A Conceptual Framework for the Progression of Balance Exercises in Persons with Balance and Vestibular Disorders

Research Article

Phys Med Rehabil Int. 2015;2(4): 1044.

A Conceptual Framework for the Progression of Balance Exercises in Persons with Balance and Vestibular Disorders

Klatt BN1*, Carender WJ2, Lin CC1, Alsubaie SA1, Kinnaird CR3, Sienko KH4 and Whitney SL1

1Department of Physical Therapy, University of Pittsburgh, USA

2Department of Otolaryngology, University of Michigan Health System, USA

3Department of Mechanical Engineering, University of Michigan, USA

4Departments of Mechanical and Biomedical Engineering, University of Michigan, USA

*Corresponding author: Brooke Klatt, Department of Physical Therapy, University of Pittsburgh, 203 Lothrop St, Pittsburgh, PA 15213,USA

Received: March 30, 2015; Accepted: April 27, 2015; Published: April 28, 2015

Abstract

There is little information in peer-reviewed literature to specifically guide the choice of exercise for persons with balance and vestibular disorders. The purpose of this study is to provide a rationale for the establishment of a progression framework and propose a logical sequence in progressing balance exercises for persons with vestibular disorders. Our preliminary conceptual framework was developed by a multidisciplinary team of physical therapists and engineers with extensive experience with people with vestibular disorders. Balance exercises are grouped into six different categories: static standing, compliant surface, weight shifting, modified center of gravity, gait, and vestibulo-ocular reflex (VOR). Through a systematized literature review, interviews and focus group discussions with physical therapists and postural control experts, and pilot studies involving repeated trials of each exercise, exercise progressions for each category were developed and ranked in order of degree of difficulty. Clinical expertise and experience guided decision making for the exercise progressions. Hundreds of exercise combinations were discussed and research is ongoing to validate the hypothesized rankings. The six exercise categories can be incorporated into a balance training program and the framework for exercise progression can be used to guide less experienced practitioners in the development of a balance program. It may also assist clinicians and researchers to design, develop, and progress interventions within a treatment plan of care, or within research trials. A structured exercise framework has the potential to maximize postural control, decrease symptoms of dizziness/visual vertigo, and provide "rules" for exercise progression for persons with vestibular disorders. The conceptual framework may also be applicable to persons with other balance-related issues.

Keywords: Balance; Exercise; Physical therapy; Progression; Rehabilitation; Vestibular

Abbreviations

BES Test: Balance Evaluation Systems Test; COG: Center of Gravity; COP: Center of Pressure; EC: Eyes Closed; EO: Eyes Open; PA: Pennsylvania; USA: United States of America; VOR: Vestibulo-Ocular Reflex

Introduction

When designing a vestibular rehabilitation program, experienced clinicians often progress balance exercises in a similar way, but there is limited literature to guide less experienced practitioners in the development of balance programs. In addition to the obvious concern regarding the quality of care provided to a client, the lack of a systematic progression framework for balance exercises also impacts how clinicians and researchers design, develop, and progress interventions or research trials. A structured exercise framework has the potential to maximize postural control, decrease symptoms of dizziness/vertigo, and provide "rules" for exercise progression for persons with balance and vestibular disorders.

While the mechanisms and measurement of balance are complex, the term balance has been described concisely as the body posture that

prevents falling [1]. Balance is dependent upon the input of the visual, vestibular, and somatosensory systems [2], therefore any exercise that alters or removes the input of any of those sensory systems could be classified as a balance exercise. Balance exercises are part of a vestibular rehabilitation program, which is specifically indicated for individuals who have balance impairments of vestibular origin [3]. In addition to challenging our sensory inputs, rehabilitation for an individual with vestibular hypofunctionutilizes the strategies of adaptation, habituation, or substitution [4]. A systematic review completed in 2007 concluded that there is moderate to strong evidence suggesting that vestibular rehabilitation is effective for adults with chronic dizziness [5]. Research shows significant improvements in postural control [6-11], functional balance [12, 13], vestibulo-ocular reflex (VOR) gain [7], subjective dizziness symptoms [6, 9, 10, 12], motion sensitivity [8], and quality of life [14]. The literature also indicates that this type of rehabilitation is appropriate for people who have peripheral [9, 13] or central etiology [13, 15], and/or unilateral [5, 11] or bilateral hypofunction [11, 16]. Not pertinent to progression, but within the realm of vestibular rehabilitation, are canal repositioning maneuvers, which are a type of treatment intervention utilized for individuals with the diagnosis of benign paroxysmal positional vertigo [4, 17].

