Evaluating functional ability in older adults' object retrieval behavior from kitchen furniture using OpenPose and REBA

Abstract

The purpose of this study is to evaluate, through analysis, the ability of older persons to retrieve items from kitchen cabinets. To achieve this goal, data were collected from 128 valid questionnaires and supplemented with field research and user interviews. The study revealed that the elderly's behavior in retrieving items from kitchen spaces is characterized by both high frequency and difficulty. For this experiment, a total of 42 participants, comprising 21 males and 21 females from the self-care elderly population in the Yangtze River Delta region, were recruited. Two different experimental settings were arranged: one with kitchen utensils arranged in a straight line and another with a purpose-made chest of drawers with varying heights. Video recordings using the Logitech C930C were utilized to capture the gestures and behaviors of the elderly while retrieving objects from the kitchen cupboards (cabinets). By employing a combination of the OpenPose model and the Rapid Entire Body Assessment (REBA) method, which involves calculating human posture angles, REBA scores, and determining the risk level of Work-Related Musculoskeletal Disorders (WMSDs), a risk assessment framework for manual operations associated with WMSDs was developed. Using the angle data acquired from the user operation experiment as parameters, a gradient model of the elderly user's operational capability was established. The findings indicated a significant impact of neck, trunk, and knee movements on the subjects (P < 0.001). The participants were able to distinguish between different levels of exertion, categorizing movements as 'easy', 'moderate,' or 'strenuous.' These results form the basis for a comfort gradient model for leaning over and retrieving items. Given the prevalent conditions of bone and joint degeneration and osteoporosis among the elderly population, it is evident that they face challenges when accessing items in the kitchen. Therefore, investigating the elderly's execution abilities during the retrieval process becomes crucial. Understanding how different cabinet heights impact the joint angles of the elderly can be instrumental in optimizing cabinet designs for elderly users, thereby reducing their physical exertion in the kitchen and enhancing their comfort levels. This research holds significant value in improving the quality of life for the elderly population at home and fostering the advancement of elderly-friendly design principles.

Keywords: Aging-friendly design of cabinets; Behavioural ability to pick up objects; Openpose technology; REBA assessment method; The elderly.

Fig. 1

Behaviour flow of the elderly taking objects. Among them, (a) describes the behaviour process of the elderly taking high objects, and (b) describes the behaviour process of the elderly taking low objects.

Fig. 2

Behavioural capacity assessment model construction process.

Fig. 3

Experimental equipment.

Fig. 4

(a) Human motion plane details. (b) Details of key points of joint movement.

Fig. 5

REBA assessment worksheet.

Fig. 6

Experiment procedure.

Fig. 7

Take-use behaviour stage. The neck offset angle θ1, the upper arm offset angle θ2, the lower arm offset angle θ3, the trunk offset angle θ4, Thigh offset angle θ5, thigh and calf included angle θ6, and calf ground included angle θ7.

Fig. 8

Bent over behaviour stage. The neck offset angle θ1, the upper arm offset angle θ2, the lower arm offset angle θ3, the trunk offset angle θ4, Thigh offset angle θ5, thigh and calf included angle θ6, and calf ground included angle θ7.

Fig. 9

Executive ability gradient.