Dynamic longitudinal evaluation of the utility of the Berg Balance Scale in individuals with motor incomplete spinal cord injury

Abstract

Objectives: To examine the utility of the Berg Balance Scale among patients with motor incomplete spinal cord injuries (SCIs), to determine how the utility of the Berg Balance Scale changes over time with activity-based therapy, and to identify differences in scale utility across patient groups defined by status of recovery.

Design: Prospective observational cohort.

Setting: The NeuroRecovery Network (NRN), a network of clinical centers for patients with motor incomplete SCI.

Participants: Patients with motor incomplete SCI (n=124) with American Spinal Injury Association Impairment Scale grade C or D, who were enrolled in the NRN between February 2008 and June 2009.

Intervention: Standardized locomotor training.

Main outcome measure: The Berg Balance Scale items were examined with longitudinal principal components analyses. Patients were categorized by phase using the Neuromuscular Recovery Scale.

Results: In the full sample, the first principal component explained a large percentage of overall scale variance (77%), items were loaded homogeneously on the first principal component, and item scores were well correlated with first principal component scores. In subgroups of low and high functioning of patients, first principal component variance accounting was reduced (49%) and only a few of the simplest and most difficult items substantially loaded onto the first principal component. Item loading coefficients evolved over time as patients recovered, with simpler items becoming less important to the full scale and difficult items more important.

Conclusions: The utility of the Berg Balance Scale in patients with motor incomplete SCI in early and advanced phases of recovery is limited. Specific item utility changes as patients recover. Thus, a more comprehensive and dynamic instrument is necessary to adequately measure balance across the spectrum of patients with motor incomplete SCI.