Leg Muscles Shift Their Function According to Need During Cycling

January 4, 2021
Cyclists on bicycle ergometer at Simon Fraser University courtesy of Adrian Lai

Andrew Biewener, Charles P. Lyman Professor of Biology and Director of the Concord Field Station, collaborated with colleagues at Simon Fraser University, Burnaby, BC, to examine varying muscle functions in humans during different motor activities. The study published in the Journal of Experimental Biology measured muscle contractions of animals that were then used to develop musculoskeletal simulations of human cycling.

The study shows that although cycling is often considered a seemingly simple, reciprocal task, leg muscles shift their function according to changes in demands placed on them by shifting into higher gears and pedalling faster. When gears were increased in torque and slower pedalling was used leg muscles were activated more strongly to increase their work and power output. Whereas, at lower gears torque and fast pedalling, muscles shifted to a more ‘spring-like’ behavior, actively stretching and then shortening to improve their economy and reduce their power output.

Modeling studies on animals were conducted at the Concord Field Station by Prof. Biewener. Image of cyclists on the bicycle ergometer at Simon Fraser University by lead author Adrian Lai.

See also: Faculty News, 2021