Aquatic Physical Therapy: Dynamic Movements
Class
Article
Department
Health, Physical Education, and Recreation
Faculty Mentor
Eadric Bressel
Presentation Type
Oral Presentation
Abstract
Aquatic-based plyometrics may be of particular interest to clinicians working with older adults or individuals experiencing load-induced discomfort, given the comparable improvements and lessened impact of plyometric exercises performed in the water. Buoyancy, fluid resistance, and hydrostatic pressure are key physical properties of water that underscore the potential of aquatic-based exercise prescriptions as attractive alternatives to traditional, land-based performance and rehabilitation programming. The purpose of the present study was to quantify characteristics of the take-off and flight phase in plyometric movements and to assess how key mechanical variables influence jumping movements performed in the water. Seven recreationally active male adults were asked to volunteer as participants. Each participant performed, in random order, two commonly prescribed jumping movements in three different environmental conditions (1 land, 2 aquatic). All jumps were performed on a waterproof force platform (1000 Hz, AMTI, Columbus, OH). Using sectioned force platform data, the following were computed as dependent measures: Initial velocity (m*-1), time to apex (s), jump time (s), percent of time in lightening phase (%), propulsive impulse (N*s), max force (N, BW), and rate of force development (F*s-1, BW*s-1). Regression models assessed the relationship between initial velocity and time to apex. Statistical differences across conditions for remaining dependent measures were assessed using ANOVA methods. On land, the results suggest a linear relationship (R2 = 0.924, F = 232.6, p < 0.001) between initial velocity and time to apex, matching theoretical expectations. Different trends were observed for both aquatic conditions, with the statistical relationship between time to apex and initial velocity being quadratic (R2 = 0.663, F = 14.8, p < 0.001; R2 = 0.743, F = 18.8, p < 0.001). Additionally, normalized RFD was significantly greater for jumps performed in the water and increased with increasing depth of immersion (p < 0.001). This suggests that, for jumping movements performed in the water, fluid resistance holds greater influence over the characteristics of vertical acceleration than does the unloading effect of buoyancy. The quadratic underestimation of time to apex observed in the present study is likely to have implications on proprioception and jump landing characteristics.
Start Date
4-9-2015 11:00 AM
Aquatic Physical Therapy: Dynamic Movements
Aquatic-based plyometrics may be of particular interest to clinicians working with older adults or individuals experiencing load-induced discomfort, given the comparable improvements and lessened impact of plyometric exercises performed in the water. Buoyancy, fluid resistance, and hydrostatic pressure are key physical properties of water that underscore the potential of aquatic-based exercise prescriptions as attractive alternatives to traditional, land-based performance and rehabilitation programming. The purpose of the present study was to quantify characteristics of the take-off and flight phase in plyometric movements and to assess how key mechanical variables influence jumping movements performed in the water. Seven recreationally active male adults were asked to volunteer as participants. Each participant performed, in random order, two commonly prescribed jumping movements in three different environmental conditions (1 land, 2 aquatic). All jumps were performed on a waterproof force platform (1000 Hz, AMTI, Columbus, OH). Using sectioned force platform data, the following were computed as dependent measures: Initial velocity (m*-1), time to apex (s), jump time (s), percent of time in lightening phase (%), propulsive impulse (N*s), max force (N, BW), and rate of force development (F*s-1, BW*s-1). Regression models assessed the relationship between initial velocity and time to apex. Statistical differences across conditions for remaining dependent measures were assessed using ANOVA methods. On land, the results suggest a linear relationship (R2 = 0.924, F = 232.6, p < 0.001) between initial velocity and time to apex, matching theoretical expectations. Different trends were observed for both aquatic conditions, with the statistical relationship between time to apex and initial velocity being quadratic (R2 = 0.663, F = 14.8, p < 0.001; R2 = 0.743, F = 18.8, p < 0.001). Additionally, normalized RFD was significantly greater for jumps performed in the water and increased with increasing depth of immersion (p < 0.001). This suggests that, for jumping movements performed in the water, fluid resistance holds greater influence over the characteristics of vertical acceleration than does the unloading effect of buoyancy. The quadratic underestimation of time to apex observed in the present study is likely to have implications on proprioception and jump landing characteristics.