When a prime mover muscle contracts, what happens to the opposite muscle?

When a prime mover muscle contracts, the opposite muscle, known as the antagonist, typically relaxes. This phenomenon is part of the reciprocal inhibition mechanism, where the action of one muscle (the prime mover) leads to the relaxation of another muscle that opposes its action. For example, when the biceps contract to flex the elbow, the triceps muscle, which extends the elbow, must relax to allow the movement to occur smoothly. This coordinated action ensures that movements can be executed efficiently, avoiding any potential for injury or discomfort.