Isokinetic Hamstrings-to-Quadriceps Peak Torque Ratio in Combat Sports: A Systematic Review and Meta-analysis

Combat sports are very demanding in terms of physical fitness as well as the risk of injury. Elite athletes during daily training due to specific movements can develop significant muscle asymmetry that can affect injury. The aim of this study was to systematically review the existing literature with respect to total average value of hamstrings- to-quadriceps (H/Q) 60°·s-1 and H/Q 180°·s-1 in judo, karate, taekwondo and wrestling. We placed special emphasis on sex-based differences and possible asymmetries between legs in terms of isokinetic performance. This document was developed and reported in accordance with the Guidelines for Preferred Reports for Systematic Reviews and Meta-Analyzes (PRISMA). Web of Science, PubMed and Google Scholar were searched for the relevant studies. Studies were included in the review if they were original and written in English and had to have H/Q ratio measured as an outcome. In total, data from 243 athletes from eleven studies included studies was analysed. The Mean of H/Q 60°·s-1 for all sports were: 58.33% for the right leg and 58.91% for the left leg. Women had higher values: 59.38% vs. 57.42% for the right leg and 61.35% vs. 56.56% for the left leg. The Mean of H/Q 180°·s-1 for all sports were: 71.44% for the right leg and 71.35% for the left leg. Women had higher values: 75.76% vs. 69.04% for the right leg and 73.39% vs. 70.33% for the left leg. All these values, combined for all sports, and divided into subgroups according to gender, show that they are within the recommended values. Combined results for all included studies showed that there was no asymmetry between the left and right leg. According to the results of the balance of the mentioned agonists and antagonists, which are crucial for knee joint stabilization during dynamic muscle contractions, we can conclude that athletes in combat sports do not represent a risk group.