---
title: "DC 5309 - Group IX. Function: The forearm muscles act in strong grasping movements and are supplemented by the intrinsic muscles in delicate manipulative movements. Intrinsic muscles of hand: Thenar eminence; short flexor, opponens, abductor and adductor of thumb; hypothenar eminence; short flexor, opponens and abductor of little finger; 4 lumbricales; 4 dorsal and 3 palmar interossei"
diagnostic_code: "5309"
body_system: "Muscle Injuries"
cfr_section: "§ 4.73"
canonical: "https://veteranai.co/va-rating-schedule/muscle-injuries/5309-group-ix-function-the-forearm-muscles-act-in-strong-grasping"
source: "https://www.ecfr.gov/current/title-38/section-4.73"
updated: "2026-07-21T20:08:50.269001Z"
---

# DC 5309 - Group IX. Function: The forearm muscles act in strong grasping movements and are supplemented by the intrinsic muscles in delicate manipulative movements. Intrinsic muscles of hand: Thenar eminence; short flexor, opponens, abductor and adductor of thumb; hypothenar eminence; short flexor, opponens and abductor of little finger; 4 lumbricales; 4 dorsal and 3 palmar interossei

Rated under § 4.73. Body system: Muscle Injuries.

The hand is so compact a structure that isolated muscle injuries are rare, being nearly always complicated with injuries of bones, joints, tendons, etc. Rate on limitation of motion, minimum 10 percent.

## Rating criteria

No itemised criteria have been extracted for this code. Use the official source.

## Notes

- Note: The hand is so compact a structure that isolated muscle injuries are rare, being nearly always complicated with injuries of bones, joints, tendons, etc. Rate on limitation of motion, minimum 10 percent.

# VA Disability Rating: Muscle Group IX — Hand and Forearm Muscles (Diagnostic Code 5309)

**Body System:** Muscle Injuries
**Regulation:** 38 CFR § 4.73

## Understanding Muscle Group IX

Muscle Group IX covers the muscles that power the movements of your hand and forearm. According to the VA rating schedule, these muscles work together in the following ways:

- **Forearm muscles** act in strong grasping movements and are supplemented by the intrinsic muscles of the hand during delicate, manipulative movements.
- **Intrinsic muscles of the hand** include:
  - The **thenar eminence** — the short flexor, opponens, abductor, and adductor of the thumb
  - The **hypothenar eminence** — the short flexor, opponens, and abductor of the little finger
  - The **4 lumbricales**
  - The **4 dorsal and 3 palmar interossei**

Together, these muscles support both the powerful grip used for grasping and the fine, precise movements used in tasks that require dexterity.

## How the VA Rates This Condition

The VA notes that the hand is such a compact structure that isolated muscle injuries are rare — they are nearly always complicated by injuries to the bones, joints, tendons, or other structures.

Because of this, **Muscle Group IX injuries are rated based on limitation of motion**, with a **minimum rating of 10 percent**.

## What the VA Looks For

When evaluating a Muscle Group IX injury, the VA considers:

- The **limitation of motion** affecting the hand and related structures
- The fact that hand muscle injuries typically occur **alongside injuries to bones, joints, and tendons**, given how compact the hand is

The rating is assigned according to limitation of motion, and a rating of at least 10 percent is applied as the minimum for this muscle group.

Source: https://www.ecfr.gov/current/title-38/section-4.73