Bike riding is low-impact exercise with a small risk of injury compared to more demanding sports. Recumbent bikes offer many advantages over traditional bikes. Riding a recumbent bike burns calories and works leg muscles while supporting the back and shoulders. According to "Bicycling Life," recumbent bikes offer improved safety, reduction of upper body injury and increased comfort over traditional bikes. However, the trade-off for these advantages may be stress to the knee.
Design of Recumbent Bikes
Recumbent bikes can be stationary or mobile; the stationary form of recumbent bike is a common addition to gyms across the U.S. The rider of a recumbent bike reclines with his back and shoulders supported and his legs elevated to waist level while pedaling. This position maintains the same angle between back and legs as on a conventional bicycle, while providing a more comfortable riding position.
Patellofemoral Pain Syndrome
Patellofemoral pain syndrome is characterized by pain under the knee cap during knee flexion and extension. Most commonly affecting women, patellofemoral pain syndrome can be caused by increasing mileage or resistance too quickly. The source of the pain is a malalignment of the the knee cap on the underlying tissues. According to emedx.com, patellofemoral pain syndrome can be prevented by maintaining strong and flexible quadriceps and hamstring muscle. Physical therapists can treat this condition by alleviating pain and by prescribing an individualized exercise program to restore muscle balance.
Patellar tendonitis, or jumper's knee, is a painful inflammation of the patellar tendon, and is often caused in cyclists by overuse. The patellar tendon is the connection from the quadriceps muscle in the front of the leg to the bone. Diagnosis of jumper's knee is made by pressing on the tendon directly below the knee cap to elicit a pain response. Jumper's knee typically resolves with rest and gentle exercise, but if pain persists, consult a physician.
The knee joint contains several bursa, or fluid-filled sacs. The most common symptom of bursitis is a large amount of swelling and pain in a small, localized area. The most common form is superficial and deep infrapatellar bursitis, which results from mechanical irritation to the front of the knee. Superficial pes anserinus bursitis results in pain on the inside of the knee. Biking for an excessive amount of time could lead to any of these types of bursitis.
Iliotibial Band Syndrome
The iliotibial band, or IT band, extends from the outside of the hip all the way to the outside of the knee. The structure is a thick fibrous band of tissue. "Cycling Performance Tips" states that IT band syndrome can occur at the knee when the IT band gets tight over time and begins to rub over a bony part of the knee called the lateral epicondyle. This can be very painful. Stretching the IT band by crossing one leg over the other in the standing position and side bending at the hips can loosen the structure and alleviate the pain.