Recording-2025-03-12T04:44:24.124Z

Measures of Muscle Performance

• Understanding various measures of muscle performance provides insights into clinical utility and research applications.

Electromyography (EMG)

• Definition: A technique to measure muscle activation timing and magnitude.

• Types:

  • Surface EMG: Non-invasive, records electrical activity from the skin surface.

  • Intramuscular EMG: More invasive, provides localized activity data.

• Limitations:

  • EMG does not measure muscle force or strength directly.

  • Not always practical in clinical settings due to equipment requirements.

Muscle Force Measurement

• Overview: Muscle force quantification is more applicable in research settings, especially in vitro.

• Formula: Requires precise measurements of lever arms related to the load and the muscle.

  • Challenges exist in vivo due to joint rotation complexities and multi-plane movements.

Dynamometers

• Function: Devices used to measure muscle force and torque.

• Gold Standard:

  • Considered the best method for measuring various performance metrics (e.g., concentric and eccentric contractions).

• Types:

  • Biodex System: Large, expensive, predominantly found in research environments.

  • Handheld Dynamometers: More economical, commonly used in clinical practice (e.g., hand therapy).

• Expensive Equipment: While providing accurate measures, they are not always accessible in clinical settings.

Alternatives for Muscle Strength Assessment

• Free Weight Assessments:

  • One Rep Max (1RM)

  • 10 Rep Maximum (10RM)

  • Repetitions until muscle failure

  • Useful for quantifiable strength measures in clinical practice.

• Manual Muscle Testing (MMT):

  • Widely used assessment technique across physiotherapy settings.

  • Involves the Oxford scale for grading muscle strength but lacks quantifiability and reliability compared to dynamometers.