Mouse with your arm™: Facilitating forearm support using the chair armrest to prevent and mitigate musculoskeletal disorders

Abstract

BACKGROUND:

Musculoskeletal disorders (MSDs) can be prevented by avoiding trauma caused by poor posture, compression, force, and repetition. Neutral postures are recommended to avoid MSDs.

OBJECTIVE:

This study introduces Mouse With Your Arm™ (MWYA) methodology which promotes sitting back in a chair, using the chair’s armrest for forearm support at relaxed elbow height, matching surface and armrest height, and keeping the mouse on the surface edge. This position allows optimal task chair use, facilitates movement and neutral postures, avoids compression and contact stress, and is effective in mitigating MSDs.

METHOD:

MWYA was applied and measured in the field for more 23 years providing over 3,500 individualized assessments to integrate a participant’s unique characteristics, reported health concerns, tasks, tools, and environment to achieve and sustain whole-body neutral and comfortable working postures.

RESULTS:

Previous research has consistently recommended use of forearm support by a desk, apparatus, or wrist rest, and resulted in non-neutral, static postures and measured health consequences. By using armrests for support, MWYA avoids the potential of MSDs as can be caused by these previously endorsed postures.

CONCLUSION:

By applying the five MWYA principles, computer users comprehend neutral posture and put forth the effort essential to creating healthy human computer relationships.

Keywords

Disability management health ergonomics rehabilitation posture holistic

1 Introduction

In our technology-centric world, some of the most pervasive workplace health risks are associated with computer use. Microsoft found that 85% of workers in the United States experience discomfort on a daily basis and often ergonomic strategies and accessories are not available or employees do not act to address their pain [1]. Conversely, in some cases people expect to solve their comfort issues by adopting the latest trends, such as sit-to-stand desks, active seating, special keyboards, or newly designed input devices.

Ergonomics is the relationship between a person and their environment. When the relationship is poor, individuals are exposed to musculoskeletal disorders (MSDs). According to the Center for Disease Control and National Occupational Safety and Health Administration there are two types of ergonomic risk controls: engineering controls and administrative controls [2]. Engineering controls remove potential risk through design and use of a product such as an assembly line or ergonomic task chair. Administrative controls remove risk through changing processes or procedures such as job rotation or body position. Currently, engineering controls are considered more effective while administrative controls are described “to be less effective than other measures, requiring significant effort by the affected workers” [2, p1]. The ergonomic industry has consistently focused on engineering controls as a panacea for MSDs. The distinction between engineering and administrative controls is misleading; to achieve success, they must be interdependent. A surgeon’s scalpel is an engineering control for removing a tumor, but the surgeon’s training is an administrative control. Removing the tumor requires both scalpel and surgeon. Our ergonomic industry is focused on the scalpel and not on an investment on behalf of the worker [3].

In 2015, according to the Bureau of Labor Statistics, MSDs accounted for 31% of all worker injury and illness cases and are among the most frequently reported causes of days away from work [4]. Stewart et al. [5] estimated a cost of $61.2 billion per year in pain-related lost productivity, and MSDs account for 27% of total estimated work-related cost-of-pain conditions in the US workforce. The National Occupational Research Agenda for Musculoskeletal Health identified MSDs as a leading cause of occupational injuries and the largest burden for workers’ compensation costs, disability, and productivity losses [6]. The World Health Organization reports that MSDs are prevalent representing “the most common cause of severe long-term pain and physical disability” [7, p9]. Approximately one in three people worldwide and one in two American adults have a musculoskeletal condition [8].

Studies have found that the computer mouse is a frequently used work tool [9, 10]. It is shown to be associated with awkward postures such as shoulder abduction and arm discomfort [9 , 11–16]. It is believed there is no perfect methodology and “no standardized set of methods to investigate non keyboard input devices” (mice) [17, p92]. Harvey and Peper predict there will be an increase in upper extremity MSDs due to users abducting their arms to reach a mouse [18]. Woods et al. identified the international concern over health issues related to mouse use, how our individual methods determine risks, and that health implications are not fully understood [17].

