Therex Lecture 3 Flashcards
What is stretching?
Stretching is a therapeutic maneuver to:
- Increase mobility of soft tissues, and subsequently…
- Improve ROM by lengthening structures that have adaptively shortened and become hypomobile over time
What is dynamic and passive flexibility?
Dynamic flexibility is active mobility, which is affected by tissue resistance during movement
Passive flexibility is passive movement through ROM, affected by extensibility of muscles/connective tissue
Flexibility is dictated by no resistance AND no pain (similar to how Grade 1 mob can turn into Grade 3 in the presence of pain)
What are factors that contribute to restricted motion?
Factors that contribute to restricted motion are:
- extrinsic prolonged immobilization (casts and splits, skeletal traction)
- intrinsic prolonged immobilization (pain, joint inflammation, skin disorders, bony blocks, vascular disorders, muscle, tendon, or fascial disorders)
- sedentary lifestyle and habitual faulty or asymmetrical postures
- paralysis, tonal abnormalities, muscle imabalances
- postural malalignment
What is hypomobility? What can hypomobility lead to? What are factors that contribute to hypomobility?
Hypomobility is decreased flexibility
Hypomobility can lead to contractures
Factors that contribute to hypomobility are:
- shortened muscles (stiffness/tightness - adaptable shortening of muscles over time)
- scar tissues
- lack of strength
- altered proprioception
- immobilization
- spasticity
- motor control
What is hypermobility? What are factors that contribute to hypermobility? What can hypermobility lead to?
Hypermobility is increased flexibility
Factors that contribute to hypermobility are:
- poor motor control
Hypermobility can lead to pain and movement dysfunction
**in some cases, hypermobility can improve function - by using selective stretching, we can promote ROM that may translate to function for that individual
According to the literature, what is stretching considered to do?
According to the literature, stretching is considered to:
- increase flexibility and ROM (strong)
- promote injury prevention (weak)
- promote enhanced performance (weak)
According to the literature, at what point does stretching become effective?
According to the literature:
- short (<30 seconds) and inconsistent bouts of stretching are ineffectual in changing performance and tissue length (however, perceived changes in tolerance happens)
- tissue length changes come from regular >30 second bouts of load (passive or active)
- in tissue affected by chronic contracture, serial casting is recommended and has good outcomes (increase in flexibility due to gradual increase in position of casting)
What is a contracture? What are the effects of contractures?
A contracture is an adaptive shortening of muscle-tendon unit and other soft tissues crossing/surrounding joint
The effects of contractures are:
- resistance to passive or active stretch,
- limitation of ROM
What are the types of contractures?
The types of contractures are:
- myostatic contracture
- pseudomyostatic contracture
- fibrotic contracture
- arthrogenic contracture
What is a myostatic contracture?
Myostatic contractures are when there is loss of ROM, but there is no muscle pathology
What is a pseudomyostatic contracture?
Pseudomyostatic contracture is when there is an ‘apparent contracture’ with resistance to passive stretch from a CNS lesion, muscle spasm, guarding or pain
It is “pseudo” because it seems like musculoskeletal but it is more neuro
– inhibitory techniques can be used to achieve full length
What is a fibrotic contracture?
Fibrotic contracture (irreversible contracture) is a result of prolonged immobilization (casting/bracing)
It is often resistant to change
In fibrotic contractures, the periarticular tissue may be involved, but the pathology involved is due to muscle tissue
Fibrotic contractures may require surgery or sustained stretch over hours (in the form of progressive casting/splinting)
What is arthrogenic contracture and periarticular contracture?
Arthrogenic contracture and periarticular contracture are intra-articular pathologies that result from the joint
They limit joint capsule mobility and normal arthrokinematic motion
An example is arthritis
What are the properties of contractile and non-contractile tissue?
The properties of contractile and non-contractile tissue are:
- contractile tissue is in muscle
- noncontractile tissue is in connective tissue
- noncontractile tissue has viscal elasticity while contractile does not
Both tissue types have:
- elasticity (the ability to return to pre-stretch length after stretch)
- plasticity (increased length of tissue after removal of strength force)
What happens to the contractile elements when the tissue is stretched?
