Intro to Stretching and ROM
PROM limitations
-does not prevent muscle atrophy -no increase in strength or endurance -does not increase circulation to the extent that AA/AROM will -does not allow for motor learning
AROM: Indications
-to initiate strengthening -when there are ROM restrictions but NO contraindications to active moevment -Muscle pumping after surgery to prevent blood clots -Motor learning can happen
AROM limitations
-will not inc strength well (have to add resistance) -not generalizable to other mvmnts in other positions
7 Factors that Effect Stretching
1. Velocity of stretch 2. Intensity of stretch 3. Duration of stretch 4. Number of repetitions 5. Length of the stretching program 6. Frequency 7. Temperature of the Tissue
Frequency and Length of Stretching Program
1x/wk for 6 weeks minimum to increase ROM Typically the range is from 2-5 sessions/day Be aware of tisue damage signs such as muscle soreness, low grade inflammation.
Performance dose dependent?
<30 sec stretch, no reduction in performance 30-45s stretch, no clear pattern >60s stretch, decrease in strength and performance
Dynamic Streching
A slow, stead mvmnt thru the functional excursion of a muscle that typically occurs as a multi-segment motion Stretching force is NOT held at end range This kind is most suited as a warm up rather than as a means of correcting muscle flex. Reduces hysteresis and lubricates the muscle proteins (titin) NS readiness for mvmnt improves Takes advantage of reciprocal inhibition and causes muscles to contract in new ROM
Why must passive stretching be passive?
Active contraction of the muscle will decrease the effectiveness of stretching the PEC -passive tension during the stretch has minimal effect on tendon because the stiffness of the tendon is about 100x that of muscle.
How does the body adapt to Stretch Weakness, and give an example.
Adapts by adding sarcomeres Long muscles ALLOW dysfunction, cause weakness, and make problems in other places So Lower/Middle Trap with stretch weakness cause issues at the shoulder, but not at the low back
Why does stretching decrease balance?
Affects proprioceptors. If muscle is lengthened, I have loosened the CT around the muscle. So a muscle spindle is also changed in length, acutely, and it makes them want to have a muscle contraction. If they aren't the same length as extrafusal fibers, the ability to control and detect length will change
Velocity of Stretch
Apply and release at a slow rate Minimize muscle contraction during stretching, reduce risk of injury, and post-stretch muscle soreness, reduces muscle guarding More opportunity to mitigate the viscoelastic effects of connective tissue (reduces hysteresis and behaves more elastic)
Tight Weakness: Adaptations and Ex
Body Adapts: removing sarcomeres Short muscles cause problems in the same region. Hamstrings are a great example. Tightness can also cause weakness
Does creep happen in elastic or plastic?
Both, but is permanent in plastic.
Static Stretching
Can do: Manual, self-stretch, or mechanical (serial cast) A slow, sustained, tolerable force is applied to the muscle tendon unit and held for specified period. Stretching force is constant and can be repetitive. Principles of creep and stress relaxation apply Creep: constant load, see inc ROM Stress Relax: constant ROM, see dec load
How can we assure muscle relaxation is taking place>
Conscious relaxation of the muscle- breathing/distractions Reflex response to stretching. Stretch too much, makes muscle contract.
PNF: Agonist Contract Relax: Example with Hamstring
Consider the hamstring: Leg is in SLR, go to the point of barrier, contract hip flexor and quad to pull into further SLR. There will be slight motion, but not much actively. Relax the leg, and PT pushes into further SLR. Once relaxed, they hold the new position.
Characteristics of Viscoelastic behavior and the effects of stretching
Creep: tissue length increases with constant load. Stress Relaxation: load decreases when the length is constant Hysteresis: return to the resting length-minimized after 10 mins of stretch
Ballistic Stretching
Cyclic, rhythmic stretching Various speeds, sloow to fast (usually fast) Not usually rec-potential for muscle injury May have place in final stages of prep for a sport If it activates the stretch refelx causing the stretched muscle to contract then the force will be transmitted primarily to the MTJ and the tendon causing strain on the tendon.
Other aspects of performance that may be affected by stretching
Decreased balance Decreased reaction time Decreased jump height
What did a single bout of stretching do to the MVC?
Decreases the MVC by ~5% for up to 2 hours after a single bout of stretching, can be as high as 22%. Shifts the Torque angle cure to the right
How can we tell the difference between being a flexibility issue or a ROM issue?
Depends on the end feel! If bony, capsular it is ROM. If it is what you expect from the muscle: firm, see the muscle pop or the tendons pop up
Because of the negative effects of stretching, what is suggested?
Dynamic warm up (little effect on increasing ROM) AROM/Ballistic stretch and active stretch techniques combined to increase rom.