There are examples of successful exercise programs used by clinicians that treat individuals with balance deficits, but these examples fall short of providing details regarding the rationale for how participants were progressed. For example, Gill-Body et al. (1997) described the results of rehabilitation programs for two individuals with cerebellar lesions in a case report; both patients had subjective and objective improvements in postural stability following a 6-week physical therapy exercise program focusing on stability challenges [18]. The experienced clinician prescribed a three phase treatment program with individualized treatment activities chosen based on each person’s specific impairments and one of the programs included eye-head coordination exercises. While all of the exercises are justified examples of activities to include in a balance program, they do not provide a hierarchy for progression for less experienced practitioners, or for standardized practice.

Alsalaheen et al. (2013) examined chart reviews for 114 patients receiving vestibular rehabilitation for dizziness and imbalance following a concussion to determine the prescription of exercises based on pre-determined categories [19]. The most commonly prescribed exercises were eye-head coordination, standing static balance, and ambulation exercises [19]. This report also indicated the presence of "preferred prescription patterns" and further discussed the importance of understanding patterns used by experienced clinicians to improve quality of care in managing persons postconcussion [19].

It is evident that some balance exercises are more challenging than others, however there currently is not an accepted hierarchy, or sequence to follow, related to the level of difficulty for a specific exercise, which considers all of the possible variables that contribute to balance. Some of the variables to consider include whether or not the exercise is: static or dynamic; completed with a specific foot stance (feet apart, feet together, semi-tandem, tandem, or single leg stance); performed on a firm, foam, or ramped surface; performed with visual input (i.e., eyes open or closed); implemented during ambulation (multitude of variations); or performed with a gaze stability challenge [20]. The aim of this research is to develop a preliminary conceptual framework for progressing balance exercises. The justifications for the chosen sequences are based on established principles of exercise, theories of motor control, and consideration of how variations in sensory input alter the degree of challenge for any given exercise.

Methods

The theoretical framework described below is the product of a collaborative team of physical therapists and engineers with extensive experience in the realm of vestibular rehabilitation. Because some of the exercises have not yet been studied experimentally for progression validation, clinical expertise guided some aspects of the progressions within the framework. Most of the rankings, which are ranked in order of degree of difficulty, were primarily based on information collected from a scoping literature review, interviews and focus group discussions with physical therapists and postural control experts, as well as pilot studies involving repeated trials of each exercise were completed. Hundreds of exercise combinations were discussed and research is ongoing to validate the hypothesized hierarchy.

When developing this framework, the determination of our proposed progression was based not only on clinical expertise and literature related to the characteristics of a balance exercise, but also with consideration to theories of postural control and motor learning. As we ranked the exercises in order of increasing balance difficulty, we were cognizant of biomechanical principles that determine postural stability, specifically, the difference of center of pressure (COP) and center of gravity (COG) [1]. For clinical application, it has been synthesized that people who have larger COP-COG differences in static standing are at greater fall risk than individuals with smaller values [21]. However, large COP-COG differences are needed to maintain balance for perturbed standing, therefore small COP-COG differences during dynamic standing tasks place a person at greater fall risk [21]. This notion is important to consider as an exercise adds variables that make it more dynamic.

Results

We propose the incorporation of six different exercise categories when developing a balance program with functional goal to improve postural control: static standing, compliant surface standing, weight shifting, modified center of gravity, gait, and gaze stabilization or vestibulo-ocular reflex (VOR) training. These categories correspond to the six different balance control systems that are included in the balance evaluation systems Test [22]. Within each category there are variants with modifications that distinguish each exercise (Figure 1) and affect the level of exercise difficulty. The progression framework ranks each exercise in order of difficulty within each category (Tables 1-5).