Leg Length Differences – a case study
A bicycle is considered to most as a symmetrical machine, therefore, in order to power a symmetrical machine, the user has to be as symmetrical (functionally) as possible. Cyclists with leg length discrepancy could be in a tricky and potentially risky situation for injuries.
Here we have a client that experience severe saddle discomfort, mainly numbness in the groin area during riding. Physical assessments were conducted during his bikefit, it was found out that he has a minor leg length discrepancy which he was unaware of. His leg length discrepancy was taken into account during the analysis. (We physically measured the distance from ASIS to the medial malleolus.)
Further analysis was done using geBioMized saddle pressure software. It was determined that his leg length discrepancy, together with incorrect bike setup was the main cause of his saddle discomfort, resulting in more pressure on the left side of his saddle. In order to relief his saddle discomfort during his ride, client tend to make slight changes to his sitting position, and this in turn affected his overall effective reach, pelvic tilt, and effective saddle height.
The presence of his leg length discrepancy causes him severe saddle discomfort which led to the presence of compensated reach as well. Necessary adjustments were done in order to ensure we take into account his leg length discrepancy (such as shimming the shorter leg), lowering the saddle to resolve his saddle discomfort issue while not having any form of compensated reach.
Recommendations were given as well, such as a change in bike components, pedalling technique, stretches, and exercises.