Taken from an article:
by Nathan Wei, MD, FACP, FACR
Nathan Wei is a nationally known board-certified rheumatologist and author of the Second Opinion Arthritis Treatment Kit.
Knee and hip pain are the most common cycling injuries. The most common cause of knee and hip pain in cyclists is iliotibial band (IT band) syndrome. The IT band is a thick fibrous band of tissue, which runs on the outside of the leg from the hip to the knee. Pain is caused when the band becomes tight and rubs over the bony prominences of the hip (greater trochanter) and/or the knee (lateral condyle). Tight inflexible leg muscles may worsen the condition. Pain may also be caused by inappropriate seat position, saddle position, cleat alignment, or by individual anatomy.
A simple seat height adjustment may ease the forces placed on the knee. If the seat is too low, too much stress is placed on the knee from the patellar and quadriceps tendons. If the seat is too high, pain may develop behind the knee because of stress on the hamstring insertion. Therefore, proper seat height is essential.
There are several different ways to determine proper seat height. The easiest way to do this is to allow one pedal to drop to the 6 o’clock position and observe the angle of flexion in the knee joint. There should be a 25-30 degree flexion in the knee when the pedal is at the bottom most point. Another method is to measure your inseam (in centimeters) and multiply this measurement by 0.883. This should be your distance from the top of the seat to the center of the bottom bracket. Your hips should not rock back and forth when you pedal – that means your legs have to stretch too far to reach the bottom of the pedal stroke. If your hips rock when pedaling, lower your saddle until you achieve a smooth pedal stroke.
Seat forward and rear position and cleat position may also contribute to knee pain. Saddles that are too far back cause the cyclist to reach for the pedal and stretch the IT band with resultant knee pain. Saddle position can be evaluated with the “plumb bob technique”. Seated with the pedal in the 3 o’clock position, a “plumb” hung from the most forward portion of the knee, should intersect the ball of the foot and the axle of the pedal.
Cadence means the number of revolutions the pedal goes around in a minute. Cyclists who pedal with a low cadence (less than 80 revolutions/minute) will often complain of knee problems. Try “spinning” in a lower gear – shift into an easier gear and pedal faster without changing your overall speed. Try to keep the cadence between 90-110rpm. Not only will this help your knee pain, but it will improve your efficiency by leaps and bounds on a long day ride.
If you are using a clipless pedal system, try adjusting the position of the cleat on your shoe. Cleats that are too far internally rotated may cause increased stress to the IT band as it crosses the outside of the knee. Cleats should be positioned fore/aft so that the ball of your foot is directly over the axle of the pedal. Rotational cleat position can be evaluated by use of a commercial/bike shop “fit kit” or rotational adjustment device – this is more important for cleats with less than 5 degrees of float. Many newer road cleats allow greater degrees of float to protect your knees.
Finally, individual anatomy may contribute to knee and hip pain. Cyclists with leg length discrepancies may develop knee pain as only one side is correctly fitted to the bicycle. This leads to increased stress inside the knee and hip joints on the improperly fitted side. Cyclists with flat feet may be more prone to excessive pronation (internal rotation) of the lower extremity causing greater stress on the IT band at the knee. Orthotics may correct the alignment of the knee and decrease or prevent medial or lateral rotational stress on the connective tissue of the ankle, knee or hip, therefore reducing the pain.
Your knee needs to track forward. Many people bike with their feet pointing outward and sometimes inward on the peddles. Your feet need to face forward or your knee will not track properly.
In order to minimize knee and hip pain in the early season, take it easy for the first few weeks. Pedal with low resistance and a cadence of 80-90rpm allowing your body to adjust again to road riding, and possibly a slightly new bike position. Also, try to minimize hard riding or hill work for the first few weeks. Stretching exercises for the lower extremities, especially for the gluteus and IT band will also help the transition into early season form. Strengthening the vastus medialis and stretching the hamstrings are also advised. Remember, any changes to your bike geometry or training plan, should be done in small increments to allow your body to adapt to the new settings.