Principles Of Stretching Flashcards
Define stretching.
Therapeutic technique used to improve jt. ROM and muscle flexibility by INCREASING the extensibility of the musculotendinous unit and connective tissues
What is an indication for stretching?
- decreased jt ROM or decreased muscle flexibility
Definition of elasticity
Ability of soft tissue to return to its previous length after a stretch is no longer applied
Viscoelasticity
Time-dependent property of soft tissue that results in resistance to stretch when it is initially applied, but allows for tissue elongation as the stretch is held for longer durations. (E.g.—idea of serial casting for spasticity)
tissue will return to previous length after the stretch is no longer applied
Plasticity
Property of soft tissue that allows for tissue elongation even affected a stretch is no longer applied
What is the stress-strain curve
Graphic representation That depicts relationship b/t the amount of force (stress) applied to connective tissue and the amount of deformation (strain) it experiences
What is the Toe region of the stress-strain curve?
Initial stress that results in the wavy collagen fibers becoming straight and aligning with one another
What is the elastic region of the stress-strain curve?
- Added stress to the tissues results in greater deformation.
- Returns to resting length if force is not maintained
- Tissues with greater stiffness will have a steeper slope in this portion of the curve
What is the plastic region of the stress-strain curve?
The addition of more stress results in PERMANENT deformation even after the stretch force is no longer applied due to the failure of bonds b/t the collagen fibers
Creep
Due to the viscoelastic property, soft tissue that is stretched for a sustained duration will elongate and not return to its original length after the load has been removed
*the principle of creep is the basis for stretching
Stress-relaxation
The longer a stretching force is maintained, the more the tension within the tissue decreases, therefore less force is required to maintain the same tissue length
What is static stretching?
- Involves placing the muscle at its maximal length and holding the position against an external force for a prolonged period
- Leads to less activation fo the muscle spindles (compared to ballistic) and thus less resistance to stretch
What is static stretching characterized by?
Low Intensity and long duration
What is the safest form of stretching?
Static Stretching
What form of stretching results in the greatest gains in tissue extensibility?
Static Stretching
How long do you hold Static Stretches?
30 seconds
What is ballistic Stretching characterized by?
High intensity; short duration
What is ballistic Stretching?
- Quick, jerky movements that result in a rapid change in muscle length.
- Muscle is placed near end-range and then patient bounces back and forth to place repetitive stretch on the muscle
- Activates the muscle spindles and result in greater resistance to stretch; therefore not as great as improving tissue extensibity
Which stretch may be more effective for preparing the muscles for athletic activity?
Ballistic—nobody really uses this because the high risk of injury and muscle soreness
What is proprioceptive neuromuscular Facilitation (PNF) stretching?
- PNF incorporates active muscle contractions into stretching techniques.
- Muscular contraction is thought to lead to muscle relaxation through the principles of autogenic or reciprocal inhibition and results in greater gains in muscle flexibility
Why would you use PNF over static stretching ?
Pt has ROM limitations due to muscle spasm as opposed to connective tissue tightness. (PNF is more effective for this)
What do common PNF Techniques include?
A. Contract-relax
B. Agonist contraction
C. Contract-relax w/ agonist contraction
What is dynamic stretching?
Involves the patient actively moving a body segment to end-range (but not beyond this limit) while the antagonis muscle relaxes and stretches.
End range is held briefly and repeated.
When is dynamic stretching most commonly used?
Used as a “warm-up” for athletic activities.
When is dynamic stretching more effective?
Effective at preparing the body for explosive movements when compared to static Stretching
