Stretching

Question 1

The degree to which a body segment can be passively moved through the available ROM and is dependent on the extensibility of muscles and connective tissues that cross and surround a joint

Answer 1

Passive flexibility

-AKA passive mobility or ROM

Question 2

A sustained or intermittent external, end-range stretch force, applied with overpressure and by manual contact or a mechanical device, elongates a shortened muscle-tendon unit and pariarticular connective tissues by moving a restricted joint just past the available ROM with the pt as relaxed as possible

Answer 2

Passive stretching

Question 3

refers to the muscle opposite the range-limiting target muscle

Answer 3

agonist

Question 4

refers to the range-limiting muscle

Answer 4

antagonist

Question 5

To perform this procedure, the patient concentrically contracts the muscle opposite the range-limiting muscle (agonist) and then holds the end range position for at least several seconds

Answer 5

Agonist contraction stretching technique

Question 6

What is the physiologic basis of AC procedure?

Answer 6

When the agonist is activated and contracts concentrically, the antagonist is reciprocally inhibited

Question 7

To perform this procedure, move limb to the point that tissue resistance is felt in the range-limiting target m. Then have the pt perform a resisted, pre stretch isometric contraction of the range limiting muscle followed by voluntary relaxation of that m. and an immediate concentric contraction of the agonist m.

Answer 7

hold relax agonist contraction stretching technique

Question 8

The range limiting target m is first lengthened to the point of tissue resistance. The pt then performs a pre-stretch, end-range, isometric contraction (~5 s) followed by voluntary relaxation of the range limiting target m. The limb is then passively moved into the new range

Answer 8

Hold relax stretching technique
- note: rotators of the limb (i.e., shoulder m’s) can contract concentrically while all other muscle groups should contract isometrically

Question 9

What is the physiologic evidence that supports HR stretching technique?

Answer 9

decrease in EMG activity (due to autogenic inhibition) following the sustained pre stretch isometric contraction of the muscle to be lengthened

Question 10

Area of the stress strain curve where the wavy collagen fibers straighten; a large change in length of the connective tissue occurs with only minimal stress

Answer 10

Toe region

Question 11

Area of the stress strain curve when tissue is taken to the end of its ROM and a gentle stretch is applied; if load is not maintained for a long time and released, the tissue will return to its original length and shape

Answer 11

elastic range (linear phase)

Question 12

Area of the stress strain curve that indicates the point beyond which the tissue will not return to its original shape and length; past this, sequential break of collagen occurs, resulting in loss of structure

Answer 12

elastic limit

Question 13

Area of the stress strain curve where tissue is strained and has a permanent deformation when the stress is released; the greater into this region, the greater resting length upon return; bonds break between collagen fibrils and fibers; eventually collagen fibers rupture

Answer 13

plastic region

Question 14

Area of the stress strain curve where the PT feels a lessening of the stretch force required for tissue lengthening; occurs just before tissue failure as adhesions release

Answer 14

Region of necking

Question 15

What does the slope of the curve (in the stress strain curve) represent?

Answer 15

The stiffness of the tissue

Question 16

What does the slope of stiffer tissue look like in comparison to less stiff tissue? what does i mean?

Answer 16

The slope is higher (greater) in stiffer tissue

- a greater stretch force is required to produce a unit change in length than in less dense tissue

Question 17

Contractors are an adaptive response to immobilization of soft tissue structures that cross the joint, which include:

Answer 17

1. Ligaments
2. Joint capsule
3. Aponeurosis
4. Dermis of the skin
5. Skeletal muscle
6. Neural tissues - i.e., epineurium

Question 18

What do contractors or adaptive shortening result in?

Answer 18

1. Resistance to passive stretch or active stretch

2. Limitation of joint ROM

Question 19

What factors cause contractures?

Answer 19

1. Prolonged immobilization
2. Sedentary lifestyle (i.e., asymmetric/ habitual posture)
3. paralysis
4. Postural malalignment - congenital or acquired (i.e., scoliosis or kyphosis)

Question 20

When joint is immobilized, there are specific changes that occur in skeletal m. What is there a decrease in?

Answer 20

1. Muscle length
2. Length of m. fibers
3. Flexibility of soft tissue and incr. fibrous connective tissue
4. Number of sarcomeres in series within the myofibrils (i.e., sarcomeres are absorbed)

Question 21

As a result of the loss of muscle sarcomeres, the muscle weakens and atrophies. The muscle weakens and atrophies at a faster rate if the muscle is immobilized in a _______ position

Answer 21

shortened

Question 22

Antigravity muscles atrophy and weaken at a ____ rate and to a greater extent than antagonist muscles during immobilization. For example, quadriceps femoris vs. _____.

Answer 22

faster; hamstrings

• quadriceps (antigravity) atrophy faster than hamstrings
• biceps brachii (antigravity) atrophy faster than triceps brachii

Question 23

What 3 components resist a stretch when a stretch is applied to a muscle?

Answer 23

1. Series elastic component (Rse)
2. Parallel elastic component (Rpe)
3. Contractile component (Rcc)

Question 24

The contribution of each m component to resisting the stretch depends on the muscle length. What is the length of a normal muscle? How is the total stretch resistance described mathematically?

Answer 24

100-105% of the rest length;

SR = Rse + Rpe + Rcc

Question 25

What is the length of the sarcomere at 175% rest length? what happens at this length?

Answer 25

3. 5 micrometers; over lap of actin and myosin is lost
   - at this length, the Rcc does not contribute to total SR; the total resistance is from the Rpe, which is the endomysium, perimysium and epimysium
   - main takeaway: at 175% you are stretching CONNECTIVE tissue, not the muscle

Question 26

What is normal functional excursion of skeletal muscle?

Answer 26

75-105%

Question 27

Load or force applied on soft tissue

Answer 27

Stress

Question 28

Change in length of tissue in response to applied load or force

Answer 28

Strain

Question 29

Does muscle atrophy faster if it is immobilized in a shortened or lengthened position?

Answer 29

Shortened