Summary of MU adaptations of ACL injury compared with CTRLs
| RSI-low | RSI-high | |
| AvgFR | ||
| Quadriceps | ↓ | ↓↓ |
| Hamstrings | ↑ | ↑ |
| MUAP | ↓↓ | ↓ |
| Common drive | ↓ | ↓ |
| Total force contribution (AvgFR × MUAP) | ↓↓ | ↓ |
| ΔF | ↑ | ↑ |
ACL, anterior cruciate ligament; AvgFR, average firing rate; CTRLs, controls; MU, motor unit; MUAP, MU action potential; RSI, return to sport after injury; ΔF, delta frequency.