Muhammad Osama  ( Foundation University, Institute of Rehabilitation Sciences )
Shaukat Ali  ( Shifa Tameer-e-Millat University, Islamabad )
Reem Javed Malik  ( Shifa Tameer-e-Millat University, Islamabad )

The objective of this study was to assess the association of postural musculoskeletal discomfort with computer use and to determine its contributing factors among undergraduate university students. A comparative cross sectional study with a sample of 136 students was conducted at Shifa Tameer-e-Millat University. Musculoskeletal discomfort was calculated using ssCMDQ. A positive association of musculoskeletal discomfort was found with duration of computer use (P<0.05). Significant differences were observed in musculoskeletal discomfort scores based on the type of posture adopted (P<0.05), however no significant differences were observed in terms of discomfort based on gender, ergonomic awareness and type of computer used (P>0.05). The findings of this study reveal that risk factors for postural discomfort include posture, duration and type of computer used however ergonomic awareness and gender is not associated with the buildup of musculoskeletal discomfort. Ideal posture to be adopted during computer use is supported sitting on chair with computer on desk. 
Keywords: Biomechanics, Human-computer interaction, Musculoskeletal discomfort, Posture, Ergonomics.

Introduction

The increase in the use of computers among students has exposed them to greater risks for developing musculoskeletal discomfort and disorders.¹ Computers have become a necessity, however knowledge regarding impact of amplified computer use on student education, health and wellbeing is still in the dark and little attention has been paid to postural education, biomechanical correction and ergonomic design.² It is reported that more than half of all students experience musculoskeletal symptoms associated with computer use.³ The risk factors identified for developing musculoskeletal discomfort include academic concentration, female gender, type of computer use, non-neutral body posture, looking up at a visual display unit (VDU), age and computer use >3 hours/day.¹ Neck, back and upper extremity are found to be the most common site of symptoms.^1,3 The purpose of this study was to assess the association of postural musculoskeletal discomfort with computer use, and factors that may contribute to the buildup of this discomfort.

Methods and Results

The current study was conducted at Shifa Tameer-e-Millat University, Allied Health Sciences campus from January to June 2016. Number of students at the time of study was 366 and the sample was calculated to be 162, using "Raosoft sample size calculator"4 keeping 5% margin of error, 95% confidence-interval and 75% response distribution, because of skewed distribution of data to one end, and based on the pilot study. Inclusion criteria consisted of under graduate full time students, aged 17-25 years. Exclusion criteria consisted of congenital anomalies such as leg length discrepancy, anomalies of foot and the angles of hip and knee etc., amputations and recent history of physical trauma or burns. Participants were selected using multistage random sampling, firstly stratified random sampling, followed by simple random sampling. Response rate was 82%, after excluding incomplete responses and a total of 136 students were included in the study. Musculoskeletal discomfort was calculated using \\\'Student Specific Cornell Musculoskeletal Discomfort Questionnaire (ssCMDQ)\\\', which is both valid and reliable with Cronbach\\\'s Alpha greater than 0.95 for each sub scale and range of Kappa coefficient was between 0.690 to 0.949 for frequency, 0.801 to 0.979 for severity and 0.778 to 0.944 for frequency with p value less than 0.001.5 The different types of postures adopted analyzed in the study were identified via piloting and included in the study questionnaire. SPSS 21.0 was used for data analysis. P-value of less than 0.05 via Kolmogrovsmirnov and Shapiro Wilk test shows abnormal distribution of data thus non-parametric tests of significance were used. Ethical approval was obtained from all participants prior to data collection. The mean age of the participants was 20.3±1.3 years. A positive non-significant correlation was found between age and ssCMDQ scores (Pearson Correlation= 0.132 and P-value= 0.127). The most common sites of discomfort were neck (75.7%), lower back (62.5%), upper back (58.8%), right shoulder (52.9%), left shoulder (44.1%) and buttocks/hips (36%). The mean and median values of computer use was 2.75±1.79 and 3.00±1.00 hours per day respectively and mean value for frequency of computer use was 5.51±1.95 days per week. No significant difference was observed among the categories of ergonomic awareness, gender and type of computer used (Table-1),



however a significant difference in discomfort was observed based on type of posture adopted (Table-2).



A significant positive correlation (pearson correlation= 0.208) was found between frequency of computer use in terms of days/week and ssCMDQ scores with a p-value of 0.015. Similarly a significant positive correlation (Pearson correlation= 0.293) was found between duration of computer use per day and ssCMDQ scores with a p-value of 0.001.

