Wearing a Wetsuit Alters Upper Extremity Motion during Simulated Surfboard Paddling

Abstract

Surfers often wear wetsuits while paddling in the ocean. This neoprene covering may be beneficial to upper extremity movement by helping to improve proprioceptive acuity, or it may be detrimental by providing increased resistance. The purpose of this study was to evaluate the effects of wearing a wetsuit on muscle activation, upper extremity motion, heart rate, and oxygen consumption during simulated surfboard paddling in the laboratory. Twelve male, recreational surfers performed two paddling trials at a constant workload on a swim bench ergometer both with and without a wetsuit. Kinematic data and EMG were acquired from the right arm via motion capture, and oxygen consumption and heart rate were recorded with a metabolic cart and heart rate monitor. Wearing a wetsuit had no significant effect on oxygen consumption or heart rate. A significant increase in EMG activation was observed for the middle deltoid but not for any of the other shoulder muscle evaluated. Finally, approximate entropy and estimates of the maximum Lyapunov exponent increased significantly for vertical trajectory of the right wrist (i.e. stroke height) when a wetsuit was worn. These results suggest that a 2mm wetsuit has little effect on the energy cost of paddling at lower workloads but does affect arm motion. These changes may be the result of enhanced proprioceptive acuity due to mechanical compression from the wetsuit.

Fig 1. Experimental setup.

Modified swim bench ergometer, marker placement, and VO₂ mask.

Fig 2

Left: Percent false nearest neighbors for a range of embedding dimensions for wrist trajectory in the vertical direction. An embedding dimension of 4 was utilized for calculation of maximal Lyapunov exponents. Right: sample divergence curve used to calculate maximal Lyapunov exponents for a single subject. Short term values were calculated over 0–1 stroke and long term values were calculated over 4–10 strokes.

Fig 3. Mean sagittal plane trajectory for the right wrist with and without a wetsuit.

Horizontal line represents and estimate for water level, though subjects paddled an ergometer in the absence of water. The point of greatest anterior (caudal) position of the hand determined the beginning of the stroke, and the propulsive and return phases occurred at approximately 20–70% (bottom of trajectory) and 70 to 20% (top of trajectory) of the stroke cycle, respectively.

Fig 4

Top: Three dimensional state space plots for a representative subject for wrist movement in the vertical direction. An embedding delay of 20 was used. Bottom: Raw wrist trajectory in the vertical direction.

Fig 5. Mean EMG activation of select shoulder and trunk muscles throughout the paddling stroke.

EMG data were rectified, filtered, and averaged across all complete strokes per subject, then across all subjects. The horizontal access defines the percentage of the stroke cycle (0% represents the beginning, 100% represents the end of the cycle). Grey lines represent the no wetsuit condition, while the black lines represent the wetsuit condition.