Biomechanics of Gait Analysis PDF

Overview of Human Locomotion and Gait Evaluation Cherri S. Choate, DPM Human Locomotion   Gait Cycle  Concepts  Components  Center of Pressure Gait Evaluation  Observations  Treatment application Gait Cycle Concepts  The gait cycle consists of a cycle of repetitive motions  Each cycle consi...

Overview of Human Locomotion and Gait Evaluation Cherri S. Choate, DPM Human Locomotion   Gait Cycle  Concepts  Components  Center of Pressure Gait Evaluation  Observations  Treatment application Gait Cycle Concepts  The gait cycle consists of a cycle of repetitive motions  Each cycle consists of heel contact of the support limb to heel contact again of that same limb  Each gait cycle consists of two phases:  Stance (≈ 58-62%)  Swing (≈ 38-42%) Gait Cycle Components You must know the following… Phases of Gait Periods of Gait Moments of Gait Events of Gait …by the end of the lecture Phases of the Gait Cycle  Stance Phase  Swing Phase HC HC 0% 10% 20% 30% 40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 80% 90% Swing Phase of Gait Stance Phase of Gait 0% 70% 27% 67% 100% FFL HO TO 100% Gait Cycle Periods  Stance Phase   CONTACT PERIOD  Midstance Period  Propulsion Period  Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 27% FFL 67% HO No Periods Swing Phase of Gait Stance Phase of Gait 0% Swing Phase 100% TO 0% HC Gait Cycle Periods  0% Stance Phase   Contact Period  MIDSTANCE PERIOD  Propulsion Period 10% 20% 30% Swing Phase  40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 70% 80% 90% 100% Swing Phase of Gait Stance Phase of Gait 0% No Periods 27% 67% 100% 0% FFL HO TO HC Gait Cycle Periods Stance Phase   Contact   Period  10% 20% 30% PERIOD 40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 70% 80% 90% 100% Swing Phase of Gait Stance Phase of Gait 0% No Periods Midstance Period  PROPULSION 0% Swing Phase 27% 67% 100% 0% FFL HO TO HC Gait Cycle Periods Stance Phase  0%   Contact Period  Midstance Period  Propulsion Period 10% 20% 30% Swing Phase  40% 50% 60% HC 70% 80% 90% 100% Swing Phase of Gait Stance Phase of Gait Contact Period Midstance Period Propulsion Period 27% 40% 33% 0% No PERIODS 27% 67% 100% 0% FFL HO TO HC Moments of Gait HC 0% HC 10% 20% 30% 40% 50% 60% 70% 80% 90% Swing Phase of Gait Stance Phase of Gait Contact Period Midstance Period Propulsion Period 27% 40% 33% 0% 27% 67% 100% HC FFL HO TO MOMENTS 100% Review  Stance Phase  Contact Period   Midstance Period   Forefoot Loading Moment Heel Off Moment Propulsion Period   Heel Contact Moment Forefoot Loading Moment Heel Off Moment  Toe Off Moment Swing Phase  No Periods  Toe Off Moment  Heel Contact Moment Gait Cycle Events  Normal movements of the body during gait  Focus on:  Hip  Ankle  STJ  1st Ray Phases of the Gait Cycle  Stance Phase  Swing Phase HC 0% HC 10% 20% 30% 40% 50% 60% 70% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 90% Swing Phase of Gait Stance Phase of Gait 0% 80% 27% 67% 100% FFL HO TO 100% Gait Cycle Events At the Beginning of Contact  Hip joint is internally rotating and flexed  Ankle joint is dorsiflexed  STJ is supinated Gait Cycle Events Heel Contact→Forefoot Loading Pelvis and leg continues to internally rotate Hip joint moves from flexed to extended Ankle joint starts plantarflexing to get forefoot to the ground Subtalar joint pronates (CKC) Lateral side of the foot loads 1st ray plantarflexes Phases of the Gait Cycle  Stance Phase  Swing Phase HC 0% HC 10% 20% 30% 40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 80% 90% Swing Phase of Gait Stance Phase of Gait 0% 70% 27% 67% 100% FFL HO TO 100% Gait Cycle Events At Beginning of Midstance  The pelvis and hip start externally rotating  The hip continues to extend  AJ is plantarflexed  STJ is pronated (but not pronating) Gait Cycle Events Forefoot Loading→Heel Off Pelvis, femur, and tibia continue to externally rotate as opposite leg moves through the swing phase Hip joint moves to full extension Ankle joint starts CKC dorsiflexion STJ supinates to NP by the end of Midstance Heel comes off the ground Phases of the Gait Cycle  Stance Phase  Swing Phase HC 0% HC 10% 20% 30% 40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 80% 90% Swing Phase of Gait Stance Phase of Gait 0% 70% 27% 67% 100% FFL HO TO 100% Gait Cycle Events At Beginning of Heel Off  The pelvis and hip joint are externally rotated  The hip joint is extended  AJ is 10 degrees plantarflexed and heel is completely unweighted  STJ is in neutral position Gait Cycle Events Heel Off →Toe Off  Pelvis, and femur continue to externally rotate  Hip joint begins to flex again in early propulsion  Ankle joint plantarflexes through propulsion to about 20 degrees plantarflexed  STJ continues to supinate Phases of the Gait Cycle  Stance Phase  Swing Phase HC 0% HC 10% 20% 30% 40% 50% 60% Contact Period Midstance Period Propulsion Period 27% 40% 33% HC 80% 90% Swing Phase of Gait Stance Phase of Gait 0% 70% 27% 67% 100% FFL HO TO 100% Gait Cycle Events At Beginning of Swing  The pelvis and hip are externally rotated  The hip joint is flexed  AJ is plantarflexed 20 degrees  STJ is supinated Gait Cycle Events Toe Off →Heel Contact Pelvis, and femur start to internally rotate Hip joint continues to flex Ankle joint rapidly dorsiflexes STJ supinates Gait Cycle Events  Heel hits the ground Gait Cycle Events  Heel hits the ground inverted Gait Cycle Events  Subtalar joint pronates from the Ground Reactive Force (GRF) Gait Cycle Events  Midtarsal joint unlocks Gait Cycle Events  Leg internally rotates Gait Cycle Events  Lateral side of the foot hits the ground Gait Cycle Events  First ray plantarflexes… gently bringing forefoot to ground Gait Cycle Events  Opposite limb swings forward externally rotating the support leg… supinating the STJ and locking the MTJ Gait Cycle Events  Tibia moves forward, on what is now a rigid lever, causing the heel to lift Gait Cycle Events  The leg swings forward with the foot supinated ready to contact the ground inverted Gait Cycle Events Forces During Gait Ground Reactive Force  GRF greater than body weight at two points   At forefoot loading Just after heel off Center of Pressure STABLE FOOT UNSTABLE FOOT STABLE FOOT GAIT EVALUATION Observations of Gait   Use gait cycle markers to evaluate  Heel contact  Forefoot loading  Heel Off  Toe Off Basic observations  Stance Position of Calcaneus at Heel Contact  Midfoot motion during Midstance  Timing of Heel Off   Swing  Extensor Firing during Stance Stance Observations Heel Contact Position  Normal:  Inverted  Possibilities  Inverted  Everted  Perpendicular Midtarsal Stability during Midstance  Normal  Stable  No Motion after FFL Choices –Stable after FFL –Unstable after FFL Heel Off Timing  Normal   Heel should remain on the ground as the hallux of the swing leg passes the malleolus of the support leg Possibilities  Heel comes off ground earlier  Heel comes off ground later Swing Observation Extensor Substitution  Some humans hold their foot maximally pronated during swing using their extensor digitorum longus  This tells us two things:  The foot will hit and remain maximally pronated through the entire stance phase of the gait cycle  The patient has a propensity to develop shin splints Summary  Gait Cycle  Concepts  Phases, Periods, Moments,  Events during gait  Pressures during gait  Gait Evaluation  Normal observations  Heel Contact Position  Midtarsal Stability during Midstance  Ground Reactive Forces  Heel Off Timing  Center of Pressure  Extensor Substitution Thank You