K3 - intro to kinesiology PDF

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intro to kinesiology...

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Most common type of lever in human body = 3rd class levers mechanical advantage = capacity to balance and overcome resistance Force arm = distance between axis and force Resistance arm = distance between axis and resistance When does the joint have a mechanical advantage? if force arm is greater than the resistance arm 2nd class levers mechanical advantage YES the force arm is always greater than resistance arm -advantage of strength 3rd class levers mechanical advantage NO the force arm is less than resistance arm advantage of speed 1st class levers mechanical advantage VARIES depends on axis advantage of speed and strength Dynamic biomechanics: osteokinematics = observable movement of bones (classified using planes/axes) Dynamic biomechanics: planes of movement -sagittal plane (right/left) -frontal/coronal plane (front/back) -transverse plane (upper/lower) Direction of the movement is determined by...? axis Axes are ________________ to the planes perpendicular

Sagittal axis = movements are in what plane? horizontally front to back movements in frontal/coronal plane Frontal/coronal axis = movements are in what plane? horizontally side to side movements are in sagittal plane longitudinal/vertical axis = movements are in what plane? vertical line - rotational movements are in transverse/horizontal plane Classification of joints -synarthroidal joint -amphiarthrosis joint -diarthrosis joint Synarthroidal joint = immoveable Amphiarthrosis joint = slightly moveable Diarthrosis joint = freely moveable Types of joints = uniaxial biaxial triaxial/multiaxial Uniaxial joint = movement in one axis (ex: elbow joint) Biaxial joint = movement in two axes (ex: wrist - flex/ext, rad/uln deviation) Triaxial/multiaxial joint = movement in all axes including all movements possible

(ex: shoulder - flex/ext, abd/add, int/ext) Types of uniaxial joints -hinge joints: allows flexion/extension -pivot joints: allows rotary movement Types of biaxial joints -condyloid/ellipsoid joints (one oval condyle fits into elliptical socket) -saddle joint (convex in one plane/concave in the other) Types of triaxial joints -ball and socket joints -gliding/plane joints -non axial joints - linear movement (ex: carpal bones joints, acromioclavicular) ***Closed packed position -maximal surface contact between the bones -attaching ligaments are under tension -capsular structures are taut -maximal joint stability ***Open/Loose packed position -joint surfaces do not fit perfectly -less stable -allow accessory movements of other joints athrokinematics = description of movement of articulating surfaces in relation to the direction of movement of extremity Fundamental movements between joint surfaces -rolling -slide -combined roll-sliding -spin Rolling motion of joints -surfaces are incongruent -new points on one surface meets new points on opposing surface -results in angular motion of bone -in normal joints, pure rolling doesn't occur but is in combo with sliding/spinning...