Biomechanical Principles Flashcards
Degrees of freedom
number of axis of rotation x2
1st Class lever
Fulcrum is between effort and load (powerful)
Fulcrum
pivot point
Effort
applied force
Load
Resistance
2nd class lever
load is between fulcrum and effort (powerful)
3rd class lever
Effort is between fulcrum and load (speed + most common in the human body)
Isometric contraction
Pull equals resistance
Eccentric contraction
Pull is less than resistance
Concentric contraction
Pull exceeds resistance
Tone
Continuous, low level contraction
Passive influence
Muscles influence via elasticity without contracting
Active influence
Contractions and tone
Reflexive activity
Sensory stimulation directly influences contraction level
Voluntary muscle
the ability to turn muscles “on” and “off”
Length-tension impact with muscles
change in strength with change in length
Lombard’s Paradox
standing up, both quads and hamstrings pull on the same pivot point, but length-tension helps us to stand up
Vertebrae with highest level of torsional stiffness
T12-L1, also has a high rate of spinal injury
Cervical coupling
Lateral flexion coupled with ipsilateral rotation
