What is the antagonist muscle during an abdominal curl?

During an abdominal curl, the antagonist muscle refers to the muscle that opposes the action being performed by the prime mover (the muscle primarily responsible for the movement). In this case, the prime mover during an abdominal curl is the abdominal muscles, which flex the spine.

The erector spinae group, located along the spine, functions as the antagonist during this movement. As the abdominal muscles contract to curl the torso forward, the erector spinae must relax and stretch to allow this flexion to occur. This relationship between the prime mover and the antagonist is essential for coordinated movement and stability. When one set of muscles contracts, the opposing set must lengthen, which helps to maintain balance and prevent injury.

In contrast, the other muscles listed—abdominals, quadriceps, and gluteus maximus—do not fit the role of antagonist in this scenario. The abdominals are the prime movers, while the quadriceps and gluteus maximus are more active in actions involving the lower body rather than opposing the action of the abdominal curl.