Hand-Held Myometer

Clinical Summary

Jump to: Tool Description | Interpretability | Measurement Property Summary

Tool Description

  • a portable device used as a quantitative method of muscle contraction (primarily for upper limb).
  • 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. 

ICF Domain:

Body Function and Structures – subcategory: Neuromusculoskeletal and Movement-Related Functions & Structures

Number of Items:

n/a

Brief Instructions for Administration & Scoring

Administration:

  • Clinician administered; performance measure.
  • The mean force of three administrations for each muscle group tested is preferred and some investigators suggest a practice trial. 5 to 10 seconds rest break between trials is suggested.
  • The starting position of the individual and the myometer is critical (though it seems starting position has not been standardized in the literature for different muscles)
  • Encouragement to maximize muscle contraction is suggested.
  • 30 minutesis required for a bilateral assessment of the upper extremities. Additionally, multiple position changes are required to capture maximal muscle contractions.

Equipment:

  • A myometer.

Scoring:

  • The recommended unit of measurement is kg in order avoid interpretation issues. Measurements are generally rounded to the nearest kg.  

Interpretability

MCID: not available
SEM & MDC:
SEM and MDC calculated from data in Aufsesser et al. 2003:

 

Tester 1

Tester 2

Muscle

SEM (lbs)

MDC (lbs)

SEM (lbs)

MDC (lbs)

Left biceps

5.05

14.01

1.84

5.10

Right biceps

2.94

8.15

2.96

8.21

Left triceps

2.91

8.08

2.17

6.01

Right triceps

3.26

9.04

2.44

6.76

Left wrist extensors

2.71

7.51

1.73

4.80

Right wrist extensors

2.94

8.14

0.26

0.73

  • Normative values for various adult age groups for the general population are available.
  • A predicted muscle force can be calculated by taking into consideration the individual’s sex, weight, and age.
  • By comparing the predicted force to the observed force, an estimate of percentage of deficit may be determined.
  • No normative data for the SCI population have been reported.       

Languages:

n/a

Training Required:

No formal training required, but examiners should be familiar with the techniques and proper administration.

Availability:

Myometers are available for purchase from medical/rehabilitation equipment vendors. 

Clinical Considerations

  • Myometer testing presents an objective, quantifiable method of measuring muscle strength. However this does not necessarily reflect function.
  • Initial cost of the myometer may be seen as a limitation to its general use.
  • Computer software is available to assist with data analyses.
  • It is superior to manual muscle testing 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.

Measurement Property Summary

# of studies reporting psychometric properties: 8

Reliability:

  • Inter-rater reliability is poor to excellent (ICC=0.21-0.89). This variability may be due to the lack of standardization for starting position and for muscles tested.
  • Intra-rater reliability is excellent (ICC=0.93-0.99) for the make technique for the biceps, triceps and wrist extensors.
  • Intra-rater and inter-rater reliability has been tested for a variety of muscles (elbow flexors and extensors, shoulder rotation, plantar flexors, intrinsic hand muscles, etc.)

[Aufsesser 2003, Burns 2005, May et al. 1997, LaMontagne et al. 1998, Jacquemin et al. 2004, Herbison et al. 1996, Schwartz et al. 1992]

Validity:

  • Correlation of hand-held myometry with Manual Muscle Testing ranges from:
    •  poor to excellent for individuals with paraplegia (Spearman’s r=0.26-0.67)
    • adequate to excellentfor individuals with tetraplegia (Spearman’s r=0.50-0.95).

[May et al. 1997, Jacquemin 2004, Herbison et al. 1996, Noreau & Vachon 1998]

Responsiveness:

No values were reported for the responsiveness of hand-held myometry for the SCI population at this time.

Floor/ceiling effect:

No values were reported for the presence of floor/ceiling effects in hand-held myometry for the SCI population.

Reviewer

Dr. William Miller, Christie Chan

Date Last Updated:

 Feb 1, 2013