The sport of cycling has grown in popularity in recent years. Spurred on by Lance Armstrong’s successes in the Tour de France and the increasing popularity of mountain biking (the first Olympic mountain bike race was held at the 1996 summer games in Atlanta), participation in bicycling is second only to swimming.
The Bureau of Transportation Statistics at the U.S. Department of Transportation estimates that more than 49 million Americans ride bicycles at least monthly, with over 5 million people riding at least 20 days per month. Cycling creates a tremendous demand on the lower extremities since they are responsible for producing a majority of the energy imparted to the bike. The high reactive forces created between the foot and the pedal produce loads that often adversely affect the joints and muscles of the legs and feet, leading to overuse injuries.
The incidence of lower extremity injury in cycling is high. One study of over 500 recreational cyclists reported 85 percent of the cyclists experienced one or more overuse injuries, 36 percent of which required medical treatment.
The main causes of overuse injuries in cyclists include a poorly fitting bicycle, musculoskeletal imbalances and training errors. Cycling is very repetitive. During one hour of cycling, a rider may average up to 5,000 pedal revolutions. The smallest amount of malalignment, whether it is anatomic or equipment-related, can lead to dysfunction, impaired performance and injury. In order to evaluate and treat a cycling athlete properly, the clinician needs a basic understanding of bicycle fitting, the proper selection of cycling shoes and foot orthoses (if indicated), and how anatomic factors and training errors contribute to these overuse injuries.
Ensuring The Best Size Fit For Bicycles
The frame size is the single most important aspect of the bicycle and the proper size is vital to safety, performance and injury-free biking. Correct frame size is determined by straddling the bike in a standing position. Lift the entire bike off the floor until the top tube is pressing against the crotch. The distance between the bottom of the bike’s tires and the floor should be 1 to 2 inches for a road bike and 3 to 6 inches for a mountain bike.
Correctly positioning the saddle will help maximize power and stability while minimizing the risk of lower extremity pain. To set the saddle height, the cyclist should sit on the bike in a normal riding position with the crank arms straight up and down. With the ball of the foot on the pedal in the 6 o’clock position, the biker should bend the knee at an angle of 25 to 30 degrees. Some mountain bikers prefer a lower seat to improve off-road stability and maneuverability.
To set the saddle fore and aft position, one should drop a plumb line from the front of the cyclist’s patella while he or she is sitting on the bike with the crank arms horizontal. Adjust the saddle forward or backward until the kneecap of the front leg is directly over the pedal axle. Some mountain bikers prefer to have the saddle about one-half inch back from this position in order to improve rear wheel traction while climbing. The biker may then adjust the saddle for tilt. The saddle should be level or slightly upward for men and level or slightly downward for women.
Foot placement varies depending on what type of pedal system the rider is using. If the bike has simple platform pedals or pedals with toe clips and straps, the widest part of the foot should center over the pedal axle. If the rider uses clipless pedals (which firmly attach to cleats bolted to the cycling shoes), one should adjust the cleats so foot placement on the pedals is the same as the natural foot position during ambulation. Most modern pedal systems offer a choice of cleats. Some fix the foot to the pedal in a single position while others allow some internal and external rotation (floating) of the foot while pedaling. The latter type may be less likely to cause overuse injuries. One can post cleats with spacers to help correct faulty biomechanics created by pronated or supinated feet.
How The Right Cycling Shoes Benefit Patients
For the casual rider who does not have any known foot problems, cross-training shoes provide the necessary support across the arch and instep in a shoe that can be used for other purposes. They also provide the heel lift that cycling shoes give. Cyclists who are a bit more serious about the sport will frequently buy bicycle touring shoes. The touring shoe’s stiff sole protects the foot from the pedal and is somewhat more efficient in transmitting force to the pedal. However, one may also use this shoe for walking.
Cleated cycling shoes are made specifically for bicycle riding. The cleat on the bottom of a cycling shoe secures the foot to the pedal, allowing the cyclist to pull back the foot forcefully during the recovery phase as well as push down during the power phase without fear that the foot will come off the pedal. The traditional cleat has a groove underneath in which a portion of the pedal sits. The strap of the toe clip holds the groove of the cleat on the pedal. The strapless cleats and pedal systems secure the foot to the pedal in a similar manner to ski boot binding systems. Some strapless systems allow transverse plane motion.
A cleated cycling shoe has a rigid plastic, wood or leather sole to prevent the cleat from being torn away from the sole and to protect the cyclist’s foot from the pedal. Another advantage to a rigid sole cycling shoe is that it will not twist as much as a recreational shoe. If the foot has a tendency to roll inward with pronation, the sole of the firmer shoe will not twist with the foot, facilitating foot stability.
Wedging is one shoe modification that can help realign the lower extremity during the pedal cycle. The wedges are generally varus in nature and one can usually apply them to the sole or inside of the front of the shoe.
Some cleated cycling shoes have a forefoot valgus wedge built into the sole that will tilt the lower extremity closer to the bicycle. This creates a more aerodynamic position but can create biomechanical problems for many cyclists. When examining the shoe, the sports clinician should always set the shoe down on the counter edge as if the cleat were on the pedal and check that the bottom of the front of the shoe is parallel to the edge of the table.
