Table II. —Relative risk of knee pain between different tertiles of knee loading in 12 months.
| Knee loading | Tertiles | Range in each tertile | Total knees | Risk of any knee pain | Risk of frequent knee pain | ||||
|---|---|---|---|---|---|---|---|---|---|
| Knees with any pain * | RR (95% CI)** |
P value | Knees with frequent pain * | RR (95% CI)** |
P value | ||||
| KAM (Nm/kg) |
Low (reference) | ≤0.596 | 103 | 18 (17.5%) | 1.00 | - | 2 (1.9%) |
1.00 | - |
| Medium | 0.597-0.722 | 104 | 25 (24.0%) | 1.49 (0.68, 3.27) |
0.325 | 5 (4.8%) |
2.38 (0.17, 34.1) |
0.523 | |
| High | ≥0.723 | 107 | 22 (20.6%) | 1.34 (0.58, 3.08) |
0.498 | 7 (6.5%) |
4.49 (0.34, 59.0) |
0.254 | |
| KFM (Nm/kg) |
Low (reference) | ≤0.175 | 104 | 21 (20.2%) | 1.00 | - | 5 (4.8%) |
1.00 | - |
| Medium | 0.176-0.383 | 107 | 25 (23.4%) | 1.31 (0.62, 2.77) |
0.484 | 5 (4.7%) |
1.01 (0.22, 4.60) |
0.990 | |
| High | ≥0.384 | 103 | 19 (18.4%) | 0.91 (0.35, 2.39) |
0.855 | 4 (3.9%) |
0.89 (0.14, 5.71) |
0.900 | |
*Number (%) of knees; **controlling for age, gender, body height, comorbidities, activity level, and walking speed; RR: adjusted relative risk; 95% CI: 95% confidence interval of RR. KAM: peak knee adduction moment; KFM: peak knee flexion moment.