What is the role of an agonist muscle during movement?

The role of an agonist muscle during movement is to contract, which is essential for generating force and producing movement at a joint. When an agonist muscle activates, it is primarily responsible for the action you want to perform, such as flexion, extension, or rotation, depending on the specific movement. For example, during a bicep curl, the biceps brachii acts as the agonist by contracting to lift the forearm toward the shoulder.

In contrast, other muscle types play different roles. Muscles that relax during movement are known as antagonists; they allow the agonist to exert its force. Muscles that remain stationary typically serve as fixators or stabilizers and help maintain posture or stabilize a joint rather than actively move it. Stabilizing muscles assist in providing the appropriate base for the agonist's action but do not contribute to the movement directly. Understanding these distinctions is crucial for comprehending how muscles work together to facilitate efficient and effective movement in activities like Pilates.