European companies make many shoes over lasts designed for the narrower European foot. When cyclists have complaints that may be caused by excessive compression, the sports specialist should check the cyclist’s shoes first.
Can Orthotic Modifications Have An Impact?
Ideally, the foot orthosis for cycling should be as rigid as possible in order to have the greatest influence on the foot. Foot orthoses for the cyclist help reduce misalignment of the overly pronated foot. One should employ an intrinsic forefoot post because it takes up less room in the shoe. The forefoot post should accommodate the forefoot and rearfoot (subtalar and tibia) varum components one observes when the cyclist is in the angle and base of cycling. If the cyclist has extensive rearfoot varus, one should wedge the shoe to accommodate the tibial component and use the foot orthosis to accommodate the subtalar component.
In many instances, it is advisable to add a forefoot extension to the orthotic. In regard to the forefoot extension, one may use a soft material to provide cushioning if it does not make the shoes too tight. The forefoot extension can also have a wedge shape. The varus wedge is almost always the appropriate choice. In addition to helping align the leg by bringing the shoe up to the foot, the varus wedge can distribute the force more evenly across the forefoot. Distributing force over a larger surface area of the foot reduces compression.
What Causes Overuse Injuries And How To Treat Them
More often than not, iliotibial band syndrome is the result of over-training, a tight iliotibial band, varus alignment of the lower extremity, internal tibial torsion, overpronation or incorrect seat height. It is often accompanied by trochanteric bursitis and is characterized by pain and point tenderness over the greater trochanter. Iliotibial band syndrome can also produce symptoms at the knee joint or its insertion site on the tibia. Management of this condition consists of iliotibial band stretching, ice massage, nonsteroidal antiinflammatory drugs, orthoses and cleat and/or saddle adjustment (see “Recommended Bike Adjustments For Common Overuse Injuries” below).
Patella femoral pain, chondromalacia and infrapatella tendinitis are common problems in cyclists. Patella femoral pain is often referred to as biker’s knee and is associated with patella malalignment, increased Q angle, valgus foot and leg alignment, overpronation, a saddle that is too low or forward, poor cleat adjustment or alignment. Treatment includes correcting the mechanical factors related to the bicycle; improving foot alignment with foot orthoses or medial wedging between the shoe and cleat; and ensuring proper stretching of the vastus medialis.
Patella tendinitis presents with pain at the proximal or distal pole of the patella that increases with the extension of the knee, especially against resistance. The mechanical factors usually associated with patella tendinitis are incorrect seat height and improper saddle fitting. This condition can also result from valgus leg alignment, internal tibial torsion and overpronation while pedaling.
In addition to correcting the mechanical and foot/leg alignment factors, cyclists should decrease the intensity of rides and the resistance they are pedaling against by using lower gears and higher cadence until decreased symptoms permit a return to increased training.
Achilles tendinitis and plantar fasciitis are overuse injuries that can be caused by training errors or riding with the seat height too low. Biomechanical conditions contributing to
these injuries include overpronation and a leg length discrepancy. Plantar fasciitis may also be caused by old or worn out biking shoes. The shank or rigid sole of the biking shoe becomes more pliable, causing excessive flex in the shoe and strain on the plantar fascia.
Achilles tendinitis is marked by pain in the Achilles tendon and occasionally the insertion. Patients have increased pain when toeing off or standing on their toes and pedaling. Plantar fasciitis usually presents with pain at the plantar fascia insertion of the medial calcaneus.
Treatment and management of these conditions consist of therapeutic exercise including stretching, ice massage and NSAIDs. Both conditions benefit from the use of foot orthoses and night splints. In the case of a leg length discrepancy, one should first correct any existing overpronation, proceed to fit the bike to the long leg and then address the short leg with orthoses or shim between the shoe and cleat. The thickness of the shim should be less than the measured discrepancy. The cyclist can aid recovery by decreasing riding time and intensity. Riding at a higher cadence with low resistance may also help.
Since the foot is tightly bound into the shoe, one commonly sees problems related to compression in cyclists. Symptoms associated with neuromas, bunions, hammertoes, blisters and subungual hematomas arise with inappropriate shoe fit or too tight straps or toe clips.
Treatment requires selecting shoes of the proper length and width, and ensuring an adequate toe box height. Complaints of metatarsalgia may be the result of tight shoes or a lack of shock absorption to the forefoot of the shoe. Certain types of pedals, especially those that are serrated (“rat trap”), may cause metatarsal pain.
Shoes with cleats concentrate pressure on one focal area of the foot and can also be the cause of metatarsalgia. Employing shock attenuating insoles can reduce pressure to the bottom of the foot but exercise caution with this approach. If the shoe is too tight to begin with, one may compound the cyclist’s foot problems by placing bulky materials in the shoe.
Dr. Caselli is a Staff Podiatrist at the VA Hudson Valley Health Care System in Montrose, N.Y. He is also an Adjunct Professor at the New York College of Podiatric Medicine and is a Fellow of the American College of Sports Medicine.
Dr. Rzonca is a Staff Podiatrist at the VA Hudson Valley Health Care System in Montrose, N.Y. He is the Former Chairman of the Department of Orthopedic Sciences at the New York College of Podiatric Medicine.
Dr. Rainieri is the Program Manager of the Podiatry Service at the VA Hudson Valley Health Care System in Montrose, N.Y.
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