ANAT30007 Lecture Notes - Lecture 33: Weight Transfer, Bipedalism, Anatomical Terms Of Motion
17 Jun 2018
School
Department
Course
Professor
Humans: LL more body weight, UL lower body weight
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Human bipedal walking is better balanced
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Weight transfer in bipedal locomotion
Effect of gravity causes rotational axes
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Locomotor Page 7
Effect of gravity causes rotational axes
in joints and result in moment arms
that cause flexion or extension
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Effects of gravity resisted by ligaments
or muscles
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Lumbosacral angle: use erector spinae
to make postural changes
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Hip: extensor moment, iliopsoas and
iliofemoral ligament important
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Knee: knee capsule
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Ankle: plantar muscles (gastroc+sol)
work against gravity
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Gait cycle
Heel strike: dorsiflexors/quads contract concentrically; gluts+hams contract eccentrically
(antagonistic)
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Loading response: dorsiflexors contract eccentrically
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Midstance: triceps start contraction
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Terminal stance: plantar flexors contract
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Preswing: adductors pull knee into midline
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Mid-swing: glut med/min (contralateral abductors) prevent tilt; iliopsoas/rectus femoris flex
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Double support occurs at the start of heel strike and start of swing phase
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Pelvis
Locomotor Page 8
Document Summary
Humans: ll more body weight, ul lower body weight. Effect of gravity causes rotational axes in joints and result in moment arms that cause flexion or extension. Effects of gravity resisted by ligaments or muscles. Lumbosacral angle: use erector spinae to make postural changes. Hip: extensor moment, iliopsoas and iliofemoral ligament important. Heel strike: dorsiflexors/quads contract concentrically; gluts+hams contract eccentrically (antagonistic) Mid-swing: glut med/min (contralateral abductors) prevent tilt; iliopsoas/rectus femoris flex. Double support occurs at the start of heel strike and start of swing phase. Humans: shorter iliac blades, positioned laterally - gives glut med/min a more lateral position (change from extensors to abductors and medial rotators) Sciatic notch deep in humans, shallow in chimps. High bicondylar angle of femur - valgus knee. Long neck of femur: increases moment arm of glut med/min. Shorter neck of femur - shorter moment arm of gluts.
