Table 8 Pooled and single study results for kinetic, kinematic and muscle activation variables at the knee
Variable | Preferred SR versus Increased SR | Preferred SR versus Reduced SR | |||
|---|---|---|---|---|---|
Kinetics | Peak patellar tendon force |  + 10% [36] | 0.68 (0.16, 1.21) |  − 10% [36] |  − 0.72 ( − 1.24,  − 0.19) |
| Â | Peak PFJ stress | 0.56 (0.07, 1.05) | Â | Â | |
|  | Peak PFJ reaction force |  + 10% [29] | 0.66 ( − 0.07, 1.40) |  |  |
|  | PFJS-time integral |  + 10% [33] | 0.65 ( − 0.01, 1.30) |  |  |
|  | PFJS-time integral/km |  + 10% [5] | 0.49 ( − 0.16, 1.14) |  |  |
|  | Peak knee extensor moment |  + 5% [49] | 0.17 ( − 0.25, 0.58) |  − 5% [49] |  − 0.33 ( − 0.75, 0.09) |
|  |  | 0.50 (0.18, 0.81) |  − 10% [49] |  − 0.33 ( − 0.75, 0.09) | |
|  | Negative knee work |  + 5% [49] |  − 0.51 ( − 0.93,  − 0.09) |  − 5% [49] | 0.50 (0.08, 0.91) |
|  |  |  − 0.84 ( − 1.20,  − 0.48) | 0.88 (0.52, 1.25) | ||
|  | Positive knee work |  + 5% [49] | 0.49 (0.07, 0.91) |  − 5% [49] |  − 0.21 ( − 0.62, 0.21) |
|  |  |  + 10% [49] | 0.75 (0.32, 1.18) |  − 10% [49] |  − 0.53 ( − 0.95,  − 0.10) |
|  | Average positive knee power (stance) |  + 8% [26] | 0.41 [ − 0.29, 1.11] |  − 8% [26] |  − 0.22 [ − 0.92, 0.47] |
|  |  |  + 15% [26] | 0.68 [ − 0.04, 1.39] |  − 15% [26] |  − 0.47 [ − 1.17, 0.24] |
|  | Average positive knee power (swing) |  + 8% [26] | 0.22 [ − 0.48, 0.91] |  − 8% [26] | 0.00 [ − 0.69, 0.69] |
|  |  |  + 15% [26] | 0.22 [ − 0.48, 0.91] |  − 15% [26] | 0.22 [ − 0.48, 0.91] |
|  | Eccentric knee work per stance |  + 7.5% (8 sessions) [40] | 1.02 (0.27, 1.76) |  |  |
|  |  |  + 7.5% (4 − weeks) [40] | 0.79 (0.07, 1.51) |  |  |
|  | Eccentric knee work per km |  + 7.5% (8 sessions) [40] | 0.02 ( − 0.68, 0.71) |  |  |
|  |  |  + 7.5% (4 − weeks) [40] | 0.57 ( − 0.14, 1.28) |  |  |
|  | Max knee flexion velocity during stance |  + 5% [45] | 0.28 ( − 0.61, 1.16) |  − 5% [45] |  − 0.28 ( − 1.17, 0.60) |
|  |  |  + 10% [45] | 0.67 ( − 0.24, 1.57) |  − 10% [45] |  − 0.92 ( − 1.86, 0.01) |
|  | VL muscle activity—stance 0–15% |  + 5% [32] | 0.18 ( − 0.24, 0.59) |  |  |
|  |  |  + 10% [32] | 0.17 ( − 0.25, 0.58) |  |  |
|  | VL muscle activity—swing 80–90% |  + 5% [32] |  − 0.44 ( − 0.86,  − 0.02) |  |  |
|  |  |  + 10% [32] |  − 0.43 ( − 0.85,  − 0.01) |  |  |
|  | VL muscle activity—swing 90–100% |  + 5% [32] | 0.12 ( − 0.30, 0.53) |  |  |
|  |  |  + 10% [32] | 0.11 ( − 0.30, 0.52) |  |  |
|  | RF muscle activity—stance 0–15% |  + 5% [32] | 0.09 ( − 0.32, 0.51) |  |  |
|  |  |  + 10% [32] | 0.00 ( − 0.41, 0.41) |  |  |
|  | RF muscle activity—stance 30–50%% |  + 5% [32] | 0.00 ( − 0.41, 0.41) |  |  |
