The amount of force your calf muscle puts into bending your knee depends on both the angle of your knee and your ankle. Because this muscle stretches across both joints, changing your ankle position changes how stretched the muscle is, which directly changes how much force it can generate at the knee.

Your calf muscle works best at bending your knee when your leg is completely straight, and it loses strength very quickly as you start to bend it. This means how well your calf can help bend your knee depends entirely on the exact angle of your knee joint.

Your calf muscle works best when your knee is slightly bent, but it struggles to push hard when you bend your knee all the way down. This happens because the muscle gets too short when bent deeply, which stops it from contracting properly.

Bending your knee changes which calf muscle does more work when you push off the ground. Straight legs make the outer calf muscle work harder, while bent knees shift the effort to the deeper calf muscle.

Your calf muscle is strongest at pushing off or bending your knee when your leg is completely straight. As you bend your knee more, it gets much weaker because the muscle becomes too shortened to generate full force.

The calf muscle that helps bend your knee works best when your leg is almost straight, and its strength drops off quickly when your knee is bent too far. This happens because of how the muscle's leverage and length change at different angles.