Discussion

According to the current study the posture associated with maximum discomfort was \\\'using computer/ laptop/tablet lying supine and head flexed\\\' which conforms to the findings of Ariens et al stating flexion of the neck during computer use to be associated with neck pain.⁶ The current study\\\'s results reinforce the fact that poor body posture can contribute towards the development of postural discomfort as indicated by existing evidence.¹ A similar study conducted in the University of Hong Kong showed the postures adopted during computer/VDU use by students included supported sitting (19.2%), forward sitting (31.5%), slumped sitting (18.1%), supine (10.1%), side lying (10.1%) and lying (10.7%). However the study did not conclude which posture was associated with maximum discomfort.⁷ No gender related difference was observed unlike the existing evidence showing female gender to be a risk factor.⁸ Previous studies conducted by Peer & Gibney,⁹ Mendez et al¹⁰ and Calik BB et al⁸ reported duration of computer use to be 2.9, 3.2 and 3.1 hours/day respectively, similar to that of the current study. The duration of computer use was found to have a positive correlation with musculoskeletal discomfort which is consistent with the existing literature.¹ Even though a greater amount of neck flexion is associated with the use of portable computers, they tend to provide a greater task variety and postural variation as compared to desktops. Perhaps that is the reason; portable computers are found to have lesser amount of associated postural discomfort as compared to desktop computers. Laptop was the most commonly used computer similar to a previous study showing 77.3% students used a laptop, 71% used a desktop and 48.3% used a tablet.⁷ No significant difference in discomfort levels was observed based on ergonomic awareness, reinforcing the fact that ergonomic interventions are not effective in eliminating the buildup of musculoskeletal discomfort.¹¹ A study conducted by Peper & Gibney⁹ show that 81% of the students adopted different techniques such as change in posture, rest breaks and stretching maneuvers to lessen discomfort buildup. Thus the practice of supplementary rest breaks and exercise breaks need to be promoted among the students, as it changes the loading pattern of different musculoskeletal structures and prevents buildup of discomfort.¹²

Conclusion

Risk factors for postural discomfort include posture and duration and type of computer used. Ergonomic awareness and gender are not associated with the buildup of musculoskeletal discomfort. Ideal posture to be adopted during computer use is supported sitting on a chair with computer on desk.

Limitations and Recommendations

The population parameter and thus the sample size were very small and only subjective measurement of discomfort was carried out.

Acknowledgement: We would like to acknowledge Dr. Alan Hedge and Cornell University for using "Student Specific Cornell Musculoskeletal Discomfort Questionnaire (ssCMDQ)"
Disclaimer: This manuscript is a part of a research conducted at Shifa Tameer-e-Millat University titled: "Postural deviations among allied health university students associated with computer / VDU use", and ethical approval was received from Institutional Review Board and Ethics Committee, Shifa International Hospital. (IRB # 536-3852015).
Conflict of Interest: None.
Funding Sources: None.

References

1.  Schlossberg EB, Morrow S, Llosa AE, Mamary E, Dietrich P, Rempel DM. Upper extremity pain and computer use among engineering graduate students. Am JInd Med. 2004; 46: 297-303.
2.  Laeser KL, Maxwell LE, Hedge A. The effect of computer workstation design on student posture. J Res Comput Educ 1998; 31:173-88.
3.  Katz JN, Amick BC, Carroll BB, Hollis C, Fossel AH, Coley CM. Prevalence of upper extremity musculoskeletal disorders in college students. Am J Med. 2000; 109: 586-8.
4.  Raosoft Sample Size Claculator. Raosoft Inc; 2004. (Online) [Cited 2016 January]; Available from URL: http://www.raosoft.com/samplesize.html.
5.  Shariat A, Tamrin, SBM, Arumugam M, Ramasamy R. The bahasa melayu version of cornell musculoskeletal discomfort questionnaire (CMDQ): reliability and validity study in Malaysia. Work. 2016; 54: 171-8.
6.  Ariëns GAM, Bongers PM, Douwes M, Miedema M, Hoogendoorn W, van der Wal G, et al. Are neck flexion, neck rotation, and sitting at work risk factors for neck pain? Results of a prospective cohort study. Occup Environ Med. 2001; 58: 200-7.
7.  Woo EH, White P, Lai CW. Musculoskeletal impact of the use of various types of electronic devices on university students in Hong Kong: An evaluation by means of self-reported questionnaire. Man Ther. 2016; 26: 47-53.
8.  Calik BB, Yagci N, Gursoy S, Zencir M. Upper extremities and spinal musculoskeletal disorders and risk factors in students using computers. Pak J Med Sci 2014; 30: 1361-66.
9.  Peper E, Gibney K, editors. Computer related symptoms: a major problem for college students. Proceedings of the 30th meeting of the Association for Applied Psychophysiology and Biofeedback. Appl Psychophysiol Biofeedback; 1999.
10.  Menéndez CC, Amick III BC, Jenkins M, Janowitz I, Rempel DM, Robertson M, et al. A multi-method study evaluating computing-related risk factors among college students. Work. 2007; 28: 287-97.
11.  Sauter SL, Schleifer LM, Knutson SJ. Work posture, workstation design, and musculoskeletal discomfort in a VDT data entry task. Hum Factors 1991; 33: 151-67.
12.  Osama M, Jan MB, Darain H. The effect of rest breaks as compared to exercise breaks in reducing musculoskeletal discomfort in static workstation office workers. Ann Allied Health Sci. [Randomized Controlled Trial]. 2015; 1: 44-8.