Analysis Fundamentals (ch. 1-4) Flashcards
What does isokinetic mean?
constant joint velocity
If there is constant external load, like in lifting free weights, what is the term for that?
isoinertial
Joint torque is a product of what?
muscle force and moment arm
What is muscle force dependent on?
1) muscle structure
2) muscle activation
3) mechanical properties (length/tension, force/velocity)
What are the A and I bands of muscle cell structure?
A = length of only thick filament (stays same) I = length of only thin filament (shortens in contraction)
Name the layers of CT surrounding muscle tissue, most exterior to most interior.
Epimysium -> perimysium -> endomysium -> sarcolemma
What are the myofilaments?
actin and myosin; make up a myofibril, which make up myofiber
Which alignment of sarcomeres is better for force, parallel or in series?
parallel (more CSA)
Are sarcomeres in series better for force or excursion?
excursion
What band anchors the thin filament?
z-band
How do you find the force for a pinnate muscle?
take the force and multiply it by the cosine of the angle
What does fiber length give you an estimate of?
amount of excursion from the muscle (since fiber length is counting the sarcomeres in series)
What does physiological CSA give you an estimate of?
it’s on an oblique angle, taking into account the pinnation angle, so it gives you an approximate force capacity value
Which has more excursion, soleus or sartorius?
sartorius, b/c it’s longer
What dictates the degree of fiber excursion?
muscle fiber length
What dictates maximal strength of a muscle?
physiological CSA
T/F: Muscle length and muscle tension are proportional.
true, after the critical length
What’s the difference between active and passive insufficiency?
- passive = muscle can’t lengthen far enough, since a full stretch at multiple joints can’t occur (filaments too far apart to produce active tension)
• muscle trying to lengthen at 2 joints simultaneously - active = muscle can’t shorten far enough; excessive overlap of contraction sites
• muscle trying to contract at 2 joints simultaneously
How many degrees of freedom do ellipsoidal joints have? What’s an example of this kind of joint?
- 2 degrees of freedom
- radiocarpal joint
What’s an example of a condyloid joint?
the knuckle, MCP; has 2 degrees of freedom
How many degrees of freedom do plane joints have? What’s an example of a plane joint?
- 3 degrees of freedom
- facet joints, AC joint
What’s the difference between a 2nd class lever and a 3rd class lever?
2nd = resistance at end (better mechanical advantage) 3rd = load at end (better velocity)
What type of joint has irregular joint arranged in a haphazard fashion?
synarthrosis joints
Do ellipsoid joints have flattened concave or convex surfaces?
flattened convex
What’s an example of a condyloid joint?
tibiofemoral, MCPs
What is akylosis?
When the joint fuses together; can be due to inflammation or genetics
- ex: akylosing spondylitis = spinal fusion
What’s the difference between arthrodesis and pseudoarthrosis?
arthrodesis = moving joint up surgically pseudoarthrosis = improper healing of a broken bone, resulting in pseudo joint (non-union)
What do synovial plica do?
increase surface area