Chapter 9

1. Chapter 9 Evaluation of Gait

2. Introduction • Gait Analysis – functional evaluation of a person’s walking or running style • Systematic method of identifying specific deviations in the gait pattern and determining their cause and implications • Goals of analysis vary

3. Introduction • Dysfunctional or antalgic gait can arise from acute or chronic injury or improper biomechanics • Prohibits normal weight-bearing • Influences stresses placed on joint surfaces • Predisposes patient to additional injury • Rehabilitation and/or correction of biomechanics

4. Observation Techniques • Process of gathering, organizing, and interpreting sensory information • Observation best obtained by using stop-action video • Video can be slowed down and replayed • Permanent record on file • Limb position, ROM, speed of motion, force production, timing of events in gait cycle

5. Observation Techniques • Treadmills • Pros and cons • Stride length • Guidelines for observational gait analysis • Page 304 • Auditory information (cadence) • Correlate findings with orthopedic and postural evaluations • Figure 9-2, pages 305-306

6. Gait Cycle • Represents the combined function of the lower extremity, pelvis, and spinal column • Walking – cyclical motion, bipedal • Center of gravity • Easily displaced in the desired direction • Positioned high, second sacral segment • Greater portion of body weight is located in trunk, head, and shoulders • Figure 9-3, page 307

7. Gait Cycle • Components of normal walking gait do not transfer to most athletic activities • Specific to the motion: • Force distribution across the foot, muscle actions, joint motions, and center of gravity

8. Normal Gait • Normal cadence = 107 (+ 2.7) steps per minute • Normal stride length = 75 (+ 1.6) cm • Symmetrical and uninterrupted rhythm • Terminology – Table 9-1, page 307 • Rancho Los Amigos

9. Normal Gait • Affected by intrinsic factors • Joint ROM • Muscle strength • Body type • Gender • Affected by extrinsic factors • Incline of surface • Surface type • footwear

10. Gait Phases • Stance Phase • Initial contact of heel until toe breaks contact with surface (toe-off) • Swing Phase • Between toe-off and next initial contact • Open kinetic chain, non-weight bearing • Limb repositions itself • Figure 9-4, page 308

11. Gait Phases • During walking – one leg is in stance phase while the other leg is in the swing phase • Efficient walking • Minimal upward and side-to-side motion • Maximal forward motion • Rotation of pelvis in transverse plane adds to step length

12. Stance Phase • 60% of gait cycle • Closed kinetic chain during weight-bearing, allows forces from lower extremity to be transmitted to ground, producing movement • Leg decelerates just before initial contact, preventing injury to heel • Enables balance and push off

13. Stance Phase • 5 distinct periods: • Initial contact • Loading response • midstance • terminal stance • Preswing • Box 9-1, pages 310-311

14. Initial Contact • Begins with foot touching surface • Contact should be through lateral aspect of plantar surface • Opposite limb is ending with toe-off • Subtalar joint – supinated @ 5 degrees • Talocrural joint – dorsiflexed • Both limbs in contact with surface

15. Loading Response • Response to absorption of body weight by initiating flattening of the foot • Subtalar joint – pronates • Unlocks midtarsal joints, allowing foot to become flexible • Tibial internal rotation – increased medial forces at foot, leg, knee • Talocrural joint – plantarflexes

16. Loading Response • Muscle support – decelerates pronation and plantarflexion • Hip remains flexed • Period lasts until double limb support has ended

17. Midstance • Begins as body weight moves over stationary support limb and ends when center of gravity is directly over the foot • Subtalar joint – supinates • Locks midtarsal joints, makes foot a rigid lever • Preparing for efficiency during propulsion • Talocrural joint – dorsiflexes • Hip moves into extension

18. Terminal Stance • Starts as center of gravity passes over the foot and ends just before the contralateral limb makes contact with the ground • Body moves forward with weight shifting over metatarsal heads until contralateral limb provides new base of support • Toes extended, tibia externally rotated • Subtalar joint – supinated • Hip and knee continue to flex

19. Preswing • Transitional period of double support • Limb is uploaded and prepared to swing • Begins with initial contact of contralateral limb and ends with toe-off of stance limb

20. Swing Phase • Begins as soon as the toes leave the surface and terminates when the limb next makes contact with the surface • Gravity assists in pulling leg mass down • Momentum gained at toe-ff helps carry leg through the swing phase • Three periods • Initial swing, midswing, terminal swing • Box 9-2, pages 312-313

21. Initial Swing • Begins at the point where toes leave the ground and continues until knee reaches its maximum range of flexion (@ 60O) • Femur advances • Ankle dorsiflexes, allowing toe clearance • Subtalar joint - pronation

22. Midswing • Knee extends until tibia is vertical to surface • Thigh continues to advance, toe clearance is ensured, propulsion continues • Talocrural joint – dorsiflexed to neutral or slight dorsiflexion

23. Terminal Swing • Occurs from end of midswing to initial contact period of the stance phase • Trunk is erect • Thigh decelerates for heel contact • Knee extends to create step length for heel contact • Step length – distance traveled between initial contacts of right and left foot • Subtalar joint - supination

24. Qualitative Observation of Gait • Rise and fall of the body in vertical direction = 5cm • Path of center of gravity is sinusoidal or a smooth curve • No sharp braking • As speed increase, arm action is involved • Questions to address during gait analysis • Page 309

25. Running Gait • Series of smoothly coordinated jumps executed from one foot to the other foot • Purpose – to move body from one position to another at a moderate to fast speed • As speed increase – techniques changes • Arm swing ROM, stride length, cadence, and knee flexion ROM

26. Running Gait • Muscular force and speed of contraction also change • Control pronation during loading response and initiate supination prior to preswing

27. Walking versus Running Gait • 2 distinct differences: • Flight phase – neither foot is in contact with the ground • At no time are both feet in contact with the surface at the same time • Stance phase • Walking – 62% of the cycle; Running – 33% of the cycle • Same joints used • Differences in degrees of motion and timing of actions • Figure 9-5, page 314

28. Ground Reaction Forces • Every contact of the foot with the surface generates an upward reaction force • GRFs are measured and compared • Figure 9-6, page 315 • Vertical component of GRF during running is 2 to 3 times the runner’s body weight • Classified as rearfoot, midfoot, or forefoot strikers

29. Ground Reaction Forces • Factors influencing GRF patterns: • Running speed • Running style • Ground surface • Grade of incline • Shoes/orthotics • Questions to address during observation of running gait • Page 315

30. Pathologies Affecting the Gait Cycle • Box 9-3, page 316 • Table 9-2, page 317 • Acute Lower Extremity Strains and Sprains • Overuse Injuries • Leg Length Discrepancies • Functional Bracing