Table 4.

Metadata* stored in c3d files.

Structure	Labels	Format	Dim.	Unit	Description
Subject	age	Integer	1 × 1	years	Age
	gender	Integer	1 × 1	none	0: woman, 1: man
	weight	Real	1 × 1	kg	Body weight
	height	Real	1 × 1	mm	Participant size
	R_legLength	Real	1 × 1	mm	Right leg length+
	L_legLength	Real	1 × 1	mm	Left leg length
Event	Right_Foot_Strike1	Real	1 × 1	s	First right foot strike timing
	Right_Foot_Strike2	Real	1 × 1	s	Second right foot strike timing
	Right_Foot_Off	Real	1 × 1 or 1 × 2	s	Right foot off timings
	Left_Foot_Strike1	Real	1 × 1	s	First left foot strike timing
	Left_Foot_Strike2	Real	1 × 1	s	Second left foot strike timing
	Left_Foot_Off	Real	1 × 1 or 1 × 2	s	Left foot off timings

*Additional metadata are stored by default (i.e. Copyright, Force_Platform, Point, Analog, Trial, Event_Context).

⁺Leg length is measured between the anterior-superior iliac spine and the medial tibial malleolus.