Saturday, January 19, 2013

Bike fit analysis: With Gale Anderson and Liz Gilbert

Last Saturday, Gale Anderson and Liz Gilbert, physical therapists from Therapeutic Associates, Mt. Spokane Physical Therapy, spent a part of their Saturday with me to analyze my position and body mechanics on my bike. For the last couple of months, I have been working through rehabilitation for unremitting knee pain, and I wanted to rule out any kind of alignment on the bike that may be causing or exacerbating the discomfort I feel in my knee.

Upon arriving, Liz helped me set up my bike on the trainer, and I proceeded to warm up until Gale arrived. Once he pulled out his measuring tool—a device physical therapists like to call a goniometer—he took measurements from the side: shoulder-to-trunk and knee-to-hip angles, among others. Liz set up a laser beam in front of me that spanned the distance from the middle of my cleat to my knee so they could videotape the amount of deviation from that beam through each pedal stroke. When the video was delayed and replayed, my right knee tended to cross midline far more than my left one did. This surprised us all, considering I have sought Gale’s help for the last 2 months to address left knee pain.

Gale had me increase my resistance to see how my form changed. Under a greater load to push during both seated and standing positions, he and Liz observed even greater deviation of my right knee, as it tended to almost hit my top tube.

Several reasons may explain why my right knee tends to fall more medially than my left. First, it could simply be the way I’m structurally made. In this case, Gale could make some adjustments on the bike to better tailor my body position. Second, my hip abductors could stand to use some strengthening. In all honesty, many runners and cyclists struggle with knee, sciatic, and back pain as a result of weak hip abductors. This essential muscle group works to control hip movement by acting as important stabilizers, especially upon footfall while running. In cycling (and running) weak hips oftentimes cause the knees to fall inward and create increased strain on soft tissue structures found in the medial knee.

The third reason could be related to foot pronation. Gale had me stand in front of him to assess how much the arches along the medial borders of my feet fell toward the ground. While foot pronation in certain parts of the gait cycle (especially footfall in running) is normal, the small intrinsic muscles of the feet must contract adequately during the push-off phase of gait (or the downward pedal stroke during cycling) to prevent poor body alignment higher up the kinetic chain (i.e. the ankle, knee, and hip).

My right arch fell closer to the ground during standing than my left one did, suggesting its weakness may be contributing to the poor alignment of my right knee, which may mean my left knee could be compensating for my right, hence a potential reason for left knee pain. I can blame my knee pain on one or several reasons. Yet you’ll soon frustrate yourself to no end, and you’ll realize what makes the work of a physical therapist so challenging. You can go around in circles to try to find the answer or reason for an injury, but you’ll soon realize how every joint, every muscle attached to each joint, and every movement you make impacts every other joint and every other muscle attached to each and every other joint. (In school they taught us the benefits of “stress management.”)

While not the ultimate solution, Gale unscrewed the cleats on the bottom of my cycling shoes and inserted a plastic wedge whose medial surface (the side that goes under my big toe) is slightly thicker than the lateral one. If nothing else, it will encourage me to shift some weight toward the lateral side of my foot in an effort to minimize the amount of downward motion that occurs in my medial arch. (Balance exercises on a Bosu ball, Dynadisk, or foam mat might be better alternatives for a long-term solution in an effort to strengthen the muscles in my feet and lower legs.

Gale and Liz don’t consider what they do a typical “bike fit.” While they can analyze the fit and take the measurements, Gale admits he doesn’t have all the tools needed to make the big adjustments he can suggest his patient make. What he can do, however, is use his extensive knowledge of anatomy and biomechanics to tweak a cyclist’s position on the bike in an effort to remediate a nagging pain or discomfort experienced on and/or off the bike. He can also assess how someone rides to determine what personalized adjustments he might need to make for his patient.

You can visit Mt. Spokane Physical Therapy’s website HERE