The Effect of Changes in Bicycle Pedal Width on the Segments and Joints Kinematics of Lower Extremity: Analysis of the Risk of Knee Overuse Injuries with Pedaling

Pain and overuse injuries of the knee joint is prevalent among cyclists. The bicycle adjustment in accordance to the cyclist’s body mechanics is a common way to reduce the risk of overuse injuries. The aim of this study was to investigate the effect of changes in bicycle pedal width on the segments and joints kinematics of lower extremity and its’ association with the risk of knee overuse injuries during pedaling.

10 professional cyclists of Shiraz city pedaled at 100% of maximum power output at four different pedal width (Q0: conventional pedal width, Q1: Q0+1cm, Q2: Q0+2cm and Q3: Q0+3cm). Angle of lower extremity segments and joints were recorded three dimensionally for thirty seconds during pedaling in each pedal width by myoMotion system. Minimum, maximum, and mean angles and range of motion variables of hip and ankle (sagittal plane), knee joint (sagittal and frontal plane) and thigh and shank angles in frontal plane were calculated. One-way repeated measures ANOVA and Bonferroni post-hoc test were used to identify significant changes.

The statistical results showed that changes in pedal width had significant effect of on minimum (P=0.035), maximum (P=0.042), and mean (P=0.02) of shank abduction/adduction and minimum (P=0.015), mean (P=0.022) and range of motion (P=0.018) of ankle plantar/dorsi flexion, while change in pedal width had no significant effect on other kinematics parameters.

The results indicate that pedal width of Q1 has the more potential to lower the risk of knee injury and provide increased efficiency whilst cycling; Still, the standard pedal width of road bikes (Q0) seemed not appropriate for professional Iranian cyclists since they increases the risk of knee joint overuse injuries.