When the tissue is stretched:
- the connective tissue (series elastic component) is stretched
- the actin/myosin filaments slide apart and sarcomeres lengthen
- upon release, resting length is restored (if stretch is brief)
The series elastic component is a non-contractile element that lies in series of muscle tissue (contractile tissue). This can be connective tissue bridges, tendons, muscle membranes, etc
Where can Type I collagen fibers be found? What forces increase Type I collagen?
Type I collagen fibers can be found in skin, tendons, organs, and bones.
Ligaments and tendons both increase Type I collagen in response to tensile forces (stretching)
What is a load? What does it depend on?
A load is a force applied to a structure
A load depends on the magnitude, direction, rate of force applied, and the size/composition of the tissue
– this will affect the response to the load (aka structure dictates function)
What are the regions of the Stress-Strain curve?
The regions of the Stress-Strain curve are:
- toe region: deformation with little force applied
- elastic region/linear region: where the strain is proportional to the tissue’s ability to resist force
- elastic limit: a point where beyond it, the tissue will not return to its original length
- plastic region: permanent deformation of the tissue - causes disruption in tissue that prevents it from going back
- ultimate failure point: failure of tissue (grade 3 sprain)
**the greater the slope of the elastic region, the greater the “stiffness” that is associated with the tissue
What are the clinical applications to the regions of the stress strain curve?
The clinical applications to the regions of the stress strain curve are:
- Toe region: Tests for ligament integrity (non-injured state); tendon slack taken up by attached muscle before force transmitted to bone (~1%-2% strain).
- Elastic region: Stress/strain that occurs with normal, daily activities (~4% strain)
- Plastic region: Grade I (early) and II (late) ligament sprains and tendon strains
- Failure: rupture if middle of tendon/ligament fails; avulsion if failure is at bony attachment; fracture if in bone
** Failure rate refers to how slow loading rate tends to create avulsions or fractures; fast loading rates tend to create mid-substance tears
** In general, ligaments and tendons are able to deform more than cartilage, and cartilage is able to deform more than bone
What are the changes in collagen that affect the stress-strain response?
The changes in collagen that affect the stress strain response are:
- immobilization - tissue weakens; adhesions form (increased cross-linkage of disorganized collagen and less effective inter-fibrillar components)
- inactivity - decrease in size and amount of collagen (weakens the tissue); increased predominance of elastin (increases compliance)
- age - decreases maximal tensile strength; rate of adaptation to stress is slower
- corticosteroids - decreases tensile strength of collagen; fibrocyte death in tissue surrounding injection site
- injury - acute stage (type III collagen is synthesized - weaker than mature type I collagen); sub-acute and chronic remodeling (different force tolerance)
- other - nutritional deficiences; hormonal imbalance; dialysis
When is it appropriate to stretch a patient?
It is appropriate to stretch a patient when:
- there is a potential for structural deformity due to limited ROM (adhesions, contractures, scar tissue, etc)
- anytime a patient’s function is impaired secondary to hypomobility
What are some precautions to stretching?
Precautions to stretching include:
- Hypermobility (Joint subluxation)
- Patient’s age (advanced)
- Osteoporosis
- Fractures
- Weak muscles
What are some contraindications for stretching?
Contraindications for stretching include:
- Bony Block
- Non-Union Fracture
- Acute Inflammation or Infection (Edematous tissue)
- Sharp or Acute Pain With Elongation
- Hematoma or Tissue Trauma
- Hypermobility (Dislocation)
- When hypomobility provides stability and/or neuro-muscular control
According to research, what are the effects of immobilization on muscle?
According to research, the effects of immobilization on muscle are:
1) Loss of contractile proteins, leading to decreased muscle weight and cross-section area
2) Shortening of the muscle which leads to decreased sarcomere length
3) Decreased serial sarcomere number (Decreased force/velocity production)
Atrophy and weakness result from the loss of contractile proteins (myofibrils)
The extent of these changes depend on many factors but more commonly due to:
- Duration of immobilization
- Limb position during immobilization
