Hamstring-to-Quadriceps Strength Ratios in Women Team Sport Athletes: A Systematic Review

Women experience a higher rate of anterior cruciate ligament (ACL) injuries than men. Muscle imbalance, in particular hamstring-to-quadriceps (H:Q) strength ratio, is considered a risk factor for ACL injury. The purpose of this systematic review was to identify isokinetic H:Q strength ratios in women team sport athletes and determine whether cutoff values, determined from research with predominantly males, of >0.6 for conventional ratio (Hamstringconcentric:Quadricepsconcentric [CR]) and >1.0 for functional ratio (Hamstringeccentric:Quadricepsconcentric [FR]) were met. The CR (0.6) was not met for team ([mean +/- SD: 0.56 +/- 0.08]), field (0.57 +/- 0.08), and court (0.56 +/- 0.08) sports. Handball presented the highest (0.58 +/- 0.07), and softball presented the lowest CRs (0.47 +/- 0.06). The FR (1.0) was not met for team (0.69 +/- 0.14), field (0.85 +/- 0.14), and court (0.65 +/- 0.14) sports. Soccer presented the highest (0.85 +/- 0.14) and handball the lowest (0.66 +/- 0.13) FRs. When assessing hamstring and quadriceps strength balance, women team sport athletes did not meet CR or FR values, which may contribute to increased ACL injury risk. H:Q ratios below cutoff values may indicate compromised hamstring strength. It is recommended practitioners implement strength exercises aimed to improve H:Q ratios.