Table 1 Outcome parameters

 Duty cycle

Percentage of stance phase over the whole cycle duration

%

anteroposterior

 Step length

Anteroposterior distance between contralateral heel markers at their respective heel strikes plus the distance the stance foot moved back with the treadmill belt during this time

m

anteroposterior

 Step width

Mediolateral distance between contralateral heel markers at their respective heel strikes

m

mediolateral

 ML approximated COM (aCOM) sway

Difference between the ML extrema of the aCOM within each step

m

mediolateral

 ML Margins of Stability (ML MoS)

Shortest distance of the floor-projected aCOM during midstance to the nearest edge of the base of support

BoS was defined as the smallest convex hull spanning all points (heel, ankle, 5th metatarsal and 2nd metatarsal) in contact with the ground

m

mediolateral

 Step width (CoV)

Standard deviation divided by the mean of step width

m

mediolateral

 ML approximated COM (aCOM) sway (CoV)

Standard deviation divided by the mean of ML aCOM sway

m

mediolateral

 ML λ_{s pos}

Short-term maximum Lyapunov exponent from time series of ML aCOM position

arbitrary unit

mediolateral

 ML λ_{s vel}

Short-term maximum Lyapunov exponent from time series of ML aCOM velocity

arbitrary unit

mediolateral

 VT λ_{s pos}

Short-term maximum Lyapunov exponent from time series of VT aCOM positions

arbitrary unit

vertical

 VT λ_{s vel}

Short-term maximum Lyapunov exponent from time series of VT aCOM velocity

arbitrary unit

vertical