Surface Electromyographic Muscle Activity Patterns of the Upper Limb During the Twisted-Grip Handspring in Pole Dancing – A Case Study / Wei Ling Koh (2025)

Introduction: Recent development of pole dance had seen an increased focus on its athletism, and 1.56 – 2.1 injuries experienced per dancer. The twisted-grip handspring (TGH) may be associated with acute injuries due to the involvement of a twisted shoulder position and dynamic loading of the shoulder through rapid inversion while only relying on hand contact on the pole. Current resources from professionals suggest that the TGH can be safely executed if the shoulder joint is sufficiently supported by musculature. However, physical demands of the TGH, especially at the top arm, had not been researched. Therefore, this study sought to investigate muscle activation patterns of the top shoulder during performance of TGH, using surface electromyography (SEMG), and establish the preliminary physical profile of the pole dancers performing the TGH. Methods: An observational pilot case study of three advanced-elite pole dancers, with a mean age 32.34 years and 7 to 13 years of pole experience, who were able to confidently execute the TGH bilaterally and hold the end position (ayesha) was conducted. Shoulder active range of motion (AROM), shoulder maximum voluntary isometric (MVIC), shoulder joint mobility, and grip strength were assessed to establish the physical profile of the participants. SEMG activity of the latissimus dorsi, biceps brachii, and infraspinatus of the top arm were measured during the TGH and normalised using root mean square and their respective MVIC contraction to obtain peak and mean muscle activity. Results: SEMG muscle activity was observed to be greatest during entry, followed by exit, then holding phase. There was an emergence of a biceps- and latissimus dorsi-dominant movement strategy. Physical characteristics varied across participants. Shoulder abduction, extension and internal rotation AROM of participants were lower than, but grip and shoulder strength were similar or greater than circus acrobats. Lateral differences including grip asymmetry of 3.18% – 11.39% was observed. Conclusion: This study shed light on the physical demands of the TGH and highlighted clinical considerations for healthcare professionals working with pole dancers. Key points: • Screening for adequate shoulder extension, abduction, and internal rotation AROM may not be sufficient for performance of the TGH. • There were two movement strategies identified, which could be associated with increased injury risk or an adaptation post-injury but further research is warranted. • Assessment of biceps to latissimus dorsi relative strength, grip strength, and history of shoulder injury could provide healthcare professionals with information on the motor control of the top arm during the TGH.