Atypical End Feels
Empty: no end feel because the patient won't let you move them to the end Springy: Intra-articular bloc such as a torn meniscus of cartilage Muscle gaurding-involuntary muscle contraction in response to acute pain Muscle spasm: prolonged muscle contraction in response to circulatory and metabolic changes Muscle spasticity: increased tone and contraction in muscle in response to CNS influences
Typical End Feels
Firm-stretching joint capsule and ligaments Hard-bony block Soft tissue approximation-compressing or stretching soft tissue Musculuar: feels like firm
Autogenic Inhibition
GTO activation of the target muscle to be stretched with passive or active tension results in inhibition of the muscle being stretched Ib inhibitory interneuron gets input from spindles, joint afferent, cutaneous afferents, descending pathways. GTO activation may also cause excitation of the active muscle, this depends on the position and activity of the limb
Describe how the gastroc can impact DF in terms of being a 2 joint muscle
Gastroc not only DFs the foot, but flexes the knee. This is why we have to assess R1/2 in knee ext/flex. Generally you will have greater DF ROM with the knee flexed, as half of the gastroc has been put on slack.
Intensity and Duration of the Stretch
Generally, should be low intensity There is a lack of agreement in the ideal combination of single stretch duration and the total duration time, but 30sec static is most common
Potential Effects of Ballistic Stretching
Higher strain rate Inc Stiffness Store more energy Requires more force to rupture Undergo greater elongation
PNF: Contract relax
Identical to hold relax, but there is concentric contraction of TM. Trying to stimulate the GTO to allow a new barrier to occur. SO: Stretch hamstrings, slight concentric contraction (into hip extension), relax, passively move into new ROM.
Multiple Bouts of Stretching: To stretch sensation
Increase ROM 5-15° depending on the joint and duration. pt should be able to tolerate higher force at the maximum ROM. (no change in stiffness after multiple bouts
AAROM Indications/Contraindications
Indications: -progress to AROM -begin to initiate muscle activity w/o too much stress -can be useful in strengthening if MMT <3-/5 Contraindications: -when pt is only permitted to perform PROM secondary to acute injury/surgery
How does the ROM in a single joint muscle differ from the same muscle's excurison?
It doesn't. It is the same.
Common tight musles
Just think
Connective Tissue: Stress-Strain Curve
Like any other. Just go past the yield point for perm changes. When you do, it will have a new normal amount of hysteresis but also a new length. You should be able to feel this gain as you go. Depending on how long, how often, and how aggressively you do this you will see differences in permanence
Muscle Spindle
Made of Intrafusal muscle fibers Type Ia afferents: quick stretch Type II afferents: Tonic Stretch
How should you plan your treatment?
Make the plan Tell the pt the plan Prepare you surroundings Use good body mechanics Give constant feedback and monitoring
PNF: Slow Reversal Hold Relax
Move into hamstring stretch, take to barrier. Isometrically contract hamstring for 5 seconds. Now have them left into hip flexion, moving into a new barrier, then say relax. Have to do this several times This one uses autogenic and reciprocal inhibition
What is Neural Mobilization/Neural Stretching
Neuaral gliding. You will start to see dec in conduction velocity at 8%. We don't really want to stretch the nerve because it would break it down So instead we do flossing
Does stretching prevent injury?
No definitive data to link stretching to decrease injury Hard to do a good study on this Dynamic stretching does ready the nervous system and improves the elastic properties of tissues making them behave more predictably (but there is no concrete evidence that this transfers to injury prevention.)
Is there a difference between 15, 30, or 60 seconds of a stretch?
No difference between 30 and 60 seconds in a static stretch, but there was a difference between 15 and 30 seconds.
After consistent stretching for 12-15 weeks, will the changes be permenant?
No. After 3 weeks we see inc muscle elongation (due to tolerance) After 12 weeks the muscle is longer But if you stop stretching for say 6 weeks, the sarcomeres are absorbed and we lose the gains
Neil hasn't felt an empty end feel: What kind of end feel does he say pain causes?
Normally pain causes a springy end feel
When can end feel only be assessed?
Only in PROM
Different kinds of ROM
Passive ROM Active Assistive ROM Active ROM Resistive ROM
PNF: Agonist Contract Relax
Passive stretch of target muscle to point of resistance Active contraction of the opposing muscle (agonist) results in reciprocal inhibition for 3-5 seconds, then a relaxation and new ROM.
Can stretching improve athletic performance? What kinds?
Preevent: usually as a warm up Chronic repetitive stretching is to improve ROM. It may prevent overuse injuries, but won't prevent traumatic injuries.
Why stretch?
Prevent or reduce the incidence of injury Enhace athletic performance Restore normal joint or soft-tissue mobility that is contributing to pain, movement restriction, and lost function.
What do you need for contracted tissues?
Prolonged stretching or casting, but can consider minimum of 5 minute stretch in the clinic
Active ROM
Pt does the motion independently- muscle activity
What is the difference between ROM (passive) and flexibility?
ROM is referring to the joint Flexibility is referring to the muscle and CT.
