Abstract
Previous experimentation implied that longer limbed humans moderate greater bending moments along the lower limb by keeping the knees more extended during walking, particularly during the second half of the stance phase. However, doubt was raised by others that correlations of kinetic and kinematic variables with limb length could have been confounded by covariation with body mass.
In this study we aim to 1) determine which of these size variables (lower limb length, body mass) implicate kinematic moderating mechanism at the knee; 2) search for similar moderating mechanisms at the ankle. We measured kinematics and kinetics of 22 human subjects while walking on a treadmill at their preferred speed.
We analyzed associations between size variables and kinematic variables using correlation and multiple correlation analyses. Our results suggest that: 1) it is not longer limbed individuals who keep their knees more extended during the second half of the stance phase but individuals with greater body mass; 2) individuals with longer lower limbs and greater body mass tend to keep their ankles less dorsiflexed at midstance and during the later stance phase which should reduce bending moments at the ankle and tibial midshaft through moment arm shortening.
However, neither lower limb length or body mass are significantly correlated with kinematic variables at the ankle when the other size variable is controlled for.