Instrumented 30-s Chair Stand Test: evaluation of an exercise program in frail nonagenarians

Performan ce test such as the 30-second chair stand one (30-s CST) are a cornerstone for detecting early declines in functional independence. How- ever, only the total number of visually counted full stands is normally used as a clinical predictor. Recent researches in body-fixed sensors field highlight their ability to accurately evaluate movement performance based on kinematic pa- rameters. The instrumented version of the 30-s CST has revealed an interesting tool to frailty detection using this information (17,12,14). The effect of a multi- component training on a randomized controlled trial with twenty frail nonage- narians (91.9±4.1 years old) are evaluated here based on the instrumented 30-s CST. It was observed that significantly higher number of cycles was performed by the intervention group but the majority of the kinematic parameters from both groups did not significantly change in mean before and after the exercise- period. However, the RMS value of the Y-orientation (p=0.028) as well as the so-called fatigue index (13), through the performed cycles, decreased signifi- cantly in the exercised group after the intervention (p=0.028 and p=0.034 re- spectively). Other parameters such as information about the movement smooth- ness could also be interesting to detect subtle functional changes (10).