Runner’s knee pain syndrome is the term given to pain originating from the kneecap/thigh joint (that is the joint between the knee cap and thigh bone usually as a result of inflammation or tissue damage to structures of the joint).
The knee cap is situated at the front of the knee and lies within the tendon of the quads muscle (the muscle at the front of the thigh). This tendon envelops the knee cap and attaches to the top end of the shin.
Due to this relationship, the knee cap sits in front of the thigh bone forming a joint in which the bones are almost in contact with each other. The surface of each bone, however, is lined with smooth cartilage to allow cushioning between the bones.
Normally, the knee cap is aligned in the middle of this joint so that forces applied to the knee cap during activity are evenly distributed. In athletes with runners knee pain syndrome, the knee cap is usually misaligned relative to the thigh bone, which therefore places more stress through the joint during activity.
As a result, this may cause tissue damage and inflammation to structures of the joint (such as cartilage or connective tissue), with subsequent runners knee pain. In athletes with this syndrome, the misalignment of the knee cap may occur for various reasons.
One of the main causes is an imbalance in strength between two parts of the quadriceps muscle. The quadriceps muscle comprises four muscle bellies.
In the majority of cases, the outer quad is stronger than the inner quads, resulting in the knee cap being pulled towards the outside of the leg. This may result in abnormal movement of the knee cap when bending and straightening the knee.
There are numerous factors which can cause this strength imbalance of the quadriceps (such as abnormal lower limb bio-mechanics and pain inhibition). These need to be identified and corrected by a physiotherapist.
Athletes with this syndrome usually experience pain at the front of the knee and around or under the knee cap. Pain can sometimes be felt at the back of the knee or on the inner or outer aspects.
Patients usually experience an ache that may increase to a sharper pain with activity. In less severe cases, patients may only experience an ache or stiffness in the knee that increases with rest (typically at night or first thing in the morning) following activities that place stress on the joint.
These activities typically include excessive walking (especially up and down stairs or hills or on uneven surfaces), heavy lifting (particularly with knees bent), deep squatting, lunging, kneeling, running, hopping, jumping, or other activities that bend and straighten the knee during weight bearing.
The pain associated with this condition may also warm up with activity in the initial stages of injury. As the condition progresses, athletes may experience symptoms that increase during sport or activity, affecting performance.
Symptoms typically increase on firmly touching the margins of the joint. Occasionally, athletes with this condition may experience pain whilst sitting with the knee bent for prolonged periods.
There may also be an associated clicking or grinding sound when bending or straightening the knee. In more severe cases, patients may walk with a limp and sometimes may experience episodes of the knee giving way or collapsing due to pain. In chronic cases, there may be evidence of quads muscle wasting (particularly of the inner one).
Most patients with this condition heal well with appropriate physiotherapy and return to normal function in a number of weeks. Occasionally, rehabilitation can take significantly longer and may take many months in those who have had their condition for a long period of time.
Early physiotherapy treatment is vital to hasten recovery in all patients with this condition. Despite appropriate physiotherapy management, some athletes with this syndrome do not improve. When this occurs the treating physiotherapist or specialist can advise on the best course of management. The writer is a physiotherapist, Harambee Stars & Mathare United [email protected]