What is the role of a synergist muscle?

A synergist muscle plays an important role in facilitating movement by assisting the primary mover, or agonist, in performing an action. While the agonist is responsible for generating the main force and initiating the movement, synergists help to refine that movement, making it more efficient and coordinated. They can do this by stabilizing joints and providing support, but their primary function is to enhance the effectiveness of the primary mover rather than oppose or encumber it.

This is particularly important during complex movements where multiple muscles need to work together. For example, during a bicep curl, the biceps brachii is the agonist, while the brachialis and brachioradialis act as synergists to support and assist in the curling motion. The incorporation of synergist muscles helps to ensure that the movement occurs smoothly and effectively, highlighting their essential role in overall muscle function and movement mechanics.