S5L3 - Walking And Gait Flashcards
What is gait?
Mechanism by which the body is transported using coordinated movements of the major lower limb joints.
What two phases does gait consist of?
Stance phase and swing phase
What is stance phase?
60% of the gait cycle and is the time in which the foot s in contact with the floor and is weight bearing.
What is swing phase?
40% of the gait cycle. The tie during which the foot is not in contact with the ground.
What is the gait cycle?
The period of time from the initial contact to next initial contact on the same side of the body.
What five attributes are needed for normal gait?
Stability in stance Foot clearance during swing phase Pre-positioning for initial contact Adequate step length Energy conservation
What are periods of double support?
When neither leg is in stance phase. A period of time in the gait cycle where both feet are in contact with the ground. There should be 2 periods of double support in one gait cycle.
When does the double support decrease?
When the speed of your gait increases.
What is a double float?
A period of time in the gait cycle when neither foot is in contact with the ground. Must be running in order to achieve a double float.
How does the proportion of stance and swing phases vary in walking and sprinting?
In walking, 60% of the gait cycle is stance phase, 40% is swing phase
In sprinting, 40% is stance and 60% is swing.
What can the stance phase be divided into?
- Initial contact - heel strike. Centre of gravity behind the foot
- Loading response - shock of impact absorbed by knee and ankle joints. Rocks forward ready to bring the rest of the foot into contact.
- Mid stance - foot flat on the ground. Centre of gravity has shifted from behind the foot to in front of the foot.
- Terminal stance - ankle plantarflexed and heel raised.
- Pre swing - metatarsophalangeal joints flex to give a push off by the toes.
During double stance, what two subdivisions of stance phase are occurring at once?
Pre swing in one limb, loading response in the other.
What can the swing phase be divided into?
- Initial swing - knee flexes, foot clears ground
- Mid swing - hip flexes and the pelvis swings forward to enable forward progression. Dorsiflexion to neutral anatomical position.
- Terminal swing - knee extends, heel brought close to the ground in preparation for initial contact.
How is the forward progression in walking generated?
Push off of the toes during pre-swing/ powerful plantar flexion of the ankle/ flexion of the hips accentuated by the swinging motion of the pelvis.
What stops the pelvis tilting towards the supported side during walking?
Hip adductors (gluteus medius and gluteus minimus)
What is stride?
Similar to gait but measurement of distance not time. The distance from initial contact with one leg to the next initial contact with the same leg.
What is step?
Half of stride. The distance from initial contact with one leg to the initial contact with the other leg.
What is cadence?
Number of steps per minute.
What is gait analysis?
A study of a persons gait
What are the two elements to gait analysis?
Kinematics
Kinetics
Why do muscles produce force?
Provide stability ( usually by opposing gravity) Propel body segments forward through controlled movements of joints.
What are the three methods of contraction used by muscles?
Concentric contraction
Eccentric contraction
Isometric contraction
What is concentric contraction used for?
Acceleration and power generation
What is eccentric contraction used for?
Deceleration and shock absorption