The US Department of Labor–Occupational Safety and Health Association (OSHA) defines ergonomic risk factors as “the aspects of a job or task that impose a bio-mechanical stress on the worker” [19, p1]. To mitigate these exposures, The Good Working Posture for Computer Workstations (Fig. 1) was introduced by OSHA decades ago. This posture shows a method of working that is void of awkward non-neutral postures. This image and accompanying eight bullets provided by OSHA advocates neutral posture and portrays a worker using the chair’s armrests for forearm support potentially avoiding bio-mechanical stress caused by shoulder flexion or abduction and station contact stress.

Fig. 1

OSHA Good Working Posture.

Hands, wrists, and forearms are straight, in-line and roughly parallel to the floor.

Head is level, forward facing, and balanced. Generally it is in-line with the torso.

Shoulders are relaxed and upper arms hang normally at the side of the body.

Elbows stay in close to the body and are bent between 90 and 120 degrees.

Feet are fully supported by the floor or a footrest may be used if the desk height is not adjustable.

Back is fully supported with appropriate lumbar support when sitting vertical or leaning back slightly.

Thighs and hips are supported and generally parallel to the floor.

Knees are about the same height as the hips with the feet slightly forward.

The literature reviewed for this study indicates relative agreement in describing a neutral supported posture such as the OSHA Good Working Posture. This posture was consistently not replicated in studies. It appeared to be the practice of most scientific postural analyses to isolate only one or two body parts (i.e., the forearm or hand) and not address the impact of the subject’s working posture on other body parts such as the back and shoulder. Clarity was needed from authors to understand subject’s postures, tools, chair features (such as armrests), and methods such as how “forearm support” was provided. Researchers expressed consistent challenges with participants complying with intended postures, transferring lab studies to real-world application, and identifying effective training methods [20 –22]. It is in response to these challenges that this study introduces the Mouse With Your Arm (MWYA) methodology.

2 Mouse With Your Arm™ (MWYA) methodology

MWYA is a holistic, ergonomic methodology blending administrative and engineering controls for people who work at computer workstations. It structures a process for the user to learn to maintain neutral postures, proper use of the office chair, and reduction of stress and load often associated with workplace pain and discomfort. OSHA Good Working Posture (Fig. 1) is the foundation on which MWYA was built. This study is organized according to the below five principles of MWYA with each section addressing applicable research. Figure 2 demonstrates its application.

Fig. 2

Mouse With Your Arm™ Quick Reference Guide.

Sit back in a supportive chair and support the mouse forearm on the chair armrest.

Work at or below relaxed elbow height (REH).

Place mouse on the edge of the surface to avoid reaching.

Remove barriers (contact stress) to neutral posture.

Consider other variables.

2.1 Sit back in a supportive chair and support mouse forearm on the chair armrest

A well-designed office chair offers support by permitting one to sit back, avoid slouching, and allow the chair to fully support the user. Ergonomic seating standards and guidelines set by the International Organization for Standards (ISO) state that “The purpose of good seating is to provide stable body support” [23, p6]. The load of the lumbar spine is reduced when the user can rest against the back of an office chair [24]. Operating the mouse from this “go to” posture is essential to MWYA methodology.

As far back as 1920, furniture designers were addressing issues of bench seating and how to better support a worker for productivity and comfort. In response, William Harris created the Do/More Chair, marketed as “having lumbar support and adjustability to help prevent hemorrhoids, kidney trouble, constipation, and a whole host of other problems caused by slouching in competitors’ chairs” [25, p7]. Seating solutions without back supports have resulted in slumped posture and decreased comfort which can be detrimental [26]. The natural curve in our spine (lordosis) is present when we stand. This same neutral curvature can be sustained when sitting, if the chair’s lumbar support is allowed to fully engage and support the back. A properly used chair sustains lordosis and enhances comfort [27, 28]. It is beneficial to relax or lean against a backrest to assist with maintaining the lumbar curve when sitting [29] with an erect posture where the head and trunk are vertical [4, 30].

