Is Standing the Solution to Sedentary Office Work?

Prolonged Standing Work

To address these potential adverse health outcomes, one workplace response has been to directly replace the time seated with standing. However, there are negative health outcomes associated with prolonged standing (Waters & Dick, 2014), such as cardiovascular system changes, including carotid atherosclerosis (Krause et al., 2000) and varicose veins (Bahk, Kim, Jung-Choi, Jung, & Lee, 2012; Tuchsen, Hannerz, Burr, & Krause, 2005). Similar to sitting, when standing exposures are also assessed based on constraints, individuals who have reduced freedom of movement and work scheduling have higher odds ratios and prevalence of LBP reporting (Andersen, Haahr, & Frost, 2007; Macfarlane et al., 1997; Tissot, Messing, & Stock, 2009).

The rapid shift to standing workstations has been adopted often with little consideration to the ergonomic or biomechanical factors guiding how the workers will respond to and function in the redesigned workspace. In fact, both field (Andersen et al., 2007; Roelen, Schreuder, Koopmans, & Groothoff, 2008; Tissot et al., 2009) and lab studies, involving light-duty office tasks (Gallagher, Campbell, & Callaghan, 2014; Marshall, Patel, & Callaghan, 2011; Nelson-Wong, Howarth, & Callaghan, 2010) examining prolonged standing induced LBP have indicated that pain development can occur in workers who have not previously had a low-back injury. Individuals who develop pain during standing work usually experience first symptoms within 15 to 45 min (Marshall et al., 2011; Nelson-Wong et al., 2010), and pain quickly dissipates once the standing has ceased.

Using a longitudinal study to follow people who developed prolonged standing pain and non–pain developers over 3 years, Nelson-Wong and Callaghan (2014) found LBP developers were 3 times more likely to experience chronic LBP over the next 24 months, seek medical care within 3 years of their participation, and report multiple episodes of chronic LBP. Although LBP during standing is transient in nature, it appears to be a positive predictor for experiencing future chronic and recurrent LBP (Nelson-Wong & Callaghan, 2014). As a result, it is important to stress that while people reporting acute LBP development during standing have never suffered a low-back injury, they could be characterized as a preclinical group for the development of chronic LBP in the future.

Rotation of Sitting and Standing

Changing a workstation from predominantly sitting to standing may not eliminate the root issue of remaining in stationary positions for extended periods. Thus, this potential shifting of the same chronic exposure to simply another posture highlights the idea of job rotation, or the alternating of postures while performing the same work tasks.

A sit-stand workstation is defined as a workstation that allows a user to perform the same tasks from either a seated or a standing posture. These workstations allow the work surface height to be adjusted quickly and safely with minimal disruption in work performance. Thus, the theory underlying the sit-stand work paradigm consists of a worker performing his or her duties while periodically alternating between sitting and standing throughout the day to introduce postural variation.

Ergonomics training delivered with the adoption of sit-stand workstations can have a direct impact on usage patterns to achieve the alternating postures. A survey of four companies that converted to sit-stand workstations showed that only about one in five employees used the sit-stand feature at least once a day (Wilks, Mortimer, & Nylen, 2006). However, in another study, workers receiving 1.5 hr of instruction and 6 days of standing reminders during work performance stood approximately three times during the workday; in contrast, a group of workers who received minimal instruction never stood even though provided with sit-stand workstations (Robertson, Ciriello, & Garabet, 2013).

When sit-stand devices were implemented as part of a global corporate health and well-being program, they resulted in a reduction of sedentary time by 66 min per day (Pronk, Katz, Lowry, & Payfer, 2012). This reduction in sedentary exposure translated to a 54% reduction in upper-back and neck pain compared with participants’ seated work scores prior to receiving a sit-stand device (Pronk et al., 2012). A similar response was found in a group of trained workers who used the sit-to-stand feature with less reported discomfort and higher job performance (Robertson et al., 2013).

Our recent review (Karakolis & Callaghan, 2014) concluded that sit-to-stand workstations can be effective in reducing perceived discomfort and that sit-to-stand workstations do not change worker productivity. Workstations that allow rapid changes (less than 10 s movement time) between sitting and standing facilitate either a consistent productivity level or a potential increase (Karakolis, Barrett, & Callaghan, 2015). Given the potential health benefits of reducing sedentary time and the potential to reduce musculoskeletal disorders and discomfort with little to no impact on productivity, the case for implementing sit-stand workstations to reduce prolonged sedentary exposure seems warranted. However, several issues need to be considered.

First, there is some evidence suggesting that sit-stand workstations may cause an increase in reported discomfort of the upper extremities (Ebara et al., 2008) because of a different postural ratio for wrist position between seated and standing working positions (Hedge, Jagdeo, Agarwal, Rockey-Harris, 2005). In contrast, Robertson et al. (2013) reported no difference in wrist discomfort for seated workers compared with workers using sit-stand workstations.

Second, there are no ergonomics guiding standards for usage ratios for time spent between standing and sitting. A number of different ratios have been reported in sit-to-stand studies, with no physiologic or occupational justification for their usage. Approximately 50% of individuals tested develop LBP during constrained standing based on published laboratory studies (Gallagher et al., 2014; Marshall et al., 2011; Nelson-Wong & Callaghan, 2010b). Alternating between sitting and standing alone did not eliminate low-back discomfort once it had been initiated in individuals who develop LBP while standing (Gallagher et al., 2014). Further, LBP associated with standing appears to persist once developed within a working session with only temporary relief provided by sitting (Gallagher et al., 2014; Karakolis et al., 2015) and walking breaks (De Carvalho & Callaghan, 2013; Figure 1). Once exposure to standing is resumed, the pain continues to get worse.

