Which pairs of movements employ reciprocal inhibition in a set aimed at strength and flexibility?

Reciprocal inhibition refers to the process where the activation of one muscle group leads to the relaxation of its opposing muscle group. This physiological principle is often leveraged during strength training and flexibility exercises to promote better performance and reduce the risk of injury.

In the scenario described, the correct pair involves movements that incorporate reciprocal inhibition effectively. The seated leg extension targets the quadriceps by actively contracting this muscle group. As the quadriceps contract during the extension exercise, the hamstrings, which are the opposing muscle group, undergo relaxation. Following this strength exercise, performing a hamstring stretch benefits from this principle, as the hamstrings are more likely to relax due to the prior activation and contraction of the quadriceps.

The other choices involve combinations where the movements do not effectively utilize reciprocal inhibition. For example, a squat does not facilitate the same level of antagonist relaxation needed in stretches, and similarly, the Romanian deadlift and pectoralis stretch do not create the necessary opposing muscle action for reciprocal inhibition to occur. Lastly, while the triceps pushdown and stretch do involve opposing muscle groups, both actions target the same muscle group without the clear principle of reciprocal inhibition being applied as elegantly as in the seated leg extension and hamstring stretch combination.

This understanding of reciprocal inhibition