Getting the Dosage Right in Balance Exercise Prescription: the Intensity Problem

Abstract

EditorialAs our population ages, finding effective interventions to treat balance impairments is critical. In the United States Medicare spent over $31 billion in 2015 managing fall injuries. More than 800,000 people a year were hospitalized because of a fall, most often a fractured hip or head injury. Fall injuries are among the top 20 most expensive medical conditions, with an average cost of over $30,000. Furthermore, these direct costs do not account for the long-term effects of these injuries such as disability, dependence on others, lost time from work and household duties, and reduced quality of life [1]. Thus, determining effective means of preventing falls is a significant health care need.There have been a large number of investigations examining various aspects related to balance training and fall prevention, with more than 50 systematic reviews and meta-analyses of this research completed since 2009 [2]. Multiple types of balance interventions have been studied, with populations of varied ages as well as with differing disabilities, and in multiple types of settings [2,3]. However, there is no simple answer about the "best" exercise prescription to prevent falls because the construct of balance itself is so complicated [4]. The ability to maintain the center of mass within the base of support, or balance is a composite impairment that is influenced by strength, flexibility, sensation, cognition, and motor control.Despite the complexity, however, developing evidence based guidelines for effective balance exercise prescription is essential. Physical therapy exercise prescription typically follows the FITT principle [5], referring to frequency, intensity, type, and time, similar to medication administration. For example, when prescribing a drug, a physician determines the correct medication [TYPE] as well as the amount [INTENSITY] and frequency [FREQUENCY] of taking the medication, and the duration to continue taking the medication [TIME]. The physical therapy profession has taken a harder look at how we prescribe exercise over the last decade across multiple domains of practice, from acute care, to orthopedics to geriatric rehabilitation [6][7][8]. Similar to pharmacological interventions, incorrect exercise dosage can be ineffective in targeting the problem, and therefore costly in actual dollars and/or time. In addition, it can be damaging [9].Because balance is a multifactorial construct, exercise prescription is complex. It is for this reason that many individuals will do better with an exercise program customized by a physical therapist rather than attending a standardized group program [10,11]. There are often multiple types of exercise necessary to address different components of the balance problem. For example, it is common to use strengthening exercises in conjunction with exercises addressing motor control components of balance, such as seen in the widely used OTAGO exercise protocol [12]. We do have guidelines for determining types of exercise, based on an individualized evaluation [2], ...

The Balance Intensity Scales for Therapists and Exercisers Measure Balance Exercise Intensity in Older Adults: Initial Validation Using Rasch Analysis

“…The recognition that measurement of balance exercise intensity is important is growing 32 and with it the importance of the development of a method to measure this complex variable. A recent study by Espy et al 33 tested a 10-point subjective rating of perceived stability, modeled on the Borg Scale for the rating of perceived exertion 34 .…”

Contemporary Non-Surgical Considerations in the Management of People with Extra- and Intra-Articular Hip Pathologies

“…However, knowledge on the specifics of exercise prescription is a recognised barrier to exercise uptake [90]. Reintahl [91] eloquently likens exercise prescription to drug prescription. For example, the physician determines the type of medication, the amount or intensity, the frequency of intake and the duration of use.…”

Differences between physical therapist ratings, self-ratings, and posturographic measures when assessing static balance exercise intensity

“…Balance training, which is traditionally performed in a clinical setting with the instruction of a physical therapist (PT), can improve balance ability when it occurs at the appropriate dosage such that the training is at or near the limits of an individual's ability (25)(26)(27). Dosage has been described as the combination of frequency, intensity, time, and type (FITT) where frequency refers to the regularity of training sessions, intensity refers to "the degree of challenge to the balance control system relative to the capacity of the individual to maintain balance" (28), time refers to the duration of each exercise and of the session, and type refers to the exercise itself (29)(30)(31). While frequency, time, and type are easily quantified (29,31), intensity depends on both the difficulty of the exercise and the balancing ability of the individual, reflecting how challenging an exercise is for a particular individual at a specific time; it is therefore more difficult to assess (29)(30)(31).…”

“…Dosage has been described as the combination of frequency, intensity, time, and type (FITT) where frequency refers to the regularity of training sessions, intensity refers to "the degree of challenge to the balance control system relative to the capacity of the individual to maintain balance" (28), time refers to the duration of each exercise and of the session, and type refers to the exercise itself (29)(30)(31). While frequency, time, and type are easily quantified (29,31), intensity depends on both the difficulty of the exercise and the balancing ability of the individual, reflecting how challenging an exercise is for a particular individual at a specific time; it is therefore more difficult to assess (29)(30)(31). Unlike aerobic (e.g., percent of maximum heart rate) or resistance (e.g., percent of the 1-repetition maximum) exercise intensity (32), there is no standard assessment for balance exercise intensity.…”