Here is the piece:
A correct squat perfectly balances all the forces around the knees and the hips, using these muscles in exactly the way the skeletal biomechanics are designed for them to be used, over their full range of motion.
Here is the piece:
A correct squat perfectly balances all the forces around the knees and the hips, using these muscles in exactly the way the skeletal biomechanics are designed for them to be used, over their full range of motion.
The preposition over is often used to mean throughout or acting across. Thus, "over their full range of motion" means that the muscles are using their full range, stretching from one end/extreme to the other.