Berg Balance Scale

The Berg Balance Scale (BBS) provides a quantitative assessment of balance in older adults (Berg et al. 1989). It was intended for use in monitoring the clinical status of patients for effectiveness of treatment interventions over time (Berg et al. 1995).

The scale consists of 14 items requiring subjects to maintain positions or complete movement tasks of varying levels of difficulty. All items on the test are common to everyday life. Administration of the scale requires a ruler, stopwatch, chair, step or stool, space to turn 360°, and 10-15 minutes. It is administered via direct observation of task completion and items are scored 0-4 based on the ability of the individual to meet the specific time and distance requirements of the test (Berg et al. 1995; Juneja et al. 1998 A score of zero represents the inability to complete the item and a score of 4 represents the ability to complete the task independently. It is generally accepted that total scores below 45 indicate balance impairment (Berg, Wood-Dauphinee, et al. 1992; Zwick et al. 2000). Despite the use of this scale, all but one study (Feld et al. 2001) examined psychometric properties among a stroke or older adult population. Therefore, caution is advised when making generalizations to an ABI population.

Table: Characteristics of the Berg Balance Scale

Advantages. The BBS measures a number of different aspects of balance, both static and dynamic, and does so with relatively little equipment or space required (Nakamura et al. 1999; Whitney et al. 1998; Zwick et al. 2000). No specialized training is required, as the high levels of reliability reported by Berg et al. (1995) were achieved when the individuals administering the test had no specific training in the administration of the scale (Nakamura et al. 1999). The scale has also been found to have a high inter-rater and intra-rater reliability and internal consistency in the version translated into Japanese (Matsushima et al. 2014).

Limitations. The BBS has been thoroughly evaluated for use among populations of individuals who have experienced stroke. At present, information regarding the reliability and validity of the BBS when used among patients with TBI/ABI is severely limited. 

No common interpretation exists for BBS scores, their relationship to mobility status, and the use of mobility aides (Wee et al. 2003). The rating scales associated with each item, while numerically identical, have different operational definitions for each number or score. A score of 2, for example, is defined differently and has a different associated level of difficulty from item to item (Kornetti et al. 2004). There is also no common score associated with successful item completion (Kornetti et al. 2004). Use of an overall score that adds ratings with different meanings having no common reference point may not be appropriate as interpretation is difficult and very little functional information is provided about the individual patient (Kornetti et al. 2004). The BBS requires a minimal detectable change of 6 points at a 90% confidence interval (Stevenson 2001).

A recent Rasch analysis of the BBS revealed that some item ratings were not used at all or were underutilized, and others were unable to distinguish between individuals with different levels of ability (Kornetti et al. 2004). Collapsing rating scales to eliminate infrequently endorsed categories and creating a common pass/fail point for each item resulted in changes to the ordering of item difficulty, reduced tendencies for ceiling effects and an improved functional definition of the 45/56 cut-off point (Kornetti et al. 2004). 

 

Summary-Berg Balance Scale

Interpretability: There are no common standards for the interpretation of BBS scores, though there is an accepted cut-off point for the presence of balance impairment. 

Acceptability: This direct observation test would not be suited for severely affected patients as it assesses only one item relative to balance while sitting. Active individuals would find it too simple. The scale is not suited for use by proxy. 

Feasibility: The BBS requires no specialized training to administer and relatively little equipment or space.

 

Table: Berg Balance Scale Evaluation Summary

Reliability

Validity

Responsiveness

Rigor

Results

Rigor

Results

Rigor

Results

Floor/ceiling

++

 

+++ (TR)

+++(IO)

+++ (IC)

+++

+++

+++

+++

Varied

NOTE: +++=Excellent; ++=Adequate; +=Poor; N/A=insufficient information; TR=Test re-test; IC=Internal Consistency; IO=Interobserver; Varied (re. floor/ceiling effects; mixed results).