Figure 1
Overview of the musculoskeletal model and experimental procedures: (a) marker placement on the musculoskeletal model, (b) bilateral jump-landing task, and (c) fatigue protocol.
Table 1
Fatigue-protocol outcomes in children and adults
| Variables | Child | Adult | P value |
|---|---|---|---|
| Completed cycles (N) | 3.42 ± 0.51 | 3.17 ± 0.39 | 0.192 |
| Total number of jumps (N) | 136.7 ± 20.6 | 126.7 ± 15.6 | 0.195 |
| Total duration of fatigue protocol (min) | 5.05 ± 0.65 | 4.86 ± 0.58 | 0.458 |
| Final heart rate (bpm) | 193.5 ± 5.2 | 184.6 ± 4.6 | < 0.001 |
| Final OMNI-RPE | 8.4 ± 0.5 | 8.6 ± 0.5 | 0.338 |
| Decline in jump height (%) | 23.8 ± 3.5 | 25.1 ± 3.8 | 0.393 |
| Interval before post-fatigue testing (s) | 10.6 ± 2.3 | 10.2 ± 2.0 | 0.654 |
Note. Values are mean ± standard deviation. OMNI-RPE, OMNI Rating of Perceived Exertion; post-fatigue testing interval, time from fatigue termination to post-fatigue testing.
Table 2
Countermovement-jump performance before and after fatigue in children and adults
| Variables | Child | Adult | P value | ||||
|---|---|---|---|---|---|---|---|
| Pre | Post | Pre | Post | Group | Fatigue | Interaction | |
| CMJ height (cm) | 24.41 ± 6.27 | 20.85 ± 5.70 | 38.47 ± 8.44 | 32.75 ± 7.25 | 0.002 | < 0.001 | 0.742 |
| Flight time (s) | 0.446 ± 0.058 | 0.412 ± 0.056 | 0.560 ± 0.061 | 0.517 ± 0.057 | < 0.001 | < 0.001 | 0.684 |
| Take-off velocity (m/s) | 2.18 ± 0.29 | 2.02 ± 0.28 | 2.74 ± 0.31 | 2.54 ± 0.29 | < 0.001 | < 0.001 | 0.706 |
Note. Values are mean ± standard deviation.
Figure 2
Landing-phase kinematic changes before and after jump-induced fatigue in children and adults: (a) subtalar frontal-plane angle, (b) ankle sagittal-plane angle, (c) knee sagittal-plane angle, (d) hip frontal-plane angle, and (e) hip sagittal-plane angle. Upper plots show mean ± standard deviation waveforms, and lower plots show SPM results; shaded regions indicate significant clusters.
Figure 3
Landing-phase kinetic changes before and after jump-induced fatigue in children and adults: (a) subtalar frontal-plane moment, (b) ankle sagittal-plane moment, (c) knee sagittal-plane moment, (d) hip frontal-plane moment, and (e) hip sagittal-plane moment. Upper plots show mean ± standard deviation waveforms, lower plots show SPM results, and shaded regions indicate significant clusters.
Figure 4
Peak joint angles before and after jump-induced fatigue in children and adults: (a) subtalar frontal-plane angle, (b) ankle sagittal-plane angle, (c) knee sagittal-plane angle, (d) hip sagittal-plane angle, and (e) hip frontal-plane angle. Values are mean ± standard deviation.
Figure 5
Initial-contact joint angles before and after jump-induced fatigue in children and adults: (a) subtalar frontal-plane angle, (b) ankle sagittal-plane angle, (c) knee sagittal-plane angle, (d) hip sagittal-plane angle, and (e) hip frontal-plane angle. Values are mean ± standard deviation.
Figure 6
Peak kinetic variables before and after jump-induced fatigue in children and adults: (a) subtalar frontal-plane moment, (b) ankle sagittal-plane moment, (c) knee sagittal-plane moment, (d) hip sagittal-plane moment, (e) hip frontal-plane moment, and (f) vertical ground reaction force (vGRF). Values are mean ± standard deviation.