Upper extremity augmentation of lower extremity kinetics during countermovement vertical jumps
| Autor: | Daniel J. Fraschetti, Michael E. Feltner, Robert J. Crisp |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Adult
Male musculoskeletal diseases Physical Therapy Sports Therapy and Rehabilitation Kinematics medicine.disease_cause Weight-Bearing Jumping medicine Humans Torque Orthopedics and Sports Medicine Ground reaction force Simulation Mathematics Orthodontics Leg Biomechanics Body movement Trunk Biomechanical Phenomena medicine.anatomical_structure Arm Female Joints Ankle human activities Muscle Contraction Sports |
| Zdroj: | Journal of Sports Sciences. 17:449-466 |
| ISSN: | 1466-447X 0264-0414 |
| Popis: | Twenty-five volleyball players (14 males, 11 females) were videotaped (60 Hz) performing countermovement vertical jumps with and without an arm swing. Ground reaction force and video-based coordinate data were collected simultaneously. The resultant joint force and torque at the hip, knee, ankle and shoulder for two trials per subject per condition were computed and normalized. Average kinematic, resultant joint force and torque data were compared using repeated-measures analysis of variance. Larger values were recorded for the vertical velocity of the centre of mass at take-off in the jumps with (mean 2.75, s = 0.3 m.s-1) versus without (mean 2.44, s = 0.23 m.s-1) an arm swing. The jumps with no arm swing produced larger torques at the hip during the first third of the propulsive phase (from zero to maximum vertical velocity of the centre of mass). During the final two-thirds of the propulsive phase, the arm swing augmented hip extensor torques by slowing the rate of trunk extension and placing the hip extensor muscles in slower concentric conditions that favoured the generation of larger forces and resultant joint torques. During the first two-thirds of the propulsive phase, knee extensor torque increased by 28% in the jumps with an arm swing, but maintained a relatively constant magnitude in the jumps with no arm swing. |
| Databáze: | OpenAIRE |
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