Introduction to Kinesiology Flashcards
Osteokinematics
describes motion of bones relative to the three cardinal planes of the body
3 Cardinal Planes of the Body
Sagittal
Frontal
Transverse
Sagittal Plane
divides the body into left and right sections
Frontal Plane
divides the body into front and back sections
Transverse Plane
divides the body into upper and lower sections
Movement in Sagittal Plane
dorsiflexion and planter flexion
flexion and extension
forward bending and backward bending
Movement in Frontal Plane
abduction and adduction
lateral flexion
ulnar and radial deviation
eversion and inversion
Movement in Transverse Plane
internal and external rotation
axial rotation
Axis of Rotation
bones rotate around a joint in a plane that is perpendicular to an axis of rotation
Where is the Axis of Rotation Usually located
Typically located thorough convex member of joint
(ex. shoulder has movement in all 3 planes, so has 3 axes of rotation)
Movements in Axis or Rotation
flexion/extension occur around a medial lateral axis
abduction/adduction occur around a anterior- posterior axis
internal/ external rotation occur around a vertical axis
Degrees of Freedom
number of independent directions of movements allowed at a joint, corresponds to however many planes they have movement in
Proximal Segment Perspective
rotate against relatively fixed distal segment (closed chain)
Distal segment Perspective
rotate against a relatively fixed proximal segment (open chain)
Arthrokinematics
motion that occurs between articular surgaces of joints
Fundamental Movements Between Joint Surfaces
roll
slide
spin
Roll
multiple points along one rotating articular surface contact multiple points on another articular surface (tire rotating on pavement)
Slide
single point on one articular surface contacts multiple points on another articular surface (non rotating tire skidding across ice)
Spin
single point of one articular surface rotates on a single point on another articular surface (toy top rotating on one spot on the floor)
Closed and Loose Packed Positions at Joint
pairs of articular surfaces within most joints “fits” best, usually near end ROM
Closed-Packed Position
Position of maximal congruency where most ligaments and parts of capsule pulled taut providing joint stability
Loose- Packed Position
Accessory movements where most ligaments are slackened and joint is least congruent near midrange
Kinetics
Branch of the study of mechanics that describes effect of forces on body
Force
newtons second law, quantity of force can be measured by product of mass(m) that receives the push or pull, multiplied by acceleration (a) F=ma
Musculoskeletal Forces
force that acts on body often referred to generically a load that move, fixate, or otherwise stabilize body have potential to deform and injure
Stress-strain Curve
Changes as function of time and loading
Time
tissues in which physical properties associated with stress strain curve change as a function of time considered viscoelastic
Creep
Describes progressive strain of material when exposed to constant load overtime, is reversible
Creep Phenomenon
Explains why people are taller in am vs pm; constant compression caused by body weight on spine throughout the day squeezes small amount of fluid out of IVD; fluid is reabsorbed at night while in non-weight bearing positions
Rate
slope of stress-strain curve when placed under tension or compression increases throughout Its elastic range as rate of loading increases; rate sensitivity of viscoelastic connective tissues may protect surrounding structures of MSK system
Internal Forces
produced from structures located within body, can be active or passive
External Forces
produced by forces acting outside the body, usually originate from either gravity pulling or external load
Two Outcomes of Forces Exerted on Body
forces can potentially translate a body segment
if forces applied at some distance perpendicular to axis of rotation can also produce potential rotation of joint
Movement Arm
perpendicular distance between axis of rotation and joint
Torque
product of a force and its movement T= F*d
What Happens When Force Acts Without a Movement Arm?
can push or pull an object generally in linear fashion, whereas torque rotates around Axis of rotation
When can a muscle produce torque across a joint?
if It produces a force in plane perpendicular to axis of rotation of interest
acts with associated moment arm distance > zero
an active muscle is incapable of producing torque if force either pierces or parallel associated axis of rotation
Isometric
Occurs when muscle produces pulling force while maintaining constant length
internal torque = external torque
no muscle shortening or rotation at joint
Concentric
occurs as muscle produces pulling force as It contracts(shortens)
internal torque> external torque
contracting muscles creates rotation of joint in direction of pull of activates muscle
Eccentric
occurs as muscle produces pulling force as It is being lengthened by another more dominant force
internal torque< external torque
