A multimodal assessment of balance in elderly and young adults

// Gregory W. King 1 , Eduardo L. Abreu 1,2 , An-Lin Cheng 1,2 , Keyna K. Chertoff 1,2 , Leticia Brotto 1,3 , Patricia J. Kelly 2 and Marco Brotto 1,2,3 1 Human Balance and Ambulation Research Laboratory, School of Computing and Engineering, University of Missouri, Kansas City, MO, USA 2 Muscle Biology Research Group (MUBIG), School of Nursing and Health Studies, University of Missouri, Kansas City, MO, USA 3 Current address: Bone-Muscle Collaborative Sciences, College of Nursing and Health Innovation, University of Texas, Arlington, TX, USA Correspondence to: Gregory W. King, email: // Keywords : aging, balance, strength, troponin, posture, Gerotarget Received : July 20, 2015 Accepted : February 03, 2016 Published : February 26, 2016 Abstract Falling is a significant health issue among elderly adults. Given the multifactorial nature of falls, effective balance and fall risk assessment must take into account factors from multiple sources. Here we investigate the relationship between fall risk and a diverse set of biochemical and biomechanical variables including: skeletal muscle-specific troponin T (sTnT), maximal strength measures derived from isometric grip and leg extension tasks, and postural sway captured from a force platform during a quiet stance task. These measures were performed in eight young and eleven elderly adults, along with estimates of fall risk derived from the Tinetti Balance Assessment. We observed age-related effects in all measurements, including a trend toward increased sTnT levels, increased postural sway, reduced upper and lower extremity strength, and reduced balance scores. We observed a negative correlation between balance scores and sTnT levels, suggesting its use as a biomarker for fall risk. We observed a significant positive correlation between balance scores and strength measures, adding support to the notion that muscle strength plays a significant role in postural control. We observed a significant negative correlation between balance scores and postural sway, suggesting that fall risk is associated with more loosely controlled center of mass regulation.