|  |  |  + 10% [32] |  − 0.42 ( − 0.84, 0.00) |  |  |
|  | RF muscle activity—swing 80–90% |  + 5% [32] | 0.00 ( − 0.41, 0.41) |  |  |
|  |  |  + 10% [32] |  − 0.23 ( − 0.64, 0.18) |  |  |
|  | RF muscle activity—swing 90–100% |  + 5% [32] |  − 0.39 ( − 0.81, 0.03) |  |  |
|  |  |  + 10% [32] |  − 0.78 ( − 1.21,  − 0.35) |  |  |
|  | LHAMS muscle activity—stance 0–15% |  + 5% [32] | 0.00 ( − 0.41, 0.41) |  |  |
|  |  |  + 10% [32] |  − 0.15 ( − 0.56, 0.27) |  |  |
|  | LHAMS muscle activity—swing 70–80% |  + 5% [32] | 0.12 ( − 0.29, 0.54) |  |  |
|  |  |  + 10% [32] |  − 0.26,  − 0.68, 0.15) |  |  |
|  | LHAMS muscle activity—swing 80–90% |  + 5% [32] |  − 0.10 ( − 0.51, 0.31) |  |  |
|  |  |  + 10% [32] |  − 0.16 ( − 0.58, 0.25) |  |  |
|  | LHAMS muscle activity—swing 90–100% |  + 5% [32] |  − 0.10 ( − 0.52, 0.31) |  |  |
|  |  |  + 10% [32] | 0.00 ( − 0.41, 0.41) |  |  |
|  | MHAMS muscle activity—stance 0–15% |  + 5% [32] |  − 0.22 ( − 0.63, 0.20) |  |  |
|  |  |  + 10% [32] |  − 0.20 ( − 0.61, 0.22) |  |  |
|  | MHAMS muscle activity—swing 70–80% |  + 5% [32] |  − 0.12 ( − 0.54, 0.29) |  |  |
|  |  |  + 10% [32] |  − 0.40 ( − 0.81, 0.02) |  |  |
|  | MHAMS muscle activity—swing 80–90% |  + 5% [32] | 0.09 ( − 0.33, 0.50) |  |  |
|  |  |  + 10% [32] |  − 0.08 ( − 0.49, 0.34) |  |  |
|  | MHAMS muscle activity—swing 90–100% |  + 5% [32] |  − 0.20 ( − 0.61, 0.22) |  |  |
|  |  |  + 10% [32] |  − 0.10 ( − 0.52, 0.31) |  |  |
|  | BF positive work |  + 10% [51] | 0.00 ( − 0.51, 0.51) |  − 10% [51] | 0.06 ( − 0.44, 0.57) |
|  | BF negative work |  + 10% [51] | 0.25 ( − 0.26, 0.75) |  − 10% [51] |  − 0.07 ( − 0.57, 0.44) |
|  | SMEM positive work |  + 10% [51] | 0.00 ( − 0.51, 0.51) |  − 10% [51] |  − 0.27 ( − 0.78, 0.23) |
|  | SMEM negative work |  + 10% [51] | 0.44 ( − 0.07, 0.95 |  − 10% [51] |  − 0.24 ( − 0.75, 0.27) |
|  | RF positive work |  + 10% [51] | 0.29 ( − 0.22, 0.80) |  − 10% [51] |  − 0.22 ( − 0.73, 0.29) |
|  | RF negative work |  + 10% [51] |  − 0.12 ( − 0.62, 0.39) |  − 10% [51] | 0.22 ( − 0.29, 0.73) |
|  | Hamstring peak force |  + 10% [30] | 0.06 ( − 0.57, 0.70) |  − 10% [30] |  − 1.28 ( − 1.98,  − 0.57) |
|  | Hamstring impulse |  + 10% [30] | 0.28 ( − 0.36, 0.92) |  − 10% [30] |  − 0.24 ( − 0.88, 0.39) |
|  | Hamstring impulse/km |  + 10% [30] | 0.00 ( − 0.64, 0.64) |  − 10% [30] |  − 0.11 ( − 0.74, 0.53) |
|  | Quadriceps peak force |  + 10% [30] | 1.87 (1.09, 2.64) |  − 10% [30] |  − 1.82 ( − 2.59,  − 1.05) |
|  | Quadriceps impulse |  + 10% [30] | 0.71 (0.05, 1.37) |  − 10% [30] |  − 0.89 ( − 1.56,  − 0.22) |
