The idea behind this exercise is applying progressive gradients of resistance that encourage the faulty motion (pulling the leg into adduction and internal rotation) to facilitate increased activation of the gluteus medius/minimus and small lateral rotators to create an anti-adduction/internal rotation force by forcing the brain to work against the unwanted motion (better central nervous system activation). Decreasing such moments at the knee will reduce IT Band issues, patellofemoral pain, ACL injury risk and overuse problems often seen in running.

The video below from my online column for PFP magazine demonstrates how to execute this exercise. It is a great corrective and prehab training activity.