Why is the QL so important to runners? The QL is a deep back muscle that connects the twelfth rib to the lumbar vertebrae and the top of the hip bone. It's primary functions are to bend your body from side to side and bring your hips up to your chest which is exactly the movements used whilst running and therefore a muscle that is constantly being used. Why does it often get uncomfortable? Due to the position and motions our body goes through whilst running which can greatly