lecture 11 levers and torque

Question 1

The _____ experienced by an object is determined by adding up all the individual force vectors acting upon that object

Answer 1

net force

Question 2

The force created by the muscle is called a ____

Answer 2

force vector.

Question 3

Two vectors can be added together to determine the _____

Answer 3

result (or resultant)

Question 4

Vertical component (rotary component) of the force vector is _____ to the moving bony lever

Answer 4

perpendicular

Question 5

______ completes the right angle triangle and either acts to compress or distract the joint

Answer 5

Horizontal component

Question 6

At joint angles less than 90 degrees the horizontal component of the force is ____

Answer 6

stabilizing (compressive

Question 7

At joint angles of 90 degrees as in Figure B, the horizontal component of the force is_____

Answer 7

neutral

Question 8

At joint angles greater than 90 degrees the horizontal component of the force
is ____

Answer 8

destabilizing (distracting)

Question 9

vectors have ___ and ____

Answer 9

magnitude and direction

Question 10

Increasing the angle of pull increases the _______ of the muscular force and improves efficiency of the muscle

Answer 10

rotary component

Question 11

pulleys increase _____

Answer 11

rotary component

Question 12

Levers are rigid bars (bones in our case) that act around a _____ when a force is applied

Answer 12

fulcrum (joint)

Question 13

First Class Lever Axis lies between _____and _______

Answer 13

effort (force), resistance

Question 14

First Class Lever advantage

Answer 14

balance

Question 15

example of first class lever

Answer 15

occiput on c1

Question 16

Second Class Lever Resistance lies between the ______ and the _____

Answer 16

effort force, fulcrum (axis

Question 17

Third Class Lever Effort force lies between ____ and the____

Answer 17

fulcrum, resistance

Question 18

third class lever example

Answer 18

bicep flexion

Question 19

Third Class Lever Advantage ______ end despite small ROM at effort end of lever

Answer 19

increased ROM at resistance

Question 20

Third Class Lever Disadvantage ___

Answer 20

large effort required to overcome resistance

Question 21

**a joint force of 30 degrees is stabilizing or destabilizing

Answer 21

stabilizing

Question 22

_____ is the turning or rotary force generated by a muscle

Answer 22

Torque

Question 23

_____ is the perpendicular distance between the muscle force vector and the axis of rotation

Answer 23

Moment arm

Question 24

The _____ component generates rotation and is perpendicular to the moving bony lever

Answer 24

vertical (Y-axis)

Question 25

The _____ vector acts to compress or distract the joint

Answer 25

horizontal

Question 26

the _____vector is a factor in producing torque

Answer 26

vertical

Question 27

***Torque is ____ when the muscle force vector is applied at 90 degrees to its bony lever as this is when the moment arm is longest

Answer 27

greatest

Question 28

In the case of knee extension, the patella increases the _____ for the force of quads as a group

Answer 28

moment arm