Researchers at the Northwestern University Prosthetics-Orthotics Center (NUPOC), Chicago, Illinois, evaluated the validity and reliability of the Berg Balance Scale (BBS) in accurately and precisely measuring balance in individuals with lower-limb amputations to help assess rehabilitation progress and identify individuals who are at a greater risk of falling. The study concluded that the BBS is consistent and valid, with high inter-rater reliability, but may not be able to discriminate between individuals with greater or lesser fall risk. The results were published online July 15 in the Archives of Physical Medicine and Rehabilitation.
The cross-sectional study was performed with 30 individuals (20 men; 54±12 years of age), 13 of whom had a unilateral transtibial amputation, 14 with a unilateral transfemoral amputation, and three with bilateral amputations. Three of the participants’ amputations were congenital, six were caused by infection, seven were dysvascular-related, and 14 had traumatic causes.
Data was collected using the BBS, two-minute walk test, L test of functional mobility, Prosthesis Evaluation Questionnaire mobility subscale, Activities-specific Balance Confidence Scale, and the Frenchay Activities Index. Participants also self-reported frequency of prosthesis use, number of falls in the previous 12 months, fear of falling, and daily mobility aid use.
Of the 14 tasks included in the BBS, participants experienced the greatest difficulty performing tasks 8 (reaching forward), 11 (turning 360 degrees), 13 (tandem standing), and 14 (standing on one leg). The researchers attribute this to the limited range of motion and passive nature of lower-limb prostheses. And even though all study participants with unilateral amputations elected to stand on their sound leg when asked to stand on one leg, 40 percent of all subjects could not stand for more than ten seconds. The researchers noted that this “emphasizes an important balance impairment that may negatively affect safe ambulation,” and should be included as part of rehabilitation therapy training.
Relationships between the BBS scores and those of the other outcome measures were all statistically significant, and significant group differences in BBS scores were observed for fear of falling and mobility aid use, but not for more than two falls in the previous 12 months. BBS items that involved reaching forward, turning 360 degrees, tandem standing, and standing on one leg had relatively greater frequencies of lower scores across participants.
Editor’s note: This story was adapted from materials provided by NUPOC.
