Flashcards in Exam 1 Part 4 Deck (34)
How is toughness measured?
by the total energy required to cause material failure; total area under the stress/strain curve
Rank in order of toughness: bone, ligament, tendon.
tendons are tougher than ligaments which are tougher than bones
Which is more ductile, tendons or ligaments?
Rank in order of strength: tendons, ligaments, bones.
bones are stronger than tendons which are stronger than ligaments
What is the term for the ability to return to the original shape when the load is removed?
What is the yield point?
the point at which the applied stress can lead to permanent deformation
What is the term for the nonlinear response of the material after yield point where some deformation will persist after removal of the stress?
What is the term for the property of materials to resist loads that produce shear or tensile forces?
What does viscous stretch refer to?
Viscous (plastic) stretch refers to putty-like behavior: the linear deformation produced by tensile stress remains even after the stress is removed
What three time dependent characteristics will viscoelastic structures show?
creep, hysteresis, and relaxation
What is creep?
continued deformation over time when constantly loaded which occurs dues to the expulsion of water
What is the eventual decrease in stress which corresponds to creep, that will occur as a fluid is no longer exuded?
What is the term for the energy loss exhibited by viscoelastic materials when they are subjected to loading and unloading cycles?
What is the toe region?
normal range of motion requiring little force
T/F: Grade one sprains are considered micro-failure.
T/F: Grade Two sprains are considered micro-failure.
False; Grade two (and three) sprains are macro-failure
What are the 3 characteristic stages of healing strains/sprains?
inflammation, repair, and remodeling
T/F: Inflammation, repair and remodeling which follow strains/sprains are distinct stages that do not overlap.
False; inflammation can last 72 hours while repair can begin at 48 hours. Also, repair can last up to 6 weeks while remodeling can begin at 3 weeks.
T/F: A sprain is an injury to a tendon.
False; sprain=ligament, strain=tendon
Think about straining your muscles to lift something heavy. Or just that tendon and strain both have a "T"
What muscles are most at risk of straining?
fusiform muscles crossing 2 joints: hamstrings, rectus femoris, medial gastrocnemius, biceps brachii
Which grades of strains will be painful to contract? Which may have a palpable defect?
Grade 1 and 2;
What grade of strain will involve about 1/4-1/2 of the muscle/tendon torn?
Grade two strain
T/F: A grade 1 strain will show little or no weakness or loss of function.
Would an injury to a capsule be considered a strain or a sprain?
Sprain (non-contractile tissues)
T/F: All grades of sprains will show a decrease in range of motion.
False; 1 and 2 decrease, but grade 3 may show an increased ROM
When is a joint capsule at a Loose Pack Position?
When the capsule has the most slack and the joint is at its resting position
When is a joint capsule in the Closed Pack Position?
When the joint surfaces are in the closest approximation
When are the spinal facets in a close pack position? Glenohumeral joint?
abduction and external rotation
T/F: All joints with a capsule have a capsular pattern which are patterns of restriction in a joint.