SpinalBioMech Midterm 2 Lec 4-7 Flashcards
(56 cards)
Define Mechanical Advantage
Measure of mechanical effiency of a lever system
What is a mechanical advantage dependent on?
the type of lever system & the relationship btw the torque of an external force & the torque of a muscular force
(determined by length of MAs)
M Ad means?
mechanical advantage
What does EA stand for
Effort Arm
RA stands for ?
Resistance arm
Third class levers do what type of action?
Concentric Contraction
+>1 = mechanical _________
Advantage
0< 1 = mechanical ____________
disadvantage
Second class levers do _________ movements
eccentric
Which lever system is always at disadvantage?
Third-class levers
The effort force magnitude must always exceed the _______ ________ magnitude
Resistance force
The effort force magnitude must always _______ the resistance force magnitude
exceed
The third class lever systems the mechanical advantage is (less/ greater) than one
LESS
Second class levers are always at the mechanical _______
advantage
The mechanical advantage of of a second class lever is ______ than 1
M Ad = greater than one
First class levers can be at mechanical advantage, disadvantage, or neutral.
they are most often at mechaical ______
disadvantage
_______ chain has one end of segment or set of segments is free to move in space
Open chain
Open chains are :
where one end of the segment is free to move in space
Define closed chain
both sends of the segment are not free to move in space
1st class:
vs.
2nd class:
vs.
3rd class:
1st class: advantage, disadvantage, neurtal
2nd class: always mech. advantage
3rd: always disadvantage
The fxn of a joint is dependent on what 2 variables ?
- structure (design)
- Composition (materials)
More mobility of a joint = ______ stability
Less
The more stable a joint = _______ movement
less
