What action do the C7 nerve root and triceps tendon primarily control?

The C7 nerve root plays a crucial role in the motor control of the muscles responsible for elbow and wrist extension, primarily through its innervation of the triceps muscle. When the triceps muscle contracts, it extends the elbow joint, and consequently, it is instrumental in allowing movements that involve extending the arm and also supports wrist extension.

This nerve root supplies not just the triceps but also contributes to the radial nerve, which innervates other muscles involved in wrist extension. Therefore, recognizing the anatomy and function associated with the C7 nerve root is essential in understanding its primary role in the control of these joint movements. The action of elbow and wrist extension encompasses a critical function in various athletic and daily activities, illustrating the importance of this nerve root in overall upper limb functionality.