1. Gait Analysis – Objectives
To learn and understand:
The general descriptive and temporal elements of the normal walking movement
The important features and components of both the swing and stance phases of the gait cycle
The joint range of motion and muscle activity during walking
The differences between movement patterns, muscle activity, range of motion, and forces of walking and running
The clinical methods of studying gait
Gait changes with normal ageing

2. Gait Analysis – Outline
Source:
Jones, K. & Barker, K. (1996) Human Movement Explained, pp (on reserve)
Clinical uses of gait analysis
The gait cycle
Range of motion at the joints in walking
Running analysis
Muscle activity
Clinical methods of gait analysis
Gait changes with age and disease

3. Clinical uses of gait analysis
Assesses the degree and extent of departure from the norm
Documents changes due to therapeutic interventions
Evaluates results of rehab (improvement)

4. Walking Analysis … the process
A gait cycle consists of two steps, or one stride “the activities that occur from the point of initial contact of one lower extremity to the point at which the same extremity contacts the ground again”
During one gait cycle, each extremity passes through two phases, a single stance phase and a single swing phase.

5. The Gait Cycle:

6. Walking – The Stance Phase

7. Components of the Stance Phase
Stance phase comprises 60% of the gait cycle
Heel strike – moment when the heel first strikes the ground
Foot flat – from heel strike to when the full foot is in contact with the ground
Midstance – body weight is directly over the stance leg
Heel off – moment the heel of the stance leg leaves the ground
Toe off – when only the toe of the stance leg is in contact with the ground

8. Walking – The Swing Phase

9. Components of the Swing Phase
Swing phase comprises 40% of the gait cycle
Acceleration – the toe of the stance leg leaves the ground and begins to swing forward
Midswing – the swinging leg is directly beneath the body
Deceleration – the swinging leg continues forward towards knee extension but is slowing down as it travels, stopping just prior to full knee extension and heel contact with the ground

11. GRF while walking

12. GRF while walking

13. Range of motion at the joints
Trunk - As left leg moves forward, pelvis rotates clockwise as viewed from above 7 deg
Hip Joint (30 deg flex at HS strike, 180 deg at TO)
Stance - extension, adduction, internal rotation
Swing - flexion/extension, abduction, ext rotation
Knee joint deg at HS, 160 deg at mid-stance
Ankle joint - Neutral at HS, hinges down during support, and plantar flexes at TO . ROM 30 deg
COM displacement +5 cm bilaterally and vertically (Fig 15.3)

14. Running Analysis…...
Running is similar to walking BUT, it differs significantly in a number of ways, for example:
No period of “double support”
Float periods (both feet airborne)
Requires greater balance
Requires greater strength
Requires greater ROM at hip, knee, and ankle joints
Involves greater excursion of center of mass
Involves greater ground reaction forces

15. Running – A Gait Cycle

19. Muscle Activity in Running...
Glut. Max. & med. -- active at the beginning of the stance phase (concentrically) and again at the end of the swing phase (eccentrically).
Iliopsoas -- active during a portion of the swing phase (concentrically).
Quadriceps -- 1st 10% of the stance phase (eccentrically) and last 20% of the swing phase (concentrically).
Hamstrings -- initial portion of the swing phase (concentric) and at the end of the swing phase (eccentric).
Plantar flexors (gastrocnemius & soleus) – Mid and latter part of stance phase

20. Clinical Methods of Studying Gait
Observational techniques (use checklist, and videotape when possible)(Slide 17)
Quantitative analysis – when more precise info is needed
time-distance measurements (stop watch, footswitches) (Slide 18)
Kinetic techniques (Slide 19 & 20)
Kinematic analysis
Videotaping, semi-automated imaging (Slide 21)
Combined kinematic and kinetic (Slides 20 & 21)

21. Sample gait checklist

22. Analysis aids: Timing of foot contact

23. Analysis aids: Pressure on bottom of feet

24. Force Plates – Measurement of ground reaction forces

25. Optoelectric system - Vicon

26. Gait changes with normal ageing
Lower walking speeds
Shorter step and stride lengths
Reduced plantar flexor force production
Reduced hip extension
Reduced pelvic girdle and hip rotation
Increased double support time
Greater variation in stride width
Wider base of support