KIN 365 1st Edition Exam 3 Study Guide Mechanical Components of Movement I II III IV Systems and Frames of Reference a System i Body or group of bodies or objects whose motion is to be examined b Frame of Reference i Stationary ii Moving Orientation in Space a Body composed of movable segments or links that move fluidly through planes of motion and around axis of rotation b Movement in relationship with the i Ground ii Special planes and axes 1 Includes both a Horizontal planes and axes b Vertical planes and axes Orientation in Space Planes of Motion a Planes of motion i Sagittal 1 Vertical plane 2 Divides right and lef ii Frontal 1 Vertical plane 2 Front and back iii Horizontal 1 Horizontal plane 2 Top and bottom Orientation in Space Axis of rotation a Axis of rotation i All planes have an axis of rotation ii Any axis that passes through body s center of gravity is considered a principle or cardinal plane 1 Think of it as line that runs perpendicular to one of planes of body iii Axis 1 Mediolateral 2 Anteroposterior 3 Superoinferior b Body and segmental planes and axis i Each axis of rotation corresponds to a plane of motion 1 Mediolateral AOR Sagittal plane 2 Anteroposterior AOR Frontal plane V 3 Superoinferior AOR Horizontal plane c Mediolateral axis i Runs across midline as if body cut in half at waist ii Perpendicular to sagittal plane iii Rotating around mediolateral axis occurs in sagittal plane of motion iv Ex 1 Flexion extension of knee hip elbow wrist 2 Plantar and dorsi flexion of ankle d Anteroposterior Axis i Runs across midline as if cutting body in half through belly button ii Perpendicular to frontal plane iii Rotation around Anteroposterior axis occurs in frontal plane of motion iv Ex 1 Abduction adduction of hip shoulder 2 Lateral flexion of spine 3 Eversion inversion of foot at subtalar and transverse tarsal joints e Superoinferior Axis i Cuts body in half through forehead nose dividing body into right and lef halves ii Perpendicular to transverse plane iii Rotating around superoinferior axis occurs in transverse plane of motion iv Ex 1 Internal external rotation of shoulder 2 Protraction retraction 3 Supination pronation of hand 4 Horizontal flexion extension at hip shoulder Types of Motion a Two main types of motion occur through these planes and around the axes i Linear straight line ii Rotary around fixed axis of rotation b Linear motion i Two main types 1 Rectilinear a Movement in straight line b Ex i Running 50 meters 2 Curvilinear a Movement NOT in straight line NOR around a fixed axis b Ex i Arch of a baseball afer hit by a bat ii High jump ii Linear displacement 1 How to measure or quantify linear motion 2 Ex a Ran 50 meters b Hit baseball 550 feet c Rotary i Movement of an object around a fixed or restricted axis ii Ex 1 Bending knee while walking a Rotary movement around knee axis iii Three components 1 Torque a Turning force responsible for rotation b Produces rotary motion 2 Angular displacement a Measurement of rotary motion b Calculated in degrees i Even though some points of motion move farther or faster than others ALL angles are the same degree 3 Radius of rotation a Distance from axis of rotation to the object i Greater the radius of rotation of a point the longer the curvilinear or circular path it forms around axis VI Force a Causes or tends to cause some kind of change in the motion or shape of an object or body b Can be measured in i Pounds lb feet per pound ii Newtons N meters per Newton c Product of mass and acceleration i Mass amount of matter in body ii Acceleration speed at which the object is moving d Pressure i Force acting over a given area ii Force area iii Can be measured in 1 Lbs in 2 pounds per square inch 2 N m 2 Newtons per square meter iv Ex 1 Snow shoes 2 By increasing area and distributing same weight over larger area decreased pressure e Mass gravity and weight i Mass 1 Amount of stuff matter object 2 Key is amount ii Weight 1 Mass in relation to gravity 2 Effect gravity has on mass iii Farther away from center axis less weight iv Center of gravity 1 Point at which all of the mass of an object body is evenly distributed ie no net torque 2 Point in space not a real object 3 Can be outside of an object body a Boomerang diver in folded position f VII Inertia i Property of a body or object that resists change in motion ii Ex 1 When an elevator goes up quickly and then stops you briefly keep moving iii Directionally proportional to mass 1 More mass an object has the more inertia the object has Force and Movement a Force i Something that possesses the capability to cause a change in motion of a system 1 Pull of a push on an object in an attempt to affect the object s motion or shape ii Result of interactions action reaction 1 If no net force no change in motion iii Measured in Newton s 1 1 Newton force required to give a 1 kg mass an acceleration of 1 m s s iv Two main types 1 Internal intrinsic forces a Forces acting within defined system 2 External extrinsic forces a Forces that interact with the system from the outside 3 Only external forces can cause a change in motion of a body or object a Newton s first law of motion law of inertia i If forces action on an object system are balanced the acceleration of that object will be zero ii An object will only accelerate change its direction if there is a net or unbalanced force acting on it iii A system at rest will stay at rest and a system in motion will stay in motion in a straight line until acted upon by an external force 4 Internal forces only cause change in shape of the system v Muscles can be both the internal force that doesn t cause change in motion and the external force that does cause a change in motion 1 Only when muscle is the external force does it cause the change in motion a Walking i Internal force muscle pushing against ground ii External force ground reaction fore pushing back up against us iii It is the external force the ground reaction force that actually causes movement b Properties of Force i Magnitude 1 Because force is vector quantity has magnitude 2 Amount or size of the force applied ii Direction 1 Because force is vector quantity has direction VIII 2 Way in which the force is applied a Upward downward forward backward iii Point of application 1 Point or location where force is applied iv Line of action 1 Path along which vector travels Force Vectors a Vector quantity i Has magnitude and direction ii Ex weight b Scalar quantity …