My office staff was ordering supplies this past week and asked me a question that had not come out of her mouth yet: how many more heel lift are you going to use in the next few months ? The question was prompted by an unusual cluster of cases of true anatomical short leg that needed heel lift correction and led me to raid the lift box into oblivion. This cluster is highly unusual. When I look back over the past 24 years, I probably set up a patient for a heel lift about 6 times a year, and I have done that much in the past couple of months alone. The topic of "short leg" is poorly understood and I thought it may be good timing to dedicate a few entries to the topic.First, we should understand that almost nobody has perfectly even lower limbs if you were to measure them from the lateral hip to the lateral ankle. However in most cases, that is of no clinical significance as the body has the ability to absorb a certain amount of leg differential with some compensatory pelvic rotation and lumbar shift to the side of the short leg. The rule of thumb is that the body can absorb and compensate for the first 6 mm with no adverse effect, and some patients may be able to compensate for a little more. How and how well the body compensates for a leg differential depends on a variety of factors, but mostly boils down to 2 of them: the age at which you developed the leg differential and how abruptly the body developed a leg differential. A youngster with a slow growth plate in the femur who develops a short leg during a 36 months growth spurt will actually develop a larger sacrum ala on the side of the short leg over time and nearly completely level off their pelvis up to 8 mm. A 30 year old adult with a bad ankle fracture or a 70 year old with a knee replacement that loses 10 mm of leg length overnite will have fewer options to compensate and thus more likely to become acutely symptomatic as a result. https://www.youtube.com/watch?v=jhpAcZ12ACs
