Hi. This question is on the assessment and I’m having trouble understanding how the ulnar nerve (correct answer) performs MCP flex of the second digit. I had marked C8 nerve root
During manual muscle testing, you find weakness in metacarpophalangeal flexion of the second digit, adduction of the thumb, and flexion of the proximal interphalangeal joint of the fourth digit. Which structure may be responsible for this pattern of weakness?
C8 nerve root
Thanks for this question! The stem provides some mixed information, indicating a couple possible differentials. Given the limited information, we must make a decision based on prevalence. Isolated C8-T1 radiculopathy is rare. Ulnar nerve entrapments are much more common. The article linked below provides some more information.