Nerve damage in the leg (sciatic nerve) and hip motion loss are the two back-related conditions this page rates, each under its own diagnostic code. At Rank and Pay, we publish plain-language guides on Department of Veterans Affairs (VA) disability ratings.
Under 38 Code of Federal Regulations (CFR) 3.310(a), any disability proximately due to or the result of a service-connected disease or injury is service connected. When secondary service connection is established, the secondary condition is considered a part of the original condition. The listed sciatic nerve and hip conditions are rated under their own criteria, separately from the spine criteria. To see how VA rates the back itself, read VA rating for back pain.
Secondary Conditions to Lower Back Pain and Their VA Ratings
The rating schedules in Title 38 establish specific percentage tiers for peripheral nerve conditions and joint motion loss. Diagnostic code 8520 covers sciatic nerve paralysis, while codes 5251 through 5253 rate limitations of the thigh and hip.
| Condition | Diagnostic Code | Rating Tiers | Governing Regulation |
|---|---|---|---|
| Sciatic Nerve Paralysis | 8520 | 10%, 20%, 40%, 60% (incomplete); 80% (complete) | 38 CFR 4.124a |
| Thigh Limitation of Extension | 5251 | 10% (extension limited to 5 degrees) | 38 CFR 4.71a |
| Thigh Limitation of Flexion | 5252 | 10%, 20%, 30%, 40% | 38 CFR 4.71a |
| Impairment of Thigh (Abduction, Adduction, Rotation) | 5253 | 10%, 20% | 38 CFR 4.71a |
Whether a specific secondary condition is caused by a lower back disability remains a medical question. VA decides whether a secondary condition is due to the back on the evidence.
How Secondary Service Connection and Aggravation Work Under 38 CFR 3.310
38 CFR 3.310 addresses secondary service connection and aggravation. The first rule is 38 CFR 3.310(a). The second rule, for aggravation, is 38 CFR 3.310(b).
Under 38 CFR 3.310(a), a secondary disability must be proximately due to or the result of an existing service-connected disease or injury.
Under 38 CFR 3.310(b), any increase in severity of a non-service-connected condition will be service connected if that increase is proximately due to your service-connected disability. The aggravation must not be due to the natural progress of the non-service-connected disease. To concede aggravation, VA requires a baseline level of severity established by one of these forms of medical evidence:
- Medical evidence created before the onset of aggravation that records the original severity.
- The earliest medical evidence created between the onset of aggravation and receipt of medical evidence establishing the current severity level.
The VA will not concede aggravation if this baseline medical evidence is missing from the record. For more details on the submission process, read our guide to filing a secondary claim.
Sciatic Nerve and Radiculopathy Ratings Under 38 CFR 4.124a
Diagnostic code 8520 appears in the Diseases of the Peripheral Nerves schedule. In 38 CFR 4.71a, Note (1) of the spine formula explicitly states that the VA must evaluate any associated objective neurologic abnormalities separately under an appropriate diagnostic code.
Diagnostic code 8520 in 38 CFR 4.124a covers paralysis of the sciatic nerve. Complete paralysis is assigned an 80 percent rating. Under the regulation, complete paralysis means the foot dangles and drops, no active movement is possible in muscles below the knee, and knee flexion is weakened or very rarely lost.
Incomplete paralysis of the sciatic nerve indicates a degree of lost or impaired function substantially less than complete paralysis. The regulation establishes four incomplete rating tiers under code 8520:
- Mild incomplete paralysis: 10 percent.
- Moderate incomplete paralysis: 20 percent.
- Moderately severe incomplete paralysis: 40 percent.
- Severe incomplete paralysis with marked muscular atrophy: 60 percent.
The text before the peripheral nerve tables provides two rules for nerve evaluations. First, when nerve involvement is wholly sensory, the rating should be for the mild (10 percent) or at most the moderate (20 percent) degree. Second, peripheral nerve schedule ratings reflect unilateral involvement. When both legs suffer sciatic nerve impairment, the ratings combine with the application of the bilateral factor. The schedule also lists diagnostic code 8620 for sciatic neuritis and diagnostic code 8720 for sciatic neuralgia after code 8520.
