Table 2.
Mean and standard deviation, 95 % CI of EMG activity of the VMO and VL muscles
| VL | VMO | |||||||
|---|---|---|---|---|---|---|---|---|
| MF(Hz) | MPF(Hz) | RMS(μV) | IEMG(μVs) | MF(Hz) | MPF(Hz) | RMS(μV) | IEMG(μVs) | |
| DS* | 56.66 ± 5.53 | 68.14 ± 6.38 | 103.31 ± 44.54 | 8.02 ± 3.45 | 55.88 ± 5.17 | 65.57 ± 4.96b | 85.02 ± 41.19b | 6.72 ± 3.20b |
| (54.60–58.72) | (65.76–70.52) | (86.68–119.94) | (6.73–9.30) | (53.95–58.72) | (62.72–66.42) | (69.64–100.40) | (5.53–7.92) | |
| DS-HA* | 57.21 ± 4.93 | 67.79 ± 5.83 | 113.00 ± 41.08 | 8.82 ± 3.15 | 56.51 ± 5.97 | 65.47 ± 6.08 | 105.81 ± 44.23a | 8.30 ± 3.55a |
| (55.37–59.05) | (65.61–69.96) | (97.66–128.34) | (7.65–9.99) | (54.27–58.74) | (63.20–67.74) | (89.30–122.33) | (6.98–9.63) | |
| DS** | 56.45 ± 5.99 | 68.30 ± 7.64 | 99.25 ± 31.14 | 7.83 ± 2.48 | 56.68 ± 6.45 | 66.53 ± 7.56 | 104.10 ± 48.75 | 8.27 ± 3.81 |
| (54.90–58.00) | (66.33–70.27) | (91.21–107.29) | (7.19–8.48) | (55.02–58.35) | (64.58– 68.49) | (91.51–116.70) | (7.25–9.25) | |
| DS-HA** | 56.58 ± 6.01 | 68.10 ± 7.94 | 103.18 ± 40.55 | 8.13 ± 3.25 | 56.50 ± 6.45 | 66.45 ± 7.92 | 109.50 ± 63.47 | 8.63 ± 4.97 |
| (55.03–58.14) | (66.05–70.15) | (92.71–113.66) | (7.29–8.97) | (54.83–58.17) | (64.40–68.50) | (93.10–125.90) | (7.35–9.92) | |
DS double-leg semisquat exercise, DS-HA double-leg semisquat exercise with hip adduction
95 % CI 95 % confidence intervals
*PFPS subjects **healthy subjects
aElectric activity of the VMO muscles was significantly greater during DS-HA exercise than during DS exercise (P < 0.05)
bElectric activity of the VL muscle was significantly greater than that of the VMO muscle during DS exercise (P < 0.05)