Scientific/Clinical Article| Volume 20, ISSUE 4, P311-325, October 2007

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The Ab-Adductometer: A New Device for Measuring the Muscle Strength and Function of the Thumb


      The purpose of this study was to present normative values for thumb abduction and adduction and also to present measures of reliability of the measuring system arising from the use of the Ab-Adductometer. With the Ab-Adductometer, we obtained abductor and adductor measurements of intrinsic muscle strength of the healthy hand thumb in 600 volunteers. Handgrip strength values were obtained with the Jamar dynamometer. Age and male–female specific reference ranges for the Ab-Adductometer and the Jamar dynamometer are presented. This study, with a very large number of volunteer subjects, 600, presents reference ranges for pure palmar adduction and abduction of the thumb. The results indicate that the Ab-Adductometer is a clinically useful device for the purpose of quantitatively measuring thumb adduction and abduction strength at various starting angles of thumb abduction relative to the plane of the palm. The device may be especially helpful in the evaluation of compressive neuropathies of the median or ulnar nerves such as carpal tunnel syndrome or cubital tunnel syndrome as well as for primary disease of the peripheral nerves that affect intrinsic muscles and for thumb function in proximal conditions such as tetraplegia and brachial plexopathy.
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      JHT Read for Credit

      Quiz: Article #068

      Record your answers on the Return Answer Form found on the tear-out coupon at the back of this issue. There is only one best answer for each question.
      • #1.
        The subjects in this study were
        • a.
          300 normal adults plus 300 injured adults
        • b.
          600 students
        • c.
          600 normal adults
        • d.
          600 injured adults
      • #2.
        When tested the contractions were
        • a.
        • b.
        • c.
        • d.
      • #3.
        The device tested is
        • a.
          inappropriate for research applications
        • b.
          modestly expensive
        • c.
        • d.
          not available for clinical use
      • #4.
        The correlations shown were
        • a.
          high for age and weight
        • b.
          higher for age than weight
        • c.
          higher for weight than age
        • d.
          not statistically significant
      • #5.
        This study questions the validity of previously published grip norms
        • a.
        • b.
      When submitting to the HTCC for recertification, please batch your JHT RFC certificates in groups of three or more to get full credit.