Excessive pronation: a major biomechanical determinant in the development of chondromalacia and pelvic lists

Abstract

Based on statistical analysis of 97 chronic low back patients, a pelvic list model has been proposed explaining the correlation between leg length discrepancies (LLD) and sciatica. This model suggests that asymmetrical pronation patterns (one pedal arch dropping more than the contralateral pedal arch) initiates a forward downward rotation within the sacroiliac joint. Entrapment of the sciatic nerve between the piriformis muscle and sacrospinous ligament occurs. Clinically, paresis is observed: numbness, weakness and eventually paralysis of the affected limb. Based on this work, the authors have comprised a classification dividing LLD into two main categories: functional and anatomical. Functional LLD have been subdivided into two types of lists: static and dynamic. Treatment based on a combination of chiropractic and podiatric therapy is presented with a 6-month follow-up. Analysis of the success in this tandem approach is very promising. Concurrently, a chondromalacia model is proposed explaining the pathomechanical events associated with oblique tracking patellar syndrome. The authors suggest that excessive pronation is the causative factor directing asynchronous rotation between the shank and femur. This forces the patella out of its normal tracking groove, which, in turn, generates erosion between the inferior margin of the patella and femoral epicondyles.