gait Flashcards
full gait cycle
stance 60%
1. heel strike
2. foot flat
3. mid-stance
4. push off
Swing 40%
5. initial swing - acceleration
6. mid swing
7. terminal swing- deceleration
stride
- stance
- swing
stance
- weight acceptance
- single limb support
swing
- limb advancement
weight acceptance
- initial contact
- loading response
single limb support
- mid- stance
- terminal stance
- pre swing
limb advancement
- pre swing
- initial swing acceleration
- mid swing
- terminal swing deceleration
dorsiflexion
- heelstrike
- contact phase
plantarflexion
mid-stance
toe off- propulsive phase
3 rockers
- heel
- ankle
- forefoot
heel rocker
- heel = fulcrum as the foot rolls into plantar flexion.
- pretibial muscles eccentrically contract to decelerate the foot drop and pull the tibia forward.
ankle rocker
- ankle = fulcrum and the tibia rolls forward due to forward momentum.
- The soleus (primarily) eccentrically contracts to decelerate the forward progression of the tibia over the talus.
- Ankle and forefoot rocker can be compromised by imbalances in strength and length of the gastroc/soleus group and anterior compartment muscles.
forefoot rocker
- Tibial progression continues and the gastroc/soleus groups contract to decelerate the rate of forward limb movement.
- This, along with forward momentum, passive tension in the posterior compartment muscles, active contraction of the posterior compartment and foot intrinsics and windlass effect of the plantar fascia results in heel lift.
distribution of pressure throughout stance phase
heel strike - 0%
forefoot contact - 20%
heel lift- 55%
peak forefoot loading - 78%
toe off - 100%
componants of stance
- Early in stance trunk is displaced laterally with hip adduction and foot eversion of stance limb
- Hip mostly extended
- Hip extension and ankle DF transport trunk from behind to in front of stance foot
- Ankle PF propels body forwards at the end
- COG is moved over stance foot for single support phase
- Knee in flexion at early and late stages but mostly in extension
- Requires adequate postural control and linear extension
initial contact
hip flexed- 16°, knee flexes
dorsiflexion-plantarflexion
loading response
- hip extends and ankle DF further
- knee flexes 15°
- foot pronates - unlocking of mid tarsal joint- mobile foot/shock absorbsion
midstance
- hip extension, body aligned over stance limb
- lateral pelvic displacement -5°
- knee extension
- foot begins supinating and foot becomes rigid lever
terminal stance
- peak hip ext- 11°
- knee flexion begins
- plantarflexion initiated
pre-swing
- hip flexion (begins late stance)
- knee flexes to 30°
- plantarflexion 18 degrees at toe off
key componants of swing
- Hip extension in late stance and movement of body mass over stance foot allow hip flexors a mechanical advantage at start of swing
- Requires ability to let go of extension
- Leg advances using momentum and muscle activity
- Acceleration to deceleration
- Limb positioned for acceptance of weight
initial swing
- hip flexion
- knee flexion
- toe extension
- ankle dorsiflexion until reaches PG
mid swing
- pendular forces propel limb, relatively little muscular force required
- hip flexes to 20°
- knee flexes to 65° and then accelerates into extension 1/3 through swing
- foot pronates to aid ground clearance
terminal swing
- knee extension 2° decelerates
- dorsiflexion
- foot decelerates and supinates in prep for heel strike
stride defintion & lengths
- heel contact to heel contact of ipsilateral foot
**male **
velocity m/s- 1.36
stride frequency steps/second- 1.8
stride length meteres- 1.51
female
velocity m/s- 1.3
stride frequency steps/second- 1.98
stride length meteres- 1.32
weight acceptance
initial contact and loadiing response
single limb support
mid stance,
terminal stance,
pre swing
Limb advancement
initial swing,
mid swing,
terminal swing
Anterior/Posterior View
Arm position – carrying angle
Iliac crests, PSIS, lateral pelvic tilt, stability
Feet – toes in / out
lateral
- arm position- reciprocal swing
- trunk- spinous processes/ stability/ pelvic tilt
- knees- fixed flexion (FFD) or hyperextended
- ankles - lacking dorsiflexion
common abnormal gait patterns
- Excessive/inadequate ROM
- Head, trunk, arm, pelvis, hip, knee, ankle
- Foot position during stance
- Non-heel/toe walking
- Bilateral difference in stance/swing phase timings
- Bilateral differences in stride length
- Pelvic tilt (anterior/posterior)
- Compensatory methods adopted to maintain equilibrium and locomotion
