Human Gait. - ppt download

Gait is the process or components of walking Each person has a unique style Requires balancing on the one leg while the other moves forward and vise versa Movement of trunk and upper limbs
Gait is the process or components of walking Each person has a unique style Requires balancing on the one leg while the other moves forward and vise versa Movement of trunk and upper limbs
Normal Gait Series of rhythmical , alternating movements of the trunk & limbs which result in the forward progression of the center of gravity.
The rhythmic alternating movements of the 2 lower extremities which result in the forward movement of the body. Simply stated, it is the manner in which we walk.
Single support = 40% of gait cycle. Double support = 20%
Stance phase – activity occurring when the foot is in contact with the ground divided in to 5 main components, Heel strike, foot flat, mid stance, heel off &toe off Swing phase - activity occurring when foot is not contact with ground Divided in to 3components accelaration, mid swing & deceleration
Mid stance : total plantar surface is in touch with the ground, total body weight passes through.
Toe off (Pre swing) : fore foot is off the grond, weight is shifted to the other leg.
Mid swing : swinging leg is under the body. Deceleration ( terminal swing) : swinging leg is slowing down to start the next heel strike.
Forward rotation of the pelvis in the horizontal plane approx. 8o on the swing-phase side. Reduces the angle of hip flexion & extension. Enables a slightly longer step-length w/o further lowering of CG.
In standing, this dip is a positive Trendelenberg sign. Reduces the height of the apex of the curve of CG.
Extend an average of 40 degrees in combination with the lumbar vertebrae.
Stance phase again the knee extends and begins to flex at the heel off. The second flexion cycle occurs in swing phase with an average of 70 degrees required to clear the swinging foot from the floor.
When tibia moves over the fixed foot ankle is about 10 degrees dorsiflexion. In the heel off phase plantar flexion of 20 degrees.
Lengthens the leg at toe-off as ankle moves from dorsiflexion to plantarflexion. Smoothens the curve of CG. Reduces the lowering of CG.
Oscillations of the body’s center of gravity ( COG – S2) vary from 2 – 5cm.
Stance phase Heel strike – Quadriceps muscle before heel strike concentric contraction, at the heel strike eccentric contraction to decelerate the knee flexion Just after the HS calf muscle has a concentric then isometric contraction to stabilize foot in supination
Foot flat – dorsiflexors eccentric contraction Calf muscle eccentric contraction Mid stance & Heel off – Concentric contraction of the peroneus longus and brevis to support the toes Toe off - Rectus femoris provide
Hip flexors concentric contraction.
Single support time. Double support time. Walking base.
Pelvic movement. Walking base. Step length. Arm swinging. Position of head & trunk.
Stance phase: decreases. Swing phase: increases. Double support: decreases. Running: By definition: walking without double support. Ratio stance/swing reverses. Double support disappears. ‘Double swing’ develops.
Stride length is shorter. Initial contact with flat foot on ground. No/little reciprocal arm swinging.
Other factors are loose muscle mass, less active, poor hearing & vision. Slow walking velocity, more. time in stance phase. Increased double support. time. Reduced step length & vertical. displacement. Wider base.
Ataxic gait -- an unsteady, uncoordinated walk, employing a wide base and the feet thrown out.
Festinating gait -- a gait in which the patient involuntarily moves with short, accelerating steps, often on tiptoe, as in parkinsonism