Date of Award


Degree Type


Degree Name

Master of Science (MS)


Health, Physical Education, and Recreation


The purpose of this study was to compare dynamic stability and landing kinetics, on land and in water, between young and middle-aged adults performing plyometric exercises. Twenty adults were asked to volunteer: Young = 24.40 ± 2.63 years, n = 10 and middle-aged = 46.80 ± 3.05 years, n = 10. Participants performed three plyometric exercises (countermovement jump, squat jump, and drop landing) on land and in waist-deep water. Dynamic stability was assessed during landing for each exercise using a time to stabilization (TTS) paradigm. Kinetic measures included time to peak force, peak force, rate of force development (RFD), and impulse. Data were collected via a waterproof force plate positioned on an adjustable-depth pool floor and analyzed with a 2 (age) X 6 (condition) repeated measures ANOVA. Results revealed TTS was greater on land (1.45 ± 0.12s) than in water (1.35 ± 0.12s) for two jumps (p = 0.01). Peak force, RFD, and impulse were greater on land (33%-36%) (p < 0.01). Time to peak force was lower (20%), while normalized peak force (15%) and RFD were greater (28%), in the middle-aged compared to the young group (p = 0.04). Results indicate that young and middle-aged adults display improved dynamic stability and are exposed to lower absolute impact forces in water. The effect of age indicates middle-aged participants tend to display greater loading rates and peak forces when compared to the younger group, suggesting landing patterns that may be harmful.