College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which muscle group is eccentrically controlling elbow flexion during high-velocity movements like a tennis serve?

1. Flexor Carpi Radialis

2. Forearm flexors

3. Forearm extensor muscles

4. Subscapularis

The correct answer is: Forearm extensor muscles

During high-velocity movements such as a tennis serve, the forearm extensor muscles play a crucial role in eccentrically controlling elbow flexion. When an athlete serves, there is a rapid extension of the elbow that is followed by the flexion of the elbow as the racket moves forward. The forearm extensor muscles, primarily responsible for extending the wrist and elbow, engage eccentrically to control the rapid flexion and to stabilize the elbow joint throughout the motion. This eccentric control is essential for minimizing injury risk and maintaining precision during high-speed activities. The forearm extensors effectively manage the tension in the muscles to absorb the force generated by the fast movement rather than allowing the joint to flex uncontrollably. This control helps ensure proper biomechanics during the serve, allowing for effective power transfer without overexerting the flexor muscles or disrupting the movement's flow.