Poor Fit Can Contribute to Pain and Risk of Injury.
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ALEXANDRIA, VA, May 20, 2010 — Riders across the country will take to the streets on Friday, May 21, in celebration of National Bike to Work Day. In support of their efforts and enthusiasm, the American Physical Therapy Association (APTA) offers tips for reducing the risk of bicycle-related injury through proper bike fit.
APTA member Erik Moen, PT, and founder of BikePT and Corpore Sano Physical Therapy and Sports Performance says, "The first thing I ask of any patient complaining of bicycling-related pain is to bring the bicycle in to check for a proper fit. In most instances, a poor bike fit is the root of their problem."
Moen, who races and coaches road, cyclocross and velodrome cycling, says the most common bike fit errors include saddle heights that are either too high or too low, handlebar reach that is either too long or too short, and misalignments of the pedal and shoe. He recommends cyclists do the following to ensure proper bike fit:
Seat/Saddle. Be sure the seat, or saddle, is level. If you are sliding too far forward from a forward-tilting saddle then too much weight is being placed on your hands, arms, and lower back. If the seat is tilted backwards then you may place undue strain on your lower back and possibly experience saddle-related pain. A physical therapist can measure proper saddle height by measuring knee angle at the most extended position of the knee in common pedaling. The saddle should also be a comfortable distance from the handlebars. If it is too close then extra weight will be placed on the mid-back and arms; too far away and extra strain will be placed on the lower back and neck.
Handlebars. Handlebar position will affect hand, shoulder, neck, and back comfort. The higher the handlebars, the more weight will be placed on the saddle. Generally, taller riders should have lower handlebars in relation to the height of the saddle. According to Moen, "Proper handlebar position allows for shoulders to roughly make a 90 degree angle between the humerus and trunk." Trunk angle for the road bike cyclist is 25-35 degrees and for comfort/recreational riding is 35-90 degrees. Moen notes that riders should re-examine their bicycle fit after bad falls or crashes, due to possible re-orientation of handlebars, brakehoods, cleats, or the saddle.
Knee to Pedal. A physical therapist can also measure the angle of the knee to the pedal. The closer the angle is to 35 degrees, the better function the cyclist will have and with less stress on the knee. For the road cyclist, the angle should be 30-35 degrees. The recreational cyclist should have a 35-45 degree angle.
Foot to Pedal. The ball of the foot should be positioned over the pedal spindle for the best leverage, comfort, and efficiency, according to Moen. A stiff-soled shoe is best for comfort and performance.
"Pedaling is a skilled activity that requires aerobic conditioning," Moen says. "You should make it your goal to work toward pedaling at 80-90 revolutions per minute (advanced at 90-105 rpm). Pedaling at this rate will lessen your chance of injury."
"Good flexibility of the hamstrings, quadriceps, and gluteal muscles is crucial because these muscles generate the majority of the pedaling force and must ideally move through the pedal-stroke at 80-90 revolutions per minute." He adds, "Proper stretching, balance, and flexibility exercises help with coordination of cycling-related skills such as breaking and cornering." Moen also cautions that changes in riders' strength and flexibility affect the ability to attain certain positions on the bicycle and also may require them to re-examine their bike fit.
Moen points to bicycle accessories on the market—such as softer handlebar tape, shock absorbers for the seat post and front fork, cut-out saddles, and wider tires—that help to bring comfort to the sport. "Cycling should be about enjoyment, not pain," concludes Moen. "Proper bicycle fit will minimize discomfort and possible overuse injury, maximize economy, and ensure safe bicycle operation. Proper bicycle fit will make your ride a lot more pleasurable."
APTA's online brochure, Bike Right, Bike Fit" and tips to prevent bike fit related injuries can be found in the "consumer tips" section at www.moveforwardpt.com. Click here to 'Ask a PT' questions you may have about proper bike fit.
The American Physical Therapy Association (APTA) represents more than 74,000 physical therapists, physical therapist assistants, and students of physical therapy nationwide. Learn more about conditions physical therapists can treat and find a physical therapist in your area at www.moveforwardpt.com. Consumers are encouraged to follow us on Twitter (@moveforwardpt) and Facebook.