Performance-based outcome measures are associated with cadence variability during community ambulation among individuals with a transtibial amputation.

Abstract

In the United States, Medicare Functional Classification Level (K-level) guidelines require demonstration of cadence variability to justify higher-level prosthetic componentry prescription; however, clinical assessment of cadence variability is subjective. Currently, no clinical outcome measures are associated with cadence variability during community ambulation. Evaluate whether physical performance, i.e. 10-meter Walk Test (10mWT)-based walking speeds, L-Test, and Figure-of-8 Walk Test scores, is associated with community-based cadence variability among individuals with a transtibial amputation. Cross-sectional. Forty-nine participants, aged 18-85 years, with a unilateral transtibial amputation were included. Linear regression models were conducted to determine whether physical performance was associated with cadence variability (a unitless calculation from FitBit® One^TM minute-by-minute step counts), while controlling for sex, age, and time since amputation (<i>p</i> ⩽ .013). Beyond covariates, self-selected gait speed explained the greatest amount of variance in cadence variability (19.2%, <i>p</i> < .001). Other outcome measures explained smaller, but significant, amounts of the variance (11.1-17.1%, <i>p</i> = .001-.008). For each 0.1 m/s-increase in self-selected and fast gait speeds, or each 1-s decrease in L-Test and F8WT time, community-based cadence variability increased by 1.76, 1.07, 0.39, and 0.79, respectively (<i>p</i> < .013). In clinical settings, faster self-selected gait speed best predicted increased cadence variability during community ambulation. The 10-meter Walk Test may be prioritized during prosthetic evaluations to provide objective self-selected walking speed data, which informs the assessment of cadence variability potential outside of clinical settings.