Institutional members access full text with Ovid®

Share this article on:

Two-Year Longitudinal changes in lower limb strength and its relation to loss in function in a large cohort of patients with Duchenne Muscular Dystrophy

Batra, Abhinandan, PT, MA, PhD1; Harrington, Ann, PT, DPT, PhD2; Lott, Donovan J, PT, PhD, CSCS1; Willcocks, Rebecca, PhD1; Senesac, Claudia, PT, PhD1; McGehee, William, PT, PhD1; Xu, Dandan, MS3; Mathur, Sunita, BScPT, MSc, PhD4; Daniels, Michael J, PhD3; Rooney, William D, PhD5; Forbes, Sean C, PhD1; Triplett, William, BS1; Deol, Jasjit K, PT1; Arpan, Ishu, PT, PhD6; Bendixen, Roxanne, PhD7; Finkel, Richard, MD8; Finanger, Erika, MD9; Tennekoon, Gihan, MBBS, MRCS, LCRP10; Byrne, Barry, MD, PhD11; Russman, Barry, MD12; Sweeney, Lee H, PhD13; Walter, Glenn, PhD14; Vandenborne, Krista, PT, PhD1

American Journal of Physical Medicine & Rehabilitation: May 2, 2018 - Volume Publish Ahead of Print - Issue - p
doi: 10.1097/PHM.0000000000000957
Research Article: PDF Only

Objective The main objective of this study were to examine the effect of disease on strength in two functionally important lower limb muscles over a period of two-years in children with Duchene Muscular Dystrophy (DMD).

Design Seventy-Seven DMD children participated in this study. Plantar flexors (PF), knee extensors (KE) strength and performance on timed tests (Six-min walk, 4-stairs, 10m-walk, supine-up) was assessed yearly over two-years. Multivariate normal regression was used to assess changes in strength over time in the DMD group. Spearman correlations were computed to examine relationship between strength and function.

Results Normalized PF and KE strength, showed a significant decrease (p<0.05) over 2 years, with larger declines in KE. At baseline, KE strongly correlated with performance on timed tests. However, PF strength was found to be a stronger predictor of loss in ambulatory function. Modest correlations (r=0.19-0.34) were found between the decline in strength and functional performance over two-years.

Conclusions This study describes the loss of lower limb strength in a large cohort of DMD children over two years. The findings support that lower limb strength alone can not account for the decline in performance on functional tests and the role of other contributing factors, such as compensatory strategies, should be considered.

1Department of Physical Therapy, University of Florida, Gainesville, Florida, USA.

2Department of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.

3Department of Statistic University of Florida, Gainesville, Florida, USA.

4Department of Physical Therapy, University of Toronto, Toronto, Ontario, Canada.

5Advanced Imaging Research Center, Oregon Health and Science University, Portland, Oregon, USA.

6Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA.

7Department of Occupational Therapy, School of Health and Rehabilitation Sciences University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

8Department of Pediatrics, Nemours Childrem’s Hospital, Orlando, Florida, USA

9Department of Pediatrics, Oregon Health and Science University, Portland, Oregon, USA

10Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.

11Department of Pediatrics, University of Florida, Gainesville, Florida, USA.

12Division of Neurology, Oregon Health and Science University, Portland, Oregon, USA

13Department of Pharamacology and Therapeutics, University of Florida, Gainesville, Florida, USA.

14Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA.

Corresponding Author: Krista Vandenborne, PT, PhD, University of Florida, Dept. of Physical Therapy, Box 100154, UFHSC, Gainesville, FL 32610. kvandenb@phhp.ufl.edu. (352) 273-6085

Author Disclosures:

Competing Interest: None

Funding: Magnetic Resonance Imaging and Biomarkers in Muscular Dystrophy (NIAMS, NINDS: R01 AR056973); First author is supported by Wellstone Grant (NIAMS: U54AR052646).

Financial Benefit to authors: None

Previous presentation: None

Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.