There are four quadriceps muscles that arise from the pelvis and thigh bone and all attach to below the knee through a large tendon (patellar tendon).  The knee cap (patella) sits within the tendon as it crosses the front of the knee.  Conditions affecting the tendon will be covered under ‘knee conditions’.  Together the muscles straighten the knee but their main action is to control the bending of the knee whilst going downstairs or walking. One of the quadriceps muscles attaches above the hip and will also help to bend the hip (rectus femoris).

Injuries to the quadriceps muscle can happen in a similar way to the hamstring muscles where a sudden stop while the muscle is contracting can lead to tearing of muscle fibres, as in kicking the ground instead of the football.  The patient will present with pain in the front of the thigh with pain on straightening the knee against resistance and on stretching the area while bending the knee.

It is usually the most superficial muscle of the group that is injured and bruising and swelling are usually apparent in the muscle belly.  The muscle is treated with ice, massage, frictions and interferential therapy, as given for hamstring muscle belly injury, with advice on the progression back to full activity and the warning not to stretch too soon.