Table 3.

Mean (SD) muscle strength and co-activation variables across all diagnostic groups (* p ≤ 0.05; ** p ≤ 0.01 when compared to a matched control group)

Diagnostic groups	Mean (SD) (95% CI difference) predicted strength: quadriceps (%)	Mean (SD) (95% CI mean difference) predicted strength: hamstrings (%)	Mean (SD) (95% CI mean difference) isometric co-activation (%)	Mean (SD) (95% CI mean difference) co-activation during STS (%)
Muscle disease (n = 17)	50.6 (30.1) ** 36.9 to 88.7	55.9 (42.7) ** 32.7 to 85.4	17.4 (15.2) -1.2 to 15.1 ◊	22.3 (23.4) -18.5 to 7.9 ◊
LMN (sensory loss) (n = 18)	87.4 (27.5) -45.3 to 0.6	61.4 (22.4) ** 31.4 to 66.2	7.3 (5.1) -6.9 to 0.6 ◊	15.7 (11.0) -14.2 to 1.5
LMN (sensory intact) (n = 12)	53.4 (38.0) ** 21.5 to 78.3	55.6 (20.5) * 30.2 to 70.5	12.7 (10.9) -5.3 to 9.2 ◊	16.3 (10.6) Δ -12.8 to 6.5
UMN (n = 12)	67.2 (30.7) ** 12.1 to 65.4	55.9 (33.5) ** 19.4 to 67.1	9.4 (9.3) -7.7 to 2.9 ◊	24.7 (16.5) -7.5 to 13.6 ◊
Extra-pyramidal lesion (n = 15)	81.3 (36.4) -48.8 to 11.6	65.7 (30.6) * 13.9 to 57.0	6.7 (4.3) ** -11.2 to -3.9	14.7 (13.3) * -17.9 to 0.9 ◊
Control subjects (n = 32)	102.4 (37.0)	103.2 (30.1)	11.8 (6.2)	20.5 (12.9)

◊ non-parametric comparisons between groups were used hence, it is only possible to present approximate confidence intervals

Δ based on the means of data from 8 subjects. 4 subjects in this group used hip and trunk flexion strategies to achieve STS thus preventing calculation of co-activation at the point of the maximum knee extension moment.