What is the management of disuse myopathy?

Management of Disuse Myopathy

Early implementation of active and passive mobilization combined with muscle strengthening exercises is essential for managing disuse myopathy to prevent further muscle atrophy and promote functional recovery. 1

Understanding Disuse Myopathy

Disuse myopathy occurs following periods of inactivity or immobilization, resulting in:

• Decreased muscle mass and fiber cross-sectional area 2
• Reduced muscle strength and increased fatigability 2
• Transitions in muscle fiber types 2
• Increased insulin resistance 2

Comprehensive Management Approach

Early Mobilization

• Active or passive mobilization should be instituted as early as possible to prevent further muscle atrophy 1
• Walking and standing aids (modified walking frames, tilt tables) are safe and feasible tools to facilitate mobilization in critically ill patients 1
• Position changes and pressure relief are essential for maintaining skin integrity in immobile patients 1

Exercise Interventions

For Patients Able to Perform Voluntary Exercise:

• Submaximal and aerobic exercise is recommended over excessive resistive exercise 1
• Gentle strengthening within physiological limits to avoid overexertion 1
• Exercise parameters:
  • 3 sets of 8-10 repetitions at 50-70% of 1 repetition maximum (1RM) 1
  • Incorporate rest periods to prevent excessive fatigue 1
  • Monitor cardiorespiratory response to activity, especially in supine position 1

For Patients Unable to Perform Voluntary Exercise:

• Neuromuscular electrical stimulation (NMES) has been shown to prevent disuse muscle atrophy 3
• Positioning, splinting, passive mobilization and muscle stretching should be implemented to preserve joint mobility and skeletal muscle length 1
• Consider vibration therapy and blood flow restriction techniques when appropriate 4

Functional Training

• Focus on functional activities rather than isolated exercises 1
• Incorporate activities that enhance:
  • Self-care skills 1
  • Mobility (transfers, gait training) 1
  • Use of adaptive equipment 1

Nutritional Support

• Maintain adequate protein intake to support muscle preservation 5
• Combined exercise and nutritional interventions likely provide synergistic benefits in preventing muscle atrophy 6

Assessment and Monitoring

Regular assessment should include:

• Manual muscle testing to measure strength 1
• Functional outcome measures (timed walking tests, ability to perform daily activities) 1
• Range of motion assessment to identify emerging contractures 1
• Monitoring for signs of overwork weakness 1

Special Considerations

Critically Ill Patients

• Aerobic training and muscle strengthening, in addition to routine mobilization, improve walking distance more than mobilization alone 1
• Non-invasive ventilation during mobilization may improve exercise tolerance in appropriate patients 1

Elderly Patients

• Resistance exercises and maximal voluntary contractions (both isometric and dynamic) are powerful tools for preventing muscle atrophy 4
• Aerobic exercise should be prescribed whenever possible to reduce loss of cardiovascular capacity 4

Common Pitfalls to Avoid

• Excessive resistive and eccentric exercise can worsen muscle damage 1
• Overwork weakness can lead to further deterioration 1
• Disuse atrophy from insufficient activity 1
• Inadequate monitoring of cardiorespiratory response during exercise 1

Assistive Technology and Adaptive Equipment

• Provide appropriate assistive technology with proper training for home, educational, and work environments 1
• Consider mobility aids (manual/electric wheelchairs) when appropriate 1
• Orthotic intervention may be necessary to prevent contractures and deformity 1

By implementing these evidence-based strategies early and consistently, disuse myopathy can be effectively managed to improve functional outcomes and quality of life.