By Ben Stein, MS
In the many bike fits that I have performed over the last few years, I have noted countless instances of knee adduction and abduction while pedaling. Adduction is movement toward the midline of the body and abduction is movement away from the midline of the body. These movements can sometimes come from the feet (usually an easy fix with orthotics), from a belly getting in the way of pedaling (abduction), or can come from weakness in the hips (adduction). Either way, this type of pedaling can lead to overuse injuries or ineffective cycling mechanics. Strengthening the hips can make a big difference in pedaling mechanics, decreasing injuries, and improving power.
When we typically think of the muscles involved in pedaling, the quadriceps and hamstrings get most of our attention. However, the muscles of the hips are a third area that helps to generate a cyclists power. During the off-season, I highly suggest that athletes get into the weight room and work on the specific imbalances that have been identified by a coach or trainer. One of the imbalances that I see regularly during my bike fits is weakness in the hip and thigh muscles, specifically the medial and lateral muscles of the leg. This weakness often leads to ineffective knee movement.
There are two lateral muscles of the hip joint that contribute to abduction: the gluteus medium and the gluteus minimus. The gluteus medium’s major function is hip abduction, and assists with hip flexion, internal rotation, extension and external rotation. The gluteus minimus’s major function is hip abduction and internal rotation, assisting with flexion, and hip extension.
There are four medial muscles of the hip joint that contribute to hip adduction: Adductor longus, adductor brevis, adductor magnus, and the gracilis. The adductor longus performs adduction of the hip and assists with flexion and external rotation. The adductor brevis major function is adduction of the hip and assists with external rotation and flexion. Adductor magnus has two parts that adducts, flexes, and externally rotates the hip joint, and adducts, extends, and internally rotates the hip joint. The gracilis adducts and flexes the hip joint. What!?! That is a lot of movement around the hip joint.
The hip joint is classified as a triaxial joint, meaning it can move in all three planes of motion. If one of these muscles is stronger then the other, then this can create a muscle imbalance. A muscle imbalance is when one group of muscles becomes stronger then the opposing muscle group. Muscle imbalances can often lead to pain and poor posture. Now you can see they do a lot and why its a good reason to strengthen them and keep them balanced!
Below are a few exercises that can help stabilize your hips and may improve your pedaling:
Remember, soft knees and breath.
1: The Step Down: Step sideways off of a stair or step keeping the hips level. Watch for the standing knee moving inward and do not use opposite leg for assistance. Bend the knee and touch the floor with the heel, then back up. Repeat 2-3 sets 12-15 repetitions alternating legs. When performing this exercise you should feel it just above stepping down hip, in the butt.
2: Theraband Hip Adduction: With threaband (or strap from machine) around ankle, and leg starting outward around a 30 degree angle, move leg towards the body. Repeat 2-3 sets 12-15 repetitions. When doing these you should feel them inner thigh. Try to not use assistance and work on balance.
3: Theraband Hip Extension: With theraband (or strap from machine) around ankle, push leg behind you while keeping knee straight, but not locked. Repeat 2-3 sets 12-15 repetitions. When doing these you should feel them in the butt. Be sure to keep pelvis square.
3: Theraband Hip Abduction: With theraband (or strap from machine) around ankle, move leg out to your side, about 30 degrees, while keeping the knee straight, but not locked. Repeat 2-3 sets 12-15 repetitions. These are the best! When performing these you will feel them upper butt, keep pelvis square.
4: Theraband Hip Flexion: With theraband (or strap from machine) wrapped around ankle, kick the leg forward keeping it straight. This exercise is more likely to assist with hip flexion strength. Repeat 2-3 sets 12-15 repetitions. Keep the pelvis square and you may feel these in the quadriceps.
Other exercise suggestions include clams, side bridge hip abduction, and side bridge. These exercises and more can be found at http://www.exrx.net. I would also recommend getting a bike fit from a professional bike fitter (someone skilled in kinetic anatomy). You can also try riding in front a mirror to watch your knee movements. Most importantly, practice resistance training and start strengthening those hips!