Musculoskeletal Flashcards
What is a second class lever?
A second class lever occurs when two forces are applied on one side of an axis.
- Resistance lies between the effort force and the axis of rotation
- Few examples in the human body (toe raises)
What is a third class lever?
A third class lever occurs when two forces are applied on one side of an axis.
- The effort force lies closer than the resistance force
- Most levers in the human body are third class levers
What is a first class level?
First class lever occurs when two forces are applied on either side of an axis.
Open and closed pack positions for the vertebral column
Open packed: midway between flex ion and extension
Closed packed: maximal extension
Tempomandibular
Open and closed packed positions
Open packed: jaw slightly open
Close packed: maximal recursion (jaw clenched) OR mouth maximally opened
Sternoclavicular
Open and closed packed position
Open packed: arm resting by side
Closed packed: arm maximally elevated