What is flexibility?
musculotendinous unit's ability to elongate with the force of stretching
Put tendons, ligaments, and fascia in the order of elasticness and their characteristics:
- tendons: tightly packed collagen (low elastic)
- fascia: mainly collagen tissue (elastic variable)
- ligaments: mainly collagen tissue (most elastic)
If flexibility is limited, what does that do to ROM?
What is the connective tissue composition of flexibility?
Which is more elastic muscle of CT?
- (fast twitch is more elastic than slow twitch)
What influences flexibility in muscle?
the amount of titan
What general factors influence flexibility?
- joint bony structure
- resistance to movement within a joint
- neuromuscular and mechanical influences
Whats the difference amongst flexibility in gender?
women more flexible than men (in college kids)
What occurs with age in terms of flexibility?
- because of cross linking of collagen, inactivity, or both
What changes occur in muscles and CT during immobilization than contribute to decreased flexibility?
- muscle atrophy in 2 weeks
- increased fibrous and fatty tissue in muscle
- CT ground substance reduced leading to increased collagen cross links
- fibro-fatty CT in jt space within two weeks
- develop fibrous adhesions
What are the neuromuscular influences on ROM?
- the muscle spindle acts as a protective mechanism (spindle reflex causes contraction of the muscle, so ballistic or overstretching activates the spindle)
- golgi tendon organ when activated cauesse autogenic inhibition of contracted muscle serving as a protective mechanism
What are the mechanical responses on a single bout of flexibility?
- Decrease in overlap of thick actin and thin myosin filaments until sacromeres have reached maximum length, lengthening the CT
- the collagen fibers in CT align parallel with each other
In a study were there increases in muscle fiber length after 3 min stretches, 3x/wk, for 3 weeks?
no increase hypothesizing that the changes in ROM is from changes in the tolerance to stretching rather than an increase in fiber of CT length
What are different stretching techniques?
- manual passive stretching
- prolonged mechanical passive stretching
- cyclic mechanical stretching
- static self stretching
- ballistic stretching
- contract relax
- agonist contract
- contract relax with agonist contract
What occurs in manual passive stretching?
the therapist applices force and controls direction, intensity, velocity and duration
What occurs in prolonged mechanical passive stretching?
low intensity/load that could take 20 minutes to several hours
What occurs in cyclic mechanical stretching?
cylcic force, direction, intensity, velocity, and duration are adjusted iwth the unit
What is the general health/fitness related presciption for static stretching?
- 15-30 seconds (shown to be as effective as 60 seconds)
- repeat 4-6 times
How many times a week do you have to stretch to improve flexibility, maintain, or detrain?
- improve flexibility: 3-7 days/wk
- maintain: 1/wk
- detrain: gains are maintained 2-4 weeks
What is the static stretching prescription for people with contractures?
low-load, long duration (>2 min) which elevates the tissue temp so it lengthens the collagen
What are advantages of static stretching?
- increase ROM
- held >6 secs activates the GTO so get greater lengthing
- no partner required
What are limitations to static stretching?
- in athletes it may downtrain the spindle reflex response so the muscle spindles may not fire and increase the probability of overstretching injuries
- may result in large difference in AROM and PROM
Does static stretching prevent injuries?
No but significant deficits in flexibility are related to increased injury rates, increased rate of overuse injuries, and history of fall in elderly
What are effects of static stretching on athletic performance?
- increased flexibility of a tight muscle may increase its peak torque production
- stretching a muscle that is not tight before performance may decrease its maximal torwue production
What is the effectiveness of ballisitc stretching?
- effectiveness is limited becuase it doesn't allow time for stress-relaxation and creep to occur
- ROM results equivalent to static stretching but higher potential for injury with uncontrolled movement
How do you do contract relax stretching?
- stretch to point of tension and hold 15 seconds
- maximal isometric contraction of muscle and hold for 10 seconds
- repeat 4-6 times
What is the theory behind contract relax stretching
- isometric contraction activates the GTO reflex so the muscle being stretched relaxes better so it can be maximally elongated
- but this theory has been refuted
How does agonist contraction work?
- pt dynamically contracts the agonist (muscle opposite the tight muscle) which produces reciprocal inhibition of antagonist muscle
- the relaxed tight muscle is then more easily moved into the newly aquired ROM
How do you do contract-relax, agonist-contract, and what is the theory behind it?
- being with CR
- followed by AC
- combines autogenic and reciprocal inhibition
For hip flexion ROM what is the most important factor?
maintenance of the anterior pelvic tilt more important than method of stretching
Does the time of day impact stretching?
- flexible least in the am, so greater potential of overstretching
- flexible greatest in the afternoon
Stretch before or after exercise?
- if activity involves full ROM --> stretch prior
- if activity doesn't involve full ROM --> stretch after (jogging)
What are precautions for patients when stretching?
- recent soft tissue repair
- prolonged immobilization
- pain lasting greater than 24 hours post stretch
- edematous joints and tissues
What are contraindications for patients for stretching?
- bone block
- fracture or non-unio
- acute inflammation or infection
- sharp pain
How do you measure flexibility?
- tests of muscle length (obers, thomas)
What are tests to measure decreased flexibility?
- scratch test
- 90/90 test (hamstrings)
- Ely test (rectus femoris)
- Thomas test (iliopsoas)
- ankle DF (gastroc/soleus)
- Obers (IT band)
- Trunk Extension
What defines hypermobility?
- thumb to forearm (2)
- 5th MCP passive extension >90 (2)
- elbow hyperextension >10 (2)
- knee hyperextension >10 (2)
- palms to floor (1)
- 0-3= normal
- 4-9= ligament laxity (hypermobile)