Computational Fluid Flow Study on the Pressure Fluctuation Caused by the Vortex Flow Arising from Underwater Exercises of Arthritis Patients

Underwater exercise programs are among the nursing programs for which positive effects have been reported with regard to the promotion of good health in diverse subjects, such as patients suffering arthritis, as well as elderly people and middle-aged women. Through many previously conducted studies, subjects participating in underwater exercises have been reported to continuously experience reduced pain, and improvement in muscle strength, flexibility, sense of balance, and muscular endurance. However, few studies have delved into the fundamental phenomena of positive effects of underwater exercises on the human body. In this study, a model of the upper limbs of the human body was used in a simulation of underwater exercises to analyse the resulting pressure fluctuation on the skin of the hands and arms of the model through the methods of computational fluid dynamics. During the simulation of underwater exercises, pressure fluctuation of diverse frequencies, arising from the vortex flow around the articulations of the fingers and hands of the model, were identified and were seen to create varied cutaneous stimulations and massage effects. Such cutaneous stimulations seem to continuously excite capillary vessels situated between hands and finger joints, creating positive effects in blood circulation around pain sites of patients suffering from arthritis.