Bicycling Injuries

Bicycling Injuries

Chad A. Asplund


  • Participation in bicycling is rapidly growing.

    • In 2009, 38.1 million Americans age 7 and older were estimated to have ridden a bicycle six times or more (22).

  • There are many different ways to participate in bicycling: road cycling, mountain biking, touring/commuting, cyclocross, and BMX.

  • With the increased participation, there has been an increase in both traumatic and overuse injuries:

    • Each year, more than 500,000 people in the United States are treated in emergency departments and more than 700 people die as a result of bicycle-related injuries (10).

  • Most common areas for overuse injuries in bicycling are the knee, neck, and back (3,4).

  • Many of these overuse injuries occur secondary to improper bicycle fit or to training errors.

  • This chapter will outline the different ways people can participate in bicycling, the anatomy and fit of the bicycle, injury epidemiology, traumatic and overuse injuries, cycling-related equipment, and common training errors.


Road Cycling

  • Road racing: Open road 25-100 miles.

  • Criterium: Multiple laps around a short course.

    • Very popular in America

    • High potential for crashing/injury

  • Time trial: Race against the clock with wave start with 1-5 minutes between riders.

Mountain Biking

  • Cross-country: Longer races over variable terrain.

  • Downhill: Steep downhill race where focus is on speed; injuries occur as safety is sacrificed for speed.

  • Dual slalom: Two racers compete in downhill ski-style slalom course.


  • Long-distance road riding for recreation. Rider may be carrying panniers/saddlebags.


  • Off-road race on road-style bike, in which riders complete multiple short (1-2 mile) loops in a set time period. Obstacles require rider to dismount, remount, and carry bicycle over the course.

BMX/Trick Cycling

  • Riders compete against other riders over dirt courses of varied terrain or individually on ramps with stairs and railings, with aerial stunts. There is a high risk for injury with aerial acrobatics.

    • Fastest growing segment of U.S. cycling with 60,000 riders (14).

    • Largest portion of child and adolescent cyclists.


  • Although there are many different modes of bicycling, the general anatomy of the bicycle is similar (Fig. 88.1).

Frame Types

  • Standard road: Traditional upright geometry with top tube parallel to ground.

  • Compact road: Sloping top tube allows rider to fit smaller frame; this maximizes stiffness and minimizes weight.

  • Mountain/hybrid: Flatter geometry, heavier bicycle, may have front and/or rear suspension to absorb shock.


  • Most important attribute in the evaluation of overuse bicycling injuries.

  • Bicycle fit may be done at local bike shop with bicycle purchase or available for a fee.

  • Fit Kit and Serotta “Size Cycle” have been used (11).

    Figure 88.1: Bicycle anatomy.

  • Best frame size for cyclist is as small vertically as possible with enough length horizontally to allow a stretched out relaxed upper body. This frame will be lighter and stiffer and handle better (12).

Frame Size

  • Most important attribute for appropriate frame size is top tube length.

Top Tube Length

  • The ideal position varies here more than anywhere else for cyclists, depending on riding style, flexibility, body proportions, and frame geometry, among others.

  • Upper body position may change as riding style evolves.

  • May be measured by placing the elbow at the fore end of the saddle; outstretched fingers should touch the handlebars.

  • May also have rider, while in the drops, look straight down; the hub of the front wheel should be obscured by the handlebar.

Seat Height

  • Optimal saddle height has been estimated based on maximal power output and caloric expenditure (9).

  • Calculate height, which will be within a centimeter of 0.883 × inseam length, measured from the center of the bottom bracket to the low point of the top of the saddle. This allows full leg extension, with a slight bend in the leg at the bottom of the pedal stroke.

  • When seated on the bike with the pedal at the 6 o’clock position, there should be 20-25 degrees of flexion of the knee.

  • Alternatively, the seat may be raised until the hips start rocking when pedaling and then the seat is lowered until the rocking disappears.

Saddle Position

  • Check the position of the forward knee relative to the pedal spindle; for a neutral knee position, you’ll be able to drop a plumb line from the tibial tubercle and have it bisect the pedal spindle (knee over pedal spindle [KOPS] position) (9).

Handlebar Position

  • Most cyclists select a bar that is just as wide as their shoulders.

    • A wider bar opens the chest for better breathing and more leverage but sacrifices aerodynamics.

    • A narrower bar increases aerodynamics but sacrifices stability.

  • Handlebar height should be at or below the saddle height; how far below depends on the flexibility and experience of the cyclist.

Crank Arm Length

  • Length is based on size and riding style. Shorter crank arm length is better for quick acceleration. Long crank arms are better for pushing larger gears at a lower cadence (12).

  • To minimize oxygen consumption, crank arm length is dependent on femur length.

  • 2.33 × femur length + 55.8 cm (28). This roughly translates to:

    • Frame size < 54 cm: 170-cm crank arm

    • Frame size 55-61 cm: 172.5-cm crank arm

    • Frame size > 61 cm: 175-cm crank arm


  • Chain wheels: Large chain ring (usually 53 teeth) and small chain ring (usually 39 teeth) 53/39; recently, a more compact 50/34 chain ring combination has become more popular to allow riders to climb hills and spin at higher cadence.

  • Cassette: Cluster of gears (cogs) mounted to right of rear wheel.

  • Gear ratio: Number of teeth on chain ring divided by number of teeth on selected cog.

  • Higher ratio requires more strength, endurance, and technique.

  • Lower gear ratio allows for more spinning and higher cadence; without proper technique will yield less power.


  • Optimal cadence determined by type of race (time trial, climbing, criterium), body type, muscle fiber type, and training level (8).

  • Higher cadences put less strain on trained leg muscles.

  • Low cadences increase intramuscular pressure, reducing blood flow to the muscles during the power phase of the pedal stroke.

  • High-cadence/low-resistance training reduces the incidence of overuse injuries. Cyclists beginning a season or returning from injury should return with this type of training.

  • Cadence is individual and should be determined on a rider-by-rider basis.



May 22, 2016 | Posted by in SPORT MEDICINE | Comments Off on Bicycling Injuries
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