Kinetics and Kinematics of Gait

 Kinetics and Kinematics of Gait

Stance phase

The following table gives an insight into the kinetics and kinematics of gait during the stance phase. 

Thus during:

a. Heel strike The hip is in flexion of 25-30°, the knee is in 50° flexion and the ankle is at 0° plantar flexion.

The GRFV is anterior to the hip and knee joints, posterior to the ankle joints.

b. Foot flat The hip is still in 25-30° flexion, the knee in flexion and the ankle in plantar flexion. However, the GRFV is anterior to the hip but posterior to the

knee and ankle joints.

c. Midstance The hip is in extension the knee is also in extension and the ankle is in dorsiflexion. The GRFV is passing anterior to posterior in the hip

region, posterior to anterior in the knee region and anterior to the ankle joint.

d. Heel off During heel off the hip is in extension, the knee is passing slowly from extension to flexion and the ankle from dorsiflexion to plantar flexion.

The GRFV passes posterior to the hip, anterior to posterior in the knee and anterior at the ankle joints.

e. Toe off During toe off, the hip is in flexion, the knee is also in flexion and the ankle joint is in plantar flexion. The GRFV is posterior to hip and knee and

anterior in the ankle joints.

Swing phase 

a. During acceleration phase, the hip joint is in flexion, the knee joint is also in flexion and the ankle joint is in dorsiflexion.

b. During midswing, the hip is in flexion, the knee is in extension and the ankle joint is in dorsiflexion.

c. During deceleration phase, the hip joint progresses from flexion to extension, the knee joint from extension to flexion and the ankle joint continues tob bein dorsiflexion.

 Factors that help in shock absorption during gait:

The following joint movements help to absorb the shock of impact each time weight is shifted from one limb to the other:

1. Ankle plantar flexion

2. Subtalar pronation

3. Knee flexion

4. Hip flexion

5. Hip abduction.

FORCES RESPONSIBLE FOR GAIT

The function of the locomotor unit is to move the passenger unit forward. This is possible by contraction of the muscles and the external forces like the gravitational and ground reaction forces.

Note

Kinetics This comprises a study of the forces that produce or change the movements (the gravitational force and the ground forces).

Kinematics It is a study of the angular movements and the changes brought about by the action of various muscle groups.