Q+A: Leg-length discrepancy causes me knee pain...

Our experts answer real-life questions


Posted: 9 September 2000
by Martin Haines

Q I visited a sports injuries clinic because of a sore knee and was told that one of my legs is slightly shorter than the other and that one of my knees does not turn inwards when my leg does. I’ve been given a heel raise for one shoe, and stretching exercises. What else can I do, and when can I start running again?

A Leg-length discrepancies are often a major factor in knee pain because your body will try to compensate for them. If one leg is longer you’ll try to shorten it by flattening the foot, dropping the hip, or bending the knee excessively – all of which increases pressure on your knee.

The management of leg-length discrepancy is determined by its cause. If you were born with it, then a heel raise may well help, but only if the hips and pelvis are flexible and strong enough to cope with the change. So, before a heel raise is prescribed, you need to have your hip and knee strength and flexibility checked.

If the leg-length discrepancy is not hereditary and is caused instead by pelvic rotation or hip inflexibility (which is very common), then a heel raise is inappropriate and may even make the problem worse. The sacro-iliac joints in your pelvis must, therefore, also be checked before heel raises are prescribed. This is crucial, especially for women, for whom pelvic rotations are commonplace.

Correcting problems in the pelvis may actually reduce your leg-length discrepancy to nothing, and any biomechanical over-compensations, like foot flattening, will then be dealt with naturally by your body. This will then automatically reduce the pressure on your knee.

There are occasions with knee injuries when orthoses need to be prescribed, but the two steps above should always precede any orthotic intervention.

Now you can start dealing with the knee. If the kneecap is tight in certain directions, your therapist will want to mobilise it regularly so it resumes a normal movement pattern when you run. If the pain is below your kneecap, then soft-tissue massage may help with any scar tissue in the tendon or fat pads. Ask your therapist to show you some ‘closed-chain’ exercises – ones where your legs are working against an object; like walking. ‘Open–chain’ exercises where the limb is moving freely ‘in air’ (straight-leg raises and leg extensions) may aggravate your injury. Once these have been done, you can start thinking about exercises like leg presses (to strengthen your knee) and seated hip abductor and adductor exercises as a precursor to returning to running.—Martin Haines, chartered physiotherapist and sports injury specialist


Previous article
Q+A: How can I deal with Achilles scar tissue?
Next article
Which Injury Specialist: Podiatrists

knee, discrepancy, leg-length
TwitterStumbleUponFacebookDiggRedditGoogle

Discuss this article

We'd love you to add a comment! Please login or take half a minute to register as a free member

Smart Coach
Free, fully-personalized training plans, designed to suit your racing goals and your lifestyle.