Save
or

or

taken

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

focusNode
Didn't know it?
click below

Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size     Small Size show me how

# Biomech. pg 100-110

### Lippert ch.8 - Biomechanics pages 100-110

What are the 3 states of equilibrium? stable, unstable, and neutral [p100]
stable equilibrium occurs when an object is in a position where disturbing it would require its Center Of Gravity (COG) to be raised [p100]
example of stable equilibrium a brick or a person lying flat on the floor [p100]
unstable equilibrium occurs when only a slight force is needed to disturb the object [p100]
example of unstable equilibrium balancing a pencil on its pointed end or a person standing on one leg [p100]
neutral equilibrium exists when an object's COG is neither raised nor lowered when it is disturbed [p100]
example of neutral equilibrium a ball rolling across the floor or a person moving across the room seated in a wheelchair [p100]
What effect does lowering the COG have on an object? the object will become more stable [p100]
If an object's Line of Gravity (LOG) shifts beyond its Base of Support (BOS), what will happen to the object? the object will fall over [p101]
When a person leans to one side, their COG will move to that side. What can they do to help maintain their balance? raise their opposite arm or widen their stance [p101]
On a very windy day, how should a person stand to be the most stable? facing into the wind and placing one foot behind the other to widen their BOS in the direction of the wind [p101 & Figure 8-20]
What effect does mass have on stability? more mass = more stability [p101]
What effect does friction have on a Base of Support (BOS)? more friction = more stability [p101]
Why are patients on crutches encouraged to look down the hall instead of at their feet? Focusing on a stationary object will improve their balance as opposed to focusing on a moving object. [p101]
Name 4 simple machines and which are in the human body. lever, pulley, wheel and axle (in the human body) inclined plane (not in the body) [p102]
What are machines used to change? magnitude or direction of a force [p102]
basic rule of all simple machines the advantage gained in power is lost in distance
lever rigid bar that can rotate around a fixed point when a force is applied to overcome resistance. Example: bone. [p102]
axis A fixed point around which a lever rotates. a.k.a. fulcrum [p102]
force causes the lever to move, usually muscular, a.k.a. effort [p102]
resistance weight and/or pull that must be overcome for motion to occur a.k.a. load [p102]
force arm (FA) distance between the force and the axis [p103]
resistance arm (RA) the distance between the resistance and the axis [p103]
first class lever Force _______Resistance Axis
example of 1st class lever in human body cervical flexion and hyperextension [p104]
second class lever Axis__Resistance__Force
example of 2nd class lever in human body ankle plantar flexion [p105]
third class lever Axis__Force__Resistance
example of 3rd class lever elbow flexion pertaining to the biceps [p106]
Which type of lever favors speed and distance (ROM)? 3rd class levers [p106]
Which type of levers favor power? 2nd class levers [p106]
What type of lever is the brachioradialis normally during elbow flexion? 2nd class lever [p106]
Which type of lever will also favor speed and distance (ROM) when the axis is placed close to the force? 1st class lever [p103]
What type of lever is a wheelbarrow an example of? 2nd class lever [p104]
When does the biceps become a second class lever? during elbow extension [p107]
How does the brachioradialis become a 3rd class lever during elbow flexion? when weight is added to the hand, thus changing the resistance [p107]
pulley A grooved wheel that turns on an axle with a rope or cable riding in the groove. A pulley changes the direction or magnitude of a force. [p108]
fixed pulley simple pulley attached to a beam, acting as a 1st class lever, only to change direction [p108]
example of pulley in human body the lateral malleolus of the fibula serves as a pulley for the peroneus longus [p108]
movable pulley (not found in human body) the end of the rope is attache to a beam, the rope runs through a pulley to the other end where the force is applied, the load (resistance) is suspended from movable pulley [p108 & figure 8-34]
mechanical advantage number of times the machine multiplies the force [p108]
wheel and axle a wheel attached to and turning with an axle [p109]
example of a wheel & axle in the human body passive shoulder rotation [p109]
How does having a larger wheel change what happens at the axle? the larger wheel is essentially a longer Force Arm (FA), which needs less force to turn, but requires a longer distance [p109]
inclined plane flat surface that slants exchanging increased distance for less effort [p110]
general rule of rise over run for construction of a ramp 1 inch of rise for every 12 inches of run [last slide in ch 8 and mentioned in class]
Created by: jteich
Popular Physical Therapy sets

Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

• SPACEBAR - flip the current card
• LEFT ARROW - move card to the Don't know pile
• RIGHT ARROW - move card to Know pile
• BACKSPACE - undo the previous action

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
 "Know" box contains: Time elapsed: Retries:
restart all cards