gait 1 Flashcards
what is gait?
- any method of locomotion characterised by loading and unloasding the limbs
- the manner, style or pattern of walking
what are the** 2 phases of gait** and what %’s do they make up of the gait cycle?
- stance - 60%
- swing - 40%
define the velocity/speed of gait
- distance walked in a given time
- measured in m/s
define gait cycle
- everything that happens from initial contact of one lower limb to initial contact of the same lower limb
what is a step & what units is it measured in?
- the forward movement of one lower limb
- measured in metres
what is a** stride** and what units is it measured in?
- the forward movement of both lower limb
- ie 2 steps
- measured in metres
what is step width?
- lateral distance between 2 feet
- measured in metres
what is cadence?
- numbers of steps taken in 1 minute
what are the important temporal spatial parameters to measure for gait & what range should the values be in for each?
- speed - 1.2-1.5m/s
- cadence - 110-120 steps/min
- stride length - 1.2-1.5m
how can the height of a person affect the cadence and stride length?
tall vs small
- tall - will increase stride length and reduce cadence - as the person has long legs/levers
- small - will reduce stride length and increase cadence - as the person has shorter legs / levers
what is kinematics?
- the analysis of movement in terms of position and displacement of body segments
what is kinetics?
- description of human mvt in terms of forces which may be internal or external
what is the ground reaction force?
- the** upward force applied by the ground to the foot** in response to the downward force applied by the foot to the ground
what are the pre-requisites for normal gait?
- stability in stance
- foot clearance in swing - ie your foot isnt dragging along the ground
- pre positioning for initial contact ie dorsiflexion of ankle etc
- step length
- energy conversion
what is initial contact of the stance phase?
- The heel strike (initial response, contact response, or weight acceptance). In this subphase, the heel of the foot makes initial contact with the ground. It requires the body’s weight to be accepted by the leg making contact with the ground.
describe the** kinematics/joint motion **in **initial contact **of stance phase
- knee is in 0-5 degree flexion
- ankle in DF
- hip in 30-40 degree flexion
what is ‘loading response’ or (foot flat) of the stance phase of the gait cycle?
- The foot flat (loading response) is the second subphase when the foot rolls forward until the entire plantar surface is in contact with the ground.
Describe the joint motion and the muscle action during the loading response of the stance phase
- rapid plantar flexion of ankle - eccentric action of tib anterior muscle
-
knee flexes to 10-20 degrees - eccentric contraction of the vasti muscles
* hip - gradual extension by concentric contraction of glut max and hamstring muscles (ie hip extensors) - mid foot pronation
what is **mid stance **in the stance phase?
- The midstance starts when the weight of the body is propelled forward, so that the** greater trochanter of the femur is directly above the middle of the foot.** At this stage, our entire body weight is being balanced over one leg.
what kinematics/ joint motion & muscle action is occuring at mid stance?
ankle, knee , hip
- ankle - gradual dorsiflexion- eccentric contraction for soleus
- knee - fully extends
- hip - gradual extension - concentric contraction of hip extensors
what is terminal stance or heel off?
- begins when the heel leaves the floor and continues until the contralateral foot contacts the ground
- single leg support
what** kinematics / joint motions **and muscle actions are occuring in terminal stance ?
- ankle - peak DF (due to angle of tibia relative to the foot)
- knee starts to flex
- hip reaches peak extension
what is the ‘pre-swing’ of the stance phase of gait?
- final stage of stance phase
- pushing the toes into the ground while the ankle plantar flexes, creating forward propulsion
what joint motion occurs in the pre swing stage of stance phase?
- ankle plantarflexion rapidly before the foot leaves the ground
- knee begins to flex - 30-40 degree flexion
- hip flexion before foot leaves the ground - concentric action of iliopsoas
what is the initial swing phase?
- first swing phase
- foot is lifted off the ground
- ankle dorsiflexes and the knee flexes so that the foot and toes can be moved from the ground
- hip also flexes to bring the leg forward
what is the mid swing phase?
The mid-swing phase is the second phase when the non-weight-bearing leg passes directly beneath the body and past the weight-bearing leg. At the same time, the trunk is moved forward so that the weight of the body is directly over the weight-bearing leg
what is the terminal swing phase ?
- the foot is moved to a position in front of the body, the** knee extends** and momentum decelerates. The lower limb is now ready for heel strike and prepares to accept the transfer of body weight, for the start of the next stance phase
