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Concentric and eccentric shoulder rehabilitation biomechanics
S S Kohles1, K N Gregorczyk, T C Phillips
1Kohles Bioengineering, Portland, Oregon 97214-5135, USA. ssk@kohlesbioengineering.com
Summary
The impulse-momentum (IM) exercise technique generated higher forces and moments during concentric than eccentric loading. Males experienced significantly greater shoulder joint forces and moments than females during this rehabilitation exercise.
Area of Science:
- Biomechanics
- Rehabilitation Medicine
- Human Movement Science
Background:
- End-stage shoulder rehabilitation requires effective exercise techniques to restore function.
- Impulse-momentum (IM) principles can be applied to optimize rehabilitation exercises.
- Understanding gender-specific responses to exercise is crucial for personalized rehabilitation.
Purpose of the Study:
- To quantify shoulder joint forces and moments using an IM exercise technique.
- To investigate the influence of gender on kinetic and kinematic parameters during IM exercise.
- To compare the effects of concentric versus eccentric muscle loading on shoulder biomechanics.
Main Methods:
- Fourteen healthy adults (8 males, 6 females) participated in a repeated measures experiment.
- Subjects performed upper arm external and internal rotations on an instrumented device.
- Inverse dynamics calculations were used to determine shoulder joint forces, moments, work, and power.
Main Results:
- Concentric peak forces and moments were significantly greater than eccentric peak forces and moments (P < 0.0001).
- Peak joint forces and moments occurred during the initial concentric phase (0-45 degrees).
- Males exhibited significantly higher average resultant peak joint forces and moments compared to females (P < 0.0001).
Conclusions:
- The impulse-momentum (IM) exercise technique generates substantial joint forces and moments, particularly during concentric loading.
- Gender significantly influences the magnitude of shoulder joint forces and moments, with males experiencing higher values.
- These findings provide valuable biomechanical data for designing and implementing IM-based shoulder rehabilitation programs.
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