Effects of static stretching applied to antagonist muscles on lower extremity power output in female volleyball players

The aim of this study was to investigate the difference between peak power output (PPO) obtained during loaded jump squat exercise after static stretching applied to antagonist muscles and after dynamic stretching applied to all active muscles. 21 female volleyball players (age: 23,955,04 years, height: 181,907,54 cm, mass: 70,968,38 kg) competing at the elite level participated in this study. Measurements related to the study were performed in four separate days. In the first day, anthropometric tests were performed and 1 repetition maximum (1RM) loads (117,6222,62 kg) were assessed. In the second day, familiarization session was held to adapt participants to test conditions. In the third and fourth day loaded squat jump tests were performed using force platform (FP). In the third day, participants randomly divided into two groups: 1) only static stretching to antagonist group (SSAG), 2) dynamic stretching to all active muscles group (DSG). Passive static stretching applied to antagonists (hip flexor, knee flexor and dorsi flexor) was performed by a professional physiotherapist as 3  30 s for each muscle group at pain threshold. PPO was assessed using 3 different loads (%20, %40, %60 1RM). Each participant performed two repetitions with each load and inter repetition rest interval was 2 minutes. In the fourth day, participants changed groups and performed the same test protocol. Pairwise comparisons between PPO obtained at different loads after dynamic stretching showed that there were statistically significant difference between 20% and 60% (p=0,013) and 40% and 60% (p=0,017). Magnitudes of PPO at the related loads were assessed as 20%>40%>60%. Pairwise comparisons between PPO obtained at different loads after antagonist stretching showed that there were statistically significant difference between 20% and 60% (p=0,028) and 40% and 60% (p=0,010). Magnitudes of PPO at the related loads were assessed as 40%>20%>60%. When the PPOs at the same loads were compared between DSG and SSAG, PPO obtained at %20 1RM in DSG was statistically greater than PPO in SSAG (p=0,032). No significant difference was found in PPO at other loads. According to these results, when the lower body peak power performance of elite female volleyball players was considered, SSAG statistically impaired PPO relative to DSG at 20% 1RM and had no statistically beneficial effect on PPO at higher loads (40%, 60%1 RM) relative to DSG. Keywords: volleyball; static stretching; power; antagonist; co-activation; triple extension