Clinical estimates of three physiologic capacities explain a majority of unipedal stance time

Background

Recent prospective research indicates that unipedal stance time (UST) of < 15 s in middle/older adults increases their risk of repetitive falls within 5 to 10 years.

Aim

To determine the extent that clinical measures of three physiologic capacities, peripheral afferent acuity, processing speed, and proximal frontal plane strength, are responsible for UST.

Methods

UST, distal lower limb clinical vibratory sense, short latency go/no-go accuracy using ReacStick, and lateral plank time, were evaluated in a cohort (n = 172, 51% female, age 64.8 +/- 9.6 years) with diabetic neuropathy (n = 31), cirrhosis (n = 94), and no known neurologic disease (n = 47) using age, body mass index (BMI), sex, and medication number as covariates.

Results

Multivariate analyses demonstrated that the three variables separately, and as a composite variable (vibration time + reaction accuracy/2 + lateral plank time), were associated with UST (adjusted R² = 0.66 and 0.65, respectively) for the entire group, and for diabetic neuropathy, cirrhosis, and no known disease groups separately (adjusted R² = 0.59, 0.60, and 0.68, respectively). The composite variable also classified participants into those with UST > and < 15 s (receiver operator characteristics area under the curve (AUC) = 0.92 (95% CI = 0.88, 0.96)).

Discussion

These findings allow clinicians to identify specific physiologic deficits and develop targeted intervention strategies to improve UST.

Conclusion

Clinical estimates of three physiologic capacities predict almost 2/3 of UST variability in middle/older people, rendering age, BMI, sex, and medication number less relevant.