Analysis of gait
Kinematics Analysis
Definition:
It is a branch of mechanics which deals with description of motion without referring to it causes. So, it is a descriptive of geometrical analysis.
Parameters:
1. Spatial parameter: (Distance)
1)Step length.
2)Stride length.
3)Stride length to lower extremity length ratio.
4)Base of support.
5)Step or stride width.
6)Foot angle (degree of toe out.
2. Temporal parameter: (Time)
1)Step time.
2)Stride time.
3)Stance duration.
4)Swing duration.
5)Swing / stance ratio.
6)Speed, distance time.
7)Cadence, steps / min.
3. Angular displacement.
Spatial parameter
(Distance dimension)
Evaluation:
-It can be done via foot print using tape measurement, water, protractor, marks.
-Then draw a line of progression which is a hypothetical line corresponding with the direction of walking.
Measurement of spatial parameters:
1- Step length:
It is the linear distance in the plane ofprogression
between two successive points of footfloor
contact of the opposite feet.
(Approximately = 70 cm + 10cm)
2- Stride length:
It is the linear distance in the plane of progression between two successive points of foot floor contact of the same foot.
(Approximately = 150 cm + 15 cm)
One stride = 2 steps in one gait cycle)
3. Stride length/ Lower Extremity length ratio SL/ LEL
ratio: It is the ratio between stride length and lower
extremity length. (Nearly = 1.7 ± 0.12)
Lower extremity length:
is measured by tape measurement from greater trochanter to lateral maleollus.
4. Stride or step width:
It is the distance between two lines cutting feet equal halves (8 cm ± 3.5 cm = 10 – 15 cm)
5. Base of support: (BOS)
It is the area over which the body is supported or assumed.
Dimensions:
a- Longitudinal dimension:
The longitudinal distance between the two furthest points of two opposite feet from heel of right foot to toes of left foot.
b- Horizontal dimension:
The horizontal distance between the two furthest points of two opposite feet from lateral border of right foot to lateral border of left foot.
6. Foot angle:
It is the angle between 2 lines:
•First line is extending from second toe to the heel center.
•Second line is the line of progression or parallel to it
(7o -10o up to 20o.
2, Temporal Parameter
(Time dimension)
Evaluation: can be done by using a stop watch.
Measurement of temporal parameters:
1. Step time:
It is time interval between successive instant of foot floor contact of the opposite feet. (0.8 sec.)
2. Stride time:
It is the time interval between successive instant of foot floor contact of the same foot.
(1.09 o.o6 sec = 1.6 sec)
3. Stance duration:
It is the time while the foot is in contact with the
floor.
4. Swing duration:
It is the time while the foot is not in contact with the
floor. (0.4 sec.)
5. Swing / stance ratio:
It is the ratio between swing time and stance time
(57+ 0.02)
6. Speed: It is distance / time.
- In male: 89 meter/min.
- In female: 74 meter/min. (45 cm / sec)
7. Cadence:
It means number of steps per unit time.
(11o + 6 steps /min)
Slow: 60 – 70 Steps / min.
Medium: 80 – 90 Steps / min.
Fast: 120 Steps / min.
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