Smart Vest for Real-Time Postural Biofeedback and Ergonomic Risk Assessment

Abstract

Work-related musculoskeletal disorders (WRMSDs) are a serious worldwide health concern, that can result in the worker's permanent disability and an economic burden of up to 2% of the Gross Domestic Product (GDP). This paper presents the design and development of an innovative smart garment for real-time ergonomic risk assessment. It aims to empower operators with posture awareness and provide objective data to ergonomists. The system is based on inertial sensors and implements a biofeedback strategy that uses haptic stimulus to warn the user about hazard postures, enabling more ergonomic postures. To allow an easy data analysis, a graphical interface was developed in MATLAB. This framework was validated with 5 subjects, in a simulated scenario with 5 tasks that included a collaborative robot arm. The results showed that providing real-time biofeedback to the subject improves posture awareness, and has a significant impact on reducing the ergonomic risk, with reductions of up to 39.8% of the time spent in hazard postures. The wearable technology and developed methodologies are a promising tool to complement the ergonomist diagnoses of hazard tasks and workspaces and to reduce the risk of musculoskeletal disorders. INDEX TERMS Ergonomic risk assessment, biofeedback, inertial measurement units, wearables design, WRMSDs.

Wearable Devices for Ergonomics: A Systematic Literature Review

“…The trunk and upper extremities also represent the part of the body on which other types of wearable devices can be worn: smart garments [ 48 , 51 ] and body-mounted smartphones [ 60 , 61 ]. If a smart garment can be put easily and readily on the users, a body-mounted smartphone is only partially ready to wear.…”

“…Besides systems based on sensors, smart garments, a body-mounted smartphone, a robot, and an insole pressure system have been developed for evaluating and facing the adoption of awkward postures. In particular, the smart garment by Cerqueira et al [ 48 ] and the body-mounted smartphone by Nath et al [ 61 ] are proposed for explicitly dealing with tasks requiring awkward postures. This type of task is also investigated by Lins et al [ 56 ] and Yan et al [ 64 ] that describe wearable devices based on sensor systems.…”

“…The other 5 studies permit both assessing and improving ergonomic risk factors. Two of them [ 48 , 51 ] describe smart garments that monitor real-time postures displayed thanks to a Graphical User Interface (GUI), and implement a feedback strategy. The feedback strategy followed by the studies are different: in Cerqueira et al [ 48 ] the biofeedback is provided by vibrotactile motors, while in Ferreira et al [ 51 ] visual feedback is realised through luminous signalling.…”

“…Two of them [ 48 , 51 ] describe smart garments that monitor real-time postures displayed thanks to a Graphical User Interface (GUI), and implement a feedback strategy. The feedback strategy followed by the studies are different: in Cerqueira et al [ 48 ] the biofeedback is provided by vibrotactile motors, while in Ferreira et al [ 51 ] visual feedback is realised through luminous signalling. As an alternative to visual feedback, alarm sounds by means of a smartphone application are proposed for warning users when ergonomically hazardous operational postures and holding time leading to lower back and neck pain are detected [ 64 ].…”

“…In particular, 4 studies out of 24 (Caputo et al [ 39 , 40 , 41 ], Antwi-Afari et al [ 46 ], Valero et al [ 63 ], Yan et al [ 64 ]) refer to the International Standard ISO 11226 [ 65 ] that concerns the acceptability of static working postures, and the suggestion of ergonomic recommendations for different work tasks performed by adult workers. Other 4 studies described in 5 papers [ 43 , 44 , 48 , 50 , 59 ] propose wearable devices to assess postures on the basis of Rapid Upper Limb Assessment (RULA), i.e., a survey method for investigating work-related upper limb disorders [ 66 ]. In addition to the RULA method, Peppoloni et al [ 43 , 44 ] also employ Strain Index (SI), i.e., a job analysis methodology for risk of distal upper extremity disorders [ 67 ].…”