Maury A. Nussbaum

Virginia Polytechnic Institute and State University | VT · Department of Industrial and Systems Engineering

We assessed the effects of using a passive back-support exoskeleton (BSE) on lower limb joint kinematics and kinetics during level walking. Twenty young, healthy participants completed level walking trials while wearing a BSE (backXTM) with three different levels of hip-extension support torque (i.e., no torque, low, and high) and in a control cond...

OCCUPATIONAL APPLICATIONSResults of the current exploratory study suggest that use of an exoskeleton (EXO) has the potential to be accepted by workers as an intervention in diverse manufacturing environments. Also evident were that the major factors contributing to EXO-use-intention are perceived comfort, task-technology fit, perceived safety, and...

Objective: Examine arm-support exoskeleton (ASE) user experience over time, identify factors contributing to ASE intention-to-use, and explore whether ASE use may influence the number of medical visits. Methods: An 18-month, longitudinal study with ASE (n = 65) and control groups (n = 133) completed at nine automotive manufacturing facilities....

Background Back-support exoskeletons (BSEs) are a promising intervention to mitigate physical demands at work. Although growing evidence indicates that BSEs can reduce low-back physical demands, there is limited understanding of potential unintended consequences of BSE use, including the risk of falls. Research question Does using a BSE adversely...

Whole-body powered exoskeletons (WB-PEXOs) can be effective in reducing the physical demands of heavy occupational work, yet almost no empirical evidence exists on the effects of WB-PEXO use. This study assessed the effects of WB-PEXO use on back and leg muscle activities during lab-based simulations of load handling tasks. Six participants (4M, 2F...

Background Exoskeleton (EXO) technologies are a promising ergonomic intervention to reduce the risk of work-related musculoskeletal disorders, with efficacy supported by laboratory- and field-based studies. However, there is a lack of field-based evidence on long-term effects of EXO use on physical demands. Methods A longitudinal, controlled resea...

The pattern of work and rest can influence both physical fatigue and task performance in manual operations. However, there is relatively limited evidence regarding the influences of specific work/rest schedules in tasks requiring high repetitiveness and precision demands, along with relatively low exertion levels. Eighteen participants completed an...

The use of inertial measurement units (IMUs) for monitoring and classifying physical activities has received substantial attention in recent years, both in occupational and non-occupational contexts. However, a “user-friendly” approach is needed to promote this approach to quantify physical demands in actual workplaces. We explored the use of a sin...

Back-support exoskeletons (BSEs) are a promising ergonomic intervention to mitigate the risk of occupational low back pain. Although growing evidence points to the beneficial effects of BSEs, specifically in reducing low-back physical demands, there is limited understanding of potential unintended consequences of BSE use on neuromuscular control of...

With rapid advancements in exoskeleton technologies, a whole-body powered exoskeleton (WB-PEXO) for augmenting human physical capacity (a “super-operator”) is generating increasing attention as an integral part of Industry 4.0. Our understanding of WB-PEXO use is lagging, however, largely due to the lack of detailed evaluations via human-subjects t...

Occupational exoskeletons (EXOs) provide the opportunity to reduce fatigue and physical demands, however little is known about adoption and use of such technologies especially among varying company sizes and especially small to medium sized enterprises (SMEs). Ten focus groups (including seven SMEs) were held across the state of Ohio, with particip...

The use of inertial measurement units (IMUs) for monitoring and classifying physical activities has received substantial attention in recent years, both in occupational and non occupational contexts. However, a “userfriendly” approach is needed to promote this approach to quantify physical demands in actual workplaces. We explored the use of a sing...

Unstable sitting is used commonly to evaluate trunk postural control (TPC), typically via measures based on center-of-pressure (CoP) time series. However, these measures do not directly reflect underlying control/movement strategies. We quantified trunk-pelvis coordination during unstable sitting using vector coding (VC) and correlated such coordin...

While occupational back-support exoskeletons (BSEs) are considered as potential workplace interventions, BSE use may compromise postural control. Thus, we investigated the effects of passive BSEs on postural balance during quiet upright stance and functional limits of stability. Twenty healthy adults completed trials of quiet upright stance with di...

The objective of this study was to assess the effects of using back support exoskeletons (BSE) on slip- and trip- related fall risks during level walking. Twenty participants completed level walking while wearing a BSE with three different levels of external torque (i.e., no torque, low torque, and high torque) and in a control (no-exoskeleton) con...

