Chapter 3: Kinesiology Flashcards
What is a motive force?
Causes an increase in speed or a change in direction
What is a resistive force?
Resists the motion of another external force
Define concentric
The muscle is acting as the motive force
The muscle shortens as it creates tension
Define eccentric
The muscle is acting as the resisting force (against gravity)
The muscle lengthens as it creates tension
Define isometric contraction
When muscle tension is being produced without the muscle changing in length
In what plane do flexion and extension occur?
Sagittal Plane
In what plane do abduction and adduction occur?
Frontal Plane
In what plane does internal/external rotation occur?
Transverse Plane
What is a closed chain exercise?
One where the end of the chain farthest from the body is fixed
i.e. when the feet are fixed on the floor during a squat
Closed chain exercises compress joints and help to stabilize them
Closed chain exercises involve more muscles and joints than open chain exercises, which leads to better neuromuscular coordination and overall stability at the joints
What is an open chain exercise?
Where the end of the chain is free or open such as during leg extensions the feet are in the air
Open chain exercises tend to involve more shearing forces at the joints
What are Penniform muscles?
The muscle fibers run diagonal to the line of pull. Allows a greater number of fibers to be packaged into a given cross-sectional area
Designed for higher force production
Example: Quadriceps
What are Longitudinal Muscles?
Long, thin muscles with parallel fibers that run in the same direction as the length of the muscles
Allows for speed of contraction, yet it’s force production is small
Example: sartorius, Rectus abdominus
Define co-contraction
When the agonist and antagonist muscles contract simultaneously to stabilize the joint.
Example: the torso muscles stabilize the spine safely to move an external resistance
Define Joint Mobility
The range of uninhibited movement around a joint or body segment
Define Joint Stability
The ability to maintain or control joint movement or position
