physiological basis of flexilibility
TRANSCRIPT
PHYSIOLOGICAL BASIS OF PHYSIOLOGICAL BASIS OF FLEXILIBILITYFLEXILIBILITY
Please refer to CHAPTER 20 of Plowman (2011): Neuromuscular Aspects of Movementpp. 583-612
FLEXIBILITYFLEXIBILITYAbility of a joint or a series of joints
to move smoothly & easily through a FULL RANGE OF MOTION.
DYNAMIC FLEXIBILITY- degree to which a joint can be moved by a muscle contraction ACTIVE RANGE OF MOTION)
STATIC FLEXIBILITY- degree to which a joint may be PASSIVELY moved to the end points in the range of motion
FACTORS AFFECTING FACTORS AFFECTING FLEXIBILITYFLEXIBILITYBony structuresExcessive fatSkin (scarring- tissues become
inelastic)Muscle & tendonsConnective tissue- ligamentsNeural tissue tightnesshypermobilityu
MEASURING FLEXIBILITYMEASURING FLEXIBILITY
In the LABORATORYMeasured through angular displacement
(in degrees)GONIOMETERFLEXOMETER
In the FIELDMeasurement of linear distances
between segments or from an external objectsE.g. Sit-and-reach
GONIOMETER FLEXOMETER
STUDIES AND STUDIES AND COMMON BELIEFS ON COMMON BELIEFS ON FLEXIBILITYFLEXIBILITY
FEMALES AS THE MORE FEMALES AS THE MORE FLEXIBLE SPECIESFLEXIBLE SPECIES
NO consistent data on INFLUENCE OF SEX on flexibility◦Women are ONLY more flexible than
men when HIP FLEXIBILITY is measured
◦Studies show that there is no generalized pattern of flexibility superiority of females over males.
READ MORE IN Plowman (2011) page 599- 600
AGE & FLEXIBILITTYAGE & FLEXIBILITTYBetween 10-15 years oldLumbar flexibility- decreasesLateral flexion- increases
Hip flexibility-increases steadily for women from 10-18 y.o-decreases 5-13 y.o., increase
Studies equivocal: some show a decline, some show no difference
FLEXIBILITY EITHER DECLINES OR STAYS THE SAME THROUGH THE ADULT YEARS, DEPENDING ON THE INDIVIDUAL’S LEVEL OF ACTIVITY
STRETCHING TECHNIQUESSTRETCHING TECHNIQUES
1. BALLISTIC2. DYNAMIC3. STATIC4. PROPRIOCEPTIVE
NEUROMUSCULAR FACILITATION
READ MORE IN Plowman (2011) page 601-603
BALLISTIC◦Involves bouncing movements◦Repetitive contractions of Agonist lead to
quick stretches of the Antagonist muscle◦Effective in improving ROM◦If force from jerks & pulls exceeds tissue
extensibility-muscle injury
DYNAMIC◦Consists of controlled stretches w/c are
recommended prior to beginning an acivity◦Focuses on functional movements
STATIC◦Passive stretching of an antagonist muscle
by placing it in a maximal stretch and holding it
15- 30 seconds, 3-4 repetitions per joint
PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION(PNF)◦A technique that combines alternating
contractions & stretches◦Consists of 10 seconds active push
phases + 10 seconds passive relaxation phase
slow-reversal-hold relax Contract-relax Hold-relax
NEUROPHYSIOLOGICAL NEUROPHYSIOLOGICAL BASIS OF STRETCHINGBASIS OF STRETCHING
The Reflex ArcThe Reflex Arc
Reflex – rapid, predictable, and involuntary responses to stimuli
Reflex arc – direct route from a sensory neuron, to an interneuron, to an effector
Simple Reflex ArcSimple Reflex Arc
Types of Reflexes and RegulationTypes of Reflexes and Regulation
Autonomic reflexes
Smooth muscle regulation
Heart and blood pressure regulation
Regulation of glands
Digestive system regulation
Somatic reflexes
Activation of skeletal muscles
MYOTATIC (STRETCH) MYOTATIC (STRETCH) REFLEXREFLEXOccurs in response to a sudden
change in LENGTHWhen a muscle is quickly
stretched, MUSCLE SPINDLE fibers (mechanoreceptors) are activated causing s REFLEX CONTRACTION
Muscle spindlesMuscle spindles
INVERSE MYOTATIC INVERSE MYOTATIC REFLEXREFLEXContraction of a skeletal muscle
or stretching increases TENSION and stimulates the GOLGI TENDON ORGANS (GTO)
Results in a REFLEX RELAXATIONServes as protective function
against tension that might cause muscle & tendons to be torn
Golgi Tendon Organs Golgi Tendon Organs (GTO)(GTO)
slow stretches exceeding six (6) seconds causes REFLEX RELAXATION, allowing muscle to stretch through relaxation to exceeding extensibility limit
REFLEX INHIBITION- reflex relaxation of the antagonist muscle in response to contraction of the agonist◦(e.g.contraction of quadriceps
muscle relaxes the hamstrings muscle group)
PHYSIOLOGICAL RESPONSES PHYSIOLOGICAL RESPONSES TO STRETCHINGTO STRETCHINGDelayed Onset Muscle Soreness
◦No definite studies pointing to a decreases in DOMS with stretching
Range of Motion◦15-30 seconds of stretching more
effective ◦No additional benefit beyond 30sec.
Stretch◦Increased ROM from acute bout of
stretching lasts for 60-120 minutes
Injury Prevention◦Stretching before exercise DOES NOT
necessarily prevent Injury from occurring.◦ Individuals with Poor flexibility for the
performance of a task , however, puts them at greater risk for injury
Performance◦Belief that stretching can enhance
performance NOT SUPPORTED BY LITERATURE.
◦Some studies show decrease in muscle strength after pre-activity stretching
◦Pre-stretching may NEGATIVELY AFFECT jumping.