Investigation of the relationship between lower extremity strength and balance in the menstrual cycle in women athletes

Aim: The aim of this study is to examine isokinetic knee strength and balance in different phases of the menstrual cycle in female athletes. Material and Method: The subject group of the research consists of 21 female athletes between the ages of 18-25 from different sports branches. Isokinetic knee strength tests at different angular speeds (60°, 180° and 240°/sec) on the right and left lower extremity sides in the menstrual cycle, Y balance test, five different Functional Performance Tests (FPT) (single hop for distance (SH), triple hop for distance (TH), crossover triple hop for distance (CH), medial side triple hop for distance (MSTH), and medial rotation hop for distance (MRH)) and CSMI-TecnoBody PK-252 singlebile leg static and dynamic balance test were applied. Results: When the right and left sides were compared between the menstrual cycle phases, 60° 180° and 240°/sec knee forces, FPTs, limb symmetry indices (USI) obtained from FPTs, Hamstring/Quadriceps (H/Q) ratios and Y balance test no significance was found (p>0.05). In the static balance test, mean Center of Pressure X (COPX) was found to be significant between the right and left sides, but there was no significance between the phases (p>0.05). There was a significant difference between follicular phase and luteal phase in static balance one-leg Forward/Bacward Standard Deviation (FBSD), and between ovulation phase and luteal phase in Average Medium/Lateral Speed (AMLS) (p<0.05). Dynamic balance between follicular phase and ovulation phase in one leg Trunk Forward/Bacward Standard Deviation (TBFSD); there was also a difference between the ovulation phase and the luteal phase (p<0.05). Conclusion: When the results of our study were evaluated, it was observed that similar findings were observed between the phases on the right and left sides in isokinetic tests, FPTs, USIs, H/Q ratios and Y balance test. In the static and dynamic balance, single and double foot evaluations, significant differences in menstrual cycle phases showed that changes in female sex hormones may affect the balance. Keywords: Menstrual cycle, Functional performance tests, Isokinetic strength, Knee strength.