Week 1 Flashcards
(19 cards)
What two distinct components specifically make-up a persons “flexibility”?
The joint’s range of motion
Muscle flexibility
What is the definition of “flexibility” as defined by deVries?
Defined as the range of motion available In a joint.
What is static flexibility?
The measured ROM available about a joint or series of joints.
What is dynamic flexibility?
The measure of resistance to active motion about a joint or series of joints.
What are the two types of extracellular fibers that play a significant role in a persons flexibility and warrant consideration by the physical therapist?
Collagen and elastin are the two extracellular fibers that warrant the consideration of the physical therapist.
The load bearing ability of collagen is dependent on its structural properties. What are the three structural properties of collagen that establish its “collagen-fiber suspension bridge”?
Material properties of the collagen (physical and mechanical properties)
Size of the collagen fibrils - (area and length)
Organization of the fibrils
Describe the formation of a tendon by identifying the tendon hierarchy?
Tendon > fascicles > fibril > sub fibrils > micro-fibrils> tropo-collagen
What makes up ground substance?
Composed of glucoaminoglycans (GAG) and water
Substance which the collagen fibrils are embedded
What is the function of ground substance in normal tissue?
Normally a viscous gel
Serves to provide lubrication between collagen fibers where they cross.
What are the three mechanical properties of connective tissue?
Elasticity
Viscoelasticity
Plasticity
What are the three physical properties of connective tissue?
The physical properties exhibited are force relaxation, creep, and hysteresis.
What are the four zones of the load-deformation (also known as stress-stain) curve, and the percent of collagen fiber deformation that occurs in each of the zones?
Zone I- the toe region of the curve 2%
Zone II - the linear region 4%
Zone III- is the region of primary failure 6% to 10%
Zone IV- 13% to 15% complete failure
What are the six anatomical elements that are possible contributors to muscle stiffness (or resistance to deformation)?
- Adhesion of one fibrils to another or between muscle and overlying subcutaneous tissue
- The epimysium
- The perimysium and endomysium
- The sarcolemma
- Contractile elements within the muscle fiber
- The associated tendons and their insertion
What is elasticity?
Spring-like behavior where elongation which is produced by tensile load, is recovered after the load is removed.
What is viscoelasticity?
Allows slow deformation with an imperfect recovery once the deforming force has been removed. The recovery is the result of the elasticity and the imperfection is the result of viscosity. Not permanent
What is plasticity?
Permits permanent plastic deformation
What is force relaxation?
The decrease in the amount of force required to maintain a tissue at a set amount of displacement or deformation overtime. The rate at which the force is applied will affect the resulting relaxation of the tissue.
What is a creep response?
Ability of the tissue to deform over time while constant force is being imposed upon it.
What is a Hysteresis response?
Amount of relaxation a tissue has undergone during any single cycle of deformation and relaxation
