Table 1.

Biomechanical variables considered

Variable	Units	Definition	Determination
Stance duration	Seconds	Interval between foot landing and take-off	Interval between the vertical negative velocity peak for the centre of the foot (computed as the barycentre of the big toe and heel markers) and the point of minimal big toe contact
Swing duration	Seconds	Take-off duration of one foot and landing of the other	Interval between minimal big toe contact with one foot and vertical negative velocity peak for the centre of the other foot
Reactivity	None	Ratio between swing duration and stance duration
Stride frequency	Hertz	Number of strides executed in 1 s
Step length	Metres	Ratio between distance covered and total number of steps
Foot orientation at impact	Degrees	Angle between the vector linking the heel marker to the 5th metatarsal marker and the horizontal axis in the sagittal plane. Positive angles represent dorsiflexion
Vertical amplitude of CG	Metres	Vertical motion of the CG during one whole stride	CG defined as the barycentre of the four pelvic markers
Lateral amplitude of CG	Metres	Lateral of the CG during one whole stride	CG defined as the barycentre of the four pelvic markers