Why is it more difficult to perform a sit-up when the hands are clasped behind the head then when the arms are kept at the side?

Question

Quizplus · Accepted Answer

When the hands are clasped behind the head, the distance from the pivot point (usually around the hips or lower back) to the point where the force is applied (in this case, the weight of the upper body including the arms and head) is increased. This increased distance is referred to as the resistance arm. A longer resistance arm means that for the same amount of force, the torque (rotational force) around the pivot point is increased, making the movement more difficult.

Why Is It More Difficult to Perform a Sit-Up When