TABLE 2.
Performance of the model for the prediction of hip contact forces. Avg and Rg stand for average (arithmetic mean) and range, and NA means Not Available. Only one trial was available for WS of HSR and SD of PFL. R 2 is the coefficient of determination, exp. peak is the experimental peak and WN, WS, WF, SU, SD, CD, and CU stand for normal walking, slow walking, fast walking, stair ascent, stair descent, sitting down and standing up, respectively.
| Subject | Activity | RMSE (%BW) | R 2 (Rg) | 1st peak of HCF | 2nd peak of HCF | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg | Rg | Magnitude error (% exp. peak) | Timing error (% gait cycle) | Magnitude error (% exp. peak) | Timing error (% gait cycle) | |||||||
| Avg | Rg | Avg | Rg | Avg | Rg | Avg | Rg | |||||
| HSR | WN | 42.0 | 35.5–50.2 | 0.96–0.98 | 29.1 | 25.4–34.8 | 1.4 | 0–3.0 | 32.1 | 16.4–51.0 | 1.2 | 0–2.8 |
| WS | 30.6 | NA | 0.98 | 24.0 | NA | 0.1 | NA | 27.0 | NA | 2.9 | NA | |
| WF | 56.0 | 46.5–67.9 | 0.89–0.96 | 26.0 | 17.9–36.8 | 1.8 | 0.1–3.1 | 9.1 | 0.6–12.8 | 1.3 | 0.1–3.4 | |
| SU | 32.7 | 29.0–38.6 | 0.91–0.96 | 2.9 | 1.2–5.2 | 2.1 | 0.1–6.0 | 10.8 | 5.6–21.1 | 2.7 | 0–7.9 | |
| SD | 44.5 | 35.3–52.7 | 0.94–0.99 | 4.3 | 1.0–7.7 | 2.1 | 1.6–3.1 | 17.0 | 0.5–28.3 | 0.9 | 0–1.5 | |
| CU | 32.2 | 25.9–39.4 | 0.80–0.95 | 6.1 | 0.6–10.4 | 6.0 | 1.7–9.1 | NA | NA | NA | NA | |
| CD | 14.9 | 12.6–18.8 | 0.94–0.98 | 6.4 | 0.1–17.5 | 1.4 | 0–3.3 | NA | NA | NA | NA | |
| KWR | WN | 50.7 | 43.5–61.3 | 0.86–0.95 | 30.9 | 25.5–38.8 | 2.4 | 0.1–5.6 | 15.0 | 1.1–25.1 | 1.4 | 0–3.2 |
| WS | 48.2 | 39.2–60.9 | 0.86–0.94 | 21.0 | 8.8–31.5 | 3.7 | 2.9–4.4 | 14.0 | 5.2–18.5 | 1.5 | 0.1–4.7 | |
| WF | 63.2 | 56.1–68.7 | 0.84–0.92 | 37.4 | 23.1–44.9 | 1.8 | 0.1–3.0 | 26.9 | 16.1–41.5 | 1.1 | 0.1–2.7 | |
| SU | 61.1 | 39.8–76.4 | 0.83–0.94 | 10.6 | 3.1–15.0 | 2.9 | 1.5–7.7 | 35.0 | 16.3–49.4 | 1.5 | 0.1–4.7 | |
| SD | 61.8 | 56.6–69.1 | 0.85–0.91 | 17.3 | 13.6–22.9 | 1.8 | 0–3.1 | 44.8 | 31.5–58.9 | 0.5 | 0.1–1.4 | |
| CU | 25.0 | 22.0–30.2 | 0.92–0.96 | 4.2 | 1.6–10.0 | 1.1 | 0.1–2.9 | NA | NA | NA | NA | |
| CD | 19.9 | 13.0–30.1 | 0.87–0.97 | 10.2 | 4.3–17.3 | 4.9 | 1.4–10.6 | NA | NA | NA | NA | |
| PFL | WN | 50.4 | 39.5–54.9 | 0.88–0.96 | 23.0 | 3.3–36.2 | 12.4 | 2.9–21.0 | NA | NA | NA | NA |
| WS | 44.2 | 34.1–49.2 | 0.95–0.98 | 4.2 | 0.6–11.8 | 1.7 | 0–3.5 | NA | NA | NA | NA | |
| WF | 60.9 | 56.1–68.3 | 0.83–0.90 | 44.6 | 38.4–59.7 | 14.4 | 12.0–18.8 | NA | NA | NA | NA | |
| SU | 31.1 | 29.8–32.3 | 0.93–0.96 | 10.3 | 8.5–11.9 | 0.2 | 0.1–0.3 | 32.8 | 28.8–35.0 | 2.0 | 1.4–3.1 | |
| SD | 45.7 | 28.2–63.1 | 0.80–0.96 | 33.7 | 22.8–44.6 | 2.3 | 0.6–4.0 | 20.5 | 2.3–38.8 | 2.6 | 1.6–3.6 | |
| CU | 38.2 | 30.6–52.6 | 0.69–0.85 | 24.8 | 19.3–28.9 | 7.0 | 3.5–11.0 | NA | NA | NA | NA | |
| CD | 16.5 | 11.2–21.4 | 0.93–0.97 | 11.7 | 4.5–17.8 | 4.4 | 0.1–14.0 | NA | NA | NA | NA | |