We examined the effects of side-dominance on the laterality of standing stability
using ground reaction force, motion capture ( MoCap ), and EMG data in healthy young
adults. We recruited participants with strong right ( n = 15) and left ( n = 9) hand
and leg dominance (side-dominance). They stood on one or two legs on a pair of synchronized
force platforms for 50 s with 60 s rest between three randomized stance trials. In
addition to 23 CoP -related variables, we also computed six MoCap variables representing
each lower-limb joint motion time series. Moreover, 39 time- and frequency-domain
features of EMG data from five muscles in three muscle groups were analyzed. Data
from the multitude of biosignals converged and revealed concordant patterns: no differences
occurred between left- and right-side dominant participants in kinetic, kinematic,
or EMG outcomes during bipedal stance. Regarding single leg stance, larger knee but
lower ankle joint kinematic values appeared in left vs right-sided participants during
non-dominant stance. Left-vs right-sided participants also had lower medial gastrocnemius
EMG activation during non-dominant stance. While right-side dominant participants
always produced larger values for kinematic data of ankle joint and medial gastrocnemius
EMG activation during non-dominant vs dominant unilateral stance, this pattern was
the opposite for left-sided participants, showing larger values when standing on their
dominant vs non-dominant leg, i.e., participants had a more stable balance when standing
on their right leg. Our results suggest that side-dominance affects biomechanical
and neuromuscular control strategies during unilateral standing.
