when performing a single leg raise what is happening to the muscles?

Question

i was told this would be isotoncially working the hip and isometrically working the knee, but what does this really mean? this exercise is being performed for an ACL repair.

Answer 1

Isotonic: Muscle contraction with visible joint movement at a variable speed with constant external resistance.

Isometric: Muscle contraction with no visible joint movement.

With straight leg raises, movement occurs at your hip joint (isotonic), but not at your knee joint (isometric).

The benefit of the isometric contraction at the knee joint is that it does not put excessive torque on your ACL graft.

Answer 2

Not so much the hip because you will be seated while doing the exercise so the hip won't come into play that much, if at all.

The mucles involved will be mainly the quadracep muscle (thigh muscle) and muscles at the back of the knee. They will have blood pumped to them during the exercise and if supplied with protein they should develop or strenghten, (or in the case of your acl improve) If this is a part of a rehab programme make sure you know how to do it and you are supervised, at least in the first few sessions.

Take care
Hope things work out for you.