Muscle synergy and performance characteristics during regular jump shooting in basketball players of different skill levels: a non-negative matrix factorization analysis.

Objective: This study aimed to compare shooting success probability, muscle activation, and muscle synergy characteristics during regular jump shots between Elite and Recreational basketball players under different shooting-distance conditions. Methods: Twenty-four male basketball players were classified into Elite and Recreational groups based on their pre-existing basketball expertise, competitive experience, and training background. Mid-range and long-range regular jump shots were assessed using synchronized surface electromyography and high-speed video. Electromyographic signals were recorded using a Delsys Trigno Wireless EMG System, and movement events were captured using a Photron FASTCAM Mini AX200 camera with TTL synchronization. The analysis window was defined from knee-flexion onset to ball release. Muscle activation was quantified using MVC-normalized root mean square (RMS), and muscle synergies were extracted using non-negative matrix factorization. Shooting success was analyzed using a binomial generalized linear mixed model, with group, shooting distance, and their interaction included as fixed effects and participant identity included as a random effect. RMS and muscle synergy variables were compared between groups using independent-samples t-tests with Benjamini-Hochberg false discovery rate (FDR) correction. Results: The binomial generalized linear mixed model revealed that Elite players had a higher probability of successful shots than Recreational players (OR = 4.63, 95% CI: 3.21-6.67, P < 0.001). Long-range shooting significantly reduced shooting success probability compared with mid-range shooting (OR = 0.38, 95% CI: 0.27-0.53, P < 0.001), while the Group × Distance interaction was not significant (OR = 0.71, 95% CI: 0.43-1.17, P = 0.184). After FDR correction, Elite players showed lower RA activation and higher VL and MG activation during mid-range shooting. During long-range shooting, Elite players exhibited lower AD and TB activation and higher VL activation. Muscle synergy differences were mainly reflected in muscle weight distribution, involving VL and BF during mid-range shooting and VL, BF, AD, and RA during long-range shooting. No significant group differences were observed in synergy activation duration or time to peak activation. Conclusion: Elite basketball players demonstrated higher shooting success probability and distinct neuromuscular control strategies during regular jump shots. These differences were characterized by altered activation patterns of RA, VL, MG, AD, and TB, together with modified muscle weight contributions within synergy modules. These findings provide biomechanical evidence for understanding skill-related differences in regular jump-shot performance and may inform targeted basketball shooting training strategies.