Table 3.
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.