Biomechanics & Kinesiology Flashcards
What is kinesiology?
The science of movement and both the active and passive structures involved.
What is biomechanics?
The science of both internal and external forces on the body.
What is kinetics?
The study of forces acting on the body.
What are some external forces on the body?
- Gravity
- Friction
- Balance and stability - depending on the height of COG and width of BOS
What are some internal forces on the body?
- Muscles
- Tendons
- Ligaments
- Joints
What are some examples of force systems?
- Acceleration
- Velocity
- Force
In terms of the lever system, what is the axis represented as?
Fulcrum
In terms of the lever system, what is the resistance represented as?
Load
In terms of the lever system, what is the effort/output force represented as?
Effort
What is the effort arm? (EA)
The distance between the fulcrum and the effort
What is the load arm? (LA)
The distance between the fulcrum and the load
Describe first class levers
- The forces of effort and load are situated on opposite ends of the lever
- The fulcrum is positioned in between the effort and the load
- This is a very stable lever system
- MA is equal to 1
Give an example of a first class lever
Effort: Neck extensors
Fulcrum: Alantoccipial joint
Load: weight of head and the jaw
Describe second class levers
- The forces of effort AND load are positioned on the same side of the fulcrum
- The load is closer to the fulcrum than the effort
- A relatively small effort can overcome the load
- However ROM is reduced
- MA is more than 1
Give an example of a second class lever
Effort: Gastrocnemius
Fulcrum: Toes
Load: Weight of the body through the leg
Describe third class levers
- The forces of effort AND load are positioned on the same side of the fulcrum
- The effort is closer to the fulcrum than the load
- Sacrifice MA for increased speed and increased ROM
- Most levers in the body are third class
- MA is less than 1
Give an example of a third class lever
Effort: Biceps
Fulcrum: Elbow joint
Load: Object in hand
What is mechanical advantage? (MA)
The ratio of the force that performs the useful work of a machine to the force that is applied to the machine.
Write the equation for mechanical advantage
Zoe write it down