|  | Quadriceps impulse/km |  + 10% [30] | 0.31 ( − 0.33, 0.95) |  − 10% [30] |  − 0.46 ( − 1.10, 0.19) |
|  | Peak VL muscle force |  + 10% [36] | 0.76 (0.24, 1.29) |  − 10% [36] |  − 0.81 ( − 1.34,  − 0.28) |
|  | Peak RF muscle force |  + 10% [36] |  − 0.21 ( − 0.72, 0.30) |  − 10% [36] | 0.44 ( − 0.08, 0.95) |
|  | Peak BF muscle force |  + 10% [36] | 0.00 ( − 0.51, 0.51) |  − 10% [36] | 0.56 (0.05, 1.08) |
|  | Peak SMEM muscle force |  + 10% [36] |  − 0.20 ( − 0.71, 0.31) |  − 10% [36] | 0.59 (0.07, 1.11) |
|  | Peak BF muscle force—stance |  + 10% [50] |  − 0.24 ( − 0.75, 0.27) |  − 10% [50] | 0.18 ( − 0.33, 0.68) |
|  | Peak BF muscle force—late swing |  + 10% [50] |  − 0.06 ( − 0.57, 0.44) |  − 10% [50] | 0.53 (0.02, 1.05) |
|  | Peak SMEM muscle force—stance |  + 10% [50] |  − 0.27 ( − 0.78, 0.24) |  − 10% [50] | 0.20 ( − 0.31, 0.71) |
|  | Peak SMEM muscle force—late swing |  + 10% [51] |  − 0.19 ( − 0.70, 0.32) |  − 10% [51] | 0.60 (0.08, 1.12) |
|  | Peak RF muscle force—stance |  + 10% [51] | 0.37 ( − 0.14, 0.88) |  − 10% [51] |  − 0.36 ( − 0.87, 0.15) |
|  | Peak RF muscle force—early swing |  + 10% [51] |  − 0.68 ( − 1.20,  − 0.15) |  − 10% [51] | 0.47 ( − 0.04, 0.98) |
Kinematics | Peak knee flexion angle |  + 5% [49] | 0.47 (0.05, 0.89) |  − 5% [49] |  − 0.37 ( − 0.78, 0.05) |
|  |  |  + 7.5% (at 12 weeks) [38] | 0.39 ( − 0.42, 1.20) |  |  |
|  |  | 0.66 (0.40, 0.92) |  − 10% [49] |  − 0.92 ( − 1.35,  − 0.48) | |
|  |  |  + 10% (at 4 − weeks) [23] | 0.91 (0.06, 1.76) |  |  |
|  |  |  + 10% (at 12 − weeks) [23] | 0.60 ( − 0.22, 1.43) |  |  |
|  | Peak knee flexion % of GC |  + 10% [47] |  − 0.44 ( − 1.33, 0.45) |  |  |
|  | Knee flexion excursion |  + 10% [47] | 1.67 (0.62, 2.73) |  |  |
|  | Average knee ADD/ABD at IC |  + 10% [34] |  − 0.10 ( − 0.60, 0.40) |  |  |
|  | Average knee ADD/ABD during stance phase |  + 10% [34] |  − 0.06 ( − 0.56, 0.44) |  |  |
|  | Peak knee ADD/ABD during stance phase |  + 10% [34] | 0.17 ( − 0.33, 0.66) |  |  |
|  | Average knee ER at IC |  + 10% [34] |  − 0.11 ( − 0.61, 0.39) |  |  |
|  | Average knee ER during stance phase |  + 10% [34] |  − 0.03 ( − 0.53, 0.46) |  |  |
|  | Peak knee ER during stance phase |  + 10% [34] |  − 0.09 ( − 0.59, 0.41) |  |  |
|  | Peak knee IR angle |  + 10% [46] |  − 0.14 ( − 1.02, 0.73) |  |  |
|  | Peak knee IR % of GC |  + 10% [47] |  − 0.29 ( − 1.17, 0.59) |  |  |
|  | Average knee flexion at IC |  − 0.19 ( − 0.57, 0.18) | 0.15 ( − 0.22, 0.53) | ||
|  |  |  − 0.23 ( − 0.53, 0.07) | 0.18 ( − 0.20, 0.55) | ||
|  | Average knee flexion during stance phase |  + 10% [34] | 0.28 ( − 0.22, 0.78) |  |  |