Abstract
BACKGROUND: Current research relates jaw clenching to athletic performance, in terms of force and agility. However, the impact of jaw clenching on sports accuracy is unclear. OBJECTIVES: To analyse the impact of jaw position and chewing type on free-throw accuracy and electromyographic (EMG) activity of masticatory muscles during free-throws. METHODS: Cross-sectional study with 25 female basketball players aged 18-44. Each participant executed 18 free-throws under three different jaw conditions: mandibular rest, maximum intercuspation, and with interdental cotton rolls, in randomised order. RESULTS: Chewing type and jaw position were not associated with shooting accuracy (p = 0.106; p = 0.778). There was a positive correlation between EMG activity of the right masseter and free-throw accuracy at maximum intercuspation (r(s) = 0.402; p = 0.046). In contrast, negative correlations were found with other muscles when the occlusal vertical dimension was altered (r(s) = -0.619, p = 0.001; r(s) = -0.490; p = 0.013; r(s) = -0.534; p = 0.006). The chewing type affected the EMG of the left masseter in the altered occlusal vertical dimension (H = 6.969; p = 0.031). Significant differences in EMG recordings were observed across different mandibular positions during free-throws (p < 0.001). CONCLUSIONS: While jaw positioning and chewing type do not impact free-throw accuracy in amateur female basketball players, the EMG activity of masticatory muscles is linked to shooting performance. This highlights the need for further research on motor behaviour of masticatory muscles in precision sports, especially for athletes using intraoral devices.