Knee Alignment And Muscle Strength Ratios In Division III Female Soccer Players With Reconstructed Anterior Cruciate Ligament

Abstract

INTRO: Anterior cruciate ligament tears are very common in sports that require contact, hard landing from jumps, or cutting, like soccer. Analyzing an athlete’s knee valgus and muscle strength ratios may help reduce their risk for injury. OBJECTIVE: To compare knee valgus angles and the hamstring to quadriceps femoris strength ratio between healthy female Division III soccer athletes and athletes with ACL reconstruction, as surrogates for knee (re)injury risk. METHODS: Thirteen non-injured and three injured athletes completed a vertical drop jump (VDJ) from a 31 cm box and 1 Repetition Maximum tests (1RM) using seated knee curl and seated knee extension machines. Baseline and landing knee valgus angles (KVA) were measured using Dartfish software. RESULTS: There was a significant difference in quadriceps to hamstring ratio between injured and non-injured athletes (p=0.03), with injured individuals having an average ratio of 0.89 and non-injured 0.71. No significant difference was found in KVA from VDJ between injured and non-injured subjects (p=0.87). No significant relationship was found between KVA and quadriceps to hamstring ratios. CONCLUSION: There are significant differences in hamstring to quadriceps strength ratios in injured female DIII soccer players compared to non-injured, suggesting it is a better screening than VDJ. KVA cannot be predicted by quadriceps to hamstring ratio and injury history.