Recovering from knee injury – the importance of correct exercises
There are many different reasons for knee pain, ranging from osteoarthritis or ‘wear and tear’ in the joint as we age, to traumatic injuries such as cartilage tears, which disrupt the shock absorbing ‘cushions’ between the joint and sometimes require surgery. Also, common in athletes such as runners, is an unexplained pain at the front of the knee during activity, known as ‘anterior knee pain’.
There are several theories as to what causes this pain at the front of the knee, but most physios agree that muscle control around the knee joint is part of the problem. The knee itself is actually two distinct joints – one formed between the main bones of the thigh, which is a hinge involved in bending and straightening, and a second formed by the kneecap (patella) gliding in a special groove at the lower end of the thigh bone. This is controlled by the thigh muscles, as they attach just below the knee. Weakness in these thigh muscles (which may be after an injury, lack of exercise or due to pain) may mean that the kneecap is not kept as snugly in the groove as it should be, and therefore the kneecap is able to drift a little out of its track. This can cause stresses on the soft tissues around the knee and increase the wear and tear on the cartilage surface behind the kneecap, as well as abnormal loading of other surfaces of the joint during activity such as sport.
As the thigh muscles are the biggest group involved in strength and stability around the knee, of course they are important in controlling and minimising knee pain, and should therefore be the focus on strengthening exercises. However, other muscles around the area, such as, the iliotibial band down the outside of the thigh, also exert a force on the kneecap and if tight, can be a source of the maltracking or sideways drift of the kneecap. Also, hamstrings can play a part and need to be strong to enable the heel to lift after each running stride.
One of the most important muscle groups are the gluteal muscles of the buttock. Weakness of these muscles causes the thigh to fall inwards when under load, increasing the force on the knee and potentially maximising the chances of the drift sideways of the kneecap. You can test this easily by observing yourself in a mirror whilst standing on one leg, trying to slightly bend your knee. Your kneecap should stay facing forward and look as if it is in line with your toes; if you see your thigh moving inside your toes, for example – falling inwards, chances are that weak gluteal muscles are to blame.
Good physiotherapy will address this imbalance by giving you the right exercises to do, as well as mobilising the joint, taping to stabilise and relieving your pain with electrotherapy or possibly acupuncture.