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Kinetic analysis of stair descent: Part 1. Forwards step-over-step descent
Tyler Cluff1, D Gordon E Robertson
1Sensorimotor Neuroscience Laboratory, Department of Kinesiology and MiNDS Neuroscience Institute, McMaster University, Hamilton, Ontario, Canada. clufft@mcmaster.ca
Gait & Posture
|February 5, 2011
Summary
During stair descent, knee extensors primarily dissipate energy, but ankle muscles become key when increasing speed. Steady-state biomechanics may not occur in the first gait cycle.
Area of Science:
- Biomechanics
- Human Locomotion
- Gait Analysis
Background:
- Stair descent involves complex lower extremity movements.
- Understanding joint mechanics is crucial for injury prevention and rehabilitation.
Purpose of the Study:
- To investigate lower extremity joint mechanics during the initiation of stair descent.
- To determine the influence of progression velocity on these mechanics.
Main Methods:
- Seventeen healthy subjects descended a five-step staircase.
- Kinematic and kinetic data were collected for joint moments and powers.
- Analysis focused on the initiation gait cycle versus steady-state conditions.
Main Results:
- Knee extensor (K3) and hip flexor (H2) moments/powers were largely independent of velocity and reached steady-state after the first cycle.
- Ankle plantiflexor (A1) moment, power, and work increased with progression velocity.
- Steady-state biomechanics may not be achieved within the first gait cycle.
Conclusions:
- Knee extensors are primary energy dissipaters in stair descent.
- Ankle plantiflexors are critical for dissipating energy associated with increased descent velocity.
- Gait cycle and progression velocity influence lower extremity function during stair descent.
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