A Comparison of Four Approaches to Evaluate the Sit-to-Stand Movement

Abstract

The sit-to-stand test (STS) is a simple test of function in older people that can identify people at risk of falls. The aim of this study was to develop two novel methods of evaluating performance in the STS using a low-cost RGB camera and another an instrumented chair containing load cells in the seat of the chair to detect center of pressure movements and ground reaction forces. The two systems were compared to a Kinect and a force plate. Twenty-one younger subjects were tested when performing two 5STS movements at self-selected slow and normal speeds while 16 older fallers were tested when performing one 5STS at a selfselected pace. All methods had acceptable limits of agreement with an expert for total STS time for younger subjects and older fallers, with smaller errors observed for the chair (-0.18 ± 0.17 s) and force plate (-0.19 ± 0.79 s) than for the RGB camera (-0.30 ± 0.51 s) and the Kinect (-0.38 ± 0.50 s) for older fallers. The chair had the smallest limits of agreement compared to the expert for both younger and older participants. The new device was also able to estimate movement velocity, which could be used to estimate muscle power during the STS movement. Subsequent studies will test the device against opto-electronic systems, incorporate additional sensors, and then develop predictive equations for measures of physical function.

Sit-To-Stand Movement Evaluated Using an Inertial Measurement Unit Embedded in Smart Glasses—A Validation Study

“…influence STS performance [ 10 ]. Consequently, many studies have attempted to gain insight into the STS movement through biomechanical analyses with various systems such as force plates, combined with or without optoelectronic systems [ 8 , 11 , 12 , 13 , 14 , 15 ], video analysis [ 16 ], goniometry [ 17 , 18 ], and more recently accelerometry [ 15 , 19 , 20 , 21 ]. The recent technological progress involving wearable sensors allows for a more comprehensive analysis of the biomechanical kinematic variables of STS in clinical settings [ 22 ], which could be used in place of expensive and time-consuming biomechanical laboratory evaluations [ 23 ].…”

Comparison of Human Interpretation and a Rule-Based Algorithm for Instrumented Sit-to-Stand Test

“…In the study, 19) the results of the phase-determination rule-based algorithm interpreting the time-weight curve of a loadcell-embedded chair were generally similar, although researchers adopted a percent cut-off value to define phases rather than the absolute weight value as used in the present study. Al- though a single loadcell sensor could reliably measure STS, as demonstrated by Shukla et al 19) , we noted that rule-based algorithms based on loadcell data were sometimes less reliable in capturing STS phases, especially in frail and underweight female patients in real-world settings. To address this issue, we added a Li-DAR set at 45° to further acquire time-distance data by tracking the distance between the sensor and buttock of the participants.…”

“…Previous studies have attempted to capture the dynamics of 5STS using different sensors such as accelerometers, motion capture devices, force plates, depth cameras, and RGB cameras. [18][19][20][26][27][28][29] Shukla et al 19) showed that a force plate or loadcell-embedded seat could more accurately capture 5STS than depth or RGB cameras, with a smaller mean error size compared to a human expert examiner. In the study, 19) the results of the phase-determination rule-based algorithm interpreting the time-weight curve of a loadcell-embedded chair were generally similar, although researchers adopted a percent cut-off value to define phases rather than the absolute weight value as used in the present study.…”

“…[18][19][20][26][27][28][29] Shukla et al 19) showed that a force plate or loadcell-embedded seat could more accurately capture 5STS than depth or RGB cameras, with a smaller mean error size compared to a human expert examiner. In the study, 19) the results of the phase-determination rule-based algorithm interpreting the time-weight curve of a loadcell-embedded chair were generally similar, although researchers adopted a percent cut-off value to define phases rather than the absolute weight value as used in the present study. Al- though a single loadcell sensor could reliably measure STS, as demonstrated by Shukla et al 19) , we noted that rule-based algorithms based on loadcell data were sometimes less reliable in capturing STS phases, especially in frail and underweight female patients in real-world settings.…”

“…ies have adopted 5STS using a simple chair and stopwatch, researchers have also developed instrumented approaches using sensors of varying modalities to automatically or semi-automatically acquire 5STS measurements to minimize inter-rater variability and collect additional information during test protocols. [18][19][20][21] We previously developed a multi-sensor kiosk to semi-automatically perform SPPB using light detection and ranging (LiDAR) and loadcells to facilitate physical performance assessments in both clinical and research settings. 21) Electronic SPPB (eSPPB) was comparable to SPPB performed manually by a single experienced examiner.…”