Hip and Thigh Limitation Ratings Under 38 CFR 4.71a
Hip limitations can be evaluated alongside a back disability if medical evidence shows the hip impairment is secondary to the lumbar spine. Title 38 CFR 4.71a provides rating codes for limitations of thigh and hip motion:
- Diagnostic code 5251: Thigh limitation of extension is rated 10 percent when extension is limited to 5 degrees.
- Diagnostic code 5252: Thigh limitation of flexion is rated 10 percent when flexion is limited to 45 degrees, 20 percent at 30 degrees, 30 percent at 20 degrees, and 40 percent at 10 degrees.
- Diagnostic code 5253: Impairment of the thigh provides a 20 percent rating for limitation of abduction with motion lost beyond 10 degrees. It provides a 10 percent rating for limitation of adduction when you cannot cross your legs. It also provides a 10 percent rating for limitation of rotation when you cannot toe-out more than 15 degrees with the affected leg.
The hip schedule also lists codes 5250 and 5254. Diagnostic code 5250 rates hip ankylosis at 60 percent when favorable (flexion between 20 and 40 degrees with slight adduction or abduction), 70 percent when intermediate, and 90 percent when unfavorable. Diagnostic code 5254 rates a flail joint of the hip at 80 percent. Learn more on our hip conditions VA rating page.
The regulation itself does not state whether or how often back problems cause hip limitations.
How the VA Rates the Primary Back Condition
Your secondary rating does not replace your primary spine rating. The VA rates the primary spine condition under the General Rating Formula for Diseases and Injuries of the Spine in 38 CFR 4.71a, which applies to diagnostic codes 5235 through 5243.
The spine formula includes range-of-motion criteria. Normal thoracolumbar forward flexion is zero to 90 degrees, and normal combined range of motion is 240 degrees. The formula establishes the following rating tiers:
- 10 percent: Forward flexion greater than 60 degrees but not greater than 85 degrees; or combined range of motion greater than 120 degrees but not greater than 235 degrees; or muscle spasm, guarding, or localized tenderness not resulting in abnormal gait or abnormal spinal contour; or vertebral body fracture with loss of 50 percent or more of height.
- 20 percent: Forward flexion greater than 30 degrees but not greater than 60 degrees; or combined range of motion not greater than 120 degrees; or muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour.
- 40 percent: Forward flexion of 30 degrees or less; or favorable ankylosis of the entire thoracolumbar spine.
- 50 percent: Unfavorable ankylosis of the entire thoracolumbar spine.
- 100 percent: Unfavorable ankylosis of the entire spine.
Other conditions need their own sources and are not covered here.
VA combines multiple disability ratings under its own rules. See VA's page on disability ratings.
Who This Is Not For
A secondary claim based on a lower back condition requires that back condition to be service connected. If your lumbar spine condition is not service connected, it cannot serve as the service-connected condition for a secondary claim under 38 CFR 3.310. If your back condition is not yet service connected, file a claim for the back condition first; see filing a VA claim.
This page does not cover conditions outside the cited sciatic nerve and hip rating tables.
What Would Change This Answer
An independent cause, rather than the back condition, would change the answer to whether a condition is secondary to the back. Under 38 CFR 3.310(a), secondary service connection requires the disability to be proximately due to or the result of a service-connected disease or injury.
An amendment changing the rating criteria in 38 CFR 4.71a or 38 CFR 4.124a would change this answer.
To advance your claim, obtain your complete medical records documenting both your primary back impairment and any secondary nerve or hip symptoms, then schedule an appointment with an accredited Veterans Service Officer (VSO) for free assistance.
This page provides general information only and does not constitute legal or medical advice. Rank and Pay is not affiliated with the Department of Veterans Affairs.