PHYSIOMECHANICAL MODEL OF SHALLOW WATER WALKING: DRAG AND BUOYANCY FORCES AFFECTING THE COST OF TRANSPORT

Although the physiologic and biomechanical responses of shallow water walking (SWW) have been studied extensively, a physiomechanical model aiming to define the mechanical determinants of cost of transport (C) of SWW is lacking. Therefore, we investigated the SWW by healthy men at different speeds (0.2, 0.4, 0.6 m/s) and depths (knee, hip, umbilical, xiphoid). The objectives of this study were 1) to analyze the C response during SWW by healthy men and 2) to propose a physiomechanical model of SWW by determining the C response and its correlation with drag force and buoyancy forces during SWW. The C had a minimal value at intermediary speeds only in the knee depth, while in the other deeper depths, the C presented a monotonic rise with the speed increase. A minimum C was found at hip depth during 0.2 m/s, suggesting an optimization between the effects of buoyancy and drag forces at this condition. These findings could be applied in the exercise prescription of SWW for different populations, as indicators of the relative importance of hydrostatic and hydrodynamic forces effects on energy expenditure during SWW