We'll work up some more posts on the problems casued by leg-length inequality (LLI) but I wanted to create a shopping list of the causes of leg-length inequality and came up with the following:

Anatomical:
1. Fracture or disease loss of bone. The classic one.
2. Genetic conditions.
3. Nutritional deficiency leading to leg-length loss.

Functional:
1. Sacroiliac joint dysfunctions leading to pelvic obliquity – and I think the most common, at least in my clinic.
2. The iliosacral joint is restricted on the superior or inferior transverse, or the sagittal axes. This may result from many causes including joint, muscle, osseous or compensatory considerations.
3. Hip joint dysfunction causing compensatory alterations by the joint and muscles that move the joint.
4. I am told that a growth in muscle mass itself. The vastus lateralis muscle appears to push the iliotibial band laterally leading to femoral angle compensations to maintain a line of progression during the gait cycle. This is often misdiagnosed as I-T band syndrome and subsequently treated incorrectly.
5. And the internal rotators of the lower limb being chronically short or in a state of contracture though I hate this sort of diagnosis as there’s never a decent answer to the why?
6. Likewise, short hamstring muscles as these are short because of the leg-length inequality.
7. And apparently, failure or incorrect loading of the Back Force Transmission System (the longitudinal-muscle-tendon-fascia sling and the oblique dorsal muscle-fascia-tendon sling). See the proceedings of the first and second Interdisciplinary World Congress on Low Back Pain.
8. And one I found last week with a patient who has uber lax ligaments and has developed one hyperflexed knee leading to a subsequent low hip on that side.
9. etc.
But the bottom line is look for common things first, identify if they are leg issues or pelvic issues and the and only then start to panic if you can find nothing. However, after a cup of tea and once the ‘why’ is identified you can then start to get things moving.

Any others?