Common movements for identifying C7 radiculopathy in general practice

A - elbow extension

The triceps muscle, which is responsible for elbow extension, is innervated by C7 and C8 nerve roots, so weakness in this muscle would be seen in a patient with C7 radiculopathy. The deltoid and biceps muscles, responsible for shoulder abduction and elbow flexion, respectively, are innervated by C5 and C6 nerve roots with no contribution from C7. The finger abductor muscles, particularly the first dorsal interosseous and abductor digiti minimi (responsible for the motions in this picture), are innervated by C8 and T1 nerve roots with no contribution from C7.

While relatively rare in presentation (85 out of 100,000 people annually), it is more common in middle-aged males, 40-60. C7 (and C6) radiculopathy is likely to be more prevalent in a patient population that includes middle-aged adults, especially if engaged in physical labor or at a higher risk for degenerative spinal changes.

Reference:

Preston D, Shapiro B. Electromyography and Neuromuscular Disorders: Clinical-Electrophysiological Correlations. 2nd ed, 2005.