Date of Award


Degree Type


Degree Name

Master of Science




Dr. Timothy Doherty


PURPOSE: The aim of the current study was to determine if decomposition quantitative electromyography (DQEMG) reflected the clinical presentation of patients with muscular dystrophy (MD). The clinical measure which best predicted functional ability was also investigated. METHODS: Fifteen patients with fascioscapulohumeral (FSHD), limb- girdle (LGMD), and Beckers (BMD) muscular dystrophy and seven healthy controls participated in the study. Isometric strength and isotonic power of the right leg were assessed with a Biodex dynamometer. Functional ability was determined by performance on stair climb, chair rise, and gait velocity tasks. The vastus lateralis, biceps brachii, and tibialis anterior muscle groups of the right side were investigated using DQEMG. The following motor unit potential (MUP) parameters were analyzed and compared with control data: duration, amplitude, area, area-amplitude ratio, and number of phases and turns. MRI was used to evaluate right side quadriceps muscle volume. RESULTS: Patients with MD had reduced quadriceps strength, power, muscle volume and functional ability compared with controls. Maximum voluntary contraction (MVC) force was determined to correlate most strongly with patient’s functional ability. MUP duration was found to indicate the severity of the myopathy and correlated significantly with quadriceps strength, power, and muscle volume in patients with MD. CONCLUSION: DQEMG reflects the underlying pathology of the myopathy, which manifests clinically as weakness and compromised functional ability. Furthermore, the functional ability of patients with MD is strongly predicated by MVC strength.



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