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Published on: June 8, 2017
Leg stiffness and expertise in men jumping
Guillaume Laffaye1, Benoît G Bardy, Alain Durey
1Center for Research in Sport Sciences, University Paris XI, Paris, FRANCE. eglaffaye@aol.com
Medicine and Science in Sports and Exercise
|April 6, 2005
Summary
This study found that while leg stiffness didn't differ between experts and novices, jumping technique varied significantly among different sports experts. Specific impulse parameters characterized distinct jumping profiles.
Area of Science:
- Biomechanics
- Human Movement Science
- Sports Science
Background:
- The human musculoskeletal system can be modeled as a mass-spring system to analyze energy transfer during locomotion.
- Leg stiffness is a key parameter in understanding jumping and running mechanics.
Purpose of the Study:
- To investigate leg spring behavior during one-leg vertical jumps.
- To determine the contribution of impulse parameters to leg spring behavior.
- To examine the effect of jumping expertise on leg stiffness.
Main Methods:
- Subjects included handball, basketball, volleyball players, Fosbury athletes, and novices performing a run-and-jump test.
- Kinematic and kinetic data were collected using motion capture and force plates.
- Jumping conditions ranged from 55% to 95% of maximum jump height.
Main Results:
- Leg stiffness decreased with increased jumping height.
- Contact time decreased, while leg shortening at takeoff increased with jumping height.
- No significant difference in leg stiffness was found between experts and novices, but principal component analysis revealed distinct performance factors.
Conclusions:
- While leg stiffness itself did not differentiate experts from novices, the contribution of leg stiffness to jump height varied.
- Distinct jumping profiles were identified among different sports expertise groups, characterized by sport-specific impulse parameters.
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