quiz 1 Flashcards
the scientific study of motion and the active and passive forces involved
kinesiology
what axis does the sagittal plane move around
frontal/x-axis
sagittal plane
divides left and right
horizontal plane
divides top and bottom
what axis does the horizontal plane move around
vertical/y-axis
what axis does the frontal plane move arond
sagittal/z-axis
degrees of freedom
number of planes available for a joint to move through
having a separation of the bones and the presence of a joint cavity
diarthrodial/synovial joint
connected by a hyaline or fibrocartilage producing little movement
cartilaginous joint
has no separation or joint cavity
fibrous joint
contractile unit of muscle
sarcomere
sliding filament theory of muscle contraction
muscles can shorten to half of their resting length
developed in the non-contractile components of muscles
passive tensions
developed in the contractile elements of muscles
active tension
the point where a 2-joint muscles cannot shorten any further even though there is more range available in the joints
active insufficiency
the point where a multi-joint muscle cannot be lengthened any further without damage to the fibers, even though there are no joint range of motion restrictions
passive insufficiency
where passive insufficiency occur
in the antagonist muscle
isometric muscle contraction
contraction with no change in muscle length
no movement occurs
isotonic muscle contraction
change in muscle length causing a joint angle change
movement occurs
concentric/eccentric
isokinetic muscle contraction
speed of movement is constant, resistance changes
can only be produced with special equipment
concentric contractions
muscle actively shortening
ex: lifting up bar
eccentric contractions
muscle actively lengthening from a shortened position
ex: bring bar back down
agonist is the ___ mover
prime
antagonist muscle
opposite motion to the agonist with potential to oppose, but is usually relaxed
synergist muscles
muscles that work together to enhance a particular motion
forces that influence movement
gravity
center of gravity
constant force that affects almost every motor act characterized by heaviness or weight
gravity
point at which the downward force created by mass and gravity is equivalent or balanced on either side of a fulcrum
center of gravity
factors affecting stability
height of COG above base of support
size of base of support
location of gravity line within base
weight of body
