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Investigating the Effects of Different Working Postures on Cognitive Performance

Article

Investigating the Effects of Different Working Postures on Cognitive Performance

Abstract

Objective Individuals performance at the workplace is affected by different adopted postures. Sitting postures are mostly used during office work. Improper sitting postures may cause muscle fatigue and discomfort in the spine and also result in mental workload. Poor posture may result in human errors and delay in information processing. Previous studies have demonstrated the relationship between static sitting postures and cognitive factors such as reaction time to an auditory stimulus. Also, some recent studies have demonstrated the effect of static postures on cognitive performance. To our knowledge, none of the studies had considered the sitting and standing postures effects on cognitive performance simultaneously. The aim of this study was to evaluate cognitive performance during three different static working postures: standard sitting, standing, and self-selected sitting postures. Materials & Methods This semi-experimental design study was conducted on the twenty-nine healthy students (aged 20-30 years). The non-probability sampling method was selected. All participants provided their written informed consent. Participants with no musculoskeletal disorders, heart disease, spine surgery, and history of depression and stress were selected. Their depression status and level of stress were measured using Beck questionnaire. The study was approved by the Ethics Committee of University of Social Welfare and Rehabilitation Sciences. Subjects performed complex Stroop test and typing activity in an office-like laboratory setting at the University of Social Welfare and Rehabilitation Sciences. Stroop test lasted about 9-12 minutes, and a typing task was also designed for approximately 5 minutes for all subjects. Three random postures were selected based on common postures used in the office. The effects of the postures (standard standing, standard sitting, and self-selected sitting posture) on dependent variables such as total test duration and reaction time to congruent and incongruent stimulus, number of typing words and number of typing error were assessed with Repeated Measures ANOVA. To examine the differences between groups, the paired t-test was used. Results The results demonstrated that reaction time measure and number of typing error (accuracy) were affected by postures (P=0.001). Post hoc analysis demonstrated that reaction time was significantly different between self-selected sitting posture and standard sitting posture (P=0.001), self-selected sitting posture and standard standing posture (P=0.043), standard sitting posture and standard standing posture (P=0.001). With considering the average amount of reaction time to congruent and incongruent cases, it was observed that there is less reaction time in the standardized sitting posture (M=628.67 ms) compared to the self-selected sitting posture (M=689.41 ms) and standard standing posture (M= 675.16 ms). Also, among the three postures studied a significant difference was observed in the number of typing error words (P=0.001). The number of typing error (accuracy) was lower in this posture compared to the two other postures (M=1.58). Conclusion This study demonstrates that cognitive performance is affected by working postures. This study demonstrates that standard sitting posture is the best posture. Therefore, it is recommended that sitting posture can help in increasing cognitive performance in the workplace.
268
January 2018. Vol 18. Num 4
REHABILITATION
* Corresponding Author:
Hamid Reza Mokhtarinia, PhD
Address:
Department of Ergonomics, University of Social Welfare and Rehabilitaon Sciences, Tehran, Iran.
Tel: +98 (912) 2495248
E-Mail: hrmokhtarinia@yahoo.com
Research Paper: Invesgang the Eects of Dierent Working Postures on Cognive
Performance
1. Department of Ergonomics, University of Social Welfare and Rehabilitaon Sciences, Tehran, Iran.
2. Hematology-Oncology and Stem Cell Research Center, Tehran University of Medical Sciences, Tehran, Iran.
3. Hematologic Malignancies Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Sharareh Mohammadi1, *Hamid Reza Mokhtarinia1, Amir Salar Jafarpisheh1, Amir Kasaeian2, 3, Reza Osqueizadeh1
Objecve Individuals performance at the workplace is aected by dierent adopted postures. Sing postures
are mostly used during oce work. Improper sing postures may cause muscle fague and discomfort in the
spine and also result in mental workload. Poor posture may result in human errors and delay in informaon
processing. Previous studies have demonstrated the relaonship between stac sing postures and cogni-
ve factors such as reacon me to an auditory smulus. Also, some recent studies have demonstrated the
eect of stac postures on cognive performance. To our knowledge, none of the studies had considered the
sing and standing postures eects on cognive performance simultaneously. The aim of this study was to
evaluate cognive performance during three dierent stac working postures: standard sing, standing, and
self-selected sing postures.
Materials & Methods This semi-experimental design study was conducted on the twenty-nine healthy stu-
dents (aged 20-30 years). The non-probability sampling method was selected. All parcipants provided
their wrien informed consent. Parcipants with no musculoskeletal disorders, heart disease, spine sur-
gery, and history of depression and stress were selected. Their depression status and level of stress were
measured using Beck quesonnaire. The study was approved by the Ethics Commiee of University of
Social Welfare and Rehabilitaon Sciences. Subjects performed complex Stroop test and typing acvity
in an oce-like laboratory seng at the University of Social Welfare and Rehabilitaon Sciences. Stroop
test lasted about 9-12 minutes, and a typing task was also designed for approximately 5 minutes for all
subjects. Three random postures were selected based on common postures used in the oce. The ef-
fects of the postures (standard standing, standard sing, and self-selected sing posture) on dependent
variables such as total test duraon and reacon me to congruent and incongruent smulus, number
of typing words and number of typing error were assessed with Repeated Measures ANOVA. To examine
the dierences between groups, the paired t-test was used.
Results The results demonstrated that reacon me measure and number of typing error (accuracy) were
aected by postures (P=0.001). Post hoc analysis demonstrated that reacon me was signicantly dierent
between self-selected sing posture and standard sing posture (P=0.001), self-selected sing posture and
standard standing posture (P=0.043), standard sing posture and standard standing posture (P=0.001). With
considering the average amount of reacon me to congruent and incongruent cases, it was observed that
there is less reacon me in the standardized sing posture (M=628.67 ms) compared to the self-selected sit-
ng posture (M=689.41 ms) and standard standing posture (M= 675.16 ms). Also, among the three postures
studied a signicant dierence was observed in the number of typing error words (P=0.001). The number of
typing error (accuracy) was lower in this posture compared to the two other postures (M=1.58).
Conclusion This study demonstrates that cognive performance is aected by working postures. This study
demonstrates that standard sing posture is the best posture. Therefore, it is recommended that sing pos-
ture can help in increasing cognive performance in the workplace.
A B S T R A C T
Keywords:
Posture, Stac
work, Reacon
me, Selecve
aenon, Cognive
performance
Received: 17 Aug. 2017
Accepted: 05 Nov. 2017
Citation
Mohammadi Sh, Mokhtarinia HR, Jafarpisheh AS, Kasaeian A, Osqueizadeh R. [Inveigating the Eects of Dier-
ent Working Poures on Cognitive Performance (Persian)]. Archives of Rehabilitation. 2018; 18(4):268-277.
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