Traditional self-injurious behavior (SIB) management can place compliance demands on the caregiver and have low ecological validity and accuracy. To support an SIB monitoring system for autism spectrum disorder (ASD), we evaluated machine learning methods for detecting and distinguishing diverse SIB types. SIB episodes were captured with body-worn...

Back-support exoskeletons (BSEs) are wearable systems designed to reduce physical demands on the back, but which could have undesired effects beyond this design intention. Participants (n = 18) used two commercial BSEs to complete a brief (~15–20 s) simulated manual assembly task in varying conditions, with outcome measures that included: working p...

While there is wide evidence that the occupational use of hand tools increases the risk of musculoskeletal disorder, evidence is limited regarding manual scissors, commonly used by custom tailors for bespoke garment production. We assessed whether scissor design impacts physical demands (muscle activity, perceived discomfort, and wrist posture) and...

Self-injurious behavior (SiB) is among the most dangerous concerns in autism spectrum disorder (ASD), often requiring detailed and tedious management methods. Sensor-based behavioral monitoring could address the limitations of these methods, though the complex problem of classifying variable behavior should be addressed first. We aimed to address t...

Two passive back-support exoskeleton (BSE) designs were assessed in terms of muscular activity, energy expenditure, joint kinematics, and subjective responses. Eighteen participants (gender-balanced) completed repetitive lifting tasks in nine different conditions, involving symmetric and asymmetric postures and using two BSEs (along with no BSE as...

Trunk flexion represents a risk factor for the onset of low-back disorders, yet limited quantitative data exist regarding flexion exposures in actual working conditions. In this study, we evaluated the potential of using a single inertial measurement unit (IMU) to classify trunk flexion, in terms of amplitude, frequency, and duration, and assessed...

Objective: Monitoring technology may assist in managing self-injurious behavior (SIB), a pervasive concern in autism spectrum disorder (ASD). Affiliated stakeholder perspectives should be considered to design effective and accepted SIB monitoring methods. We examined caregiver experiences to generate design guidance for SIB monitoring technology....

Background Head-worn displays (e.g., “smart glasses”) are an emerging technology to provide information, and in many situations they might be used while walking. However, little evidence exists regarding the effects of head-worn displays on walking performance. We found earlier that “smart glasses” had smaller adverse effects on measures of gait va...

Background: Falls are the leading cause of injuries among older adults. Perturbation-based balance training (PBT) is an innovative approach to fall prevention that aims to improve the reactive balance response following perturbations such as slipping and tripping. Many of these PBT studies have targeted reactive balance after slipping or tripping,...

In modern manufacturing systems, especially assembly lines, human input is a critical resource to provide dexterity and flexibility. However, the repetitive precision tasks common in assembly lines can have adverse effects on workers and overall system performance. We present a data-driven approach to evaluating task performance using wearable sens...

Vehicle headlamps and roadway lighting are the major sources of illumination at night. These sources affect contrast - defined as the luminance difference of an object from its background - which drives visibility at night. However, the combined effect of vehicle headlamps and intersection lighting on object contrast has not been reported previousl...

Objective The aim of this study was to explore the efficacy of two different passive back-support exoskeleton (BSE) designs during repetitive lifting in different postures. Background Although BSEs have been proposed as a potential intervention for reducing physical demands, limited information is available about the impacts of different exoskelet...

Objective: To assess the efficacy of two different passive back-support exoskeleton (BSE) designs, in terms of trunk muscle activity, perceived low-back exertion, and task performance. Background: BSEs have the potential to be an effective intervention for reducing low-back physical demands, yet little is known about the impacts of different desig...

Introduction Members of the surgical team experience musculoskeletal (MS) symptoms that impact occupational health. Although the prevalence of MS symptoms in this population is well-recognized, limited interventions with sustained success exist for the operating room (OR) environment. The purpose of this work was to determine the facilitators of an...

While occupational back support exoskeletons (BSEs) are being considered as a potential intervention to reduce physical demands in tasks such as repetitive lifting (e.g., Frost, Abdoli-E, & Stevenson, 2009; Koopman, Kingma, Faber, de Looze, & van Dieën, 2019), BSE use in practice may introduce some unexpected or unintended safety challenges (Baltru...

