LOCOMOTION 3102021 SCNM ANAT 617 Locomotion 1 POSTURE

LOCOMOTION 3/10/2021 SCNM, ANAT 617, Locomotion 1

POSTURE • To attain balance and proportion of the body mass and framework • The carriage of the body as a whole, the attitude of the body, or the position of the limbs POSTURE IN REFERENCE TO LOCOMOTION • Adaptive postural control is learned during locomotion • Postural adjustments require anticipatory motor actions

POSTURAL ALIGNMENT

CENTER OF GRAVITY (CG) • DEFINITION: WHERE THE VECTOR SUM OF ALL THE FORCES OF GRAVITY ON A BODY SUM. THEREFORE, GRAVITY ACTS ON THE BODY AS IF THE ENTIRE FORCE WAS CONCENTRATED AT THE CG. • THE BALANCE POINT OF THE BODY. CG 3/10/2021 FULCRUM SCNM, ANAT 617, Locomotion 4

STANDING CENTER OF GRAVITY CG • LOCATED 1 cm POSTERIOR TO THE SACRAL PROMONTORY • IN MIDLINE OF BODY • PLUMB LINE 3/10/2021 SCNM, ANAT 617, Locomotion 5

STANDING LINE OF FORCE PASSES THROUGH HIP JOINT: NEUTRAL STABILITY PASSES JUST ANTERIOR TO KNEE JOINT: KNEE STABLE WHEN LOCKED PASSES ANTERIOR TO ANKLE JOINT: PLANTAR FLEXORS STABILIZE 3/10/2021 SCNM, ANAT 617, Locomotion 6

STANDING • WITH THE EXCEPTION OF THE PLANTAR FLEXORS, THERE IS MINIMAL MUSCULAR ACTIVITY REQUIRED TO REMAIN STANDING UPRIGHT. • WHEN CG SHIFTS, LINE OF FORCE SHIFTS AND THE BODY ACTS TO RESTORE LINE OF FORCE TO ORIGINAL POSITION. – i. e. Person standing w/out external support, abducts right leg. He doesn’t fall over because he makes an adjustment by tilting his body to the opposite side of the abduction in anticipation of the shift in his center of gravity. 3/10/2021 SCNM, ANAT 617, Locomotion 7

WALKING • Shifts in Center of Gravity – multiple planes • Developmentally humans learn to crawl before they learn to walk • Spinal Reflexes • Flexors and Extensors • Coordination of muscle groups 3/10/2021 SCNM, ANAT 617, Locomotion 8

WALKING AS RAISING & LOWERING CG • CG RAISED CG REACHES APEX BODY "FALLS" FOOT CATCHES FALL CYCLE REPEATS 3/10/2021 SCNM, ANAT 617, Locomotion 9

MOVEMENT OF CG FROM SIDE TO SIDE • CG MOVES APPROXIMATELY 1 INCH LATERALLY, TO THE WEIGHT BEARING SIDE WITH EACH STEP. 3/10/2021 SCNM, ANAT 617, Locomotion 10

MECHANICS OF MUSCULAR ACTIVITY 3/10/2021 SCNM, ANAT 617, Locomotion 11

LOCOMOTION PHASES • STANCE: the period of time during which one or two feet are on the ground • SWING: portion of the gait cycle during which a limb is being advanced forward without ground contact • ONE GAIT CYCLE: Right foot strike>Followed by left toe off>Left foot strike>Right toe off>Ends with right foot strike

STANCE PHASE ANKLE DORSIFLEXED KNEE EXTENDED HIP FLEXED HIP EXTENDED KNEE EXTENDED PLANTAR FLEXORS STABILIZE ANKLE KNEE EXTENDED HIP EXTENSORS PLANTAR FLEXORS HIP HYPEREXTENDED • HEEL STRIKE MIDSTANCE FOOT FLAT PUSH-OFF CYCLE REPEATS 3/10/2021 SCNM, ANAT 617, Locomotion 13

SWING PHASE LATERAL ROTATION COMPLETE KNEE EXTENSORS HIP FLEXORS KNEE FLEXORS DORSIFLEX LATERAL ROTATION EVERSION HAMSTRING’S DECELERATE LIMB DORSIFLEXION INVERSION • ACCELERATION MIDSWING 3/10/2021 DECELERATION CYCLE REPEATS SCNM, ANAT 617, Locomotion 14

METHODS OF GAIT ANALYSIS • • • A clinical methods performed : Electrogoniometers Electromyography (EMG) Visual gait analysis Timing the gait cycle Direct motion measurement systems

ABNORMAL GAIT PATTERNS • • • Anterior Trunk Bending Posterior Trunk Bending Lateral Trunk Bending Hyperlordosis Circumduction Steppage