An awkward or exposed posture happens when the back is not neutral or vertical. In one study Gradjean [31] found workers were in contact with the chair’s backrest only 42% of the time. Slouching forward increases the postural load [32] on the spine and increases the exposure to cumulative risk of lower back pain [33]. Using the backrest minimizes back strain and allows even distribution of pressure within the disc [34], reduces compression loading [35], and is an important variable in preventing MSDs [36]. Users resting back rather than leaning into their work addresses the significant health concerns identified with slouched postures.

The benefits of armrests in an office chair are immense when they fit the user, do not restrict access to computer input devices, and are comfortable. Amick et al. [37] found individuals that received training and a highly adjustable task chair experienced reduced symptoms. Marcus et al. [38] found the presence of armrests was associated with lower risk of neck and shoulder disorders. Woods et al. [17] noted that participants complained that there was insufficient back support from their chairs; the chairs they sat in lacked armrests. When armrests are absent, users may not sit back and receive the benefits of lumbar support. Armrests provide a method to maintain a supported posture and avoid slouching, essential when using one’s computer. There is evidence that computer users prefer relaxed, neutral postures with arm support [9]; we feel more comfortable with a supported body [17, 39].

A neutral supported forearm when using a mouse significantly reduces postural load and helps reduce pain [40]. The use of forearm support (compared to no support) revealed less shoulder muscle activity and discomfort and reduced torque by 90% [41]. A neutral posture showed the least perceived exertion and activity in trapezius muscles [41 –45]. Operating the mouse without forearm support increased the load on the trapezius muscles [41, 42] and overall muscle load compared to sitting with forearm support [17]. Several studies showed reduced muscle load in the neck and shoulder with the use of forearm support [17 , 45–47]. These studies were assessing postural load from four work methods: floating the forearm, forearm support from resting on a desk or attached support device, or wrist-based resting. The studies did not analyze the benefits of forearm support from a chair’s armrest. The use and benefits of chair armrests have received extremely limited attention. ISO ergonomic requirements for office work with visual display terminals (VDT) 9421-5 states that “armrests should not restrict ease of access to the workplace; in particular the height should not prevent the work chair being slid under the work surface” [23, p13]. However, if a chair is moved under a work surface the computer operator must place their forearms on the work surface. In fact, ISO does not require chairs to offer armrests and states that “only for special working tasks and for moments when work is interrupted, armrests can support the muscular system of neck and shoulders” [23, p13]. Therefore, many experts assert that armrests should not be used and may not even be needed [48]. Why only when work is interrupted should neck and shoulder support from a chair’s armrests be offered?

Forearm support is recognized as beneficial; however, there are health consequences resulting from the pervasive forearm desk resting method. Woods et al. [17, p80] showed forearm support on the work surface created “undesirable wrist extension.” In one study forearms supported on the desk or support boards was determined to be important for reducing muscle load and musculoskeletal pain; however, in a 6-year follow-up an increase in forearm and wrist pain was noted when using this method [49]. Lin et al. [15] trying to mitigate non-neutral postures placed the mouse near the centerline and tested alternative input devices. The authors noted that the study “is based on ideal placement of each pointing device” and with all “participants supporting their forearms on the desk surface” (p263). Wahlström et al. [50] found that an arm-based mouse operation where the forearm rested on the work surface had greater wrist extension, higher muscular activity in the trapezius muscles, and the highest ratings of perceived exertion in the neck and shoulder. A study by Cook et al. [13, p347] in which subjects obtained forearm support from the work surfaces noted that “a relationship was found between the variable of arm abduction which is specific to mouse use and symptoms in the neck.” Eight years later, still using the work surface to provide forearm support, subjects reported increased shoulder discomfort and “the proportion of participants reporting treatment for the wrist/hand had increased at follow up” [51, p111]. Goncalves et al. [45, p5] studied arm support using the desk and found participants were “weight bearing on the table” and that it is advisable for “people to keep their arms closer to the body” (i.e. reduce the shoulder flexion angle). Visser et al. [52, p215] measured “muscle activation and hand forces in computer tasks” with no chair armrests offered and concluded that “the level of muscle activity in the forearm extensor muscles during these intensive mouse tasks was surprisingly high” and “mouse tasks pose a health risk.” Do mouse tasks pose health risks or is it possible operators are not posturing themselves correctly, are confused about how to work, and are weight-bearing on the desk vs. maintaining their elbows near their sides? Even with these significant findings, the message to stop resting on the work surface has been poorly promoted.