Low back pain (LBP) remains the most prevalent and costly work-related disability in the United States, accounting for ~40% of annual musculoskeletal disorders (BLS, 2018) and imposing an economic burden of over $50 billion (Davis, 2012). Many intervention approaches have been explored to reduce the physical requirements of occupational tasks. Exam...

Upper-extremity exoskeletons (UEXO) are promising interventions for reducing the physical demands of work performed with arms elevated (e.g., overhead work). In this study, we investigated the effects of passive UEXO use on motor performance and physical demands in a repetitive precision overhead task. Eleven participants completed repetitive tappi...

Objective The objective of this study was to identify potential needs and barriers related to using exoskeletons to decrease musculoskeletal (MS) symptoms for workers in the operating room (OR). Background MS symptoms and injuries adversely impact worker health and performance in surgical environments. Half of the surgical team members (e.g., surg...

Upper-extremity exoskeletons (UEXO) are promising interventions for reducing the physical demands of work performed with arms elevated (e.g., overhead work). In this study, we investigated the effects of passive UEXO use on motor performance and physical demands in a repetitive precision overhead task. Eleven participants completed repetitive tappi...

Background: Persons with unilateral lower-limb loss are at increased risk for developing chronic low back pain. Aberrant trunk and pelvis motor behavior secondary to lower-limb loss potentially alters trunk postural control and increases demands on the trunk musculature for stability. However, it is unclear whether trunk postural control is associ...

We compared three passive exoskeleton designs in a mock drilling task under three precision requirements levels, defined by required hole sizes, in terms of physical demands (perceived exertion and muscular activation) and quality. The investigated designs were: 1) an upper-body exoskeleton mainly supporting the shoulder; and both 2) full-body, and...

Physical activities can have important impacts on human health. For example, a physically active lifestyle, which is one of the most important goals for overall health promotion, can diminish the risk for a range of physical disorders, as well as reducing health-related expenditures. Thus, a long-term goal is to detect different physical activities...

The substantial kinematic degrees-of-freedom available in human movement lead to inherent variations in a repetitive movement, or motor variability (MV). Growing evidence suggests that characterizing MV permits a better understanding of potential injury mechanisms. Several diverse methods, though, have been used to quantify MV, but limited evidence...

Purpose: Individuals who are obese, and older individuals, exhibit gait alterations that may result, in part, from walking with greater effort relative to their maximum strength capacity. The goal of this study was to investigate obesity-related and age-related differences in relative effort during gait. Methods: Four groups of women completed t...

A systems-level approach to intersection lighting design has shown that illuminating the intersection box increases drivers’ nighttime visual performance. However, for an intersection lighting design to be effective and accepted, it should not only maximize visual performance but also enhance perceived visibility and minimize glare. The goals of th...

Physical monitoring systems represent potentially powerful assessment devices to detect and describe occupational physical activities. A promising technology for such use is smart textile systems (STSs). Our goal in this exploratory study was to assess the feasibility and accuracy of using two STSs to classify several manual material handling (MMH)...

This pilot study investigated the impacts of a whole-body, powered exoskeleton on low-back muscle activation and joint ranges-of-motion (ROM) in a load carriage task performed by able-bodied individuals. The prototype exoskeleton (Guardian XO TM , Sarcos Robotics) had 16 active degrees of freedom. After an initial training period, participants (fiv...

This study investigated the effect of passive exoskeleton use on shoulder torque control in an intermittent shoulder-loading task. Sixteen participants completed 15 30-sec cycles of intermittent, isometric shoulder contraction at 90º both in the sagittal and scapular planes, with a 50% duty cycle at 30% of maximum torque; this was completed with an...

Background There is growing interest in using perturbation-based balance training to improve the reactive response to common perturbations (e.g., tripping and slipping). The goal of this study was to compare the efficacy of treadmill-based reactive balance training versus Tai Chi performed at, and among independent residents of, older adult senior...

Aging is associated with a higher risk of falls, and an impaired ability to recover balance after a postural perturbation is an important contributing factor. In turn, this impaired recovery ability likely stems from age-related decrements in lower limb strength. The purpose of this study was to investigate the effects of age-related strength loss...

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Background: Overexertion and bodily reaction remain leading causes of work-related musculoskeletal disorders. Occupational use of an exoskeleton has been recognized recently as an alternative intervention approach to reduce physical demands and fatigue experienced in a range of occupational tasks. Purpose: The current study replicated many aspects...

