Chapter 22: Interventions for Weakness in Neuromotor Disorders

Chapter Objectives

Upon completion of this chapter, the learner will be able to:

1. Describe factors influencing muscle force generation in healthy individuals and those with neurological conditions, including neural, structural, and mechanical factors.

2. Justify the rationale for and efficacy of strength training for persons with neurological conditions on the basis of current evidence.

3. Apply exercise science principles in the selection and prescription of strength training interventions to address weakness deficits in patients with neurological conditions.

4. Design a customized strength exercise program for specific areas of weakness in patients with neurological conditions, selecting from a variety of modes of strength training.

5. Discuss the benefits and preventive role of strength training in home- and community-based fitness programs for persons with progressive and nonprogressive neurological conditions to optimize functional abilities and improve health outcomes.

Introduction

Strength training is a critical ingredient in physical rehabilitation for people with neuromuscular disorders because of its potential to remediate weakness deficits, prevent secondary impairments, and promote optimal health and wellness. Muscle weakness is a primary impairment in many neurological disorders and a major contributor to activity limitations and disability (Bohannon, 2007; Cameron, 2003; Kim, 2003). Strength deficits often result in limitation of an individual’s functional abilities, which may require orthotics and/or assistive devices to ambulate and perform other functional tasks safely in the home or community. Excessive fatigue during activities of daily living (ADLs) and walking, related to weakness, can adversely affect community reintegration and quality of life (Ingles 1999; White, McCoy, 2004). Current research supports the use of strength training in persons with neuromuscular disorders as an effective intervention to enhance neuromuscular function and motor recovery (Dodd, 2002; Morris, 2004; Patten, 2004; White & Dressendorfer, 2004).

Early neurorehabilitation approaches were focused on motor retraining of selective and controlled movements, with attention to quality of movement (Bobath, 1984; Howle, 2004; Sawner, 1992). Direct strengthening exercises were discouraged based on the false assumption that these types of exercises exacerbated spasticity and adversely affected motor control. Current evidence disputes this assumption, however, and provides strong support for the efficacy of strength training in persons with neurological disorders, even in the presence of spasticity (Badics, 2002; Flansbjer, 2008; Fowler, 2001; Miller, 1997). In contrast to earlier beliefs, strengthening exercises may positively affect muscle function at the structural level by reducing muscle stiffness and at the neural level by improving recruitment and timing.

Clinicians should incorporate strengthening exercises to target weak muscles for individuals with varied neurological diagnoses, including cerebral palsy (CP), stroke/cerebrovascular accident (CVA), acquired brain injury (ABI), multiple sclerosis (MS), and Parkinson disease (PD). Special considerations for exercise prescription should be given to individuals with progressive neuromuscular diseases such as amyotrophic lateral sclerosis (ALS) (Dal Bello-Haas, 2008, 2002).

For persons with neurological disorders, a customized exercise program is required to address their specific strength deficits and restore requisite motor function for ...