Gait Analysis Overview

Gait Analysis

• Gait involves a multi-layered story, with movement primarily in the sagittal plane (flexion and extension).
• Many body segments and planes are involved in gait.
• Understanding gait terminology is crucial for more in-depth gait analysis.
• The material presented serves as a foundational component for analyzing gait.

Gait Analysis - Introduction

• Studying gait involves observing repeated falls with intention.
• The swing and stance phases of gait account for 40% and 60% respectively of the gait cycle.
• Double and single support phases are also components of gait.
• Identifying events which define phases is a key aspect.

Gait Cycle - Phases (Right Foot)

• Loading response (10% of gait cycle):
  • Initial contact (IC) - Stance phase begins, Right heel contacts ground.
  • Opposite Toe Off (OTO) - Left toe leaves the ground.
• Mid-Stance (40% of gait cycle):
  • Heel rise (HR) - Heel lifts off the ground.
  • Opposite initial contact (OIC) - Left foot makes initial contact with ground.
• Terminal Stance (TST): -Toe off (TO) - Right toe leaves the ground.
• Pre-swing (PSW):
  • Opposite initial contact (OIC) - Left foot makes initial contact with ground.

Loading Phase

• Purpose: Transitioning from a double support phase to single support.
• Mechanism: The front leg absorbs impact energy and transitions to support the entire body weight.

Mid-Stance Phase

• Purpose: Maintain stability and forward movement of the centre of mass (COM) over the supporting extremity.
• Mechanism: The COM travels over the supporting foot, ensuring efficient forward motion without disturbing balance.

Terminal-Stance Phase

• Purpose: Preparing for the transfer of weight from the supporting leg to the other.
• Mechanism: The COM moves beyond the forefoot, preparing the transition to the swing phase.

Pre-Swing Phase

• Purpose: The body prepares to undergo the swing phase of gait.
• Mechanism: Loading up the opposite leg, unloading the support limb and transferring the body weight.

Swing Phase

• Purpose: Moving the limb forward for progression and preparing to catch the fall.
• Mechanism:
  • Dual pendulum motion for limb advance
  • Swinging at the hip joint (flexion), then the knee joint (extension).
• Minimum foot clearance (MFC): Ensuring sufficient vertical space for the limb to travel.

Early Swing, Mid-Swing and Terminal Swing

• Early swing (ESW): Begins with toe-off (TO) and ends with foot adjacent (FA).
• Mid-swing (MSW): Right foot is in the same anterior/posterior position as the left foot. Peak anterior velocity of the leg.
• Terminal Swing (TSW): Begins with tibia vertical (TV) and ends with initial contact (IC). Preparing to support the body weight.

Temporal-Spatial Parameters (TSP)

• Step width: The distance between the feet.
• Stride length: The distance covered by one complete gait cycle of one leg.
• Cadence: Steps per minute.
• Gait speed: The rate of progression.

Wrapping Up

• Calculating gait speed, step length, and cadence are essential parts of the analysis.
• Determining normal, comfortable gait speed for adults is important.