Case Study: Shoulder Muscle Activity While Swimming With Different Wetsuit Conditions And Swimming Paces.

Abstract

During swimming, the wetsuit is an important piece of equipment can benefit swim performance. Triathletes can select different types of wetsuit based on personal preference, body type, and swimming technique. It is not clear if wetsuit design or swim pace influences shoulder muscle activity. PURPOSE: To determine how swimming with different types of wetsuit (HUUB design., Aegis II 3:5, Sphere) using different swimming paces influence shoulder muscle activity. METHODS: One male subject (height: 181.6cm, body mass: 81.1kg) completed total four swim conditions in a 25 m pool: 1) No wetsuit (NWS), 2) Sleeveless wetsuit (SLW), 3) Full-sleeve wetsuit (FSW), 4) Buoyancy shorts (BS) x 3 swimming paces: slow, medium, fast. A wireless waterproof EMG system (Cometa, Italy) was used to measure shoulder electromyography (EMG) (Anterior Deltoid: AD & Posterior Deltoid: PD) and swimming pace was measured by stopwatch. EMG data were averaged across 5 consecutive stroke cycles with stroke rate calculated. EMG data were normalized to NWS slow speed. RESULTS: Stroke rate (slow: 1.92 ± 0.05 Hz, medium: 1.75 ± 0.05 Hz, fast: 1.46 ± 0.06 Hz) decreased as swimming velocity (m/s) increased (NWS - Slow: 1.12 ± 0.04, Medium: 1.21 ± 0.02, Fast: 1.32 ± 0.01 / SLW - Slow: 1.27 ± 0.02, Medium: 1.34 ± 0.01, Fast: 1.52 ± 0.01 / FSW - Slow: 1.25 ± 0.02, Medium: 1.38 ± 0.02, Fast: 1.48 ± 0.04 / BS - Slow: 1.21 ± 0.02, Medium: 1.30 ± 0.01, Fast: 1.40 ± 0.02). Inspecting EMG trends, AD EMG was greatest during BS vs. other conditions and increased with swim velocity during FSW and BS conditions. PD muscle activity did not exhibit any clear pattern between conditions or across swimming velocities.Table 1: Anterior and posterior deltoid muscle activities (%NWS slow) across the wetsuit conditions.CONCLUSION: It is important to establish techniques to measure muscle activity during swimming in different wetsuit conditions since muscle activity is influenced by a complex interaction of wetsuit condition, pace, and swim technique.