MSS13 Gait

Question 1

Neurophysiology of gait

Answer 1

3 parts:

1. CNS
2. PNS
3. MSS

Question 2

Pathology affecting gait

Answer 2

• stroke
• cerebral palsy
• Parkinson
• spinal cord injury
• motor neuron disease
• spinal muscular atrophy
• peripheral neuropathy
• fracture

Question 3

Prerequisites of normal gait

Answer 3

1. ***Stability in stance
2. Sufficient ***foot clearance during swing
3. Appropriate ***swing phase pre-positioning of foot
4. Adequate ***step length
5. ***Energy conservation

Question 4

Gait cycle

Answer 4

1. Stance phase (60%)
   - **Heel strike (initial contact)
   - **Foot flat (loading response)
   - Midstance
   - **Terminal stance (heel off)
   - **Preswing (toe off)
2. Swing phase (40%)
   - Initial and Mid-swing
   - Terminal swing

Require coordination of agonist and antagonist muscle

Question 5

Walking vs Running gait cycle

Answer 5

Running:
40% stance phase
60% swing phase with Double float (leap, ***both foot off ground)

Question 6

Gait evaluation

Answer 6

• History taking
• Physical examination

1. CNS
   - stroke
   - cerebral palsy
   - degenerative disease
2. PNS
   - injury
   - peripheral neuropathy
3. MSS
   - muscle weakness
   - joint contracture (permanent shortening)
   - bone deformity

Question 7

Gait evaluation: Kinematics vs Kinetics

Answer 7

Kinematics:
describes motion without considering the forces that cause them to move (irrespective of force)
- stride length
- range of motion
- velocity

Kinetics:
describes effect of forces and torques on the motion
- ground reaction force

Question 8

Stride length
Step length
Stride / step width
Cadence

Answer 8

Stride length:
- distance between 2 successive placements of the ***same foot

Step length:
- distance by which one foot moves forward in front of the ***other one

Stride / step width:
- side to side distance between 2 feet

Cadence:
- ***number of steps in a given time

Question 9

Motion analysis in gait laboratory

Answer 9

1. video camera
2. infrared camera
3. force platform

• -> Evaluate:
• Joint rotation (of flexion and extension)
• Joint moment (of flexion and extension)
• Joint power (of generation and absorption)

Question 10

***Common abnormal gait pattern

Answer 10

1. Antalgic gait (***reduced stance phase due to pain)
2. Trendelenburg gait (hip swing)
   - weakness in **abductor muscles of the lower limb, **gluteus medius and ***gluteus minimus
3. Short limb gait
   - **knee bending (longer limb)
   - **circumduction (longer limb 畫半圓)
   - ***tiptoe (shorter limb)

Question 11

Gait abnormalities in cerebral palsy

Answer 11

1. Spasticity of calf muscle resulting in ***tiptoeing
2. Soft tissue contracture results in ***crouching
   - -> treatment: soft tissue release, foot stabilization, correct gait abnormalities

Question 12

Advances in management of gait abnormalities

Answer 12

1. Improved technology in gait analysis
2. Better understanding of the abnormalities
3. Technological advancement
   - robotic assisted gait training
   - exoskeleton for paraplegic patients (impairment in motor or sensory function of the lower extremities)