The following researchers examined engineering controls such as new input devices without changing the identified consequences of forearm resting on the station. Fernström and Ericson [53], in assessing input devices and how to reduce shoulder muscle strain from the forearm resting on the table top with a conventional mouse, introduced a different mouse and forearm cradle. Both methods of operation “increased the muscular load in the hand and forearm”(p347). When subjects supported their forearms on the work surface, Quemelo and Vieira [54, p1342] noted the vertical mouse “decreased the exposure to biomechanical risk factors for computer mouse use-related MSD”. Are these findings identifying an “improved posture” (neutral vs. conventional mouse with forearm resting on the work surface) rather than an “optimal posture” (conventional mouse with forearm supported by a chair’s armrest)?

Another method of mouse operation is a floating arm technique. This floating technique, described where only the wrist is supported, created discomfort [42, 55] This method was not preferred by Cook et al. [55, p285] noting that “forearm support [on the desk] may be preferable to the floating posture implicit in current Australian guidelines for computer workstation setup.”

Research suggests that the floating technique is not preferred, wrist-based methods (see Section 4. Remove Barriers) are problematic, and forearm resting on the desk has significant consequences. Yet, some level of forearm support is recommended for computer input device use. Many researchers believe forearm support is an important function in improving posture, promoting comfort and well-being, and stabilizing the way we sit [17 , 56–61]. Having the arm fully supported is beneficial in terms of effort and low muscle activity [17 , 47]. Within these studies forearm support was not clearly defined and/or arms resting on the station was indicated as the preferred work posture. Three studies analyzing or addressing mouse-use had chairs with armrest [15 , 44] which does not correlate to the use of the chair armrest for forearm support when operating the mouse. Zhu and Shin share that it is “recommended to use chair armrests or a table work surface to support the forearm or elbow during typing, mouse-use or touchscreen operations” [62, p1412]. The authors cite four studies to support this statement; all of the studies applied a station or support board resting posture, and did not apply a MWYA method of mouse operation.

Only one study [61] was identified as having analyzed the use of forearm support from a chair armrest when using a mouse [10–17 , 63–76]. Delisle et al., [61] demonstrated a mouse location and operation method consistent with MWYA. Delisle’s study sought to determine if the “use of height-adjustable office furniture offering forearm support on the work surface results in a reduction in muscle load while minimizing the impact on the posture of the upper limbs” (pi). Three different workstations and postures were established. The before and after examples of MYWA field application (Fig. 3) serve as two of the three workstation postures as described by the Delisle study.

Fig. 3

MWYA before and after field application and Delisle study Recreated Workstation’s A and B.

Workstation B reflects a MWYA setup where the chair armrest provides forearm support. For Workstation A the author noted “the use of forearm support (on the desk) can be beneficial at the level of the neck/shoulder region to the detriment of the wrist/forearm region” (p28). For Workstation A, there was a greater load in the anterior deltoid, and shoulder flexion and abduction were greater when resting forearms on the station while operating the mouse. The author added that workstation A is “not recommended for someone who experiences discomfort in the wrist/forearm region,” (p28) and “shoulder abduction was significantly less for Workstation B” [61, p22]. Fourteen years later, people are still resting their forearms on the work surface to the detriment of their wrist and forearms at a minimum.

