BACKGROUND: This study aimed to investigate the effect of the menstrual cycle on the coordination variability of the lower-limb joints during the taekwondo roundhouse kick in professional athletes. METHODS: Twenty professional taekwondo female athletes voluntarily participated in the study. The participants visited a laboratory thrice during their menstrual cycles' follicular, ovulation, and luteal phases. The lower-extremity kinematic data were collected during the roundhouse kick. Range of motion (ROM) and coordination variability of the lower-extremity joints in sagittal plane were calculated and compared for different menstrual cycles. FINDINGS: The results did not show significant differences in the ROM of the joints for the different menstrual cycles. Moreover, the results of a vector analysis using the repeated measures ANOVA did not show significant differences in joint coordination patterns and variability for different menstrual cycles. However, there were fluctuations in the coordination variability during the ovulation phase in the hip-ankle coupling, but this was not statistically significant. INTERPRETATION: The results suggest that female taekwondo players must be cautious of training during the ovulation phases of their menstrual cycles. However, more research is needed to better understand the effect of menstrual cycle on the coordination patterns of joints and segments.

• Keywords
• Coordination variability, Menstrual cycle, Roundhouse kick, Taekwondo,
• MeSH
• Biomechanical Phenomena MeSH
• Martial Arts * physiology   MeSH
• Lower Extremity * physiology   MeSH
• Adult MeSH
• Ankle Joint * physiology   MeSH
• Knee Joint * physiology   MeSH
• Hip Joint * physiology   MeSH
• Humans MeSH
• Menstrual Cycle * physiology   MeSH
• Young Adult MeSH
• Range of Motion, Articular * physiology   MeSH
• Athletes MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Oláh, V, Třebický, V, Maleček, J, Michalička, V, Wąsik, J, and Vágner, M. Is countermovement jump height and one repetition maximum back squat associated with the peak force of a front kick with and without carried load? J Strength Cond Res 39(8): 880-889, 2025-The front kick is a fundamental technique used in self-defense and hand to hand combat. This study aimed to test whether front kick performance, both with and without a 30-kg carried load, can be effectively estimated or tracked through commonly available testing procedures such as the countermovement jumps (CMJ) and one repetition maximum back squat (1RM BS). In 2 testing sessions, 21 male participants (mean age = 22.7 years, SD = 1.9) performed 1RM BS, 5 front kicks peak force (FK) without and with 30-kg carried load (FK30), and 3 CMJ without and with 30-kg carried load (CMJ30). A force plate measured the peak force ( N ) of the FK and FK30 and the height (cm) of the CMJ and CMJ30. Statistically significant correlations were found between CMJ and FK ( r = 0.55 [0.225-1], p = 0.005) and CMJ and 1RM BS ( r = 0.54 [0.219-1, p = 0.005]). Carried load reduced both CMJ height by 61% ( d = 3.35 [2.543-∞], p < 0.001) and FK peak force by 23% ( d = 1.33 [0.828-∞], p < 0.001), compared without load condition. A regression model using 1RM BS and CMJ explained 31.5% of FK variance, with only the height of CMJ being statistically significantly associated, β = 0.626, p = 0.015. The study demonstrates that although there is a relationship between explosive power and maximum strengths, FK is more related to CMJ height than 1RM BS. From a practical standpoint, the study suggests that explosive power shows a better association with the FK than the maximal strength. Thus, training programs focused on lower limb explosive power could allow athletes and military personnel to achieve higher FK. Combat sports trainers and hand-to-hand combat instructors may thus consider accordingly updating their training schemes, emphasizing plyometrics and other explosive training methods for enhancing the peak force of kicks.

• Keywords
• hand to hand combat, martial arts, performance, self-defense, strength, training,
• MeSH
• Biomechanical Phenomena MeSH
• Adult MeSH
• Muscle, Skeletal physiology   MeSH
• Humans MeSH
• Young Adult MeSH
• Resistance Training * methods   MeSH
• Movement physiology   MeSH
• Athletic Performance * physiology   MeSH
• Muscle Strength * physiology   MeSH
• Weight Lifting physiology   MeSH
• Weight-Bearing physiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Publication type
• Journal Article MeSH