Table 3.
Gait analysis variables with group mean differences and associated 95% confidence intervals.
| Core biomechanical variables | JIA | Controls | Mean difference (95% CI) |
|---|---|---|---|
| Kinematic/kinetic variables | |||
| Peak ankle joint moment (Nm/kg) | −1.37 (0.15) | −1.45 (0.22) | −0.09 (−0.24, 0.07) |
| Norm peak ankle joint moment | −0.005 (0.002) | −0.006 (0.002) | 0.0004 (−0.001, 0.002) |
| Peak ankle joint power (W/kg) | 1.89 (0.83) | 2.17 (0.89) | 0.28 (−0.45, 1.01) |
| Norm ankle joint power | 0.005 (0.003) | 0.004 (0.002) | −0.0003 (−0.003, 0.002) |
| Peak force initial contact (BW) | 1.06 (0.07) | 1.08 (0.13) | 0.02 (−0.64, 0.10) |
| Norm force initial contact | 0.003 (0.001) | 0.003 (0.001) | 0.0004 (−0.001, 0.001) |
| Peak force terminal stance (BW) | 1.08 (0.07) | 1.11 (0.09) | 0.04 (−0.03, 0.10) |
| Norm force terminal stance | 0.003 (0.001) | 0.003 (0.001) | −0.0002 (−0.001, 0.001) |
| Initial contact angle (°) | 16.9 (3.4) | 17.4 (3.0) | 0.5 (−2.3, 3.3) |
| Terminal stance angle (°) | −51.5 (7.4) | −52.4 (10.6) | −0.8 (−8.4, 6.8) |
| Minimum navicular height (mm) | 34 (11) | 35 (8) | 2 (−7, 10) |
| Peak rearfoot eversion (°) | −8.0 (5.7) | −7.0 (5.6) | 1.0 (−3.9, 5.9) |
| Rearfoot terminal stance ROM (°) | 12.1 (4.4) | 12.7 (6.2) | 0.6 (−3.9, 5.0) |
| Peak midfoot dorsiflexion (°) | 7.3 (3.5) | 4.3 (2.7) | −3.0 (−5.8, −0.3) |
| Peak 1st met dorsiflexion (°) | −12.6 (7.8) | −11.7 (4.2) | 0.9 (−4.7, 6.6) |
| Peak lateral forefoot abduction (°) | −5.5 (5.2) | −9.1 (4.1) | −3.6 (−7.7, 0.5) |
| Peak hallux dorsiflexion (°) | 58.0 (13.7) | 62.3 (12.2) | 4.3 (−6.9, 15.6) |
| Pressure variables | |||
| Midfoot contact area (cm2) | 19.0 (12.3) | 19.0 (4.5) | −0.0 (−8.5, 8.4) |
| Lesser toes contact area (cm2) | 7.6 (2.3) | 7.5 (3.3) | −0.2 (−2.5, 2.2) |
| Rearfoot peak pressure (kPa) | 320 (90) | 355 (113) | 35 (−51, 121) |
| 1st metatarsal peak pressure (kPa) | 281 (103) | 325 (179) | 43.3 (−76, 163) |
| Lateral forefoot peak pressure (kPa) | 248 (180) | 247 (62) | −1.1 (−125, 122) |
| Spatiotemporal parameters | |||
| Step length (cm) | 59.9 (6.5) | 63.4 (9.9) | 3.5 (−3.5, 10.4) |
| Norm step length (cm) | 0.7 (0.1) | 0.8 (0.1) | 0.0 (−0.1, 0.1) |
| Double support time (%GC) | 19.8 (4.3) | 19.0 (3.3) | −0.7 (−4.1, 2.6) |
| Cycle time (s) | 1.1 (0.2) | 1.1 (0.1) | −0.0 (−0.1, 0.1) |
| Walking velocity (cm/s) | 108.0 (17.2) | 115.8 (20.7) | 7.8 (−8.3, 23.9) |
| Norm walking velocity | 38.5 (7.3) | 40.6 (6.3) | 2.1 (−3.8, 8.0) |
| Cadence (steps/min) | 128.2 (45.8) | 118.6 (11.1) | −9.7 (−40.5, 21.2) |
| Norm cadence | 36.6 (11.8) | 34.3 (3.4) | 3.9 (−10.2, 5.8) |
CI: confidence interval; BW: body weight; ROM: range of motion; GC: gait cycle; Norm: dimensionless normalisation [28].