KinesiologyQuiz1Weeks1-3 Flashcards
Kinematics
branch of mechanics that describes the motion of a body, without regard to the forces or torque that may produce the motion
Translation vs. Rotation
Translation: linear motion in which all parts of a rigid body move parallel to and in the same direction as every other part of the body Rotation: motion in which an assumed rigid body moves in a circular path around some pivot point (axis of rotation)
Motion of the body during walking
center of mass of the human body (just anterior to the sacrum) moves in a curvilinear manner
Active vs. Passive movements
Active: caused by stimulated muscles Passive: caused by sources other than active muscle contraction i.e. gravity, tension in connective tissue, etc.
Osteokinematics
motion of bones relative to the three principal planes of the body: sagittal, frontal, and horizontal
Sagittal Plane
flexion and extension; dorsiflexion and plantar flexion; forward and backward bending
Frontal Plane
abduction and adduction; lateral flexion; ulnar and radial deviation; eversion and inversion
Horizontal Plane
internal (medial) and external (lateral) rotation; axial rotation
Axis of Rotation
bones rotate around a joint in a plane that is perpendicular to the axis of rotation, axis of rotation will shift throughout movement (imperfect sphere)
Medial-lateral (ML) axis of rotation (shoulder)
flexion and extension
Anterior-posterior (AP) axis of rotation (shoulder)
abduction and adduction
Vertical axis of rotation (shoulder)
internal and external rotation
Degrees of Freedom
number of independent movements allowed at a joint; up to 3 degrees of angular freedom at a joint (3 dimensions of space)
Accessory movements
slight passive translations that occur in most joints defined in 3 linear directions
Two perspectives of joint movement
1) proximal segment can rotate against the relatively fixed distal segment; 2) distal segment can rotate against a relatively fixed proximal segment; (knee flexion only describes relative motion)
Kinematic Chain
Open: distal segment of a kinematic chain is not fixed to the earth or other immovable object; Closed: distal segment is fixed to the earth or other immovable object; (used to describe relative segment kinematics)
Arthrokinematics
describes the motion that occurs between the articular surfaces of a joint, most surfaces are curved (convex and concave)
Fundamental movements between joint surfaces
Roll: multiple points contact multiple points; Slide: single point contacts multiple points; Spin: single point contacts single point
Convex-on-concave movement
roll and slide occur in opposite directions (abduction of shoulder)
Concave-on-convex movement
roll and slide occur in same direction (tibial-on-femoral knee extension)
Example of spin movement
radius of forearm on capitulum of humerus during pronation; internal and external rotation of the 90-degree abducted glenohumeral joint; flexion and extension of the hip
Close-packed position
position of joint’s maximal congruency, accessory motions are minimal (usually near the end range, knee’s is full extension)
Open (Loose)-packed position
all positions other than a joint’s close-packed position, accessory movements are maximal (typically at mid-range, biased toward flexion)
Kinetics
branch of mechanics that describes the effect of forces on the body