     





       
       
  



 
       
        
        



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
         

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      

      
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       
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

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



  






1. Beck Depression Inventory quesonnaire
2. Beck Anxiety Inventory quesonnaire
3. Random Sampling





      








  


   
       
  

       
        
    
   



   




      
          

   


4. Body Mass Index
5. John Ridley Stroop
6. Congruent
7. Incongruent











     





SPSS


      
P
F

        
         
P
P
8. ANOVA with repeated measure
P

          

MmsMms
Mms



       
P
     F 

P
 P        




    Mms
     




FP
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   FP
   F  

  F  
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  F  

   FP
F  
  F  


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       
      
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   
F  P
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
        
       
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       
  
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    
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
          
9. Cohen
10. Paced Auditory Serial Addion



       
        







  

    






          






       
       
       

  











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... The workplace environment elements that affect workers' comfort and satisfaction include workplace design, body posture, ambient environment conditions, lighting, and acoustical and visual privacy. These environmental factors can be a source of stress for office workers and may influence physiological response, satisfaction, cognitive performance, and health (Clements-Croome, 2006;Collie et al., 2012;Hayes et al., 2015;Lindberg et al., 2018;Mohammadi et al., 2018;Newsham et al., 2004). Moreover, poor workplace design may lead to increased cycle times and lower work quality, as well as exposure to high forces and awkward postures. ...
... Furthermore, Tian et al. identified a reduction in the HbO at the DLPFC in subjects with posttraumatic stress disorder (Arnsten et al., 2015;Tian et al., 2014). Similarly, in support of these findings, Mohammadi et al. found that working postures can influence cognitive performance (Mohammadi et al., 2018), and Shadidi et al. reported a correlation between psychosocial stressor, upper trapezius muscles, and posture (Shahidi et al., 2013). ...
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Objective The purpose of this study is to examine the effect of the workstation type on the severity of mental stress by means of measuring prefrontal cortex (PFC) activation using functional near-infrared spectroscopy. Background Workstation type is known to influence worker’s health and performance. Despite the practical implications of ergonomic workstations, limited information is available regarding their impact on brain activity and executive functions. Method Ten healthy participants performed a Montreal imaging stress task (MIST) in ergonomic and nonergonomic workstations to investigate their effects on the severity of the induced mental stress. Results Cortical hemodynamic changes in the PFC were observed during the MIST in both the ergonomic and nonergonomic workstations. However, the ergonomic workstation exhibited improved MIST performance, which was positively correlated with the cortical activation on the right ventrolateral and the left dorsolateral PFC, as well as a marked decrease in salivary alpha‐amylase activity compared with that of the nonergonomic workstation. Further analysis using the NASA Task Load Index revealed a higher weighted workload score in the nonergonomic workstation than that in the ergonomic workstation. Conclusion The findings suggest that ergonomic workstations could significantly improve cognitive functioning and human capabilities at work compared to a nonergonomic workstation. Application Such a study could provide critical information on workstation design and development of mental stress that can be overlooked during traditional workstation design and mental stress assessments.
... Jay and Andersen [62] reported improved complex attention in sitting workstations, but no significant difference was found in other cognitive functions. The results of the study conducted by Mohammadi et al. [63] also showed improved selective attention in a sitting position in comparison to standing. ...
