What are the requirements for gait
Progression: ability to generate a basic locomotor pattern (bodily movement eg. Walking) that can move the body in the desired direction
Postural control: ability to control the body’s position in space to accomplish both orientation and all aspects of stability, including steady-state, reactive, and anticipatory balance control.
Adaptation: ability to adapt gait (progression and postural control) to meet the individual’s goals and the demands of the environment.
What are the neural controls of gait
Cortex – adaptation to goals and environment
Cerebellum – coordination, timing size of response, tone = stability
Brainstem/Basal ganglia – movement initiation, muscle activation and speed control
Spinal cord – normal rhythmic patterns (central pattern generators). Modulate reflex action
Somatosensory – visual, vestibular, mechanoreceptors contribute to recovery of gait stability following contact with an obstacle
Describe the action of the hip extensors during gait
Late phase of swing phase = act to decelerate hip flexion, start hip extension and prepare for weight acceptance
Heel contact to mid stance = support body weight and generate hip extension
Swing phase = Glut. Max is mostly inactive
Describe the action of the hip flexors during gait
Terminal stance = 30-50% of gait, eccentric contraction to decelerate hip extension
Swing phase = active only during first half of swing, second half is due to the forwards momentum (inertia) of the lower limb
Describe the action of the knee flexors during gait
Heel contact = knee flexors active just before and after heel contact
Before = decelerate the knee extension for placement of foot on the ground
After = contribute to hip extension
Describe the action of the ankle and foot dorsiflexors during gait
Heel contact = eccentric contraction to decelerate plantarflexion, if not tib. Ant. Actions would have foot slap
Swing phase = dorsiflex (prevent toes from dragging on the ground)
Describe the action of the ankle plantar flexors during gait
Stance phase
Active most of the time, from 10% of gait cycle to heel off = eccentric contraction
Heel off to toe off = concentric contraction for forwards propulsion
What are the functional tasks of gait
- Weight acceptance; transfer of body weight soon as it contacts the ground, acts for shock absorption and maintain/preserve forward momentum
- Single limb support; support entire body weight, forward progression of body weight, maintain stability
- Limb advancement; advancing the limb forward and prepares for initial contact
What are the spatial parameters of the gait cycle
- Stride length – distance covered by 2 sequential points of initial contact on the same foot
- Step length – distance between a point on one foot and the same point on the contralateral foot
- Foot angle – angle between the line of progression from the mid heel and the line of progression between the mid heel and the base of the second metatarsal
. Positive foot angle is when foot face outwards – negative when inwards - Step width – distance between the line of progression between each foot
What are the temporal parameters for the gait cycles
- Cadence – number of steps per unit time – normal 100-120 steps/min
- Velocity – Rate of linear forward movement of body – distance over time
When are the peaks and low oscillations of the gait cycle
This peaks at mid-stance phase of each limb, but is the lowest when both feet are in contact with the ground
