# The Effect of Neuromuscular Fatigue on the Spatiotemporal Coordination of Rowing
## 4 Discussion
This mix of responses might be due to the variations in participant anthropometrics or specific sex effects [19] present within the dataset, causing individuals to adapt to any neuromuscular fatigue in different ways. Future work will be necessary to uncover individual response characteristics to a fatiguing rowing bout, including assessing the relative injury risk in those who respond with significant changes in joint posture or in the spatiotemporal coordination of multi-joint dynamics. Specifically, those who respond to fatigue by increasing spine flexion [12] and their deviation phase (i.e., variation) would potentially be at an added injury risk due to the incidence of high-flexion postures (which place the passive elements of the trunk into strain) coupled with more variable motor patterns, which may suggest poorer control, and thereby increase the potential for high-flexion tissue loads to exceed an underlying tissue tolerance. The findings of this study provide insights into the spatiotemporal coordination patterns of rowers during ergometer training. The current findings demonstrate that the fatigue-related changes to the spatiotemporal coordination of a rowing movement were limited during a 2000 m near maximal effort row on an ergometer. It is possible that the changes to the spatiotemporal coordination of the rowing stroke were masked by the use of an indoor ergometer and may be present during less-constrained on-water rowing movements. However, since this study did not compare the two types of training (i.e., ergometer vs. on-water), future studies should investigate this claim by evaluating the differences in fatigue-related changes in the spatiotemporal coordination of rowing on an ergometer versus on-water rowing, as this could provide coaches with important information to improve the design of their coaching interventions. The results from these prospective studies could assist coaches in providing athletes with more optimal training interventions to enhance their performance while minimizing the likelihood of injury occurring. In addition to the constraints imposed from ergometer rowing, the heterogeneity of the responses to the 2000 m rowing bout should be emphasized, as this might have masked significant changes in coordination due to fatigue present within the aggregate data analyses. This would mean that individualized training is important, as different rowers may respond uniquely to various training stimuli. When interpreting the results of this study, some limitations must be taken into consideration. First, due to limitations imposed by the COVID-19 pandemic, the convenience sample evaluated here was relatively small (\(n=20\)). Despite this, this work builds on those published previously which assess posterior pelvic tilt at the catch position [18] and increased thoracic curvature with muscle fatigue [12] but only had a sample size of \(n=8\) and \(n=10\) participants, respectively. Second, most of the participants primarily rooved with the same coach, which could have resulted in their rowing movements being similar. An increase in the diversity of the participants could increase the generalizability of the study. Third, the fatigue measure implemented here was the Borg-10 RPE scale, which is inherently subjective. This could have resulted in a less accurate measure of fatigue, as people's perception of fatigue is not the same [20]. In addition, this is a global measure of fatigue, which means that specific areas of the body of interest might not be fatigued. A solution to gauge fatigue for future studies could be to use heart rate monitors or sEMG sensors [21] to objectively quantify local muscle fatigue occurring within the paraspinal musculature or elsewhere. Fourth, the intensity and duration of movement might have introduced a minor drift due to the movement of the IMU sensors. If drift was present, it could have caused the measured joint angles to gradually deviate from their true values.