The Berg Balance Scale (BBS) by Berg et al. (1989) is a performance-based measure designed to quantitatively assess a person’s balance and fall risk. Originally designed for older community-dwelling adults through direct observation of their performance, the BBS has shown to be valid across multiple patient populations where balance is of primary concern (Berg, Wood-Dauphinee, Williams, & Maki, 1992). The assessment consists of 15 items that measure the person’s ability to maintain balance, either statically or while performing various functional movements, for a specified duration of time (Blum & Korner-Bitensky, 2008). Each item is scored along a 5-point scale of 0 to 4 where 0 indicates the lowest level of function and 4 the highest. The maximum possible score is 56 and is indicative of less fall risk. The BBS takes less than 30 minutes to complete.
• Standing with eyes closed
• Standing with feet together
• Reaching forward with outstretched arm
• Retrieving object from floor
• Turning to look behind
• Turning 360 degrees
• Placing alternate foot on stool
• Standing with one foot in front
• Standing on one foot
Adapted from Stevenson, T. (2001). Detecting change in patients with stroke using the Berg Balance Scale). Australian Journal of Physiotherapy, 47(1), 30.
Early research by its author involving 32 individual raters across a number of therapy disciplines using 35 stroke patients and 28 elderly rehabilitation residents found that initial results showed excellent agreement for both inter- and intra-rater reliability with intra-class correlation coefficients of r = 0.98 and 0.97, respectively. In addition, standardized Cronbach’s alpha estimates were high in both elderly residents (α = 0.87) and stroke patients (α = 0.98), indicating strong internal consistency (Berg, 1992). A longitudinal study, also involving its author, of elderly and stroke subjects examined at baseline, and at 3, 6, and 9 months, and at 2, 4, 6, and 12 weeks (stroke) found that Cronbach’s alphas at each evaluation were greater than 0.83 and 0.97 showing strong internal consistency for the measure (Berg, Wood-Dauphine, & Williams, 1995). A study by Conradsson et al. (2007) (n = 45; mean age, 82 years; mean Mini-Mental State Examination, 17.5) found test-retest reliability to be excellent at r = 0.97 where the mean score was 30.3 points. Subsequent research, also involving stroke patients, found that correlations between the BBS and the Barthel Index were excellent with a range of 0.80 to 0.94 (Blum & Korner-Bitensky, 2008). The same study found that correlations between the BBS and Fugl-Meyer balance subscale were considered adequate to excellent with a range of 0.62 to 0.94. Results of a study by Chou et al. (2006) generally concur with results mentioned previously where they too found excellent correlations between the BBS and the Barthel Index at 0.88 and between the BBS and the motor functioning subscale of the Fugl-Meyer Assessment (0.71) 2 weeks post-stroke. (Blum & Korner-Bitensky, 2008). A study by Muir, Berg, Chesworth, and Speechley (2008) argued that dichotomizing the BBS at a score of 45 (those above and those below) resulted in the following probabilities for falling: 58% (20/34) of people with BBS scores at or below 45 fell, whereas only 39% of people (60/153) with scores above 45 fell. Further analysis suggested that the optimal single cutoff value for any fall was 54 and that for multiple falls it was 53 and for injurious falls it was also 54. The high cutoff values required to optimize sensitivity in each fall outcome category suggest that balance impairment alone may not define increased fall risk and that falls are frequent among people with scores above 45 (Muir, Berg, Chesworth, & Speechley, 2008). Finally, an examination to identify elderly people (age range: 65 to 94 years old) who are at risk for falling found that at a cutoff score of 35 the BBS had a sensitivity of 30% and specificity of 96%, at 40 the sensitivity was 45% and specificity was 96%, and at the suggested cutoff score of 45 sensitivity was 64% and specificity was 90% (Riddle & Stratford, 1999).
Riddle and Stratford (1999) argue that the BBS is an easy-to-administer, safe, simple, and reasonably brief measure of balance for elderly people that has a good amount of research in support of its use in clinical practice. The assessment can also be used to monitor several aspects of the therapeutic process such as a person’s response to treatment. The BBS could also be considered a naturalistic type of assessment since elements resemble common everyday activities. No special training or certifications are needed and it has also displayed high inter- and intrarater agreement as well as strong correlations with other accepted outcome measures.
Falls and the risk of falling in general can be complex, and several mechanisms may complicate the issue (i.e., disease process, medication, cognitive decline, or the aging process) increasing a person’s chances of falling, thus quantifying that risk may be difficult. The problem is highlighted by the fact that validation efforts that have argued that a cutoff score of 45/56 is necessary for independent ambulation and that failure to reach this score indicate a need to consider a gait aid, provision of assistance or supervision have not generally been accepted. As Stevenson, Connelly, Murray, Hugget, and Overend (2010) suggest, currently there is not enough evidence for using BBS scores to prescribe gait aids as limitations of the identified threshold values resulted in the misclassification of > 25% of subjects involving clients who were 65 years of age or older who were able to complete the 2-Minute Walk Test with or without a gait aid, suggesting further research is needed to identify threshold values along with specific subject populations. Other studies have also noted the presence of floor/ceiling effects.
The BBS is an activity-based observational tool whereby the rater scores client performance as he or she engages in 14 balance activities. Of the maximum possible score of 56 its author suggests the following interpretation of results: 0 to 20, wheelchair bound; 21 to 40, walking with assistance; 41 to 56, independent ambulation; and scores ≤ 45 as indicative of a high risk of falling. There is also some research to suggest that a change of 8 points is necessary to document a change in function between 2 administrations. Tools needed are a stop watch; 2 chairs, 1 with arm rests; measuring tape/ruler; an object to pick up off the floor; 15 feet of walkway; and a step stool.
The BBS is free to use in clinical practice. Use of the measure in research and/or publication can be obtained by contacting the creator of the original work at the address following or contacting the Copyright Clearance Center pertaining to the authors’ various publications. Further information can be found in the following journal article:
Berg, K., Wood-Dauphinee, S., Williams, J., & Maki, B. (1992). Measuring balance in the elderly: Validation of an instrument. Canadian Journal of Public Health, 83(2), S7-11.
|TYPE OF MEASURE||Performance based|
|WHAT IT ASSESSES||Fall risk|
|TIME||< 30 minutes|
Katherine Berg, PhD, PT
Executive Chair, Rehabilitation Sciences
Chair and Associate Professor
Department of Physical Therapy
University of Toronto
Toronto, Ontario, Canada