Stretching

Question 1

Elasticity

Answer 1

the ability of soft tissue to return to its previous length after a stretch is no longer applied

Question 2

viscoelasticity

Answer 2

• a 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. as with elasticity, the tissue will return to its previous length after the stretch is no longer applied

Question 3

plasticity

Answer 3

• a property of soft tissue that allows for tissue elongation even after a stretch is no longer applied

Question 4

Stress- Strain curve

Answer 4

• a graphic representation that depicts the relationship between the amount of force applied to connective tissue and the amount of deformation it experiences

Question 5

stress strain curve

–Toe region

Answer 5

• Initial stress that results in the wavy collagen fibers becoming straight and aligning with one another

Question 6

Stress-strain curve

–elastic region

Answer 6

• added stress to the tissue results in greater deformation, though the tissue returns to its resting length if the stretch force is not maintained
• Tissues with greater stiffness will have a steeper slope in this portion of the curve

Question 7

Stress-strain curve

– Plastic region

Answer 7

• the addition of more stress results in permanent deformation even after the stretch forcce is no longer applied due to teh failure of bonds between the collagen fibers

Question 8

Creep

Answer 8

• 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

Question 9

stress-relaxation

Answer 9

• 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

Question 10

static stretching

Answer 10

• involves placing the muscle at its maximal length and holding the position against an external force for a prolonged period of time.
• low intensity and long duration
• considered to be the safest form of stretching and results in the greatest gains in tissue extensibility
• leads to less activation of the muscle spindles and thus less resistance to stretch
• 30 sec has been shown to result in significant ROM gains

Question 11

Ballistic stretching

Answer 11

• characterized by quick, jerky movements that result in a rapid change in muscle length.
• muscle is placed near its end of ROM and then the patient bounces back and forth to place repetitive stretch on the muscle
• because ballistic stretching occurs quickly, it activates the muscle spindles and results in greater resistance to stretch
• not as effective for improving tissue extensibility, though it may be more effective when preparing the muscles for athletic activity.
• additionally ballistic stretching is mor elikely to lead to muscle soreness and injury due to the high intensity of stretch force

Question 12

PNF stretching

Answer 12

• 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
• more effective at treating ROM limitation due to muscle spasm as opposed to connective tissue tightness.
• Due to PNF requires active muscular control from the patient, it is not an effective technique for patients with paralysis or spasticity
• common PNF techniques include contract-relax, agonist contraction, and contract-relax with agonist contraction

Question 13

dynamic stretching

Answer 13

• involves the patient actively moving a body segment to the end of range while the antagonist muscle relaxes and stretches.
• unlike static stretches, teh end-range movement is held only briefly and is performed repeatedly. Dynamic stretching is most commonly used as “warm-up” to prepare the body for athletic activities. it is more effective at preparing teh body for explosive movements when compared to static stretching
• dynamic stretching emphasizes a movement based approach, while ballistic stretching emphasizes bouncing movements