The straight leg raise is the most commonly prescribed exercise in physical therapy for patients with knee pain. Unfortunately, it is probably the exercise that is most frequently performed incorrectly!!
How can something that looks so simple be done incorrectly? The answer lies in successful recruitment of that pesky portion of the quadriceps known as the vastus medialis or VMO. The video will explain…. (look at that piece of tape!)
People can perform straight leg raises until the cows come home without ever recruiting the VMO muscle, and that is a shame. The VMO is an integral portion of the quadriceps in that it provides a much-needed centering force on the knee cap. All too often we physical therapists are confronted with patients whose patellae do not track well due to a lack of VMO participation.
The key to successful recruitment of the VMO lies in what we call “cuing.” One very simple way to cue the VMO to contract is to stick your finger into the muscle and use the tactile cue to allow your brain and the motor pathways to “figure things out.”
Still can’t figure out how to get a solid burn in this muscle with a straight leg raise? I have two recommendations:
1. Eliminate the leg raise portion of the exercise and instead perform a “quad set.” This is a pared down exercise that requires no movement of the leg and rather instead focuses entirely on VMO facilitation. We have put a piece of tape on the VMO in the following exercise as well for clarity.
2. Be persistent. Many people will have to perform the quad set exercise for weeks before the neurological light bulb turns on. In many people the VMO has been dormant for years (due to an old knee injury or good old fashioned sedentary behavior).
The goal of the quad set is VMO recruitment and fatigue. Once you have the contraction down, bump yourself back up to the straight leg raise and see if you can keep the VMO tight for the entire leg raise. It is harder to do this than you might think, but if you master these exercises I am willing to bet that your knee pain will lessen.