OBJECTIVE: To compare the vertical component of the ground reaction force in the exercises of walking, running, stationary running and vertical jump in the water, performed in different levels of immersion. METHODS: This case study was conducted with one subject (male, 27 years, 1,80 m and 84,3 kg). An underwater force plate was used for data collection, placed at the bottom of a thermal swimming pool. The subject performed 30 valid passages for each exercise in two immersion levels: xiphoid process and hip. Data were analyzed through descriptive statistics, Student's "t" test for paired samples and ANOVA for repeated measures (p < 0,05). RESULTS: The maximum values of force in the xiphoid process and hip levels (in % of body weight) were, respectively: 39% and 48% for walking; 138% and 156% for running; 139% and 202% for stationary running; 194% and 195% for the propulsion phase of jumping; and 222% and 387% for the landing phase of jumping. CONCLUSION: When varying the type of exercise we can gradually increase the load, from walking in the xiphoid process immersion level to jumping in the hip immersion level. In order to choose the correct exercise we have to consider the objectives of the treatment/training program, increasing the load not only by decreasing the immersion level but also by the choice of the exercise type and the velocity/ rhythm of execution.
Biomechanics; Aquatic exercises; Running; Walking; Vertical jump
