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 of progression between two

successive points of foot floor contact of the opposite feet. (Approximately = 70 cm + 10 cm)

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.