Muscle Testing and Manual Muscle Testing (MMT)

Key Concepts

• Muscle Testing: Determines if a muscle is okay or weak.
• Muscle Strength: Ability to perform activities requiring high levels of muscle force.
• Maximum Voluntary Contraction (MVC): Measures maximum voluntary muscle contraction.

Break Test

• Purpose: Measures maximum muscle force.
• Procedure: Position the muscle at its greatest mechanical advantage, ask the patient to hold the position, and gradually apply resistance.
• Steps:
  1. Position the muscle optimally.
  2. Gradually apply resistance while instructing the patient not to let you break the position.
  3. Record the muscle strength based on the resistance tolerated.

Grading Systems for MMT

• Numeric System:
  • 5: Normal
  • 4: Good
  • 3: Fair
  • 2: Poor
  • 1: Trace
  • 0: Zero

Detailed Grading Criteria

• 0: No muscle contractions seen or felt.
• 1 (Trace): Muscle contraction felt but no motion.
• 2 (Poor): Full range of motion (ROM) without gravity.
• 3 (Fair): Full ROM against gravity.
  • 3+: Full ROM against gravity with minimal resistance.
• 4 (Good): Full ROM against gravity with moderate resistance.
• 5 (Normal): Full ROM against gravity with maximum resistance.

MMT Procedure

1. Start at grade 3 (Fair): Ask the patient to move against gravity.
2. Evaluate available ROM: Compare patient’s ROM to normative values (e.g., shoulder flexion norm is 160 degrees).
3. Apply resistance: Gradually increase resistance to measure muscle strength.
4. Adjust for less than full ROM:
   • If more than 50% ROM, grade as 3-.
   • If less than 50% ROM, move to gravity minimized position and re-assess.
     • If full ROM in gravity minimized position: Grade 2.
     • Apply minimal resistance: Grade 2+.
     • No resistance tolerance: Grade 2.
     • Incomplete ROM in gravity minimized position: Grade 2-.
     • Muscle contraction with no motion: Grade 1 (Trace).
     • No muscle contraction: Grade 0.

Documentation

• Details to Document:
  • Date of measurement.
  • Muscle groups tested.
  • Side of the body tested.
  • Results and any alternative positions used.
  • Signature and MMT result.

Applications in Therapy

• Muscle Weakness Patterns: Helps in identifying muscle imbalances and tracking recovery.
• Goal Setting: Goals should link muscle strength improvements to functional outcomes (e.g., lifting a child).
  • Avoid setting goals based solely on MMT grades.

Summary

• MMT helps distinguish between joint issues and muscle weakness.
• Conduct ROM assessment and MMT together for comprehensive evaluation.
• Practice and familiarity with the grading system make the process easier.

Thank you!