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Figure 1.

The introduction of breaks from sitting does not reset the pain developed during standing once it has been initiated. Visual Analogue Scale pain or discomfort scores were collected over prolonged seated and standing exposures for (A) low-back pain throughout the control and 2-min walking breaks for 13 pain developers; (B) whole-back discomfort over time for 24 participants exposed to 1 hr each of sitting, standing, and sitting-standing at a ratio of 15 min sitting to 5 min standing (3:1); and (C) pain responses of 11 standing pain developers during 15 min of sitting following 45 min of standing (1:3). Data for these figures were extracted from (A) De Carvalho and Callaghan (2013); (B) Karakolis, Barrett, and Callaghan (2015); and (C) Gallagher, Campbell, and Callaghan (2014).

The few industrial guidelines that directly specify exposure limits for prolonged seated and standing work suggest limits of 4 hr of standing during the day with 1 hr of static standing posture as well as 6 hr of sitting (Occupational Health and Safety Council of Ontario [OHSCO], 2008a, 2008b; see also Knibbe, Knibbe, & Geuze, 2003). When the health issues associated with sitting are factored into recommendations, Owen et al. (2011) suggested a 2-hr limit for discretionary sitting time per day with standing breaks or moving following 30 min of uninterrupted sitting. Historically, the sit-stand work appearing in the research literature suggested a ratio of 3:1 for seated work to standing work with beneficial biological responses (Paul, 1995; Paul & Helander, 1995).

However, in light of the health-related outcomes and a move to minimize sedentary exposure, this ratio needs to be reconsidered with the aim to minimize sitting and increase standing time. If the same ratio were reversed with a suggested target of 1:3 for seated to standing work exposures, for an 8-hr workday, this ratio would break down to 2 hr of sitting, aligning with the suggestion of Owen et al. (2011), and 6 hr of standing. However, this ratio would conflict with current ergonomics guidelines suggesting no more than 4 hr of workplace standing in total (Knibbe et al., 2003; OHSCO, 2008a, 2008b). When total diurnal sedentary exposure is considered, a reduction to between 4 and 8 hr of sitting from 8 to 11 hr or more had no additional reduction in all-cause mortality risk compared with individuals with 0 to 4 hr of daily sitting exposures (van der Ploeg et al., 2012).

When these factors are considered collectively, the ratio will vary for working time alone or total daily exposure as well as the rationale for targeting change, whether musculoskeletal discomfort or health, and will lie somewhere between 1:3 and 3:1 sitting to standing time. Nevertheless, even if the total sedentary time is unchanged, breaking up the sitting blocks with more frequent movements as opposed to long blocks of sitting with breaks has been shown to have beneficial biological impact (Owen, Healy, Matthews, & Dunstan, 2010).

Conclusions and Recommendations

In light of the given evidence, a suggested approach to rotation between sitting and standing is to increase the time in standing. Even small reductions in workplace sedentary exposure of approximately 60 min by introducing standing has proven to reduce musculoskeletal discomfort (Pronk et al., 2012; Robertson et al., 2013). From a health perspective, a reduction of total sedentary exposure by approximately 50%, from between 8 and 11 hr and more to between 4 and 8 hr produced a reduction in all-cause mortality similar to more extreme reductions in sitting to 0 to 4 hr (van der Ploeg et al., 2012).

Given these benefits with reduction in sedentary exposure, it would seem warranted to target standing durations between the existing suggestions of 1:3 and 3:1, with standing duration being 3 times the sitting duration for the 3:1 ratio (i.e., if a worker sits for 5 min, he or she can try standing for 15 min). When all factors are considered, including musculoskeletal discomfort, health implications, total diurnal seated time, and current ergonomics recommendations for total standing time, a suggested recommendation would be to target a ratio of 1:1; that is, for an 8-hr workday, attempting to have 4 hr of seated work and 4 hr of nonsedentary time composed of standing, walking, or other activities.

The optimal frequency for changing postures has not been established, but it appears prudent to try to change postures often and not wait until feeling pain or discomfort. Once pain has initiated, it persists even with postural breaks. A suggestion for newly implemented sit-stand workstations would be to limit standing to 15 min or less, which has been shown to be below the initiation time point for LBP development, and to lengthen exposures as the worker becomes accommodated to working in standing postures. Workers who changed postures more often, even though they had the same total sedentary exposure, exhibited beneficial health changes. Changing frequently from sitting to standing, even if one cannot reduce total sitting time, is beneficial. Take regular short breaks from sitting.

When exposed to prolonged standing, approximately 50% of individuals may experience LBP. A recent longitudinal study demonstrating this pain response to standing identified individuals who were 3 times more likely to seek medical help in the future for a low-back problem. In line with the rotation recommendation, individuals who are pain developers in standing may need to start with more time sitting and build up to longer periods of standing. Additionally, there may be a benefit to participating in stabilization-based exercise programs targeted toward trunk and hip strengthening.

Productivity has been shown to remain constant, even when the time to change between sitting and standing is included. However, there is little work on which tasks are best performed in the two postures.

There is little information on performing computer work while standing. Given suggestions that the wrist posture differs between seated and standing work (Hedge et al., 2005), setup of the computer monitor, keyboard, and other peripheral devices will likely not be the same between seated and standing positions. Having adjustable monitor arms will allow a different work surface-to-monitor height that is likely needed when moving between the two postures.

The addition of ergonomics training paired with implementation of a sit-stand workstation resulted in increased frequency of standing compared with frequency among untrained workers. This increased frequency also exhibited benefits of reduced discomfort and increased worker performance. Adopting sit-stand workstations in the absence of training or a health-and-wellness program yielded no marked changes in worker performance or reduction in sedentary exposure.