Lumbar Strain / Low Back Pain (Antalgic Gait) Secondary to Plantar Fasciitis (Service-Connected)

Yes. Under 38 CFR § 3.310(a), any disability proximately caused or chronically worsened by a service-connected condition is itself service-connected. Lumbar Strain / Low Back Pain (Antalgic Gait) is a documented secondary pairing for Plantar Fasciitis (Service-Connected) with moderate 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 Strain / Low Back Pain (Antalgic Gait) separately under its own 38 CFR Part 4 diagnostic code, then combines it with Plantar Fasciitis (Service-Connected) 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 Strain / Low Back Pain (Antalgic Gait) as secondary to Plantar Fasciitis (Service-Connected) is rated moderate. Plantar fasciitis produces an antalgic gait that transfers abnormal mechanical stress to the lumbar spine through the kinetic chain. Heel pain causes reduced stride length, trunk lateral shift, and pelvis obliquity during the stance phase — all of which increase asymmetric loading on lumbar intervertebral discs and facet joints. The posterior chain (gastrocnemius, hamstrings, gluteals, erector spinae) compensates for reduced push-off power, producing chronic lumbar paraspinal muscle fatigue and spasm. Biomechanical studies demonstrate that unilateral foot pain produces measurable increases in contralateral lumbar paraspinal EMG activity and intradiscal pressure. The effect is amplified in patients who must stand or walk for prolonged periods.

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.