The active straight leg raise (ASLR) assessment (as part of the FMS) is an essential part of any assessment I do on my athletes and runners. It provides a great look at a client's ability to stabilize their spine/pelvis and we observe hip separation with one hip moving into flexion and the other fixed hip moving into greater relative extension.

Why does hip disassociation matter? Simply put, a lack of ideal separation can negatively impact step and/or stride length, reduce propulsion and create other compensations that increase energy expenditure and reduce overall running form. Some deviations that may occur include hip drop, increased rotation or circumduction of the swing leg, excessive torso rotation, increased knee flexion and diminished stride length to name a few.

Lie on your back. Using a doorway, place one leg against the doorway in a position that allows you to keep the lumbar spine flat while the other leg is extended and on the floor. Next, flex the down hip to the height of the other fixed leg extending the knees. This leg will remain unsupported. Now, point the toes of the unsupported leg and reach out toward the ceiling. Slowly lower the leg to the floor or the lowest point where you can still maintain a neutral lumbar spine (a bolster may be placed beneath the leg if needed). Perform 10 repetitions and repeat 2-3 sets on each side.

Progress the activity by lowering the leg further and/or sliding closer to the doorway to increase the hip flexion and total hip separation. Do not allow the lumbar spine to extend as this is a common compensatory motion for limited mobility in the iliopsoas.

This activity will improve active mobility of flexed hip as well as promote continuous core stability and available hip extension of the opposite hip. It challenges the client's ability to disassociate the lower extremities while maintaining stability in the pelvis and core. Keep in mind it is more than just a hamstring flexibility activity as it also addresses static (pelvis/spine) and dynamic (hip) stability in asymmetrical hip separation pattern.

This separation pattern is essential for optimal running mechanics. Poor hip disassociation can lead to asymmetrical or bilateral movement flaws, thereby reducing performance and leading to compensatory motion with an elevated risk for injury. This simple technique can be done daily to enhance hip mobility and pelvic/hip stability.

Brian Schiff, PT, OCS, CSCS, is a licensed physical therapist, respected author and fitness professional. Currently, he serves as the supervisor for Athletes' Performance at Raleigh Orthopaedic in Raleigh, NC. Brian conducts live continuing education webinars and presents nationally at professional conferences and seminars on injury prevention, rehab and sport-specific training. For more information on his products and services, visit