Neuromuscular fatigue effects on Hamstring to Quadriceps Ratio in young female players

Abstract

Abstract Introduction Two of the main modifiable risk factors for suffering an injury in the anterior cruciate ligament are known to be the Hamstring-to-Quadriceps (H/Q) Ratio and neuromuscular fatigue. The main purpose of this research was to study the effect of neuromuscular fatigue on the H/Q Ratio and the maximum isometric strength of the quadriceps and hamstrings in teenage female basketball and handball players. Material and methods This is an experimental, pre-post intervention study with a sample of 19 female basketball players and 11 female handball players (17.02 ± 1.19 yo, 177.8 ± 7.2 cm and 68.6 ± 9.3 kg). To assess muscle strength, a maximum isometric strength test was performed in a 90° hip and 60° knee position. The H/Q Ratio was then calculated. The 30–15 Intermittent Fatigue Test (30–15 IFT) was used to induce fatigue, measured using the Rating of Perceived Exertion (RPE) scale. A descriptive analysis and a Student's t-test were performed to study the differences in the H/Q Ratio, muscle strength and pre-post intervention fatigue. Results Although the H/Q Ratio decreased after the 30–15 IFT, the differences were not statistically significant. Regarding strength values, the right and left quadriceps presented strength reductions of 4.52% and 5.55%, respectively. The reduction in strength was statistically significant (p ≤ 0.05), especially in the right hamstring (7.3%) and in the left hamstring (7.5%). The study conclusions suggest that leg muscular strength decreases after a fatigue test and that there is a tendency for the H/Q Ratio to decrease also.