(6) WHOLE-BODY KINEMATICS DURING STAND-UP PADDLE BOARD EXERCISE

Purpose: The purpose of this study was to identify patterns of selected joint motions associated with SUP exercise and determine if these patterns are modified with increasing exercise bout time. Methods: The following procedures were approved by the Institutional Review Board at the sponsoring university. Ten young volunteers with no paddling experience (X̄ = 21.2, SD = 1.3, five females), performed a 10-minute exercise bout on a SUP at an intensity equal to 25% of their maximum paddling power. Whole-body three-dimensional kinematic measures were obtained using inertial measurement units (IMUs). Data were collected in one-minute increments four times during the exercise bout (1^st, 4^th, 7^th and 10^th minutes). These collection increments were labeled T1, T2, T3 and T4, respectively. The joint time series waveforms were separated into individual strokes and time normalized such that each waveform was represented by 100 samples. Bilateral abduction/adduction of the shoulder, flexion/extension of the elbow, hip rotation, knee flexion/extension, and ankle dorsiflexion were selected to characterize the stroke. Mean time series waveforms were developed for each joint from the strokes collected within a given time increment. Pearson r correlation coefficients were used to assess the similarity of the shape of the mean waveforms for each joint, across the four increments. Spatial parameter mapping (SPM) was used to determine potential differences in mean amplitude across the entire waveform for each joint and increment. The pull and recovery phase of the strokes were identified and the number of significant different samples, across both movement phases, were tabulated, for each increment. To evaluate possible patterns of change with increasing exercise time, waveform comparisons between times 1 & 2, 2 & 3 and 3 & 4 were conducted. Results: In all comparisons, the Pearson R correlation coefficients were above .90 (df= 182, p = 0.001) except for the comparison between the left ankle, T1 vs T2 (.87). SPM analyses revealed that amplitude differences within a joint across the time increments had largely dissipated by T3 as the differences between T3 and T4 were minimal. Conclusions: The high correlations across all increments indicate that the basic joint motion pattern, across all measured joints, was established very early in the exercise bout, despite all subjects being novices. The amplitude differences revealed by SPM during the first 7 minutes of the exercise suggest that subjects were in the process of ‘fine tuning’ the amplitude of motion for both the arms and legs, seeking a whole-body coordination pattern that stabilized late in the exercise bout. Practical Applications: Identifying joint angle motion patterns used during SUP, as well as the time taken to stabilize these patterns when first exposed to this exercise, has important implications for developing safe and effective training protocols. Acknowledgements: None