Work-related musculoskeletal injuries and disorders remain an important problem in the construction industry. Exoskeletons are an emerging wearable technology that assists or augments a user’s physical activity or capacity. This technology is a potential solution to reduce the physical demands and fatigue experienced by construction workers and hel...

We compared different passive exoskeletal designs in terms of physical demands (maximum acceptable frequency = MAF, perceived discomfort, and muscular loading) and quality in a simulated overhead drilling task, and the moderating influence of tool mass (∼2 and ∼5 kg). Three distinct designs were used: full-body and upper-body exoskeletons with atta...

Limited information is available regarding the effective use of workplace head-worn displays (HWD), especially the choices of HWD types and user interface (UI) designs. We explored how different HWD types and UI designs affect perceived workload, usability, visual discomfort, and job performance during a simulated warehouse job involving order pick...

Background: Up to ½ of falls among older adults can occur from trips. As such, the ability to develop an effective reactive balance response may be important in reducing falls and fall injuries. Use of a treadmill to test the response to a simulated trip usually involves high-tech kinematic analyses of the balance response. Our goal was to develop...

Background: Up to ½ of falls among older adults may occur from trips and developing an effective recovery response may be important in reducing falls and fall injuries. Treadmill training to improve reactive balance has not been well studied in older adults, particularly in their home environment, and in comparison to evidence-based fall risk reduc...

Classification methods based on sparse estimation have drawn much attention recently, due to their effectiveness in processing high-dimensional data such as images. In this paper, a method to improve the performance of a sparse representation classification (SRC) approach is proposed; it is then applied to the problem of online process monitoring o...

The Department of Veterans Affairs (VA) has developed a new exam room design standard that is intended to facilitate a greater degree of patient centeredness. This new design includes a wall-mounted monitor on an armature system and a moveable table workspace. To date, however, this design has not been formally evaluated in a field setting. We cond...

High-risk occupational physical activities (OPAs) may adversely impact the physical health of workers (Valero, Sivanathan, Bosché, & Abdel-Wahab, 2016). For example, adverse OPA-related outcomes are linked to repetitive physical activities or postures that target certain muscle groups or anatomical areas, and a sedentary workstyle that appears to b...

Self-injurious behavior (SIB), such as head banging or self-hitting, is considered one of the most dangerous characteristics of autism spectrum disorder (ASD) (Mahatmya, Zobel, & Valdovinos, 2008). Clinicians traditionally rely on structured observation, which can be time-consuming and invasive. Recent technological developments in motion tracking...

Task-specific balance training is an approach to fall prevention that has the potential to reduce the number of slip-induced falls. However, a limitation of current task-specific training methods is that they require non-trivial financial and/or equipment resources. This pilot study evaluated the efficacy of two low-cost, low-tech methods for slip...

Wearable sensors and systems have become increasingly popular in recent years. Two prominent wearable technologies for human activity monitoring are smart textile systems (STSs) and inertial measurement units (IMUs). Despite ongoing advances in both, the usability aspects of these devices require further investigation, especially to facilitate futu...

The use of interactive or “smart” textiles that have sensing material(s) incorporated into them supports an emerging technology for physical activity assessment called Smart Textile Systems (STSs). STSs are an increasingly useful technology for researchers, athletes, patients, and others. In the current study, we developed and assessed a novel smar...

Continuous seated postures may increase the risk of adverse health outcomes such as low-back pain, and this risk may be influenced by several modifying influences. In the present study, we aimed to quantify the effects of continuous sitting and psychosocial stress under an unsupported sitting condition. Fourteen participants completed continuous, 4...

Trunk postural control (TPC) has been investigated in several populations and tasks. Previous work observed targeted training of TPC via isolated trunk control tasks may improve performance in other activities (e.g., walking). However, the nature of this relationship remains unknown. We therefore investigated the relationship between TPC, at both t...

Background A growing number of studies are using modified treadmills to train reactive balance after trip-like perturbations that require multiple steps to recover balance. The goal of this study was thus to develop and validate a low-tech reactive balance rating method in the context of trip-like treadmill perturbations to facilitate the implement...

The need to complete multiple tasks concurrently is a common occurrence both daily life and in occupational activities, which can often include simultaneous cognitive and physical demands. As one example, there is increasing availability of head-worn display technologies that can be employed when a user is mobile (e.g., while walking). This new met...