A biomechanical cause of low power production during FES cycling of subjects with SCI

Table 2 Concentric, eccentric and net work generated in the hip and knee joints during the propulsion and recovery phases

	Group	P1	P2	P3	P4	Total [J]
	Group	cc knee extensors/ ec hip flexors [J]	cc hip extensors/ ec knee flexors [J]	cc knee flexors/ ec hip extensors [J]	cc hip flexors/ ec knee extensors [J]	Total [J]
Concentric work mean(SD)	P1P3	12.12(2.94)	2.03(1.17)	13.86(5.76)	1.49(1.32)	29.50‡^a [ 196%]
Concentric work mean(SD)	P1P2	20.40(9.23)	2.32(1.75)	2.95(2.11)	1.56(1.12)	27.23‡^a [182%]
Eccentric work mean(SD)	P1P3	-5.79(2.70)	-1.00(1.15)	-7.29(3.86)	-0.36(0.44)	-14.44 [-96%]
Eccentric work mean(SD)	P1P2	-7.96(5.42)	-0.51(0.48)	-2.65(2.78)	-1.18(1.15)	-12.30 [-82%]
Net work mean	P1P3	6.33 [42%]	1.03 [7%]	6.57 [44%]	1.13 [8%]	15.06 [100%]
Net work mean	P1P2	12.44 [83%]	1.81 [12%]	0.30 [2%]	0.38 [3%]	14 93 [100%]
		Extension [J]		Flexion [J]
Extension & Flexion phase work mean¹	P1P3	7.36 [49%]		7.7 [51%]		15.06 [100%]
Extension & Flexion phase work mean¹	P1P2	14.25‡^b [95%]		0.68 [5%]		14.93 [100%]
		Knee [J]		Hip [J]
Net joint work mean²	P1P3	24.62†^c [163%]		-9.56 [-63%]		15.06 [100%]
Net joint work mean²	P1P2	21.66*^c[145%]		-6.73 [-45%]		14.93 [100%]
		Active [J]		Passive [J]
Active & Passive work mean(SD)	P1P3 & P1P2	10.37(8.52)		-4.59(5.79)		14.96(4.29)³

For definitions of the P1-P4 power components see Figure 1. Data is represented separately for the P1P2 and P1P3 subject groups. The percentage contributions to total net work are shown in the square brackets.
Annotations: ¹Extension phase work = net P1 + net P2; Flexion phase work = net P3 + net P4; ²Net knee work = concentric knee extensor work (P1) + eccentric knee flexor work (P2) + concentric knee flexor work (P3) + eccentric knee extensor work (P4); Net hip work = eccentric hip flexor work (P1) + concentric hip extensor work (P2) + eccentric hip extensor work (P3) + concentric hip flexor work (P4); ³Total net work = Active work - Passive work. Significant differences due to ^aconcentric vs. net work; ^bextension vs. flexion phase work; and ^cknee vs. total work comparisons. * p < 0.01, † p < 0.005 and ‡ p < 0.001.

ISSN: 1743-0003