Postural dependence of locomotion during gait initiation
Human locomotion in the changing natural environment requires that the complex interaction between postural orientation of the body segments is maintained in concert within a stable equilibrium. Anticipatory postural adjustments (APAs) that stabilise mediolateral (ML) standing balance normally precede stepping. The following study investigated how the CNS adapts posture and locomotion to perturbations of ML standing balance.
Healthy adults initiated gait whilst a resistance force was applied at the pelvis to perturb posture. Using random perturbations, step onset timing was delayed relative to the APA onset – suggesting that locomotion was withheld until expected stability conditions occurred. Additionally, stepping parameters were adapted with the APAs indicating motor prediction of the consequences of postural changes likely modified the step motor command.
These results suggest that both rapid and transient reactive adaptations in the posture and gait assembly more durable practice-dependent changes suggesting feed-forward adaptation of locomotion in response to prevailing postural conditions.
> From: Mille et al., J Neurophysiol 112 (2015) 3095-3103. All rights reserved to American Physiological Society. Click here for the Pubmed summary.