Brief summary, from the abstract
After a traumatic sport-related knee injury, young athletes show marked thigh muscle weakness in the injured leg that is worst early on, improves over the first year, then largely plateaus, leaving a roughly 10% to 11% strength gap at 24 months. The pattern looked similar regardless of injury type or sex.
- Prospective cohort following 186 youth (106 injured, 80 uninjured controls) with isokinetic knee strength tested every 6 months for 2 years.
- Injured-limb knee extensor strength was lowest at baseline (-37.1 Nm; 95% CI, -45.3 to -28.9) and still down at 6 months (-13.3 Nm; 95% CI, -20.4 to -6.2), with little further gain after 12 months (1.7 Nm; 95% CI, -14.3 to 17.6).
- Knee flexor strength was lowest at baseline (-24.6 Nm; 95% CI, -31.5 to -17.8); a residual deficit of about 10% to 11% remained for both muscle groups at 24 months.
- Exploratory analysis found no clear difference by injury type (ACL versus non-ACL) or by sex, though these subgroup comparisons were not the main, fully-powered analysis.
Clinically assessing this area? See the knee special tests.