Other studies found inconsistent evidence and/or evidence that forearm support or specific seated postures did not have a significant benefit on whole musculoskeletal symptoms/ disorders [38 , 77–79]. These studies did not provide chair armrest support and/or use a chair armrest method of mouse operation. In addition to forearm resting on the station and wrist rests (see section 4 Removing Barriers), some of the studies used support boards. Support boards cause the user to “become inhibited in their freedom and ease of movement” [80, p160], “adversely affect the upper extremities” [77, p1735], “increase the risk of musculoskeletal symptoms in the shoulders and arms” [81, p1754] and have a negative effect on overall productivity of general office tasks [82, p73]. Conlon et al. [56] indicated two studies [76, 38] did not find significant benefit from using the workstation and chair arm supports to provide forearm support for their participants. Only one of the studies had the “presence of armrests” [38] and no instruction or facilitation of chair armrest support use was applied when operating the mouse. Overall, one may conclude that forearm support from a station or a support board does not have significant health benefit.

Educating and facilitating people to engage in specific postures and proper equipment use is complicated. Generally, for neutral sitting and achieving fully sustainable lumbar lordosis, sitting back in a chair is necessary. Using chair armrests for forearm support facilitates placing the elbow next to the side, and controlling for shoulder flexion and abduction, contact stress, and bent wrists. Not resting forearms on the work surface allows users to maintain this neutral position.

2.2 Work at or below relaxed elbow height (REH)

Neutral posture can be maintained when elbows remain next to one’s sides [19 , 45] and tools we use are below relaxed elbow height (REH) [11 , 83–86]. ISO, OSHA, and Business + Institutional Furniture Manufacturers Association (BIFMA) advise that upper arms should hang vertical and the forearms horizontal when operating the mouse [19 , 83]. Input devices such as mice and keyboards should be operated at or below one’s REH, to prevent forearm exposure against the desk edge. Using input devices above REH leads to chair perching (sitting forward in a kyphotic posture), contact stress, reaching by the arms, and resting forearms and upper body weight on the work surface. Marcus et al. [38] found moving the keyboard back and obtaining forearm support on the desk or a wrist rest is better than having the keyboard at or above elbow height. These findings identified a “better-than” posture (work surface resting vs. compression on station edge) rather than an “optimal posture” (working below REH). An upper arm vertical and forearms horizontal necessitates work tools be placed at or below REH.

Lee et al. [87] found 98% of students rested their wrists and forearms on the workstation when using the mouse above REH. The authors noted no chair armrests were available and that “features influencing the use of forearm supports needs to be further examined in future research” (p112). Armrests on a chair adjusted to REH and level with the mouse support surface is an effective feature to provide forearm support. This posture allows a computer user to maintain a supported upright seated position, vertical upper arm (elbows by the side), horizontal forearm, and an absence of station contact stress.

2.3 Place mouse on the edge of the work surface to avoid reaching

The location of the mouse on the work surface has a significant impact on posture, forearm muscle activity, method of operation, and is an essential component in the relationship between mouse use and MSDs [15]. Woods et al. [17, p103], in observing a floating or forearm work surface resting posture, recognized that when using the mouse “the location and orientation on a desk affect posture of the hand, wrist, arm, and shoulder and undesirable wrist and shoulder postures occur frequently in practice,” noting problems including insufficient back support and poor position of the mouse on desks (p96). Lin et al., found that “device design and location elicit significantly different postures and forearm muscle activities during use” [15, p259]. Studies show it is difficult to maintain neutral wrist and hand postures when weight-bearing on a work surface [45]. Contrary to the MWYA recommendation to place the input devices close to the edge of the surface, Marcus et al. concluded input devices placed back on the surface to afford forearm support reduces symptoms. Their study showed an association with “increased risk of both hand arm symptoms and disorders” if the input devices were closer than 4.7” from the desk-edge to keyboard “J” key [38, p246]. As indicated in the previous section, the work surface for some participants may have been above REH. Additionally, the study did not look at participants back muscles, use of chair armrests or back rests, and “associations between musculoskeletal outcomes and mouse posture were attenuated”(p248). This study has significantly influenced other studies emulating placement of the input devices back on the work surface to afford forearm resting on the desk.

