ACSM Personal Trainer Certification Practice Exam

Which muscle is primarily involved in elbow extension during physical exercises?

1. Biceps

2. Triceps

3. Deltoids

4. Pectorals

The correct answer is: Triceps

Elbow extension is primarily facilitated by the triceps muscle. The triceps brachii, located on the back of the upper arm, has three heads (long, lateral, and medial) that work together to straighten the arm at the elbow joint. During exercises that involve extending the elbow, such as push-ups or bench presses, the triceps are engaged to counteract the flexor muscles like the biceps, which are responsible for elbow flexion. In contrast, the biceps are primarily responsible for elbow flexion, while the deltoids and pectorals play significant roles in shoulder movements rather than directly affecting elbow extension. Therefore, the triceps is the key muscle involved in this action during physical activities.