What muscles are affected by a lower motor neuron injury to C8?

A lower motor neuron injury at the C8 level primarily impacts the muscles innervated by the nerves that originate from that spinal segment. The flexor digitorum superficialis and flexor digitorum profundis are critical for finger flexion and are directly innervated by the median and ulnar nerves, which receive input from the C8 spinal root.

When there is damage to the lower motor neurons at this level, the ability to properly contract these muscles is compromised, resulting in weakness or paralysis of finger flexion. This deficit significantly affects grip and hand function, which are essential for daily activities.

The other muscles mentioned in the other options are associated with different spinal levels or nerves that do not primarily involve C8. Understanding the specific muscles linked to C8 helps in diagnosing and managing conditions resulting from lower motor neuron injuries in that area.