Researchers have sought to identify the crux of the human computer interface. Recognizing the challenges to control postural methods, they have looked to products for neutral posture solutions. Gustafsson and Hagberg [66] and Kumar and Kumar [88] assessed engineering controls (mouse design) and the risks associated with their use. Both found a neutral posture using alternative devices preferable to the conventional wrist-based mouse operation posture. Ullman et al. [14] thought a new mouse, more like a writing instrument than a traditional mouse, may allow large muscles to relax and forearm muscles to move more dynamically. They noted increased muscular activity in the neck during mouse use with forearm desk-resting. Following the report of pain or discomfort, a common response from employers was to provide an alternative device (e.g. joystick mouse or trackball) in an attempt to reduce the problem [17]. Participants had extended reaches, work surfaces above REH, input devices far from the edge of the surface, forearm resting on the station and no chair armrest support. These postural and product placement contributors to pain or discomfort may help employers recognize that the health solution for their workers may consist of investing in teaching methods of working rather than only providing product solutions.

Johnson and Kim [89, p1] report that “desks can cause discomfort too”, leading Steelcase Inc. to design a new soft edge desk to ease pressure on the forearms. A later study measured the reduction in contact pressure with a soft edge desk, however, the participants were still experiencing noted contact pressure from resting on the work surface [72]. ISO 9421-5 recommends the work surface support the hands and arms. [23, p9]. Straker et al. [71, p612] found a curved desk providing forearm support at 3 cm above elbow height resulted in increased muscle activity, shoulder elevation, and shoulder flexion/abduction. This posture places one’s work above REH and forearms against a hard surface. He concluded that desk design impacts one’s exposure to MSD risks and upper extremity muscle activities. Lintula et al. [90, p114] studied Ergorest® arm supports (forearm cradles) and concluded they “cannot be recommended for use with new ergonomic VDU tables [curved computer desks] that enable adequate rest for forearms.” These authors viewed the desk as the vessel for obtaining forearm support.

Over a century ago, punishment in the school room might include a child extending their arm in a full reach while holding a textbook in the palm of their hands [91]. Sustaining a reach is painful: there is a causal relationship between arm abduction during mouse use and work-related symptoms [13, 90]. Research shows that postures adopted while using a mouse require shoulder abduction [9 , 92–94]. Delisle et al. found when input devices were back from the edge of the surface shoulder flexion was required to reach them [61, p-27]. Lin et al. [15] determined that devices placed laterally produce greater shoulder abduction and concluded that placing devices close to the body created neutral postures. Assuming the benefits of having the mouse in closer proximity to the users, some well-intentioned researchers recommend it be placed between the keyboard and station edge [93]. This placement may improve the mouse location but requires operators to flex their shoulders when operating the keyboard. Whole-body awkward postures are removed when operators place their mouse (and keyboard) on the edge of the surface, sit back in their chair, and support their forearm on the chair’s armrest when using the mouse. This ensures that in addition to the wrist, arms, and shoulders being neutral, the back is also supported and neutral. Clinical research over the past 23 years shows this posture reduces whole-body MSD symptoms for participants.

2.4 Remove barriers (contact stress) to neutral posture

Resting on the work surface and a wrist rest creates contact stress for users and are barriers to whole-body neutral posture. In the literature review, there was no consistency when it came to the use of wrist rests. Sharing a meeting of international experts, Woods et al. [17] noted a number of problems and benefits with the use of arm and wrist support. The method used for operating a mouse has a significant impact on comfort and MSD exposures [47, 50]. A wrist-based method of operating a mouse plants the wrist on a wrist rest or desktop. Gustafsson et al. [66], applying the desktop resting approach, indicated that most mice are designed to be operated with a pronated forearm and wrist-based movements. During wrist-based mouse operation, higher forces were applied to the sides of the mouse and the highest ratings of perceived exertion were in the wrist, hand, and fingers [9 , 50]. Wrist supports did not reduce strain on the neck-shoulder region [46], but increased the load on the trapezius, [41 , 94], and doubled the pressure on the delicate tendons inside the carpal tunnel [95, 96]. Kang et al. assessed three resting positions on the desk while using three types of mice and found that users should avoid these positions. In the absence of forearm support from a chair’s armrest, they concluded that “well-padded” wrist pads would assist in “relieving the stress concentration on the pisiform area” [73 pp867-871]. Yet Marcus et al. [38, p246] found “a presence of a wrist rest was associated with increased risk of both hand arm symptoms and disorders.”

