• A comparison of four approaches to evaluate the sit-to-stand movement

      Shukla, Brajesh K.; Jain, Hiteshi; Vijay, Vivek; Yadav, Sandeep; Mathur, Arvind; Hewson, David; Indian Institute of Technology Jodhpur; Asian Centre for Medical Education, Research & Innovation, Jodhpur; University of Bedfordshire (IEEE, 2020-04-19)
      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 self-selected 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.
    • Development of an instrumented chair to identify the phases of the sit-to-stand movement

      Shukla, Brajesh K.; Jain, Hiteshi; Singh, Sandeep; Vijay, Vivek; Yadav, Sandeep; Hewson, David; Indian Institute of Technology Jodhpur; University of Bedfordshire (Springer Science and Business Media Deutschland GmbH, 2020-11-30)
      Instrumented versions of functional geriatric screening tests have been developed to improve clinical precision. Several different instrumented versions of the Sit-to-Stand (iSTS) test have been developed using a range of sensors such as accelerometers and cameras. An instrumented chair equipped with load cells and an ultrasound sensor was developed to detect phases of the STS (Sit to Stand). The chair was designed to be able to detect all the phases of the STS, including when the person was not in contact with the chair. Performance of the iSTS chair was compared between an RGB camera approach, and a data-fusion approach using the load-cell and ultrasound equipped chair. Ten adult subjects were tested performing the 5STS at two self-selected speeds. The accuracy of the load cell equipped chair was 70%, while the RGB camera achieved 76% accuracy. The ultrasound version of the chair and the fusion of the RGB and load cells technique both achieved significantly better accuracy at 86% and 89%, respectively. The new version of the instrumented chair obtained a high degree of accuracy in detecting the different phases of the STS and is suitable to detect STS phases without requiring additional sensors. Future work will test older subjects and aim to develop new parameters based on the phases of the STS as indicators of physical performance.
    • A fusion-based approach to identify the phases of the sit-to-stand test in older people

      Shukla, Brajesh K.; Jain, Hiteshi; Vijay, Vivek; Yadav, Sandeep; Hewson, David; Indian Institute of Technology Jodhpur; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2020-04-06)
      Automated clinical tests that assess quality of geriatric screening tests such as the Five-Times-Sit- To-Stand (5STS) and the Timed-Up-and-Go (TUG) are being designed to assess the decline in functional ability of elderly. The existing techniques to assess the quality of these physical activities include sensor-based techniques including body mounted sensors, force sensors and, vision and imaging sensors. These sensors have their own advantages and disadvantages towards the task of clinical assessment. In this work, we introduce a fusion- based technique to combine multiple sensors leveraging advantages of individual sensors, in such a way that the resulting assessment is more accurate. We evaluate our technique for 5STS test using a fusion of a chair and RGB sensors. In a test of 15 older people, there was no significant difference in performance between the two sensors, obtaining 76% and 73% for the RGB and chair, respectively. However, a significant improvement was obtained for the fusion technique, with 90% accuracy for all the phases of the STS test. The proposed fusion technique was observed to be better than the individual sensor assessment.
    • Instrumented analysis of the sit-to-stand movement for geriatric screening: a systematic review

      Shukla, Brajesh; Bassement, Jennifer; Vijay, Vivek; Yadav, Sandeep; Hewson, David; Indian Institute of Technology Jodhpur; Université Polytechnique Hauts-de-France; University of Bedfordshire (MDPI, 2020-11-06)
      The Sit-to-Stand (STS) is a widely used test of physical function to screen older people at risk of falls and frailty and is also one of the most important components of standard screening for sarcopenia. There have been many recent studies in which instrumented versions of the STS (iSTS) have been developed to provide additional parameters that could improve the accuracy of the STS test. This systematic review aimed to identify whether an iSTS is a viable alternative to a standard STS to detect older people at risk of falling, frailty, and sarcopenia. A total of 856 articles were found using the search strategy developed, with 12 articles retained in the review after screening based on PRISMA guidelines. Six studies evaluated the iSTS in fallers, five studies in frailty and only one study in both fallers and frailty. The results showed that power and velocity parameters extracted from an iSTS have the potential to improve the accuracy of screening when compared to a standard STS. Future work should focus on standardizing the segmentation of the STS into phases to enable comparison between studies and to develop devices integrated into the chair used for the test to improve usability.
    • A pilot study to detect balance impairment in older adults using an instrumented one-leg stance test

      Bassement, Jennifer; Shukla, Brajesh; Yadav, Sandeep; Vijay, Vivek; Mathur, Arvind; Hewson, David; Centre Hospitalier de Valenciennes; Indian Institute of Technology Jodhpur; Asian Centre for Medical Education, Research & Innovation, Jodhpur; University of Bedfordshire (American Society of Mechanical Engineers, 2020-03-12)
      The aim of this study was to investigate whether parameters from an instrumented one-leg stance on a force plate test could provide relevant information related to fall risk in older people. Twenty-five community dwelling older people and 25 young subjects performed a one-leg stance while standing on a force plate, with parameters related to transferring weight onto one leg and postural sway in singe-leg stance evaluated. Older participants were classified as being at risk of falling if their performance did not meet one of the previously-established cut-offs for the Five Times Sit-To-Stand and Timed-Up-and-Go tests. Eleven older participants were classified as having a risk of falls. The only significant difference between groups during the weight transfer phase was in the mediolateral displacement, with the fall risk group having less sway than the other groups, signifying a more precautionary approach. With respect to postural sway, both the younger subjects and the no fall risk group stabilised sufficiently to decrease their sway compared to initial values after four and six seconds, respectively. In contrast, the fall risk group was unable to stabilise during the one-leg stance, and continued to sway throughout the 10-sec recording period. These findings suggest that the normal one-leg stance test might not be suitable to detect fall risk. In contrast, an instrumented version of the test could provide valuable additional information that could identify risk of falling in older people.