1. Human Gait

2. 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

3. Normal Gait
Series of rhythmical , alternating movements of the trunk & limbs which result in the forward progression of the center of gravity

4. Gait cycle - definition
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

5. Gait cycle

6. Time Frame:
A. Stance vs. Swing:
Stance phase = 60% of gait cycle
Swing phase = 40%
B. Single vs. Double support:
Single support = 40% of gait cycle
Double support = 20%

8. Defining the terms of Gait
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

9. Gait Terminology
Heel strike (initial contact) : heel contacts the ground
Foot flat (loading response) : plantar surface come and touch the ground
Mid stance : total plantar surface is in touch with the ground, total body weight passes through

10. Heel off (Terminal stance) : heel is off the ground, initial contact of the other leg occur
Toe off (Pre swing) : fore foot is off the grond, weight is shifted to the other leg

11. Acceleration (initial swing) : swinging leg begins to move towards the body
Mid swing : swinging leg is under the body
Deceleration ( terminal swing) : swinging leg is slowing down to start the next heel strike

12. Analyzing of Gait

13. Pelvic rotation: Pelvis remains relatively level in the sagittal plane
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

14. Pelvic tilt: 5o dip of the swinging side (i.e. hip adduction)
In standing, this dip is a positive Trendelenberg sign
Reduces the height of the apex of the curve of CG

15. Hip joint
Heel strike starts with 30 degrees hip flexion and trunk moves foreword over the foot
Extend an average of 40 degrees in combination with the lumbar vertebrae

16. Knee joint
Heel strike occurs in extended knee and is immediately followed by 15 degree of knee flexion
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

17. Ankle joint
Heel strike ankle would be in neutral position, and it would rapidly plantar flex for the foot flat and mid stance phases
When tibia moves over the fixed foot ankle is about 10 degrees dorsiflexion
In the heel off phase plantar flexion of 20 degrees

18. Determinants of Gait : Foot mechanism:
Lengthens the leg at toe-off as ankle moves from dorsiflexion to plantarflexion
Smoothens the curve of CG
Reduces the lowering of CG

19. This points follow a smooth sinusoidal curve with highest level at mid stance and lowest level at double support.
Oscillations of the body’s center of gravity ( COG – S2) vary from 2 – 5cm

20. Muscle work during gait
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

21. 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

22. Swing phase
Vastus medialis, latralis & intermdius has a concentric contraction before heel strike to extend the knee
Hip flexors concentric contraction

23. Gait Parameters Walking velocity Cadence Step length Stride length
Single support time
Double support time
Walking base

24. Analyzing Gait Should observe gait from both sides and front
Pelvic movement
Walking base
Step length
Arm swinging
Position of head & trunk

25. With increasing walking speeds:
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

26. Gait of a Child Wide walking base Cadence is high
Stride length is shorter
Initial contact with flat foot on ground
No/little reciprocal arm swinging

27. Gait of Elderly Most changes occur due to fear of fall
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

28. Abnormal Gait
Antalgic gait -- limp adopted so as to avoid pain on weight-bearing structures, characterized by a very short stance phase.
Propulsive gait -- a stooped, stiff posture with the head and neck bent forward
Scissors gait -- legs flexed slightly at the hips and knees like crouching, with the knees and thighs hitting or
crossing in a scissors
like movement

30. Spastic gait -- a stiff, foot-dragging walk caused by a long muscle contraction on one side
Ataxic gait -- an unsteady, uncoordinated walk, employing a wide base and the feet thrown out

31. Steppage gait -- foot drop where the foot hangs with the toes pointing down, causing the toes to scrape the ground while walking, requiring someone to lift the leg higher than normal when walking
Waddling gait -- a duck-like walk that may appear in childhood or later in life

32. Festinating gait -- a gait in which the patient involuntarily moves with short, accelerating steps, often on tiptoe, as in parkinsonism

33. Thank You