Muscle Tone and Contractions

Muscle Tone

• Muscle tone (tonus) results from the maintenance of muscle fibers in a contracted state.
• Muscle spindles, which are sense organs in muscles, are responsible for monitoring muscle tone.
• Muscle tone is minimal during sleep.
• Muscle tone increases when a person is anxious.
• A muscle that is limp and lacks tone is described as flaccid.
• A muscle with greater-than-normal tone is described as spastic.

Muscle Contractions

• Isometric contraction happens when muscle length remains constant while the force generated by the muscles increases.
• An example of isometric contraction is pushing against an immovable wall.
• Isotonic contraction is when the muscle shortens without an increase in tension within the muscle.
• Flexing the forearm is an example of isotonic contraction.
• Energy is used during both muscle contraction and relaxation.
• The primary energy source for muscle cells is adenosine triphosphate (ATP).
• ATP is generated through cellular oxidative metabolism.

Muscle Action

• Muscle contraction produces movement.
• The body can perform a wide range of movements through the coordination of muscle groups.
• The prime mover is the muscle that causes a particular motion.
• Muscles assisting the prime mover are known as synergists.
• Muscles causing movement opposite to that of the prime mover are antagonists.
• An antagonist must relax to allow the prime mover to contract to produce a motion.

Exercise, Disuse, and Repair

• Muscles require exercise to maintain function and strength.
• Hypertrophy, or muscle enlargement, results from an increase in the size of individual muscle fibers.
• Hypertrophy happens without an increase in the number of muscle fibers.
• Atrophy is the decrease in the size of a muscle.

Gerontologic Considerations

• Multiple changes occur in the musculoskeletal system with aging.
• Aging can bring complaints of pain and joint limitations.
• Loss of height occurs due to osteoporosis (abnormal excessive bone loss).
• Kyphosis (forward curvature of the thoracic spine) is a condition related to aging.
• Thinned intervertebral discs, compressed vertebral bodies, and flexion of the knees and hips are common with aging.

Health History

• A nursing assessment of a patient with musculoskeletal dysfunction includes a health history and a physical examination.
• The nursing assessment evaluates the effects of the musculoskeletal disorder on the patient.
• Nurses assist patients with musculoskeletal problems to maintain their general health and functional status as well as treatment programs.
• Nurses also assist patients with accomplishing their activities of daily living (ADLs).

Common Symptoms

• Patients with musculoskeletal disorders may report pain, tenderness, and altered sensations during the interview and physical assessment.
• The nurse is responsible for assessing and documenting this information.

Assessing Pain

• Bone pain is typically described as a dull, deep ache that is "boring".
• Bone pain is not generally related to movement and can interfere with sleep.
• Muscular pain is described as soreness or aching.
• Muscular pain is referred to as "muscle cramps."
• Fracture pain is sharp and piercing and is relieved by immobilization.
• Sharp pain can also result from bone infection with muscle spasm or pressure on a sensory nerve.
• Joint pain is felt around or in the joint and typically worsens with movement.
• Assessing pain requires determining if the body is in proper alignment.
• Assessing pain requires determining if the joints are symmetrical or if bony deformities exist.
• Assessing pain requires looking for inflammation or arthritis, swelling, warmth, tenderness, or redness.
• Assessing pain requires evaluating pressure from traction, bed linens, a cast, or other appliances.
• Assessing pain requires evaluating for tension on the skin at a pin site.
• Successful pain management can prevent the patient from becoming increasingly withdrawn and dependent as the musculoskeletal disorder continues.

Assessing Altered Sensations

• Patients may describe paresthesias, which are sensations of burning, tingling, or numbness.
• Paresthesias may result from pressure on nerves or circulatory impairment.
• Soft tissue swelling or direct trauma to these structures can impair their function.
• The nurse assesses the neurovascular status of the involved musculoskeletal area.
• The nurse should ask if the patient is experiencing any abnormal sensations (burning, tingling, numbness).
• If the abnormal sensation involves an extremity, determine how the feeling compares to the unaffected extremity.
• Determine when the condition began and if it is getting worse.
• Determine if the patient has pain.

Past Health, Social, & Family History

• When assessing the musculoskeletal system, the nurse gathers pertinent data to include in the patient's health history.
• This information gathering includes occupation, exercise patterns, alcohol consumption, tobacco use, and dietary intake.
• Concurrent health conditions and related problems need to be considered when developing and implementing the plan of care.
• Any previous history of trauma or injury to the musculoskeletal system or a history of falls should be included as well.

Family History Assessment Related to Genetic Musculoskeletal Disorders

• Assess for other similarly affected family members in the past three generations.
• Assess for the presence of other related genetic conditions (e.g., hematologic, cardiac, integumentary conditions).
• Determine the age at onset of these genetic conditions.

The Fracture Risk Assessment Tool (FRAX®)

• The FRAX® tool was developed in 2008 by a task force convened by the World Health Organization (WHO).
• FRAX® predicts a patient's 10-year risk of fracturing a hip or other major bone (spine, forearm, or shoulder).
• The FRAX® tool may be accessed online and automatically calculates a patient's odds of fracture.
• Data entered includes risks for fracture, and include:
  • Age (risk increases with increasing age).
  • Gender (risk is higher in females).
  • Body mass index (risk is higher with lower body mass indices).
  • History of a previous fracture.
  • Parental history of hip fracture.
  • Current cigarette smoker.
  • Current use of a corticosteroid (e.g., prednisone).
  • History of rheumatoid arthritis.
  • Alcohol intake of 3 or more drinks per day.
  • History of secondary causes/risks for osteoporosis (type I diabetes, osteogenesis imperfecta, untreated long-standing hyperthyroidism, hypogonadism or premature menopause, chronic malnutrition or malabsorption syndromes, chronic liver disease).