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Ch 1. Gait Cycle. Nomenclature. Gait: feature or pattern of locomotion (walks, runs, crawls, etc) Locomotion: movement of body Gait cycle (GC): single sequence of functions (support and transfer of body weight) by one limb
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Nomenclature • Gait: feature or pattern of locomotion (walks, runs, crawls, etc) • Locomotion: movement of body • Gait cycle (GC): single sequence of functions (support and transfer of body weight) by one limb • Gait phases: division of GC stance (60%) and swing (40%) of one limb
Nomenclature • Stride: IC of one limb – next IC of same limb • Step: IC of one limb – IC of opposite limb • Cadence: # step or stride / minute • Double limb support: both feet contact with ground • Single limb support: opposite limb is in swing • Running: no double limb support
Typical SpatioTemporal Parameters Parameter Average value Velocity 80 m/min Cadence 113 steps/min Stride length 1.41 m Stance 60% Swing 40% Double support 10%, 10% J Perry: Gait analysis, 1992
Phases of Gait Cycle(Initial Contact: 0-2%) • Period: heel-strike (contra: Pre-swing) • Function: Positioning of foot to start stance with heel-rocker
Phases of Gait Cycle(Loading Response: 0-10%) • Period: Heel contact - contra toe off (contra: Pre-swing) • Function: Heel-rocker, Shock absorption
Phases of Gait Cycle(Mid-Stance: 10-30%) • 1st half of single limb support interval • Period: toe off (contra) – body weight aligned over the forefoot (heel-rise of ipsi foot) • Function: progression over the stationary(supporing) foot
Phases of Gait Cycle(Terminal Stance: 30-50%) • 2nd half of single limb stance • Period: heel-rise(ipsi) – heel-strike (contra) • Function: progression beyond the supporting foot
Phases of Gait Cycle(Pre-Swing: 50-60%) • Period: IC (contra) – toe-off (ipsi) (contra: IC & LR) • Function: positioning (preparation) of the limb for swing
Phases of Gait Cycle (Initial Swing: 60-73%) • Period: heel-off(ipsi) – ipsi foot is aligned to contra foot • Function: foot clearance of the floor & limb advancement
Phases of Gait Cycle (Mid Swing: 73-87%) • Period: limbs opposite – tibia vertical (ipsi) • Function: limb advancement & foot clearance from the floor
Phases of Gait Cycle (Terminal Swing: 87-100%) • Period: vertical tibia – heel-strike • Function: shank advance ahead of thigh & preparation for stance
Quantitative Analysis • Sophisticated quantification • Primary components - Spatiotemporal parameter - Foot pressure - Kinematics: spatial motion of joint, limb - Kinetics: moment, force - EMG: muscle activity - Energetics: energy consumption
Terminal-Swing Initial-Swing Mid-Swing
Gait cycle: sequence of stance and swing Gait parameters: stride length, step length Gait periods: stance and swing Gait phases: IC, LR, MST, TST, PSW, ISW, MSW, TSW Quantitative analysis: kinematic, kinetic, EMG, Energy Summary