BoS	base of support
MIMU	magneto-inertial measurement unit
Infrared time-of-flight	infrared time of flight
SP	stereophotogrammetric system
DS	distance sensor(s)
f(t)	specific force
a(t)	acceleration
df(t)	distance recorded by the front DS attached to the instrumented shoe
dr(t)	distance recorded by the rear DS attached to the instrumented shoe
CSS	MIMU coordinate system
CSE	Earth coordinate system
CSG	global coordinate system
CSSP	SP coordinate system
t0 and tf	flat-foot instants of the instrumented foot that determine the beginning and the end of the considered generic gait cycle
t1 and t2	first and last instants in which at least a DS records a distance different from zero within the same gait cycle
V1, V2, V3, and V4	vertices of the footprint of the instrumented foot
V5, V6, V7, and V8	vertices of the footprint of the non-instrumented foot
R	generic point of the medial side of the non-instrumented foot detected by the front DS
F	generic point of the medial side of the non-instrumented foot detected by the rear DS