biomechanics kinematics 1 and 2 (velocity and acceleration)

define human kinematics

area of biomechanics that includes description of motion without regard for the forces producing the motion

5 descriptors of motion

type, location, direction, magnitude, rate

3 types of motion

rotation, translation, combined

define rotation

angular displacement that occurs around/about an axis (center of rotation)

rotation occurs how relative to the axis

around/about

define translation

linear displacement that occurs along an axis, can be either straight line or curvilinear

translation can be either

straight line or curvilinear

combined motion is

rotation and translation

how do points move in translation

every point on the segment moves the same linear distance

how do points move in roation

every point on the segment moves the same angular distance

what does location of motion mean

reference to axis of motion

what tool is used to talk about location of motion

coordinate (reference) system

a coordinate system defines motion in a unique ____ way

objective

2 characteristics of coordinate systems

absolute (global) vs relative

cartesian or orthogonal (perpendicular)

global/absolute coordinate system

has a fixed reference point/axis/origin

relative coordinate system

describes a position based on an origin that can move

what motion occurs in the frontal plane

adduction abduction

what motion occurs in the sagittal plane

flexion and extension

what motion occurs in the horizontal/transverse plane

rotation

what type of motion occurs around coronal/mediolateral axis

sagittal plane motion (flexion, extension)

what type of motion occurs around an anteroposterior axis

frontal plane motion (adduction, abduction)

what type of motion occurs around a vertical/longitudinal/axial axis

transverse plane motion (rotation)

2 other names for vertical axis

longitudinal and axial

coronal axis AKA

mediolateral axis

motion happens around an axis that is _____/_____degrees to it

perpendicular, 90

translation describes a change in

position

how do we describe position

body (segment or point) described in terms of its distance from the origin

how do we describe orientation

body described in terms of degrees of distance from origin

what does perspective mean in motion

distal/proximal moving with respect to distal/proximal

how is magnitude measured in translation

m, cm, in etc

how is magnitude measured in rotation

degrees, radians

velocity definition

change in position over time

acceleration definition

change in velocity over time

linear velocity is velocity of a ___ ____

translating segment

angular velocity is velocity of a ___ segment

rotating

linear velocity units

m/sec

linear acceleration units

m/sec^2

angular velocity units

deg/sec

angular acceleration units

deg/sec^2