Medical Research Council (MRC) muscle scale

Indications

• 1st step in evaluating critical illness weakness/ICU-acquired weakness

Procedure

• for use in awake & cooperative patients
• grading of movement from 0 (no movement) to 5 (normal movement)
• summed maximum score for 3 movements of
  • each upper extremity
    • shoulder abduction, elbow flexion, wrist extension
  • each lower extremity
    • hip flexion, knee extension, ankle dorsiflexion

Interpretation

• a score of < 48 is considered diagnostic in the absence of other known causes

More general terms

• numerical rating scale (NRS)