An imbalance in leg lengths can be from pelvic torsion, an anatomically short leg, or a sacral upslip. This assessment can help to differentiate the cause of the imbalance.
Have your client supine on the table and do several bridges. Shake out their legs and notice how their medial malleolus on both ankles line up. If your client is obese and you can’t see the medial malleolus, place your thumb on each medial malleolus and see how your thumbs line up.
If you see a discrepancy, have your client sit up and reassess. If the discrepancy corrects when they sit up, the cause of the discrepancy likely is pelvic torsion. If there is no change upon sitting up, the cause can be from an anatomical short leg or a sacral upslip.
An anatomical short leg may be congenital or from an accident or injury. It can be corrected by using a shoe lift.