Table 3.

Significant regression coefficients of GEEs with Group (G) and Step (S) as factors, and Speed (V, km/h) as covariate (cf. Table 2)

	Int	G	S		V	G × S		G × V		S × V
Basic gait parameters
Stride length (m)	0.15		L: 0.40		0.20					L: −0.002
			N: 0.11							N: 0.02
Frequency (strides/min)	0.83		L: −0.53		0.08					L: 0.05
										N: 0.01
			N: −0.25
Rotational amplitudes
Pelvis	2.91	P: 1.44	L: 5.38		0.54					L: 0.64
			N: 1.77							N: 0.44
Thorax	8.07		L: 6.15		0.07					L: −1.23
			N: 4.27							N: −0.90
Lumbar segment	7.36		L: 4.62
			N: 1.76
Thoracic spine	0.04				0.01					L: 0.03
										N: 0.02
Lumbar spine	3.43		L: 0.65		0.63					L: 0.13
			N: −0.22							N: 0.17
Total spine	3.74				1.15					L: 1.80
										N: 1.06
Relative Fourier Phase
Thorax–lumbar	−2.69		L: 2.04		6.98	PL: −22.40				L: 10.02
						PN: −7.41
										N: 7.62
			N: −6.47
Thorax–pelvis	14.72				11.87	PL: −24.62				L: 8.75
						PN: 0.54				N: 8.33
Thorax–leg	164.57		L: −42.79		1.69			P: −2.78		L: 5.23
										N: −1.69
			N: −1.14
Lumbar–pelvis	21.24				4.73
Lumbar–leg	178.50		L: −45.00		−6.93					L: −4.97
			N: 6.52							N: −9.76
Pelvis–leg	157.76		L: −43.46		−11.55					L: −3.16
			N: 13.51
										N: −10.60
Arm swing:
Amplitude	0.14		L: −0.002		0.02					L: 0.02
			N: −0.02							N: 0.03
Arm–thorax RFP	17.15		L: 4.52		0.68			P: 5.28		L: 0.57
			N: −16.54							N: 5.48
Arm–leg RFP	153.98		L: −53.89		0.45					L: 18.88
			N: 5.55
										N: −0.11

Note that GEEs calculate regression equations. For instance, the first line should be read as: stride length equaled 0.15 + 0.40 (for large steps) or +0.11 (normal steps), +0.20 × Speed, −0.002 × Speed (for large steps) or +0.02 × Speed (normal steps), and some non-significant factors

Int intercept, P patients, L large steps, N normal steps