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- There are 2 main phases: Stance (60%) and Swing (40%)
- Each phase can be divided into 4 sub-phases - HLMT, TIMT
- Heel Strike - initial foot contact with ground
- Loading Response - transition from heel strike to mid stance
- Mid Stance - occurs when both ANKLES aligned in coronal plane
- Terminal Stance - period from midstance to toe off
- Toe off - push-off phase (also called pre-swing)
- Initial Swing - characterized by Maximum knee flexion
- Mid Swing - occurs when tibia vertical to the ground
- Terminal Swing - Deceleration begins
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- Gait cycle extends from initial contact to initial contact of the same foot
- Step measures from initial contact to initial contact of the other foot
- Stride measures from initial contact to initial contact of the same foot = 1 gait cycle
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- Stance phase comprises 3 rockers, each with distinct muscle action and Ground Reaction Force relative to the knee.
- Heel rocker (H+L) - GRF posterior to knee, eccentric lengthening of Tibialis Anterior
- Ankle Rocker (L+M+T) - GRF anterior (or in line with the knee), eccentric contraction of calf muscles.
- Quadriceps contract to prevent knee buckling, maintaining anterior GRF
- Forefoot Rocker (Toe off) - GRF returns to posterior to knee, concentric contraction of calf
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- 2 in stance phase
- 1. At Heel strike - Appropriate pre-positioning of foot
- 2. Stance phase - Stability in Stance – stable foot position
- 3 in swing phase
- 3. Swing - Adequate foot clearance in swing – adequate flexion at hip
- 4. Swing - Adequate step length
- 5. Swing - Energy conservation – minimize vertical excursion
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- These factors minimise displacement the body's center of gravity
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- Linear analysis – step length, stride length (same foot)
- Kinematics – measurement of movement with markers
- Kinetics – measure of forces and energy
- EMG – muscle activity
- Pedobarography – pressure mats
- Metabolic - VO2, Efficiency
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- According to Newton's third law, ground reaction force (GRF) is the force exerted by the ground on a body in contact with it.
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Drink water from your own cistern, flowing water from your own well. Proverbs 5:15