This crouching action is usually performed quickly and referred to as a counter-movement: the rapid bending of the legs and the movement of the arms to the person's sides constitute the counter-movement to the actual jumps range of movement. The counter-movement and the jump collectively are referred to as a counter-movement jump (CMJ).
The crouching action is usually done quickly, which is referred to as a counter-movement: this involves rapidly bending the legs and moving the arms to the sides, which serves as the counter-movement for the actual jumping range of motion. The counter-movement and jump are collectively termed a counter-movement jump (CMJ).