VARIABLES AFFECTING DURATION OF ONE-LEG STANDING

Authors: Samantha J. Eng   Rutgers Robert Wood Johnson Medical School   Phone number: 732-500-5192   Email: sje67@rwjms.rutgers.edu  

Martin J. Blaser, M.D. Rutgers Robert Wood Johnson Medical School   Phone number: 848-445-9834 Email: blaser@cabm.rutgers.edu

Maria Gloria Dominguez-Bello, Ph.D. Rutgers School of Environmental & Biological Sciences Phone number: 848-932-5648 Email: mg.dominguez-bello@rutgers.edu

Gloria A. Bachmann, M.D., M.M.S.   Rutgers Robert Wood Johnson Medical School   Phone number: 732-235-7628   Email: bachmaga@rutgers.edu 

Background: The length of time that a person can stand on one leg, which assesses both balance and strength, has emerged as a potential indicator of longevity, with shorter times linked to increased mortality risk. The goal of this study was to investigate factors that influence one-leg standing times and assess additional data that bear on the use of this test at annual health evaluations as an additional vital sign.

Methods: After IRB approval, the relationship between single leg standing time and body mass index (BMI), age, and exercise habits was assessed in 77 volunteers attending an educational fair at Rutgers University. Participants were categorized by BMI according to CDC guidelines and age group (<13, 13 to 19, the decades between 20 and 70, and >70). Also queried were time of last physical exam, time of last emergency room or urgent care visit, regular exercise type (i.e., walk/run or balance) and frequency, and sports participation.

Results: For the 77 participants, the median (+/-IQR) age was 23 (2.5) years (range 4 to 76 years). The median (+/- IQR) standing time was 64 (5) seconds, ranging from 5 to 423 seconds. Multivariant analysis was conducted to investigate whether standing time differed based on responses to the queried survey topics. A one-way ANOVA revealed statistically significant differences in standing time between participants categorized by their age group (p = 0.040) and BMI range (p = 0.033). A statistically significant difference in standing time between participants who did or did not regularly engage in balance exercises was found using a two-sample t-test assuming unequal variances (p(T<=t) two-tail = 0.007).

Conclusion: These preliminary findings suggest the possibility of using the one-leg standing test as an indicator of fitness age; that is, a patient’s standing time could be an indicator of physical age rather than calendar age. The findings also suggest that BMI and balance exercise participation are possible contributing factors. However, limitations including sample size necessitates further investigation to pinpoint specific group differences and underlying mechanisms. Future research could explore these connections through in-depth qualitative studies performed with more participants.