Gait Analysis Functional Tasks

Study Notes

Weight acceptance during initial contact and loading response.
Single limb support at midstance, when balance is most precarious.
Limb advancement during terminal stance and preswing, providing propulsive forces.

Kinematics: The science of motion during walking.
- Distance and time variables:
  - Step length: Distance between initial contact of one foot to the opposite foot.
    - Average step length in adults: 64 cm (women), 73 cm (men), 70.5 cm (overall).
  - Stride length: Distance between two successive foot contacts of the same limb.
    - Average stride length: 128 cm (women), 146 cm (men), 141 cm (overall).
  - Stride width: Horizontal distance between the midpoints of both heels.
    - Typical range for adults: 2.5 to 12.5 cm, averaging 8 cm.
  - Degree of toe out: Angle between the foot's line of progression and a line from the heel to the second toe.
    - Typical for adults: 7 degrees.
- Time variables:
  - Step time: Time spent during a single step.
  - Stride time: Time between successive foot contacts of the same foot.
  - Stance time: Time spent during the stance phase.
  - Swing time: Time when the foot is not in contact with the ground.
  - Single limb time: Time when only one limb is in contact with the ground.
  - Double limb time: Time when both feet are on the ground.
  - Swing/stance ratio: Ratio of swing time to stance time.
  - Cadence: Number of steps per minute.
    - Slow: 60-70 steps/min, Medium: 80-90 steps/min, Fast: 120 steps/min.
  - Speed: Distance traveled per unit time.
    - Average speed for men: 89 meters/min, for women: 74 meters/min.

Sagittal Plane:
- Pelvis:
  - Remains relatively level during gait, with a small anterior-posterior tilt excursion (about 3°).
- Hip joint:
  - Moves through 40° of sagittal motion in a single gait cycle.
  - Stance phase:
    - Starts at 25-30° flexion at initial contact and progresses into extension.
    - Reaches maximum hyperextension (10°) at terminal stance due to forward trunk movement.
  - Swing phase:
    - Starts near neutral and progresses into flexion.
    - Reaches peak flexion (slightly over 30°) at midswing.
  - Clinical Note: Excessive pelvic tilting can increase stress on the lumbar spine, potentially leading to low back pain.