Hand-Held Myometer

The Hand-Held Myometer is a portable device used as a quantitative and objective method of muscle assessment (Schwartz et al. 1992). Testing is performed using one of two techniques, 1) make or 2) break. The ‘make’ technique requires the examiner to resist a maximal voluntary contraction by the patient, thereby producing an isometric contraction. In the ‘break’ technique, the examiner applies adequate force to overcome the patient, thereby producing an eccentric contraction.

Number of items: N/a

Procedure/Administration: Clinician administered. The mean force of three administrations for each muscle group tested is preferred (Noreau et al. 1998) and some investigators suggest a practice trial (Andrews et al. 1996). A break of 5 to 10 seconds between trials is suggested. The starting position of the individual and the myometer is critical and encouragement to maximize muscle contraction is suggested (Noreau et al. 1998).

How scored: The recommended unit of measurement is Kg in order avoid interpretation issues. Measurements are generally rounded to the nearest Kg. 

Interpretability: Normative values for various adult age groups are available. A predicted muscle force can be calculated by taking into consideration the individual’s gender, weight, and age. By comparing the predicted force to the observed force, an estimate of percentage of deficit may be determined. However, no meaningful cut-points have been reported.  Computer software is available to assist with data analyses.

Acceptability: N/a

Languages: N/a

Usability: N/a

Time to administer: 30 minutes for a bilateral assessment of the upper extremities. And, multiple position changes are required to capture maximal muscle contractions

Time to score: N/a

Training required: N/a

Availability: N/a

Equipment required: A myometer. Initial cost of this device may be seen as a limitation to its general use.

Summary:

  • Myometer testing presents an objective, quantifiable method of measuring muscle strength. However this does not necessarily reflect function.
  • It is superior to MMT for detection of mild to moderate weakness and changes in muscle strength. It also eliminates potential bias from the evaluator for various age groups and gender.

Psychometric Summary

Reliability

Validity

Responsiveness

Results

Results

Results

Floor/ceiling

InterO: Green light

N/a

N/a

N/a

Note: TR= Test re-test; IC= Internal Consistency; Inter-O= Inter-observer; Intra-O= Intra-observer; SS= Sensitivity/Specificity; N/a= No information.

Red light= A single study involving SCI subjects which has less than adequate findings of reliability, validity, and/or responsiveness.

Yellow light= A single study involving subjects with SCI which has adequate to excellent findings of reliability, validity, and/or responsiveness.

Green light= At least 2 studies involving subjects with SCI which have adequate to excellent findings of reliability, validity, and/or responsiveness.

References

  • Andrews AW, Thomas MW, Bohannon RW. Normative Values for Isometric Muscle Force Measurements Obtained With Hand-held Dynamometers. Physical Therapy 1996; 76:248-259.
  • Burns SP, Breuninger A, Kaplan C, Marin H. Hand-Held Dynamometry in Persons with Tetraplegia. Am. J. Phys. Med. Rehabil. 2005;84:22-29.
  • Cohen ME, Herbison GJ, Shah A. Relationship Between Two Measure of Upper Extremity Strength: Manual Muscle Test Compared to Hand-Held Myometry. Arch Phys Med Rehabil 1992;73:1063-1068.
  • Noreau L & Vachon J. Comparison of three methods to assess muscular strength in individuals with spinal cord injury. Spinal Cord 1998;36:716-723.
  • Schwartz S, Cohen ME, Herbison GJ, Shah A. Relationship Between Two Measure of Upper Extremity Strength: Manual Muscle Test Compared to Hand-Held Myometry. Arch Phys Med Rehabil 1992;73:1063-1068.