Principles of Chiropractic Practice Test

Testing cervical radiculopathy relies on mapping motor weakness to the corresponding nerve root myotomes. Each root has a typical muscle group it mainly powers, so the signs line up in a recognizable pattern.

C5 is primarily associated with shoulder abduction through the deltoid. When you test this, you look for weakness or pain with resisted shoulder lifting away from the body.

C6 drives elbow flexion and wrist extension. Strength testing here looks at the biceps and brachioradialis for elbow flexion, and the wrist extensors for bringing the hand back toward the forearm.

C7 is most evident in elbow extension, tested by resisting straightening the elbow (triceps).

C8–T1 control finger flexion and the intrinsic muscles of the hand, so tests focus on curling the fingers and measuring grip and fine hand movements.

These signs fit together into a coherent pattern used to localize radiculopathy in the cervical spine. The other patterns mix in actions that don’t match the cervical myotomes (for example, ankle dorsiflexion or knee flexion point to lumbar—not cervical—roots), assign unlikely muscle actions to the wrong roots, or list non-specific symptoms like neck pain without a corresponding motor deficit. That’s why the described mapping is the best and most clinically useful.