Injury to muscles that straighten the wrist, fingers, and thumb.
Because the rating levels are defined by the criteria in § 4.56, your evidence should reflect what that section measures for muscle injuries: things such as whether the injury is a simple wound or a more complex one, the amount of muscle tissue lost or damaged, how much strength and motion remain in the wrist, fingers, and thumb, and whether the forearm can rotate normally.
Medical records documenting the original wound, surgical reports, imaging, and physical examination findings showing grip strength, range of motion of the wrist and fingers, and supination strength are all relevant. Electromyography or nerve conduction studies, if performed, may show functional loss.
Statements from you or people who know you describing how weakness or limited movement of your wrist, fingers, or thumb affects work tasks, carrying objects, writing, or other daily activities can help show the practical impact of the injury and support a higher severity level.
Conditions that are often caused or made worse by this one. If you have any of these, they may be claimable as secondary service connection.
