Knee extensor strength exhibits potential to predict function in sporadic inclusion-body myositis

Authors

  • Linda Pax Lowes PT, PhD,

    Corresponding author
    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    • Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    Search for more papers by this author
  • Lindsay Alfano DPT, PCS,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    Search for more papers by this author
  • Laurence Viollet PhD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    Search for more papers by this author
  • Xiomara Quintero Rosales MD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    2. Department of Pediatrics and Neurology, The Ohio State University College of Medicine, Columbus, Ohio, USA
    Search for more papers by this author
  • Zarife Sahenk MD, PhD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    2. Department of Pediatrics and Neurology, The Ohio State University College of Medicine, Columbus, Ohio, USA
    Search for more papers by this author
  • Brian K. Kaspar PhD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    2. Department of Pediatrics and Neurology, The Ohio State University College of Medicine, Columbus, Ohio, USA
    Search for more papers by this author
  • K. Reed Clark PhD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    Search for more papers by this author
  • Kevin M. Flanigan MD,

    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    2. Department of Pediatrics and Neurology, The Ohio State University College of Medicine, Columbus, Ohio, USA
    Search for more papers by this author
  • Jerry R. Mendell MD,

    Corresponding author
    1. Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    2. Department of Pediatrics and Neurology, The Ohio State University College of Medicine, Columbus, Ohio, USA
    • Center for Gene Therapy, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA
    Search for more papers by this author
  • Michael P. McDermott Ph.D

    1. School of Medicine and Dentistry, University of Rochester, 601 Elmwood Ave, Box 630, Rochester, New York, USA
    Search for more papers by this author

Abstract

Introduction: In this study we address the challenging issue of potential use of muscle strength to predict function in clinical trials. This has immediate relevance to translational studies that attempt to improve quadriceps strength in sporadic inclusion-body myositis (sIBM). Methods: Maximum voluntary isometric contraction testing as a measure of muscle strength and a battery of functional outcomes were tested in 85 ambulatory subjects with sIBM. Results: Marked quadriceps weakness was noted in all patients. Strength was correlated with distance walked at 2 and 6 minutes. Additional correlations were found with time to get up from a chair, climb stairs, and step up on curbs. Conclusions: Quadriceps (knee extensor) strength correlated with performance in this large cohort of sIBM subjects, which demonstrated its potential to predict function in this disease. These data provide initial support for use of muscle strength as a surrogate for function, although validation in a clinical trial is required. Muscle Nerve, 2012

Ancillary