We have all heard about the man who got rid of his backache after someone told him to put something in his shoe to make his hips more level. Well, it does happen that some of us grow one leg longer than the other one.

Is it really important to have level legs? If the legs have always been different lengths, why does the back suddenly start to hurt? The answer lies in the fact that the leg length difference causes a tilt at the bottom of spine and is constant stress to the balance of the skeleton. Sooner or later, because this delicate balance is disturbed, the area becomes painful. 

So how do chiropractors recognize a leg length difference. How do they determine its relevance to the backache and then treat it?

Some of my patients are unaware that one of their legs is shorter. This usually causes problems in their knees, pelvis, back and neck. There are a number of reasons for this. Some of the leg length differences are permanent or "anatomical" and some of them are reversible or "functional".

A permanent difference might result from trauma in the past, for example fracture or it can be caused by uneven growth in childhood. In the case of permanent change - different leg length causes imbalance in all joints including the pelvis and the spine, and has to be corrected with special insoles (orthotics) to correct leg length as much as possible. If not corrected, it causes muscle tension, joint wear and tear, back and leg pain and other symptoms. When leg length is corrected, chiropractic adjustment will restore the mobility and alignment of the joints and the correct type of exercise will even out and strengthen the muscles around your joints, including the spine and the neck.

A functional difference is caused by incorrect alignment of your pelvic bones and spine or repetitive strain. It can be corrected by a chiropractic adjustment and exercise. If repetitive strain is the cause, you also need to change the habits which caused the strain. For example, one of my patients is a carpet fitter. He has carried heavy carpet rolls on his right shoulder for 15 years, his spine curved to the left, his pelvis twisted and his left leg became 1.5cm shorter. After 2 months of chiropractic care and short home exercises, his legs are now even and his spine is straight! He also has to use both shoulders in turn when carrying carpet rolls. He actually prefers using both shoulders now because he is more body-aware and enjoys being out of pain!

Problems with feet and ankles may cause your legs to appear to be different lengths and vice versa - the leg length difference often causes foot problems, including ankle weakness and foot pain.

It is very important to understand, that your feet, knees and your spine are all the part of the same structure, and to repair one part you would have to make sure that the other parts are in a great condition.

First, let us see the most common causes of leg length difference. What causes a short leg?

• Causes from birth. These are not common but include:

1. A malformed hip joint
2. A clubfoot
3. Badly formed muscles & ligaments of the lower leg.

• Growth problems.These causes appear during childhood: 

1. Malformed hip joint socket
2. Problems of the ball of the hip
3. Stunted growth of one of the long bones of the lower limb
4. A flat foot on one side

• Acquired causes:

1. Fractures of the long bones of the legs
2. Infections of bone interrupting normal growth
3. Paralysis of the muscles from infections such as poliomyelitis or trauma
4. Arthritis of the joints such as a hip on one side, causing the joint to be held in an  abnormal position.

There are other causes. Each has to be diagnosed as accurately as possible to reach to a satisfactory solution.

How is the short leg recognized?

History: Knowing how the symptoms first started will help chiropractors to decide whether the level of the hips is relevant. The symptoms being worse when standing or walking suggests that the level of the legs is exacerbating the condition.

Examination: This is the most important stage of the diagnostic process. The chiropractor will look at the level of the hip bones and the effect this has on the shape of the spine, particularly in the lumbar area.

X-rays: These will show more accurately the relationship between the leg lengths at the level of the hip joints, the level of the hip bones and the level of the sacrum, the actual base of the spine. They help to determine the long term effects on the spine. From this, the chiropractor is able to diagnose more accurately whether the tilt should be corrected or simply stabilized.

Heel lift test: There are various tests to determine whether it will be useful to level the sacrum. The easiest way is to place a 'raise' inside the shoe. The raise height must be determined accurately to ensure maximum benefit. X-ray measurement is one possibility and can be useful when the changes in the spine are few.

If the situation is more complex, then a diagnostic procedure to assess the response in the spine will be necessary. One such test can be performed using diagnostic muscle testing. The advantages of this test are numerous. It can be performed quickly and easily, requires little equipment and provides an immediate response. More sophisticated procedures exist but do not necessarily guarantee best function.

Chiropractic management: First and most crucially, the effect of leveling the base of the spine must be established. Not all short legs should be corrected. Compensating for a short leg can make the distortion in the spine worse. This would exacerbate rather than improve the problem. If compensation is found to be necessary, the degree of compensation must be determined. This is achieved by using one or more of the methods described above. As you progress through the treatment, the chiropractor will aim to reduce the amount of lift in your shoe to the smallest amount possible.

Helping the body help itself: Before prescribing a heel-lift, the chiropractor will correct the pelvis to encourage the body to use its natural compensation abilities. The human frame achieves this through the pelvis, which, by distorting slightly, can change the level of the middle triangular bone of the pelvis, called the sacrum.

Up to one inch can be compensated in this manner. The effect of this correction will be assessed, the new lift height determined and prescribed. Wearing it until the next visit will help to correct the posture, which will be reassessed at the next visit. By doing this at each visit, the heel lift will be reduced to the minimum needed for maximum effect, the eventual aim being to have no lift if possible.

Conclusion: There are many other problems of the lower extremities that are not mentioned here. Chiropractors specialize in the mechanics of the skeleton and can recognize these problems which places them in an advantageous position to give you appropriate advice and care. Chiropractors look at the interaction of all the joints of the leg and pelvis and understand how they affect each other. They will try to correct the problem by conservative means first, in other words, by ways that do not involve surgery.

If your problem cannot be helped by gentler natural means, then other measures such as surgery will be discussed and you will be referred. In any situation, your chiropractor is probably the best person to call on first if you suspect your problem to be one involving a difference in the length of your legs.