Dainoff et al. recommends not resting hands and wrists on the desk or palm rests but being free to move [85]. The chair’s armrest serves as the mechanism to allow computer operators to be free to move, remove the work surface and wrist rest barriers to access input devices, and prevents the delicate tendons in the wrists from exposure to compression.

2.5 Consider other variables

There are vast variables influencing worker comfort and health in the office setting. This study does not address leg clearances, which if restricted can create awkward postures and exposure to MSDs. Features of chair armrests can facilitate or obstruct MWYA application. Lueder and Allie’s whitepaper [39] focused extensively on chair armrest features. Aspects of station design, installation heights, radius, and restrictive drawers can significantly impact chair placement, leg clearance, and MWYA capacity. Optimal fit of lumbar support, use of keyboards, monitors, monitor arms, and document holders were intentionally not addressed but cannot be ignored in the complex computer relationships.

Static postures (lack of movement) have been associated with an increase in MSDs [9 , 93]. In response to these issues, the phrase “your next posture is your best posture” is frequently promoted; consequently, the sit-to-stand and active seating furniture industry is thriving. Movement is beneficial and has been recommended for decades, but the movement trend could potentially mask exposures to MSD risk factors. One research review noted that seating without support will increase movement and is conceptually attractive, but probable slumped postures are likely to result and are problematic [26]. Have we have come full circle from William Harris’ Do/More chair of 100 years ago? In addition to lack of back support, the recommendation to support one’s forearms on the desk may be contributing to static posture issues. Straker et al. [71, p615] noted “some concern that forearm support (on the desk) may inhibit movement and increase muscle activity” while Lueder and Allie [39, p14] found that “armrests have been shown to improve posture and promote freedom of movement while stabilizing one’s position.”

Another contributing and complicating factor is that individuals have different preferences about what feels comfortable. Individual awareness of ideal posture, methods on how to use task chairs, and how to evaluate environments may help to reduce MSDs [86]. Over twenty-three years ago, Hagglund and Jacobs acknowledged the need for a foundation on which to build ergonomic success for VDT operators [80]. They recognized that an individualized approach was the most successful with the highest levels of satisfaction by participants. MWYA is the foundation for facilitating an ideal posture, individually owned and applied, to create a comfortable human-computer relationship.

Approaching ergonomics as a holistic endeavor is essential when manipulating variables. Asundi et al. state “The combination of the input device support surface and user upper extremities form a complex kinematic system with several degrees of freedom” and “wrist postures during computer use are a function of multiple factors other than simply keyboard tilt [97, p187].” There is no simple solution to complex problems and when trying to solve any biomechanical equation one must note that for every action there is a reaction. Successful ergonomic interventions necessitate a comprehensive analysis otherwise one product or posture recommendation may compromise the health of the individual if the consequences of that modification are not considered in a holistic manner.

3 Clinical field application

MWYA™ evolved from knowledge of OSHA’s Good Working Posture (Fig. 1) to provide support for the forearm and maintain a neutral wrist. Providing support through the use of the chair’s armrest when operating the mouse seemed intuitive and had such a positive impact it was replicated. Spanning 23 years, over 3,500 voluntary one-on-one personalized (on-site and virtual) assessments for mostly corporate clients were conducted applying MWYA while integrating the 4Es: empathy, empowerment, education, and evaluation. Real-world workers participated in roughly one-hour sessions to address any health or equipment concerns, review the nature of their work, identify work habits, and receive education on neutral posture and MWYA (Fig. 2). Approximately 90% of participants had a reported health concern and the other 10% proactively wanted to prevent MSDs. Organizational sponsors supported immediate changes, before and after images (Fig. 3 and 4), and comprehensive reporting. Immediate postural changes were made, encouraged, and documented and posture reminder cards were left for reference. At the close of the session, participants were informed they would receive the report and follow-up. Follow-up included: addressing questions, discussing need for additional professional assistance, verifying changes were made as recommended, and checking on how they were feeling (comfort and symptoms, if applicable). Participants received an Evaluation of Services form and outcomes consistently resulted in > 98% improved comfort and > 95% reduced or eliminated symptoms. The program outcomes are credited to:

Progressive employers

Application of MWYA (Fig. 2,3,4, & MWYA Link https://structuredhealth.com/MWYA)

Quality products and vendor services

Custom fitting and training of products and postural solutions

Attention and empathy for the individual’s desire to prevent and address health issues

Required follow-up

Fig. 4

Mouse With Your Arm™ before and after example.

