1. What is a lever and what it it's purpose?

2. What are the abbreviations used with levers?

3. What are the types of lever arms?

1. A rigid or semirigid body that exerts force on any object impeding its tendency to rotate. The purpose of a lever is to improve mechanical advantage. Mechanical advantages of greater than one allows the musle force to be less than the resistive force to produce an equal amount of torque

2. Fa= force applied to the lever

    Maf= moment arm of the applied force

    Fr= force resisting the levers rotation

    Mrf= moment arm of the resistive force

3. First-class lever, Second-class lever, Third-class leverl

1. Describe a first-class lever:

2. What is an example of a first-class lever in the body?

3. Is there a mechanical advantage with this lever?

1. A lever for which the muscle force and resistive force act on opposite sides of the fulcrum. 

2. The forearm while doing a triceps extension; seesaw

3. .125, and less than 1.0 is a disadvantage

1. Describe a second-class lever:

2. What is an example of a second-class lever in the body?

3. Is there a mechanical advantage with this lever?

1. A lever for which the muscle force and resistive force act on the same side of the fulcrum. 

2. The heel while in plantarflexion; wheelbarrow

3. The required muscle force is smaller than the resistive force, so there is a mechanical advantage

1. Describe a third-class lever:

2. What is an example of a third-class lever in the body?

3. Is there a mechanical advantage with this lever?

1. A lever for which the muscle force and resistive force act on the same side of the fulcrum. AFR

2. Forearm during a biceps curl; door hinge

3. The mechanical advatage is less than 1, so the muscle force has to be greater than the resistive force to produce torge equal to that produced by the resistive force. 

1. What is the mechanical advantage of the patella?

2. What are the three letter mnemonics for remember levers?

1. It keeps the quadriceps tendon closer to the knee's center of rotation, lengthening the moment arm through which the muscle force acts. Tendon insertion farther from the joint center results in the ability to lift heavier weights. 

2. FAR= 1st class, ARF= 2nd class, AFR= 3rd class

1. What is the difference between muscle flexors and extensors?

1. Flexors shorten to cause limb movement, extensors lengthen to cause limb movement. They are typically agonists (prime movers) and antagonists. 

1. What is power?

2. What is force? 

3. What is work?

4. What is strength

1. Power is the time rate of doing work: P= W/T

2. F= M * A

3. Force exerted on an object over distance: W= F* D

4. Strength is the maximal force that a muscle or muscle group can generate at a specificed velocity

1. What is the recommended percent of diet consisting of protein?

2. "            " fat?

3. "            " carbohydrates?

1. 10-15%

2. lower acceptable limit of 20%

3. 45 to 65%; 5-6 g/kg