By: Stacy Soappman, PT, OCS, DSc, FAAOMPT
It is summer and cycling season is in full swing. I ride with a number of different groups and have recently picked up three patients from those associations that all have a common factor – eccentric weakness/endurance of their gluteus medius and piriformis muscles. Two of the patients presented with knee pain and one with ankle pain.
Let’s take a few minutes to explore the biomechanics and treatment of these dysfunctions. Proper cycling technique entails utilizing the entire pedal stroke. This involves not just pushing down with your quads and gluts but also pulling up which most often involves a lot of psoas action. According to Janda, one of the functional antagonists to the psoas (hip flexor) is the opposite piriformis (external rotator). If we have an overactive/facilitated psoas we will have a weak/inhibited opposite piriformis.
One of the functional jobs of the piriformis and gluteus medius is to eccentrically control the internal rotation (knee turning inward) energy going down the kinetic chain during gait. If we have weakness of theses muscles we wind up with too much internal rotation energy going down the lower extremity chain leading to breakdown of joints distal to the hip (knee and ankle). Now even though cycling is not largely considered a weight bearing activity, if your feet are clipped into your pedals you still have some ground reaction force from your pedals.
The amount of internal rotation (knee twisting inward) energy sent down the kinetic chain at the hip has to be absorbed by the conjunct external rotation of the joints distal to it (knee and ankle). Energy cannot be created or destroyed so if you do not absorb the internal rotation energy you begin to get joint breakdown. Upon examination of these three patients they all had one thing in common – functional eccentric weakness of their hip external rotators, meaning that they had too much uncontrolled internal rotation force going down the kinetic chain. This excessive internal rotation force, at the hip, is what was causing the knee and ankle pain. The treatment for weakness of the gluteus medius and piriformis is quite simple. Initially you need to build strength then follow it with endurance as most serious cyclists are riding 20 plus miles at a time.
Here is a simple exercise progression:
1) Have the patient stand with feet shoulder width apart and have them externally rotate their legs (twist the thighs outward) without doing a “butt squeeze.” You should be able to palpate (touch) on their gluts to feel the contraction of the gluteus medius with the gluteus maximus and minimus staying quiet. The cue I give to patients is, “Turn your knees outward while keeping your feet on the floor.”
2) Once they have mastered this, have them do squats with their “knees turned out”
while keeping their knees tracking over their 3rd toes.
3) Progress to single leg squats in the above position 4)Finally, when they are ready for endurance have them do a single leg stance and then bend forward at the waist to hold onto the back of a chair or counter. With the non-weight bearing leg have them do leg lifts, circles, flex/ext the knee, etc…
The point here is to have them maintain a “knee turned out position” on the weight bearing leg for up to 2-3 min while adding a distractor with the non-weight bearing leg. Now the bigger unanswered question here is why was their psoas dysfunctional in the first place?