A patient has a herniated interveebral disc impinging on the right C5 nerve roots. Which of the following movements would most likely be affected?
**Core Concept**
The C5 nerve root is responsible for innervating muscles involved in shoulder abduction and elbow flexion. A herniated intervertebral disc impinging on this nerve root would lead to radiculopathy, resulting in weakness or paralysis of these muscles.
**Why the Correct Answer is Right**
The C5 nerve root primarily innervates the supraspinatus, infraspinatus, deltoid, and biceps brachii muscles. The supraspinatus muscle is responsible for shoulder abduction, while the deltoid and biceps brachii muscles contribute to elbow flexion. Therefore, a patient with a herniated disc impinging on the C5 nerve root would likely experience weakness in shoulder abduction and elbow flexion. This is due to the interruption of motor signals from the C5 nerve root to the affected muscles.
**Why Each Wrong Option is Incorrect**
**Option A:** Wrist extension is primarily controlled by the radial nerve, not the C5 nerve root.
**Option B:** Hip flexion is primarily controlled by the L2-L4 nerve roots, not the C5 nerve root.
**Option C:** Finger extension is primarily controlled by the C7 nerve root, not the C5 nerve root.
**Option D:** Ankle dorsiflexion is primarily controlled by the L4-L5 nerve roots, not the C5 nerve root.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the C5 nerve root is often affected in cases of cervical radiculopathy, leading to weakness in shoulder abduction and elbow flexion. This can be a classic presentation of a herniated disc in the cervical spine.
**Correct Answer:** C. Finger extension.