3.1 MWYA application example

If existing chair armrests could not provide specified and comfortable forearm support or interfered with workstation access, alternative chairs were provided. This allowed accommodation of unique anthropometrics of participants. For example, if an individual needed armrests to raise to 13” and the chair did not accommodate them because it met BIFMA G1-2013 arm support range of 7.7” to 11.4” [34] (not intended to accommodate everyone), a chair with custom 13” armrests was secured. If the chair on its highest setting (foot support provided if necessary) did not place the fixed work surface at or below REH, the surface was lowered by the facilities department or a chair with a longer cylinder was acquired.

Measurements of station height, relaxed elbow height, and chair armrest height are used when conducting a MWYA assessment. Other precise measurements essential to scientific studies are not foundational to MWYA assessments. In real-world settings people are concerned with comfort and flexibility more than degrees and angles; they just want solutions. Detailed individual clinical records and reporting occurred with the delivery of this service. This study is based on 33 years of observation, data gathering, and field service helping individuals accommodate their disabilities and be more comfortable.

4 Limitations

MWYA has been applied through the willingness of organizations to sponsor a highly personalized approach to disability prevention and management. Corporate champions appreciate the positive outcomes in terms of reduced or eliminated symptoms and improved comfort, as well as reported improved productivity and morale. However, the loss of a program champion can impact program momentum. Some organizations seek alternative approaches, such as outsourcing or automated systems, which can be perceived as more cost effective.

5 Conclusion

MSDs may be reduced by encouraging specific positions that facilitate neutral posture. This study demonstrates how, by applying OSHA’s Good Working Posture and MWYA™ operation, one can maintain neutral postures, obtain lumbar support from the chair, and reduce the stress and load often recognized as a contributing factor in workplace pain and MSDs. Unless workers are provided with the appropriate tools, such as a highly adjustable task chair with armrests, they cannot easily implement the MWYA method. Workers also need to be encouraged to obtain forearm support from their chair’s armrests as it is the vessel onto which good posture is sustained, awkward postures avoided, and comfort facilitated.

The research revealed significant ambiguity surrounding forearm support due to the omission of chair armrests, misinterpretation of forearm support methods, and lack of specification as to where forearm support is provided. Many control postures were not ideal resulting in better-than postures vs. optimal postures. Finally, the studies were looking at segments of the human body rather than whole body impact from various interventions.

A holistic approach to ergonomics addresses the entire person’s body. To sustain change and effectively address the human and financial impact of MSD’s it is essential to recognize the unified nature of administrative and engineering controls and invest in behavioral change initiatives. This study and the easily remembered MWYA method can drive future research, impact product design for chair armrests, and increase employer awareness and responsiveness to provide posture training. This approach allows computer operators to own and invest in their ergonomic solutions. With human investment comes enhanced awareness, better choices, and improved comfort and health.

Conflict of interest

None to report.

Footnotes

Acknowledgments

The author wishes to express appreciation to T. Stranz, MA for his investment, time, and encouragement to drive this research and writing; R. Habeck, PhD, for her academic perspective; and M. Dainoff PhD, for his invaluable mentoring and for recognizing the human computer interface is a “wickedly” complex adaptive system.

Thank you to the thirty-five plus authors that generously offered their time to clarify and share studies. A heartfelt thank you to D. Edwards, one of the many corporate sponsors that believed in the personalized approach to ergonomics and to the 3,500 plus participants that engaged in trying something different. A. DeKock, MLIS for her meticulous editing and my husband and children for supporting me along this journey.

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