Shoulder rotator strength in judo athletes: A cross-sectional study with different experience levels

BACKGROUND: Judo practice requires high effort from athletes, mainly focused on the upper limbs, involving the shoulder complex. OBJECTIVE: To compare the shoulder internal (IR) and external (ER) rotation peak torque and conventional ratio (ER: IR) between judo athletes from different experience levels (novice vs. advanced) and to verify the distribution of athletes according to the ER: IR ratio classification. METHODS: Thirty-nine male judo athletes were divided into two groups (advanced: 20.5 ± 2.8 years and novice: 22.1 ± 5.5 years). The athletes performed a shoulder isokinetic protocol to measure IR and ER strength and the ER: IR ratio in novice and advanced groups. Chi-square tests were used to investigate the distribution of athletes according to the different groups of ER: IR ratio classification, and t-tests were used to compare the IR and ER peak torque and the ER: IR ratio between novice and advanced groups, with the level of significance set at 5%. RESULTS: The main results showed higher values of IR peak torque (77.3 ± 15.7 N⋅m in advanced vs. 48.2 ± 8.4 N⋅m in novices; p= 0.013), and a lower ER: IR conventional ratio in advanced athletes compared to novices (0.63 ± 0.1 advanced vs. 0.73± 0.2 in novice; p= 0.01). When individual values were analyzed, advanced athletes presented higher imbalance (< 0.66 ER: IR ratio) than novices (p= 0.023). CONCLUSION: Advanced athletes presented higher shoulder IR peak torque, but higher imbalance in the ER: IR ratio than novices, probably because the long-term training induced an increase in IR strength without concomitant development in ER strength. Coaches and strength and conditioning trainers should monitor shoulder rotator strength in judo athletes to avoid muscle imbalances in this region, which is frequently employed in judo training routines.