Upload
tyrone
View
30
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Flexibility. What is Joint Flexibility?. A description of the relative ROM allowed at a joint in different directions ROM: the angle through which a joint moves from anatomical position to the extreme limit of segment motion in a particular direction. Joint Flexibility . - PowerPoint PPT Presentation
Citation preview
What is Joint Flexibility?A description of the relative ROM allowed at a joint in different directions
ROM: the angle through which a joint moves from anatomical position to the extreme limit of segment motion in a particular direction.
Joint Flexibility Range of motion is measured directionally from anatomical position (zero).
Static FlexibilityAn indicator of the relative tightness or laxity of a joint.
• the ROM present when a body segment is passively moved (by an exercise partner or clinician)
Dynamic FlexibilityROM achieved by virtue of muscle contraction
Factors That Influence Joint FlexibilityShape and Tightness
Shape of Joint ComponentsThe articulating bone surface, muscle tissue or fat terminate movement at extreme ROM.
Tightness of Muscle & CollagenStretching increases extensibility of both tissues. Lack of stretching significantly diminishes extensibility over time.
*Increased temperature increases flexibility of collagen.
NEUROMUSCULAR RESPONSE & JOINT FLEXIBILITY
Golgi Tendon Organs (GTO) Sensory receptors that influence extensibility Located in the muscle-tendon junction and in
the tendons at both ends of muscles Stimulated by tension produced by muscle
contraction or passive muscle stretch Inhibits tension in agonist muscle (promote
relaxation) & initiate tension development in antagonists
Muscle Spindles Sensory receptors that respond to:
amount of muscle (static response) rate of muscle lengthening (dynamic response)
Muscle spindles will: provoke reflex contraction in stretched muscle inhibit tension in antagonists..
Comparison of: GTO Muscle Spindle
Location
Within tendons near the muscle-tendon junction in series with muscle
fibers
Interspersed among muscle fibers in
parallel with the fibers
StimulusIncrease in muscle
tensionIncrease in muscle
length
Response
Inhibit tension development in
stretched muscle
Initiate tension development in
antagonist muscle
Initiate rapid contraction of
stretched muscle
Inhibit tension development in
antagonist muscles
Overall Effect Promote stretch in muscle being stretched
Inhibit stretch in muscle being
stretched
GTO PROMOTES RELAXATION
MUSCLE SPINDLES INHIBIT STRETCH
Therefore, maximizing GTO &
minimizing the muscle spindle increases joint flexibility.
Techniques for increasing Joint FlexibilityActive & Passive StretchingBallistic & Static StretchingPNF
Active StretchingProduced by contraction of the antagonist muscles
Ex. Quadriceps contract so that hamstrings are stretched
Advantage: exercises muscle group used to develop force
Passive StretchingProduced by a force other than tension in the antagonist muscles
Ex. Gravitational force, force applied by another body segment or by another person.
Advantage: movement can be carried out father beyond the ROM
Static StretchingMaintaining a slow, controlled, sustained stretch over time.
usually 20-30 seconds
Advantage: does not activate muscle spindle response that inhibits stretching
Ballistic StretchingSeries of quick, bouncing-type stretches.
The potential for injuries is heightened due to activation of muscle spindle which inhibits stretching
Proprioceptive Neuromuscular Facilitationa group of stretching procedures involving alternating contraction and relaxation of the muscles being stretched