Comparison between groups during the propulsive and landing phases of the single leg drop jump
| Involved | Uninvolved | Controls | Involved-uninvolved | Involved-controls | Uninvolved-controls | |||||||
| P value | d | Mean difference (95% CIs) | P value | d | Mean difference (95% CIs) | P value | d | Mean difference (95% CIs) | ||||
| Jump height (cm) | 10.6±3.4 | 13.8±3.5 | 14.4±3.1 | <0.001 | 0.92 | −3.2 (−4.0 to −2.3) | 0.001 | 1.12 | −3.7 (−6.1 to −1.4) | 0.84 | −0.6 (−2.9 to 1.8) | |
| RSI (jump height/contact time) (cm/s) | 0.30±0.10 | 0.43±0.12 | 0.43±0.12 | <0.001 | 1.18 | −0.1 (−0.2 to −0.1) | 0.001 | 1.16 | −0.1 (−0.2 to −0.1) | 0.98 | −0.01 (−0.1 to 0.1) | |
| RSR (flight time/contact time) | 0.93±0.17 | 1.10±0.19 | 1.09±0.24 | <0.001 | 0.94 | −0.2 (−0.2 to 0.1) | 0.042 | 0.76 | −0.2 (−0.3 to −0.0) | 0.98 | 0.01 (−0.1 to 0.2) | |
| Contact time (s) | 0.36±0.05 | 0.33±0.05 | 0.35±0.06 | <0.001 | 0.60 | 0.02 (0.01 to 0.04) | 0.79 | 0.01 (−0.03 to 0.1) | 0.64 | −0.01 (−0.1 to 0.02) | ||
| Peak joint motion (°) | ||||||||||||
| Hip flexion | 61.5±12.5 | 54.1±10.8 | 54.0±11.6 | <0.001 | 0.63 | 7.4 (4.3 to 10.5) | 0.09 | 7.5 (−0.9 to 15.8) | 1.00 | 0.1 (−8.3 to 8.4) | ||
| Knee flexion | 59.0±7.9 | 61.8±6.7 | 60.5±7.5 | 0.026 | 0.38 | −2.8 (−5.3 to −0.3) | 0.79 | −1.5 (−6.8 to 3.9) | 0.81 | 1.4 (−4.0 to 6.7) | ||
| Ankle dorsiflexion | 22.9±3.1 | 24.4±2.4 | 23.9±4.0 | 0.001 | 0.54 | −1.5 (−2.7 to −0.3) | 0.88 | −0.5 (−3.0 to 2.0) | 0.60 | 1.0 (−1.5 to 3.5) | ||
| Trunk flexion | 27.8±8.4 | 20.7±8.1 | 21.1±9.1 | <0.001 | 0.87 | 7.1 (4.9 to 9.4) | 0.031 | 0.75 | 6.7 (0.5 to 12.9) | 0.98 | −0.4 (−6.6 to 5.8) | |
| Anterior pelvic tilt | 30.9±7.8 | 24.4±6.8 | 25.0±7.5 | <0.001 | 0.89 | 6.5 (4.1 to 8.9) | 0.028 | 0.75 | 5.9 (0.6 to 11.2) | 0.95 | −0.6 (−5.9 to 4.7) | |
| Joint moments (Nm/kg) | ||||||||||||
| Hip flexion | −3.7±0.5 | −3.1±0.6 | −3.2±0.6 | <0.001 | 0.95 | −0.5 (−0.8 to −0.2) | 0.028 | 0.81 | −0.5 (−0.9 to −0.04) | 0.94 | 0.1 (−0.4 to 0.5) | |
| Knee flexion | −3.0±0.5 | −3.8±0.6 | −3.2±0.6 | <0.001 | 1.44 | 0.8 (0.5 to 1.1) | 0.21 | 0.3 (−0.1 to −0.7) | 0.008 | 0.88 | −0.5 (−0.9 to 0.1) | |
| Ankle dorsiflexion | −2.8±0.5 | −2.9±0.5 | −2.9±0.5 | 0.2 (−0.01 to 0.3) | 0.73 | 0.1 (−0.3 to 0.5) | 0.93 | −0.1 (−0.4 to 0.3) | ||||
| Work absorption (J/kg) | ||||||||||||
| Hip | −0.9±0.3 | −0.7±0.2 | −0.7±0.2 | 0.003 | 0.84 | −0.2 (−0.4 to −0.1) | 0.017 | 0.86 | −0.2 (−0.4 to −0.03) | 0.97 | 0.02 (−0.2 to 0.2) | |
| Knee | −0.9±0.3 | −1.1±0.3 | −1.1±0.3 | <0.001 | 0.80 | 0.2 (0.1 to 0.3) | 0.21 | 0.2 (−0.1 to 0.4) | 0.79 | −0.1 (−0.3 to 0.2) | ||
| Ankle | −0.9±0.2 | −1.1±0.3 | −1.2±0.4 | 0.022 | 0.56 | 0.1 (0.02 to 0.3) | 0.014 | 0.85 | 0.3 (0.1 to 0.6) | 0.26 | 0.2 (−0.1 to 0.4) | |
| Total | −2.7±0.5 | −2.9±0.4 | −3.0±0.5 | 0.16 | 0.1 (−0.04 to 0.3) | 0.17 | 0.3 (−0.1 to 0.6) | 0.68 | 0.1 (−0.2 to 0.5) | |||
| Work generation (J/kg) | ||||||||||||
| Hip | 1.1±0.3 | 0.8±0.3 | 0.8±0.2 | <0.001 | 0.87 | 0.2 (0.1 to 0.4) | 0.015 | 0.95 | 0.2 (0.04 to 0.4) | 0.96 | −0.02 (−0.2 to 0.2) | |
| Knee | 1.0±0.3 | 1.5±0.3 | 1.3±0.3 | <0.001 | 1.54 | −0.4 (−0.6 to −0.3) | 0.002 | 1.05 | −0.3 (−0.5 to −0.1) | 0.24 | 0.1 (−0.1 to 0.3) | |
| Ankle | 1.4±0.4 | 1.5±0.3 | 1.5±0.4 | <0.001 | 0.50 | −0.2 (−0.3 to −0.1) | 0.25 | −0.2 (−0.4 to 0.1) | 1.00 | 0.0 (−0.3 to 0.3) | ||
| Total | 3.4±0.6 | 3.8±0.6 | 3.7±0.5 | <0.001 | 0.59 | −0.4 (−0.6 to −0.2) | 0.31 | 0.3 (−0.7 to 0.2) | 0.80 | 0.1 (−0.3 to 0.5) | ||
For the ACLR athletes, data are presented for both the reconstructed (‘involved’) and contralateral (‘uninvolved’) leg along with one (randomly selected) leg of the control subjects (‘controls’) as mean±SD. The between group comparisons show p values, non-standarised mean differences and 95% CIs and effect sizes (d) only where p<0.05. Bold indicates statistically significant differences and their respective effect sizes.
ACLR, anterior cruciate ligament reconstruction; RSI, Reactive Strength Index; RSR, reactive strength ratio.