Underwater Electromyogram for Human Health Exercise

The physical qualities of water are well established and include buoyancy, water drag force, hydrostatic pressure and thermal conductivity [1]. The large difference in these physical qualities, compared to land-based activities, affect the human body in both physiologic and biomechanical aspects. An example of this is buoyancy, which acts vertically against gravity on the immersed object thus decreasing weight of the human body. The buoyancy level is equal to the mass of water displaced by the immersed object and is based on the accepted Archime‐ dean principle. When a human is immersed in water up to the level of pubis around 40% of weight is accounted for, 50% at umbilical, 60% at xiphoid, and almost 80% at the level of axillary [1, 2]. When immersed to their lower limb joint and waist in a water environment, humans can easily move, without gravitational overload, due to the buoyancy effect.