Balance confidence and turning behavior as a measure of fall risk

Highlights

• Perception of balance impacts turning in women, middle-aged, and older adults.

• Older adults modify dynamic behavior regardless of the turn type.

• Turning measures could be of great interest to assess the risk of fall.

Abstract

Background

Diminished balance confidence increases the risk of a fall and falls that occur when turning during walking are associated with an eightfold increase in hip fractures compared to when walking in a straight trajectory. Although an effect of aging on turning is revealed, the role of gender during turning is not yet clear.

Research Question

How can balance confidence impact turning behavior in younger, middle-aged, and older men and women?

Methods

This cross-sectional study included 22 young adults (11 women), 13 middle-aged adults (9 women), and 13 older adults (6 women). Participants ranked their balance confidence using the activities-specific balance confidence (ABC) scale and completed two different turns: Turn1 (around the cone) and Turn2 (turn to sit). Measures obtained for each turn included: turning time, step count, and peak trunk velocities (PTV) in pitch, yaw, and roll.

Results

In Turn1, older adults exhibited an increase in turning time and step count relative to younger adults (both p < 0.03). In Turn2, older adults showed an increase in turning time and roll PTV compared to the middle-aged group (both p < 0.02). Lower scores in ABC were significantly correlated with an increase in Turn1 time (p < 0.001) and step count (p = 0.04) in middle-aged and older adults, respectively. Bivariate correlations revealed that women with lower scores on the ABC took more time to complete both turns (both p = 0.01).

Significance

Older adults demonstrated longer turning time, more steps, and higher roll PTV while turning that were associated with decreased balance confidence scores. The association between decreased balance confidence and turning kinematics implies a relationship between turning and increased fall risk. These results suggest that testing for fall risk requires tests of activities that are performed outside traditional clinical settings and gait laboratories.

Introduction

Falls contribute to the morbidity and mortality of older adults and present a major concern for public health internationally. Individuals who experience fear of falling (FOF) have an increased risk of falls because they tend to restrict their daily activity leading to weakness and fatigue, which subsequently increases the risk of falling [1]. The risk for developing FOF is associated with many factors including a previous fall, age, and gender; older women tend to be more fearful than older men [2]. Balance confidence can mediate FOF, and recently, it is suggested that it can be a better predictor of a fall compared to FOF [3]. Balance confidence is not often revealed during standard clinical testing for balance and gait behaviors, however, which are often performed in a controlled environment. But subjective balance confidence could have great implications for the progression of independent function following physical injury. Thus, a clinical measure that would reveal the presence of balance confidence during functional locomotion would be very informative for rehabilitation interventions.

Turning, or changing direction while walking, is a typical daily activity that is required for basic functional tasks such as toileting or cooking. A successful turn requires effective interlimb coordination, changes in step length, and ground reaction forces that orient the center of mass in the new direction. Modifications in both anteroposterior (AP) and mediolateral (ML) postural reactions are also required to reduce walking velocity in the sagittal plane as the turn is initiated [4]. Turning steps account for approximately 35–40% of all steps in a typical day [5], and the daily number of turning steps increases when in tight spaces. Aging individuals turn less efficiently, as evidenced by degradation in kinematics and neuromuscular modulation [6]. Fall frequency increases in older adults with turning deficits [7]. Turning during walking is responsible for eight times as many hip fractures as ambulating in a straight trajectory [8], therefore, this activity is a potential marker for fall risk across ages and could be used as a clinical measure if an association with measures of balance confidence emerges. Exploring this association as an age continuum might reveal at what decade balance confidence begins to interfere with locomotor function. A review of the literature revealed that previous investigations of turning focused on younger and/or older adults [4,6,[9], [10], [11]]; turning behaviors in middle-aged adults has not been explored.

Additionally, studies of turning behavior ignored the factor of gender, which has a significant impact on the occurrence of falls. Compared to men, women are more susceptible to falls and to FOF [2,12]. Older women exhibit greater gait variability than their male counterparts [13], which is an additional factor linked with an increased risk of falls [14]. Additionally, balance confidence can greatly impact the turning strategy. For instance, those with decreased balance confidence tend to use more steps to initiate a turn [10]. Hence, it is important to investigate the effect of gender during turning behavior because it may reveal a need for preventative fall programs that are directed toward gender as well as age. Revealing an association between turning and balance confidence would improve the focus of preventative fall programs.

Building on previous findings on the association between turning and falls [7], we speculate that an individual’s balance confidence will impact their motor performance while turning more so than during straight walking, and a measure of this association could be useful for improving the identification of fall risk in older adults. In this study, we chose the portions of the Timed Up and Go (TUG) test that required a change in direction, i.e., turn around the cone (Turn1) and turn to sit (Turn2). These represent two types of turns (change in locomotor direction and rotation in space, respectively) that are commonly experienced in a home setting.

We explored whether balance confidence and turning performance are correlated through measures of turning time and step count across age and gender. We chose these two variables because they can be easily assessed in a clinical setting. We hypothesized that turning measures and balance confidence will be negatively correlated in older adults and women. Thus we expect that women who experience FOF [2] that is mediated by balance confidence [15] would exhibit longer turning times and greater step counts in turning performance as balance confidence diminished. We expect to see a greater change in women than men, even those with decreased balance confidence, and we would expect this degradation in turning performance to increase with advancing age.