Chapter 7: Biomechanics Flashcards
What are the anatomical planes of movement?
sagittal
frontal
transverse
What plane divides the body into right and left segments?
Sagittal plane
What’s an example of the sagittal plane?
Flexion and extension
What plane separates the body into ventral (anterior) and dorsal (posterior) segments?
Frontal (coronal) plane
What plane separates the body into superior and inferior segments?
Transverse (axial) plane
What’s an example of the frontal (coronal) plane?
abduction, adduction, and lateral
What’s an example of the transverse plane?
Rotational movements
What are the 3 primary joints forming the shoulder girdle?
The glenohumeral (GH) joint
The acromioclavicular (AC) joint
The sternoclavicular (SC) joint
The study of mechanical laws related to movement or structure is called . . .
Biomechanics
What are the two main types of biomechanic systems?
Dynamic and static
What do we call systems in motion with acceleration
that create uneven forces acting on the body?
Dynamic systems
What are the characteristics of static systems?
At rest
No acceleration
Still with no motion
Constant motion with no acceleration
What is velocity?
The direction and rate of displacement
What’s the difference between kinematics and kinetics?
Kinematics describes motions of the body
Kinetics describes the forces acting on a body in motion
What’s the most common mechanical machine with the body? What does it consist of?
Lever systems, which consist of a bar and an axis
How do levers function?
Levers rotate around an axis as a result of force applied to move weight or applied against resistance
What’s another name for an axis and force?
Fulcrum
Load or effort
The bones are the . . .
The joints are the . . .
The muscles contract to . . .
levers
axes
apply force
What’s the common lever?
Third-class
What is torque?
Turning effect of force applied to the various levers to create movement
What is eccentric force?
Force applied in a direction not in line with the center of rotation when an axis is fixed, necessary for rotation
How is torque determined?
Force x length x distance (fulcrum and the force)
How does torque affect human movement?
The length of the lever determines the amount of velocity
For example, a tennis player can strike a tennis ball harder and with more velocity with a straight arm than with a bent elbow
When is a shorter level preferred?
When speed is desired instead of velocity
What mechanisms enhance range of motion and speed or change the direction of movement?
Wheels, axles, and pulleys