CH 4: Flexibility Flashcards
What is the ability of a muscle to relax and yield to a stretch force?
Flexibility
What is the ability to move muscles and joints through full ROM
Flexibility
What is the degree of normal ROM available?
Flexibility
What can refer to various measurable components of joint motion?
Flexibility
What influences the degree of motion in joints?
- Muscles
- Tendons
- Ligaments
- Skin
- Joint capsule
- Bone geometry
What diminishes over time if tissues are not stretched or exercised using regular and proper stretching regimens?
Flexibility
What is the goal of any flexibility program?
Improve or maintain ROM at all joints
What type of flexibility occurs as a result of static stretching?
Static flexibility
What relates to moving through ROM with normal or rapid velocity?
Dynamic flexibility
Why do we measure flexibility at specific joints?
No specific composite test provides an index of an individual’s overall flexibility characteristics
What are factors that affect flexibility and joint ROM limitations?
- Age
- Gender
- Muscles
- Tendons
- Surrounding fascia
- Bone
- Fat
- Connective tissue lesions
- Skin
- Postural problems
What does the loss of muscle function and increase in intramuscular connective tissue stiffness lead to?
- Decreased ROM
- Gradual decline in efficiency of ADL performance
What are the two sensory receptors that monitor muscle activity by activating both spinal reflexes and long-loop pathways involving supraspinal centers?
Muscle spindles
-Golgi tendon organs (GTO)
What are distributed through the muscle belly using intrafusal muscle fibers (nuclear bag and chain fibers) to send info to the CNS to monitor overall muscle length and rate of change in muscles?
Muscle spindles
What monitors muscle length changes and rate of change in muscles?
Muscle spindles
What pathway’s main purpose is to compare the length of the spindle with the length of the muscle that surrounds it?
Muscle spindles
What pathway can be stimulated by (1) stretching the whole muscle (stretching the midportion of the spindle and exciting the receptor), and (2) by contracting only the end portion of the intrafusal fibers exciting the receptors (muscle length doesn’t change)?
Muscle spindles
What are muscles innervated by?
Alpha motor neurons
What are muscle spindles innervated by?
Gamma motor neurons
What stimulates the contraction of extrafusal fibers?
Alpha motor neurons
What stimulates the contraction of intrafusal fibers at the end?
Gamma motor neurons
What contraction serves as a sensitivity meter for changing lengths of the muscle?
Intrafusal fibers (muscle spindles)
If the length of the muscle surrounding the spindle is less than that of the spindle, what occurs?
Decrease in intrafusal fiber afferent activity
If the central portion of the intrafusal fiber is stretched secondary to gamma efferent activity, what occurs?
Sensory receptors discharge more impulses stimulating the alpha motor neurons to activate the extrafusal muscle fibers to contract
How do intrafusal fibers within the muscle spindle activate a muscle contraction?
(extrafusal fiber stretch) stimulate primary (Ia) and secondary (II) sensory nerve endings (afferent), sending info to the higher brain centers and to alpha motor neurons of the same muscle
What will relieve the stretch on spindles and temporarily remove the stimulus on intrafusal fibers?
Shortening of a muscle
What will adjust for new muscle length?
Gamma motor neuron (efferent) activity
What pathway is not a stretch receptor?
GTO
What pathway is a simple sensory receptor: single afferent (Ib) and no efferent connections?
GTO
What is the function of the GTO pathway?
To monitor muscle contraction
What pathway has parallel extrafusal fibers?
Muscle spindles
What pathway is situated in a series of fibers with the muscle fibers?
GTO
Where are GTOs commonly located?
Grouped around a few extrafusal muscle fibers near the aponeurosis of attachment (very few located in the tendon)
What pathway is activated by active muscle contraction?
GTO
What pathway is deactivated by active muscle contraction?
Muscle spindles
What pathway can sense muscle tension more directly in an active contraction?
GTO
What pathway can sense increasing muscle length during an active contraction?
Muscle spindles