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Purpose: This study aimed to assess cognitive and skill performances in sitting and standing workstations among 40 students of Shiraz University of Medical Sciences. Materials and Methods: In this quasi-experimental study, a total of 40 students (20 females and 20 males) participated. The tests were performed among randomly selected participants over two consecutive days as follows: Day 1: Beck depression inventory (BDI) and Beck anxiety inventory (BAI) were used to assess the severity of depression and anxiety in the study participants, respectively. Raven’s general intelligence test was used to measure intelligence quotient (IQ). Day 2: five performance assessment tests (cognitive performance assessment tests: ‘n-back’, ‘Stroop’, and ‘advanced reaction time’, and skill performance assessment tests: ‘two arm coordination’, and ‘Purdue pegboard’) were randomly selected and were presented to individuals in each workstation (sitting and standing workstations). At the end of each sitting and standing position, the comfort of the workstation was measured using a visual analogue scale (VAS). Results: The results showed no statistically significant difference between the sitting and standing positions in terms of ‘n-back’, ‘Stroop’, ‘advanced reaction time’, ‘two arm coordination’, and ‘Purdue pegboard’. Participants were more comfortable in sitting positions and more easily distracted in standing positions. Conclusions: sitting and standing positions had no significant effects on the participants’ cognitive and skill performances.
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With many digital interaction designs, we can choose to operate the devices from a variety of postures – what we call self-positioning. In this paper we test two of these choices – sitting vs standing against standard neuropsychological assessments of cognitive executive function. We show that such choices do have significant effects on various cognitive processes. We argue therefore that there is an opportunity to extend parameters of digital interaction design to include self-position in order to optimize that design’s effectiveness for its intended activity.
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Sedentary behaviour is increasing and has been identified as a potential significant health risk, particularly for desk-based employees. The development of sit-stand workstations in the workplace is one approach to reduce sedentary behaviour. However, there is uncertainty about the effects of sit-stand workstations on cognitive functioning. A sample of 36 university staff participated in a within-subjects randomised control trial examining the effect of sitting versus standing for one hour per day for five consecutive days on attention, information processing speed, short-term memory, working memory, and task efficiency. The results of the study showed no statistically significant difference in cognitive performance or work efficiency between the sitting and standing conditions, with all effect sizes being small to very small (all ds < 0.2). This result suggests that the use of sit-stand workstations is not associated with a reduction in cognitive performance. Practitioner summary Although it has been reported that the use of sit-stand desks may help offset adverse health effects of prolonged sitting, there is scant evidence about changes in productivity. This randomised control study showed that there was no difference between sitting and standing for one hour on cognitive function or task efficiency in university staff.
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Objective: In the present study, we examined the effect of working while seated, while standing, or while walking on measures of short-term memory, working memory, selective and sustained attention, and information-processing speed. Background: The advent of computer-based technology has revolutionized the adult workplace, such that average adult full-time employees spend the majority of their working day seated. Prolonged sitting is associated with increasing obesity and chronic health conditions in children and adults. One possible intervention to reduce the negative health impacts of the modern office environment involves modifying the workplace to increase incidental activity and exercise during the workday. Although modifications, such as sit-stand desks, have been shown to improve physiological function, there is mixed information regarding the impact of such office modification on individual cognitive performance and thereby the efficiency of the work environment. Method: In a fully counterbalanced randomized control trial, we assessed the cognitive performance of 45 undergraduate students for up to a 1-hr period in each condition. Results: The results indicate that there is no significant change in the measures used to assess cognitive performance associated with working while seated, while standing, or while walking at low intensity. Conclusion: These results indicate that cognitive performance is not degraded with short-term use of alternate workstations.