Slide 1Slide 2Other Fatigue EffectsSlide 4JointsSynovial JointSlide 7Intervertebral DiscsAnthropometry (Science of measuring human body)PercentilesIE 5531IE 553 Engineering of Human WorkDr. Andris FreivaldsClass #4IE 5532IE 553 Engineering of Human WorkDr. Andris FreivaldsClass #4IE 5533Other Fatigue EffectsIE 5534Other Fatigue EffectsIE 5535JointsTypes of joints:•Synovial – articulating surfaces, surrounded by capsule (shoulder, knee)•Fibrous – fibers bridge gap (skull)•Cartilage – cartilage bridges gap (vertebral discs in spinal column)IE 5536Synovial Joint•Cartilage (cells 2%)–Collagen fibers (60%)–Proteoglycan gel (38%)–Poor regeneration•Liquid (synovial fluid)–Decreases friction–Through lubrication•Hydrostatic•Squeeze film•HydrodynamicIE 5537Vertebral ColumnIE 5538Intervertebral Discs•Role in body–Cushion impacts–Deform under loads–Transfer of fluids•Degeneration–Microfractures at high loads–Loss of fluids/solids–Drying up–Weakening of fibers–Catastrophic extrusionIE 5539Anthropometry(Science of measuring human body)•Why? Problems:•Large variability•Correlation poor•Measurements–Static/dynamic–Soft tissue–Pin joints–Many linksIE 55310Percentiles•kth percentile is a value such that k% of the data are at or below this value•5th/95th per → 1.645•2.5th/97.5th → 1.96•μ ±
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