Movement Analysis Flashcards
(37 cards)
What is the fulcrum?
The part of a lever system that pivots; joints are functions of the bodies lever system
What is the resistance (load)?
load to be moved by lever system; usually involves weight when doy’s lever system is involved
What is the effort?
The force applied to move the resistance of the weight or resistance; in the body, the effort is provided by muscles exerting force
What is the lever arm?
the bone or body part being moved about a joint
What is a first class lever system?
Load down, Fulcrum up, Effort down
What is a second class lever system?
Fulcrum up, Load down, Effort up
What is a third class lever system?
Fulcrum up, Effort up, Load down
Give an example of a first class lever system
triceps cause extension of lower arm at elbow joint
Give an example of a second class lever system
gastrocnemius cause plantar flexion at ankle joint
Give an example of a third class lever system
biceps cause flexion at elbow joint
What lever system is used at head/neck?
first class
joint where skull meets spinal column is fulcrum
weight of head is load
Muscle at top of neck provide effort to left head
What is mechanical advantage?
effort arm ÷ resistance arm
large load lifted with relatively little effort
can only move load at short distances and low speeds
What is mechanical disadvantage?
lots of effort to lift relatively small load
What is the effort arm?
the distance from the effort to the fulcrum
What is the resistance arm?
the distance from the resistance to the fulcrum
What type of lever systems have a low mechanical advantage? and why?
third class
effort arm shorter than resistance arm so mechanical advantage is less than 1
What type of lever systems have a high mechanical advantage? and why?
second class
effort arm longer than resistance arm so mechanical advantage is bigger than 1
What type of lever system can have a high or low mechanical advantage and why?
first class
depends whether fulcrum is closer to effort or resistance
What is flexion?
decrease in angle of bones at a joint
What is extension?
increase in angle of bone at joint
What is abduction?
movement away from midline of body
What is adduction?
movement towards midline of body
What is rotation?
movement around an axis
What is plantar flexion?
increase angle at ankle joint (toes point down)