Table 2.

Statistics of correlation between HAWK (marker-based) and CT (anatomic) joint range of motion (ROM) for PIP and DIP joints across whole cohort, in all cases and per-finger

HAWK:CT correlation	Finger(s)	R2	p	m (°/°)	c (°)	RMSE (°)
PIP	All (n = 80)	0.955	< 0.001	0.980	− 2.782	3.782
	2 (n = 20)	0.945	< 0.001	0.948	− 0.592	3.575
	3 (n = 20)	0.907	< 0.001	1.017	− 4.195	4.098
	4 (n = 20)	0.969	< 0.001	1.038	− 5.978	2.955
	5 (n = 20)	0.970	< 0.001	0.953	− 2.541	3.940
DIP	All (n = 72)	0.923	< 0.001	0.892	4.554	3.302
	2 (n = 18)	0.928	< 0.001	0.927	3.036	2.494
	3 (n = 18)	0.940	< 0.001	0.801	7.266	2.945
	4 (n = 18)	0.949	< 0.001	0.836	6.865	2.584
	5 (n = 18)	0.928	< 0.001	1.051	− 0.588	3.822

*N.B. DIP marker was occluded for one participant. Linear regression expressed by HAWK Angle = m CT Angle + c