Abstract

Background: The isokinetic shoulder profile is commonly used to assess injury risk in overhead sports. CrossFit athletes are vulnerable to shoulder injuries due to high-load, high-repetition demands. This exploratory study aimed to evaluate the effects of a 6-week weighted jump rope (WJR) program on isokinetic shoulder performance. Methods: CrossFit athletes performed WJR sessions three times per week, integrated into their usual training. The program involved a progressive increase in total jumps per week. Isokinetic assessments of internal and external rotational peak torque and external rotation/internal rotation (ER/IR) ratios were conducted bilaterally at 60 degrees/s, 180 degrees/s, and 300 degrees/s. Paired t-tests and two-way analysis of variance (ANOVA) were used, with significance set at p < 0.05 and Cohen's d effect sizes calculated. Results: No significant changes were observed in rotational peak torque or ER/IR ratios across conditions. An exploratory sex-based difference was observed, with females showing a higher ER/IR ratio at 60 degrees/s. Discussion: No detectable changes were observed across isokinetic variables; however, the absence of a control group limits the interpretation of these preliminary findings. The sex-related difference observed at 60 degrees/s should be interpreted as an exploratory finding.