Gait Gait is a general motion composed of
translatory progression of the body as a whole, produced by rotatory movements of body segments
The head, Arms & Trunk, known as HAT make around 75% of total body weight
Each lower extremity is about 10% of total body weight
Gait Gait is more demanding on lower
extremities than does static posture.
Before one can walk they must be able to balance HAT in a erect standing posture, transfer HAT from one extremity to another, lift one lower extremity off the ground & place it in front of the other extremity in an alternating pattern
These activities require coordination, balance, proprioceptive senses, & integrity of the joints & muscles
Phases of Gait Cycle Stance Phase
Defined as the period in which some portion of the foot of the reference extremity is in contact with the ground. It extends from the point of initial foot contact of the extremity to the point at which only the toes of the same extremity are in contact with the ground.
2. Swing Phase
Defined as the period in which the foot of the reference extremity is not in contact with the ground. It extends from the instant that the toe of the reference extremity leaves the ground to just prior to initial contact of the reference extremity
Stance Phase
Begins when one extremity contacts the ground
Continues as long as the foot is on the ground
Make 60% of gait cycle
Swing Phase
Extremity does not contact the ground at any time
Begins as soon as the toe of the extremity leaves the ground
Make 40% of gait cycle
2 -Foot FlatOccurs immediately
after heel strike and is the point at which the foot fully contacts the ground
1 -Acceleration
Begins once the toe of the reference extremity has left the ground, it continues until midswing
2 -MidswingOccurs when the reference
extremity passes directly below the body. It encompasses the period immediately following maximum knee flexion & continues until the tibia is in a vertical position
Distance & Time Variables
1. Stance time2. Single support
time3. Double support
time4. Stride length5. Stride duration6. Step length7. Step duration
8. Cadence9. Walking
velocity10.Acceleration11.Speed12.Width of base
of support13.Degree of toe
out
1 -Stance Time It is the amount of time that passes
during the stance phase of one extremity in a gait cycle
2 -Single Support Time It is the amount of time that passes
during the period when only one extremity is on the ground in a gait cycle
3 -Double Support Time It is the amount of time that a person spends with both
feet on the ground during a gait cycle.
It increases in old people & people with balance disorders
It decreases as speed of walking increase
In a single gait cycle there are 2 period of double limb support
It occurs when one lower extremity is beginning its stance phase and the other lower extremity is ending its stance phase
4 -Stride Length It is the linear distance from the point of heel
strike of the reference extremity to the next heel strike of the same extremity
It decrease in old people
It increases as speed of gait increases
The length of one stride is traveled during one gait cycle
5 -Stride duration The amount of time it takes to
accomplish one stride
Stride duration = gait cycle duration
6 -Step Length It is the linear distance between two
successive points of contact of opposite extremities
7 -Step Duration The amount of time spent in a single step When there is weakness of an extremity or pain,
step duration may be decreased on the affected side, & increases on the unaffected side.
Step vs. StrideStep: A heal strike of the one lower
extremity to a heal strike of the other lower extremity
Stride: a stride contains two steps, so it's from the heal strike of one lower extremity to the next heal strike of the same lower extremity
8 -Cadence
Is the number of steps taken by a person per unit time
9 -Walking Velocity It is the rate linear forward motion of the body Walking velocity = distance walked/time
10 -Acceleration
It is the rate of change of velocity with respect to time
11 -Speed Speed of gait can be slow, free and fast
Free speed: a person's normal walking speed
12 -Width of Base of Support
It is found by measuring the linear distance between the midpoint of the heel of one foot & the same point on the other foot
It is necessary for stability, it increases it
13 -Degree of Toe Out The angle formed by each foot’s
line of progression and a line intersecting the center of the heel & the second toe represents the angle of foot placement