Which physical exam aspect is key in assessing peripheral nerve injuries?

Assessing muscle strength is crucial in evaluating peripheral nerve injuries because it directly reflects the functionality of the muscles that those nerves innervate. When a peripheral nerve injury occurs, the corresponding muscle may exhibit weakness, atrophy, or an inability to contract, all of which are indicative of nerve damage. By testing muscle strength, clinicians can determine the extent of the injury and identify which specific nerves may be affected.

In contrast, while capillary refill time and vascular assessment can provide insight into blood flow and overall limb perfusion, they do not specifically assess nerve function. Similarly, evaluating joint range of motion can reveal how well a joint is functioning but does not provide direct information about nerve integrity or muscle strength. Therefore, muscle strength assessment stands out as the primary indicator of peripheral nerve status in a clinical exam setting.