Table 3.
Comparison of kinetic and kinematic variables during balance testing between the AMTI force plate, PedarX and OpenGo.
| Mean ± SD |
Bias (%) |
95% limits of agreement (% grouped mean) |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| AMTI | PedarX | OpenGo | OpenGo vs. AMTI | PedarX vs. AMTI | OpenGo vs. PedarX | OpenGo vs. AMTI | PedarX vs. AMTI | OpenGo vs. PedarX | |
| Single- Leg Balance | |||||||||
| Fmean (N) | 751 ± 111 | 841 ± 104$ | 787 ± 145 | 51 (5%) | 105 (12%) | −53 (−6%) | 235 (30%) | 244 (29%) | 231 (27%) |
| Fmax (N) | 821 ± 122 | 923 ± 122$ | 962 ± 151$ | 153 (17%) | 114 (12%) | 39 (4%) | 268 (48%) | 255 (46%) | 261 (36%) |
| Fmin (N) | 668 ± 144 | 713 ± 131 | 488 ± 141† | −168 (−27%) | 62 (7%) | −230 (−32%) | 217 (30%) | 320 (31%) | 217 (28%) |
| SD (N) | 11.1 ± 9.9† | 28.6 ± 8.9† | 89.4 ± 23.9† | 79 (708%) | 16 (158%) | 63 (213%) | 49 (95%) | 14 (71%) | 46 (78%) |
| COP amplitude M-L (mm) | 43.3 ± 9.5† | 24.3 ± 4.4† | 17.1 ± 4.8† | −26 (−60%) | −19 (−44%) | −7 (−30%) | 15 (50%) | 14 (40%) | 5 (27%) |
| COP amplitude A-P (mm) | 81.7 ± 27.8† | 70.8 ± 26.0$ | 68.5 ± 26.2$ | −11 (−16%) | −12 (−13%) | 1 (−3%) | 35 (48%) | 15 (21%) | 39 (58%) |
| COP SD M-L (mm) | 8.5 ± 2.2† | 4.9 ± 1.0† | 3.6 ± 1.0† | −5 (−58%) | −4 (−42%) | −1 (−28%) | 4 (67%) | 3 (45%) | 2 (46%) |
| COP SD A-P (mm) | 14.2 ± 4.9 | 12.5 ± 4.5$ | 13.8 ± 6.9 | 0 (−3%) | −2 (−12%) | 2 (10%) | 8 (60%) | 3 (22%) | 9 (72%) |
| Path length M-L (mm) | 1241 ± 390† | 580 ± 146† | 357 ± 130† | −912 (−71%) | −685 (−53%) | −227 (−38%) | 606 (74%) | 534 (57%) | 219 (46%) |
| Path length A-P (mm) | 1404 ± 704 | 1041 ± 410$ | 1243 ± 415 | −150 (−11%) | −389 (−26%) | 239 (19%) | 1042 (78%) | 666 (54%) | 702 (61%) |
| Y-Excursion Test | |||||||||
| Fmean (N) | 735 ± 113 | 837 ± 106† | 752 ± 138 | 29 (2%) | 117 (14%) | −87 (−10%) | 237 (33%) | 244 (28%) | 197 (27%) |
| Fmax (N) | 865 ± 119 | 985 ± 84$ | 954 ± 169$ | 107 (10%) | 134 (14%) | −27 (−3%) | 297 (44%) | 260 (32%) | 261 (24%) |
| Fmin (N) | 614 ± 112† | 684 ± 125† | 472 ± 108† | −131 (−23%) | 80 (11%) | −211 (−31%) | 238 (32%) | 209 (31%) | 141 (25%) |
| SD (N) | 36.3 ± 11.4† | 52.5 ± 9.4† | 105.1 ± 31.3† | 72 (190%) | 17 (45%) | 55 (100%) | 62 (86%) | 25 (57%) | 69 (87%) |
| COP amplitude M-L (mm) | 51.8 ± 6.4† | 29.9 ± 5.4† | 21.0 ± 3.8† | −31 (−60%) | −22 (−42%) | −9 (−30%) | 12 (33%) | 12 (28%) | 9 (34%) |
| COP amplitude A-P (mm) | 106.9 ± 19.3† | 90.5 ± 14.5$ | 85.7 ± 17.5$ | −20 (−20%) | −18 (−15%) | −2 (−5%) | 26 (26%) | 17 (17%) | 30 (33%) |
| COP SD M-L (mm) | 11.6 ± 1.5† | 7.0 ± 1.9† | 4.7 ± 1.3† | −7 (−59%) | −5 (−40%) | −2 (−33%) | 2 (23%) | 2 (20%) | 2 (38%) |
| COP SD A-P (mm) | 23.0 ± 4.9† | 19.6 ± 4.0$ | 19.5 ± 3.8$ | −4 (−15%) | −4 (−15%) | 0 (−1%) | 5 (23%) | 3 (15%) | 6 (27%) |
| Path length M-L (mm) | 842 ± 263† | 405 ± 136† | 209 ± 65† | −645 (−75%) | −445 (−52%) | −200 (−48%) | 425 (79%) | 273 (43%) | 198 (63%) |
| Path length A-P (mm) | 1177 ± 233† | 864 ± 175† | 721 ± 138† | −495 (−39%) | −322 (−27%) | −137 (−17%) | 305 (32%) | 203 (20%) | 284 (36%) |
Fmean, mean force during balance test; Fmax, maximal force during the balance test, Fmin, minimal force during the balance test; SD, standard deviation of the force over time; COP, center of pressure; M-L, medio-lateral; A-P, anterio-posterior; †significantly different to the other two methods; $different to AMTI force plate; ‡different to PedarX.