Muscular Contractions
Which type of contraction occurs when a muscle generates force without changing length?
Isometric
What principle states that motor units either fully contract or not at all?
All-or-none
Which connective tissue connects muscle to bone?
Tendon
What are the three components of a lever?
Effort, fulcrum, load
Which part of the skeleton includes the skull and vertebral column?
Axial
During a bicep curl, lowering the weight involves which contraction?
Eccentric
Which muscle fiber type is most fatigue-resistant?
Type 1
Which type of joint allows the greatest movement?
Synovial
In the human body, most levers are:
Third class
Which term describes a position closer to the center of the body?
Proximal
Explain the difference between concentric and eccentric contractions.
Concentric = muscle shortens; eccentric = muscle lengthens while under tension.
What determines motor unit recruitment during activity?
Intensity and type of activity (size principle—smaller units recruited first).
State one main function of cartilage.
Reduces friction, absorbs shock, or supports structure.
What determines the class of a lever?
The relative positions of effort, fulcrum, and load.
Define “abduction.”
Movement away from the midline of the body.
Which contraction type involves movement at a constant speed throughout the range of motion?
Isokinetic
Which fiber type produces the greatest force?
Type IIx
Which connective tissue connects bone to bone?
Ligament
Which lever class has the greatest mechanical advantage?
Second class
Movement occurs in which of the following?
Planes and axes
Why are eccentric contractions important in injury prevention?
They control movement and deceleration, reducing strain on joints and tissues.
How do hypertrophy and atrophy affect motor unit recruitment?
Hypertrophy improves recruitment efficiency and force; atrophy reduces recruitment capacity and strength.
Explain the relationship between joint structure and function.
Joint structure determines range of motion and stability (e.g., synovial joints allow more movement but less stability).
Give one example of a lever outside the body used in sport.
Tennis racket, baseball bat, golf club, etc.
Name two planes of movement and a movement that occurs in each.