How many balance task trials are needed to accurately assess postural control measures in older women?

Taking the average of different trials is recommended for better balance assessment, but few studies have really proven this point under different balance conditions. OBJECTIVE: To assess the effects of averaging trials of five different balance tasks on postural control measures in older women. METHODS: A total of 90 older women (means: Age: 68 years; Weight: 67 kg; Height: 1.56 m; Body mass index, 27 kg/m2) participated in this study. The participants completed five balance tasks with three performance trials for each task on a force platform in random order. The participants completed a total of three 30-s trials of tasks with 30 s of rest between trials. Repeated measure ANOVA and coefficient of variation were computed to compare differences for one trial vs. averaging across two or three trials on center of pressure (COP) sway values. RESULTS: There were no significant differences (P > 0.05) in COP sway values when comparing one vs. the average of two or three trials for all balance tasks. However, the coefficient of variation was higher for three trials (10-40%) than two (6-37%) or one trial (3-23%) for COP parameters. CONCLUSIONS: Based on reduction of variability, the present study recommends the averaging of a minimum of two trials for balance assessment in older women. The results of the current study have implications for balance assessment in older people in fall prevention programs.

Body Composition, Strength, and Dietary Intake of Patients with Hip or Knee Osteoarthritis.

PURPOSE: To describe body composition (fat mass (FM) and fat-free mass (FFM)), strength, and nutritional characteristics of patients with hip or knee osteoarthritis undergoing total joint arthroplasty. METHODS: In this prospective pilot study, osteoarthritic patients underwent body composition assessment using bioelectrical impedance analysis, grip strength measurement, and completed a 24-h dietary recall during their pre-operative assessment. RESULTS: Fifty-five patients were included (∼66% females, age 43-89 years). Mean ± SD body mass index (BMI) was 32.79 ± 6.48 kg/m(2) and 62% were obese. Compared with hip osteoarthritis patients, knee osteoarthritis patients had a higher BMI (P = 0.018) and males with knee osteoarthritis had a lower grip strength (P = 0.028). There was a wide range in FM and FFM values across the BMI spectrum. Patients with a higher FM index (FMI, FM/height in m(2)) had higher levels of pain (P = 0.036) and females with higher FMI had a lower grip strength (P = 0.048). Dietary under-reporting was common and many patients did not meet recommendations for protein, vitamins C and E, or omega-3 fatty acids. Those who consumed less protein than the recommended dietary allowance were older (P = 0.018). CONCLUSIONS: A wide variability of body composition and dietary intake was observed which may impact strength and ultimately affect physical function. As such, patients with osteoarthritis may benefit from targeted nutrition and physical activity interventions before and after surgery.