Download Neuromuscular Aspects (1) - K

Plan for Week 4
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Monday, February 17
- Complete bone growth and integrity (Ch 4)
- Review problems on p. 105-106
• Introductory problems 1,2,3,8,9,10
• Additional problems 1,2,3,8,10
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Wednesday, February 19
- Introduce & review unit on joint flexibility and proprioception
(pp 123-137)
- Review for exam
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Monday, February 24
• Exam 1 Chapters 1-5
Questions on Bone Growth & Dev
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Why is bone density related to body weight?
What factors contribute to increase in bone density?
When and why is there a period of lower bone density
in young people?
Name 3 factors essential for an increase in bone
strength.
Why is osteoporosis mostly a problem with females
and the aged?
How do we prevent it?
Is there a relationship between bone health in older
people (50+ years) and bone density in youth?
Position Statement of ACSM on
Osteoporosis http://www.acsm.org/
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Weight-bearing physical activity is essential for
developing and maintaining a healthy skeleton
Strength exercises may also be beneficial, particularly
for non-weightbearing bones
An increase in physical activity for sedentary women
can prevent further inactivity-related bone loss and
can even improve bone mass
Exercise is not an adequate substitute for
postmenopausal hormone replacement
Ex programs for older women should include activities
for improving strength, flexibility, and coordination, to
lessen the likelihood of falls
Bone Growth &Structure Summary
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Quality of mechanical properties depends on
- age (bmc peaks in 20’s, declines 2 % per decade
after 30)
- nutritional status - what nutrients are important?
- type of bone - trabecular or cortical
- hormonal status -which hormones?
- duration and magnitude of stress
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Osteoporosis – nature & prevalence
- Affects aged and mostly females. Why?
- How do we prevent it?
Website on osteporosis: http://www.nof.org
National Osteoporosis Foundation
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Objectives
Identify factors contributing to joint
stability and flexibility.
 Discuss role of proprioceptors in
musculotendinous stretching exercises
 Discuss characteristics of effective
flexibility exercises, including PNF.
 Discuss common joint injuries and
pathologies
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Joint flexibility – Range of Motion (ROM)
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Static vs dynamic
Active vs passive
Measuring joint range of motion
- Direct measurement –
• Goniometer (Fig 5.9, p 127)
• Leighton flexometer (Fig 5.10, p 127)
- Indirect & composite – e.g., sit and reach
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Factors influencing joint flexibility
- Shape of articulating bone surfaces (ex.: forearm extension)
- Intervening muscle and fat (ex. : forearm flexion)
- Length of ligaments and musculotendinous units
crossing joint
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Flexibility and injury –
- Increased potential for injury when ROM is high, low, or
imbalanced
Measurement of
Flexibility
Direct
Indirect, or
composite
Techniques for increasing joint flexibility
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Focus is on increasing length of musculotendinous
units crossing the joint
Neuromuscular response to stretch
- The sensory unit
• Consists of receptors, sensory neuron
• Role is to provide feedback to provide body position and muscletendon condition sense & to enable motor control
- Proprioceptors
• cutaneous receptors (pressure-sensitive)
• Joint receptors
– pressure-sensitive Pacinian corpuscles
– Position and velocity-sensitive Ruffini endings
• Tendon receptors (stretch-sensitive golgi tendon organ, or GTO)
• Muscle receptors (stretch-sensitive muscle spindle)
- Role of proprioception in skilled movement & flexibility
Goal of stretching is to minimize spindle effect and maximize GTO
effect.
Muscle
spindle
Increasing flexibility
Active and passive stretching
 Ballistic and static stretching
 Proprioceptive Neuromuscular Facilitation:
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Proprioceptive Neuromuscular
Facilitation (PNF)
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A group of stretching procedures involving
alternating contraction and relaxation of the
muscles being stretched.
Done to take advantage of GTO response.
Requires partner or clinician
Contract-relax-antagonist-contract technique
Agonist-contract-relax method
Can significantly increase joint ROM over
single stretching session.
Common jt injuries and pathologies
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Sprains- stretching or tearing of ligaments, tendons,
and connective tissues crossing a joint
Dislocations – displacement of the articulating bones
at a joint
Bursitis – inflammation of bursae
Arthritis – inflammation with pain and swelling
- Rheumatoid arthritis
• autoimmune system disorder
- Osteoarthritis
• Joint-specific, due to wear and tear
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Website on bone and joint injuries:
- http://www.arthroscopy.com/
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Introductory problems, p 136: 3,4,5,7,8,9,10
Additional problems, p 137: 2,6,7,10