Lumbar Spine Pain / Degenerative Disc Disease Secondary to Pes Planus (Flat Feet)

Yes. Under 38 CFR § 3.310(a), any disability proximately caused or chronically worsened by a service-connected condition is itself service-connected. Lumbar Spine Pain / Degenerative Disc Disease is a documented secondary pairing for Pes Planus (Flat Feet) with emerging medical evidence. A nexus letter from a qualified physician linking the two conditions is the most reliable way to establish this connection.

The gold standard is a private nexus opinion stating — to at least a 50% probability ("at least as likely as not") — that the secondary condition was caused or aggravated by the primary service-connected condition. Peer-reviewed medical literature supporting the physiological mechanism strengthens the nexus. Treatment records documenting the onset or worsening of the secondary condition in temporal relation to the primary are supporting evidence.

The VA rates Lumbar Spine Pain / Degenerative Disc Disease separately under its own 38 CFR Part 4 diagnostic code, then combines it with Pes Planus (Flat Feet) and all other service-connected ratings using the combined ratings formula under § 4.25. The formula applies the whole-person concept: a 50% combined existing rating plus a new 30% rating yields 65% (rounded to 70%), not 80%.

38 CFR § 3.310(a) states: "Disability which is proximately due to or the result of a service-connected disease or injury shall be service connected." The aggravation variant under § 3.310(b) applies where the primary condition permanently worsens a pre-existing disability beyond its natural progression. Both standards require a showing of nexus — a medical or scientific link between the primary condition and the secondary.

The medical evidence supporting Lumbar Spine Pain / Degenerative Disc Disease as secondary to Pes Planus (Flat Feet) is rated emerging. Service-connected pes planus produces a biomechanical chain of compensation that ultimately stresses the lumbar spine. Excessive subtalar pronation → tibial internal rotation → femoral internal rotation → anterior pelvic tilt → lumbar lordosis exaggeration. The increased lumbar lordosis from foot pronation increases compressive load on the posterior lumbar facet joints and intervertebral discs. Gait studies using pressure-sensitive insoles confirm that subjects with bilateral pes planus have significantly increased lumbar paravertebral muscle EMG activity compared to subjects with normal foot arches, as the muscles work harder to stabilize an unstable kinetic chain base. Long-term, this sustained paraspinal muscle overactivation produces myofascial pain, facet arthropathy, and accelerated disc degeneration.

The VA will not solicit nexus evidence on your behalf for secondary claims. In practice, a written nexus opinion from a private physician or independent medical examiner is essential — the VA's Compensation & Pension (C&P) examiner is not required to produce a favorable nexus opinion, and the VA has discretion to weigh competing opinions. Submitting a private nexus letter at the time of filing is the most reliable strategy.