Angular velocity during hand opening. Velocity profiles of MCPJ and IPJ of a single finger of a representative healthy subject (a) and of six stroke patients (b, c, d, e, f, g) during hand opening. Delay (Δ) between IPJ and MCPJ angles are shown. Note that type 0 hand (b) showed a delay in the control range. Type I hands (c, d) revealed a reversed inter-joint coordination sequence (IPJ-MCPJ), while type II hands (e, f) showed prolonged delay with respect to controls. Type III hand (g) showed a contemporary extension of both MCPJ and IPJ.