aggravated an existing back or neck strain (§ 3.310(b)). Every grant rests on one or the other, so the numbers below divide up the granted claims only.

Direct causation is the route that carries most grants here: 81% of them found the knee limitation of flexion caused the back or neck strain, the rest found aggravation. A practical consequence for the nexus opinion: it should address both routes, because a medical opinion that only argues causation leaves the aggravation theory, a separate legal basis, on the table. See the caused-vs-aggravated guide for how the two theories differ.

On the other side: in 109 denied claims the Board looked at this pairing and found no link, meaning it decided the knee limitation of flexion neither caused nor worsened the back or neck strain. That is a separate group from the grants above, counted here so the picture is not one-sided.

We analyzed published Board decisions on this pairing to build this split. The grant split covers granted claims only; denied, remanded, and dismissed claims are not in it. Descriptive of the published record, not a prediction.

The record VA actually reviews centers on a small set of documents. We analyzed published Board decisions on these claims and ranked the records that appeared most often:

• A medical nexus opinion: the one record VA weighs most on a secondary claim, a doctor's statement linking your back or neck strain to your service-connected knee limitation of flexion and naming the mechanism.
• Range of motion measured in degrees
• In-service back or neck injury documented
• Flare-ups and additional functional loss addressed
• Radiculopathy or EMG/nerve-conduction findings
• MRI or imaging of the spine
• Physician-prescribed bed rest

The diagnostic code involved: DC 5237 (Back or Neck Strain). The rating levels for this code are in the rating section below.

Records ranked by how often published Board decisions cited them. The exam that captures most of this is covered in the C&P Exam section below. Source: Board of Veterans' Appeals decisions, RateMyVSO analysis.

What veterans who win this pairing actually put in the file, and why each piece moves the claim.

• C&P exam notes on your gait: Your knee limits how far it bends, so you walk differently to avoid pain, an antalgic gait. Make sure the exam actually writes down which leg you favor and how your walk looks different from normal. Without this on paper, the chain from knee to back is just a theory.
• Knee flexion measurements over time: Get your knee's range of motion tested and re-tested (for example, bending to only 45 degrees instead of a normal 135). This proves your knee limitation is real, severe, and lasting long enough to force your body to compensate.
• Records that describe how you move, not just how you hurt: Ask your provider to note things like a shorter stride, hip hiking, or leaning your trunk to one side. Pain complaints alone don't show the mechanical chain. Documented movement changes do.
• A clear timeline connecting knee to back or neck: Gather records showing when your knee condition started, when your walk changed, and when back or neck pain began or got worse. VA wants to see the back or neck problem come AFTER the knee problem, in that order, with the gap explained.
• Imaging of your spine (MRI or X-ray): This isn't required to win, but it helps. Imaging that shows wear, disc changes, or narrowing, especially on the side your body leans on to protect the knee, backs up the mechanical story with something VA can see, not just something you feel.
• Ongoing treatment records for your back or neck: Physical therapy visits, injections, muscle relaxers, whatever you've had. This shows your back or neck problem is real and managed medically, not a passing ache you mentioned once.
• A nexus letter from a specialist that names the exact mechanism: The letter needs the magic words, "at least as likely as not," and it needs to explain that your knee's limited flexion forces an uneven gait, which tilts your pelvis and loads your spine unevenly over time, causing strain. A generic letter that just says "knee pain and back pain, might be related" gets denied. Get it from an orthopedist or physiatrist who reviewed your actual records and timeline, not a form letter.
• Watch for the causation-versus-aggravation trap: If you had any back or neck trouble before your knee got bad, don't hide it, address it head-on. Your nexus letter should state whether the knee CAUSED the new condition or made an existing one WORSE (aggravation). VA denies claims where this distinction is left vague, so make sure your doctor picks one and explains it clearly.

The Board has granted service connection for lumbosacral strain (or a lumbar spine disability) as secondary to a knee condition in more than one published decision. In each case shown below, the veteran was already service connected for a knee disability and argued that years of favoring the bad knee, or an altered gait, led to a separate back condition. The grants below show what kind of evidence tipped the scale in the veteran's favor. Remember that these decisions are not binding on future cases, and each claim is decided on its own record.

The VA assigns one of these percentages based on what your medical record documents. Plain-language summary of the rating criteria at 38 CFR; the controlling text is the regulation itself.

Every item below comes from a pattern in the decisions on this pairing, not from general claim advice.

For the mechanics of filing itself, see the Standard Claim Guide and the Fully Developed Claim Guide.

A secondary claim moves through the same pipeline as any other. Understanding who does what helps you know who to contact and what to expect.

1. You file the claim, naming Knee Limitation of Flexion as the service-connected primary and back or neck strain as secondary. Directly with VA, through VA.gov, or with an accredited representative's help.
2. VA assigns a Veteran Service Representative (VSR) to develop the claim: gather your service treatment records, VA and private medical records, and order a C&P exam if needed.
3. The C&P exam is conducted, usually with the examiner asked to address the specific secondary theory (causation and aggravation both).
4. The file goes to a Rating Veteran Service Representative (RVSR), the "rater," who weighs the medical evidence and decides service connection and, if granted, the rating percentage.
5. VA issues the decision letter stating the outcome and the reasoning.
6. If denied or under-rated, you choose an appeal lane, Supplemental Claim, Higher-Level Review, or a Board appeal, covered below.

Who's who: VSO vs. VSR vs. Rater vs. C&P Examiner

For the full walkthrough, see Inside Your Claim and Claim Stages.

A Disability Benefits Questionnaire (DBQ) is the standardized form the examiner completes for your condition. See the DBQ Guide for how these forms work and whether a private DBQ from your own doctor can be submitted instead of relying solely on a VA exam. For what to expect and how to prepare, see the C&P Exam Prep Guide, and be specific about how your back or neck strain symptoms relate to your knee limitation of flexion timeline, treatment, and any aggravation, that is the detail a nexus opinion relies on.

Your decision letter has a narrative "reasons and bases" section and a codesheet with the rating and effective date. See the Reading Your Decision Letter Guide or use the Letter Interpreter tool to decode your own letter. If denied, you have three main lanes:

• Supplemental Claim: refile with new and relevant evidence, such as a nexus opinion that addresses the mechanism and the specific VA rationale you're rebutting. See Supplemental Claim Guide.
• Higher-Level Review (HLR): a senior reviewer looks at the same evidence again, useful if the denial rested on a legal error. See HLR Guide.
• Board Appeal: your case goes to a Veterans Law Judge, with a direct review, evidence, or hearing docket. See Board Appeal Guide.

Not sure which lane fits? See the Appeals decision guide for a side-by-side comparison.

Keep documentation of ongoing treatment, follow-up evaluations, and any updated diagnostic testing for your back or neck strain on file, this protects you if VA schedules a future reexamination. See Protect Your Rating for when a rating becomes protected and Future Reexaminations for what triggers one. If your back or neck strain worsens, see the Rating Increase Guide.