Table 1.

Description of outcome variables.

Outcome variable	Measured for/by	Quantifies
Step incidence	Anterior and posterior perturbations of standing with different perturbation magnitudes	Reactive standing balance performance
Step length correction	Anterior and posterior perturbations of walking with different magnitudes at different instances of the stance phase	Reactive walking balance performance
KCOP	Anterior and posterior perturbations of standing with different perturbation magnitudes	Reliance on COP strategy: sensorimotor transformation from COM kinematics to ankle torque during standing
Khip	Anterior and posterior perturbations of standing with different perturbation magnitudes	Reliance on hip strategy: relation between xCOM300ms and θtrunk, max
xCOMmax, non−stepping/BOS	Anterior and posterior perturbations of standing with different perturbation magnitudes	Reliance on stepping strategy: maximum xCOM excursion withstanded without initiating a step response
Maximal voluntary isometric knee-extension torque (MVIKT)	Maximum over three trials	Knee-extensor strength
NSAE of force fluctuations	Averaged over nine torque tracking tasks on the Biodex dynamometer	Motor acuity
SOT composite and subscores	Sensory organization test	Sensory acuity and organization during balance control
Beam walking score	Averaged over six trials of narrow-beam walking	Dynamic balance