Precautions/Contraindications for AROM
ROM should not be done if disruptive to healing process (aka, if pain is present) Should not be done if life threatening conditions (thrombus, acute time after MI)
Acute Stretching
Relaxation of cross-bridges Sarcomere give Short term--Minutes
Chronic Muscle Lengthening
Repetitive or sustained stretching Weeks, maybe 3 weeks: Change in "Stretch tolerance" rather than true change in muscle length.
sarcomere absorption
Shortening the muscle Prolonged immobilization in a shortened position or a lack of recurrent physiologic demand due to chronic postures
Types of Stretching
Static Ballistic Dynmaic PNF Low Load Long Duration
When ballistic stretching is appropriate, what progression should we follow?
Static stretch--> slow short end-range stretching--> slow, full-range stretching--> fast, full-range stretching
What is fast cold thought to do? Which side do you quick ice?
Stimulate the intrafusal fibers and could be used for reciprocal inhibition. You quick ice the opposing muscle group. So stretching the quads, quick ice the hamstrings
Resistive ROM
Strengthening: when there is resistance added to the moving part
Describe Autogenic Inhibition
Stretch--> Stimulates muscle spindle --> Fires on Type Ia--> Goes to SC --> goes back to AMN--> results in contraction of the same mm. SO Slow, long duration, low intensity is best for passive stretching
Explain the physiological mechanisms of muscular stretching
Takes >6 weeks, Structural lengthening by adding Sarcomeres In Series (Myofibrillogenesis, but neil likes Sarcomereogenesis) - Accomplished by sustained low load stretching (serial casting) or chronic stretching stim (repetitive) - Similar in concept to stimulus needed to cause muscle hypertrophy or bone osteogenesis -We don't understand the mechanism
Reciprocal Inhibition
Target muscle for stretching is the ANTAGONIST Activation of the agonist muscle could result in inhibition of the muscle to be stretched. Think PNF stretching
PNF: Hold Relax: What happens muscularly?
The TM (antagonist) is lengthened until slight stretch is obtained TM is then contracted maximally using ISO contraction at end of available ROM Contraction is held for 5-10 secs, and then relaxes. TM is then passively stretched to next barrier. Repeat 3-4 times
Stretching
The act of increasing the extensibility of the musculotendinous unit or other soft-tissue structures (CT-joint capsule-ligament-skin-fascia-retinaculum) Also Neural Stretching
How do we permanently change the length of the muscle
The contractile AND non-contractile component have to lengthen. Need an increase in Sarcomeres in Series, but also increase in tendon length.
PNF: Hold Relax: Theories
Theories have changed, but recent EMG evidence supports that at max, a 1 second period of relaxation of TM following the ISO rather than a longer period. Evidence suggests there is a period of muscle facilitation of the TM immediately following relaxation.
How do we get perm changes in the CT?
There muscle be micro fractures of the collagen fibrils How do you know you have hit the yield point? PAIN
Main takeaways of stretching
To increase ROM, perform low load to the point of stretch but not pain Younger tissue modifies quicker (consider longer hold times as age increases) For contracted tissue, 15-30 second hold time is NOT enough.
Temperature of the Tissue
Warmer tissues tend to loosen collagen bonds and stretch easier so warming-up with active or passive motion can help with stretching programs
Tight Weakness
Weakness which occurs due to chronic shortening of a muscle. When the short muscle is placed on stretch, the muscle is not able to generate adequate force. Typically in multi-joint mm.
Stretch Weakness
Weakness which occurs due to excessive chronic lengthening of a muscle. When the long muscle is placed on slack (shortened), the muscle has limited ability to produce force due to altered length tension relationship.
PROM Indications
When injury is acute/inflamed When pt is not able to actively move b/c of injury/coma to promote joint health
How long des it take to decrease Hysteresis and is that permenant?
about 10 minutes. Not perm. Lasts for about 10-20 mins. Flexibility/stretching/plyometrics result in dec in hysteresis. Less energy will be lost during the stretch. This is better for walking, running, and jumping as it increases the efficiency of the movement
Contraindications to stretching
bony block unstable fracture joint instability during infection when it produces severe pain (esp unexplained) in presence of hematoma over musle belly when contracture is allowing enhanced function when contracture provides joint stability recent steroid injection
Goals of PROM
maintain mobility of joint minimize contractures maintain mechanical elasticity assist in circulation moderately enhance synovial mvmnt for cartilage nutrition/diffusion dec/inhibit pain assist with healing maintain pt awareness of movement
AROM Goals
maintain physiological elasticity and contractility of muscle -provide sensory feedback (aid in learning) -inc circulation to prevent thrombosis -develop coordination and motor skill
Passive ROM
performed when the PT or another device does all the work-no muscle activity
What does shifting the torque angle curve to the right imply?
that there is more compliance, or shortening of the sarcomeres So sarcomeres shorten more and decrease force because of being further down on the L-T relationship, increasing force at long length
Active Assistive ROM
when the pt and PT share in performing the ROM-some muscle activity