Muscle Group XXI VA Disability Rating
Diagnostic Code 5321 · 38 CFR §4.73
What Is It?
Muscle Group XXI consists of the muscles of respiration, specifically the thoracic muscles including the intercostal muscles between the ribs and the diaphragm. These muscles expand and contract the rib cage to enable breathing. The intercostals pull the ribs apart during inhalation and compress them during forced exhalation. When damaged, breathing capacity is reduced, which affects exercise tolerance and overall endurance. Chest wounds from shrapnel, gunshot injuries, and blast events commonly damage these muscles.
Rating Criteria
| Rating | Criteria |
|---|---|
| 20% | Moderately severe or severe injury with significant impairment of respiratory muscle function. |
| 10% | Moderate injury with some reduction in respiratory function. |
| 0% | Slight injury with minimal impact on breathing. |
Evidence Needed
- Service records documenting the chest wound
- Treatment records including chest tube placement or surgical repair
- Pulmonary function testing showing reduced respiratory capacity
- Documentation of chest wall pain or restriction during deep breathing
- Statements about exercise intolerance and shortness of breath with activity
C&P Exam Tips
- Get pulmonary function tests to objectively measure breathing capacity
- Report chest wall pain during deep breathing, coughing, or physical exertion
- Describe your exercise tolerance and how quickly you become short of breath
- Mention if breathing is worse in certain positions
- Show chest wall scarring from the wound
How to File
File under DC 5321 with evidence of the chest muscle injury and pulmonary function testing. If the chest wound also caused lung damage, that should be rated separately under the respiratory codes. The scar from the chest wound is also separately ratable.
Common Mistakes
Not getting pulmonary function tests which provide objective evidence of breathing impairment Failing to separate the muscle injury from lung damage — both can be rated but under different codes Not claiming the chest wall scar separately Missing the reduced exercise capacity which directly results from impaired respiratory muscles
Frequently Asked Questions
Can respiratory muscle damage cause long-term breathing problems?
Yes. Damage to the intercostal muscles or scarring of the chest wall can permanently restrict how much the rib cage expands during breathing. This creates a restrictive pattern on pulmonary function tests and limits your exercise tolerance and stamina.
Is the rating for respiratory muscles separate from a lung condition rating?
Yes, they are distinct conditions. Muscle Group XXI covers the chest wall muscles, while lung conditions like COPD or pleural disease are rated under the respiratory system codes. If a chest wound damaged both the muscles and the lung, both conditions can be rated.