# Neuromuscular Assessment of a Stand-Up Paddle Stroke
## 4 Discussion
Previous research analyzing the front crawl stroke in swimming using EMG has suggested that the scapular rotators are active throughout the paddling stroke, with the greatest activity occurring during the entry and exit phases and the lowest during the propulsive phase [36; 37]. In the present study, it was found that the upper trapezius musclehad higher activity during the recovery phase and its behavior varied depending on the padding side. Specifically, when padding on the left side, the upper trapezius exhibited higher activity in the opposite arm, while when padding on the right side, the upper trapezius showed higher activity in the adjacent arm; this could be due to the fact that all of the participants were right-handed. The tibialis anterior, during the pull phase, had higher muscle activation than the gastrocnemius medialis in the lower limbs, which contrasts with [PERSON] et al. [9] findings that the gastrocnemius medialis was more activated in the standing position and during the pull phase, with the tibialis anterior reacting to the instability of the SUP board. When analyzing the upper and lower limbs together, it appears that the lower limbs act as stabilizers, helping to balance the board during the pull phase, while the upper limbs act as propulsors. This suggests that the lower limbs may be more activated during the pull phase due to their role in stabilizing the movement of the upper limbs and the board. Significant differences were observed in the muscle activation of all upper limb muscles during the pull and recovery phases of the padding stroke, as well as in the tibialis anterior muscle of the lower limb on the opposite side (right paddling side), indicating that the muscles on the opposite side play an important role during the paddling cycle, as mentioned by [PERSON] et al. [24]. This could be attributed to the compensatory mechanism of the opposite side to control the oscillations and wobbling of the SUP board, as previously reported by [PERSON] et al. [5]. Several limitations need to be acknowledged in this study. Firstly, the number of stroke cycles analyzed was relatively small, which may limit the generalizability of the findings. Future studies with a larger number of stroke cycles may provide a more comprehensive understanding of the impact of fatigue on padding mechanics. Secondly, this study did not analyze the role of core muscles in the paddling stroke cycle, which can be an important factor in the development of fatigue. Incorporating core muscle analysis into future studies may provide a more holistic view of the effects of fatigue on padding mechanics. Finally, the sample population consisted of recreational paddleboarders, which may not reflect the experiences of more experienced paddleboarders. It would be beneficial to recreate this study with a more diverse sample, including both experienced and inexperienced paddleboarders to better understand the impact of fatigue on paddling mechanics at different levels of expertise. A better understanding of the role of upper and lower body muscles during the paddling stroke can be valuable for paddleboarders looking to improve their conditioning and technique. The findings of this study suggest that training programs should be designed considering that stimulation of opposite and adjacent muscles depends on the side of the paddling stroke and stroke phases. Taking into account that the development of force applied in the propulsive and recovery phases can improve muscle recruitment, coaches and athletes should consider the importance of switching movements between the two sides of the stroke and in this way, promote balance in muscle recruitment. Therefore, incorporating these recommendations into a comprehensive training regimen can potentially improve overall paddling performance.