Analysis of cervical and shoulder neuromuscular activity during adapted swimming with and without a snorkel: Implications for rehabilitation

Conclusion Using a snorkel during adapted swimming produces changes in the level of muscle activation in the shoulder and neck. An increase in infraspinatus and a decrease in cervical erector spinae activity due to reduced head movement and an absence of significant cervical rotation when using a snorkel may lead to increased resistance and work for the shoulder. Finally, the metacentric effect on the arm decreases because the arm does not come out of the water.
Source: Science and Sports - Category: Sports Medicine Source Type: research