Self-reported workplace related ergonomic conditions as prognostic factors for musculoskeletal symptoms: the "BIT" follow up study on office workers.
OBJECTIVE
To identify prognostic ergonomic and work technique factors for musculoskeletal symptoms among office workers and in a subgroup with highly monotonous repetitive computer work.


METHODS
A baseline questionnaire was delivered to 5033 office workers in 11 Danish companies in the first months of 1999, and a follow up questionnaire was mailed in the last months of 2000 to 3361 respondents. A subgroup with highly monotonous repetitive computer work was formed including those that were repeating the same movements and/or tasks for at least 75% of the work time. The questionnaire contained questions on ergonomic factors and factors related to work technique. The outcome variables were based on the frequency of musculoskeletal symptoms during the last 12 months. Logistic regression analyses were used to identify prognostic factors for symptoms in the three body regions.


RESULTS
In total, 39%, 47%, and 51% of the symptomatic subjects had a reduced frequency of symptom days in the neck/shoulder, low back, or elbow/hand region, respectively. In all regions more men than women had reduced symptoms. In the multivariate logistic regression analyses, working no more than 75% of the work time with the computer was a prognostic factor for musculoskeletal symptoms in the neck/shoulder and elbow/hand, and a high influence on the speed of work was a prognostic factor for symptoms in the low back. In the subgroup with highly monotonous repetitive computer work, the odds ratios of the prognostic factors were similar to those for the whole group of office workers.


CONCLUSIONS
When organising computer work it is important to allow for physical variation with other work tasks, thereby avoiding working with the computer during all the work time, and further to consider the worker's own influence on the speed of work.
Juul-Kristensen
B
B
National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. bjk@ami.dk
Jensen
C
C
D000293:Adolescent; D000328:Adult; D016288:Computer Terminals; D012090:Cumulative Trauma Disorders / Q000209:etiology / Q000517:prevention & control; D004550:Elbow; D006804:Ergonomics / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006225:Hand; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000209:etiology / Q000517:prevention & control*; D009784:Occupational Diseases / Q000209:etiology / Q000517:prevention & control*; D016017:Odds Ratio; D011187:Posture; D011379:Prognosis; D012307:Risk Factors; D020069:Shoulder Pain / Q000209:etiology / Q000517:prevention & control
Ergonomics. 1997 Aug;40(8):834-48
9336107
Scand J Work Environ Health. 2002 Feb;28(1):18-24
11871848
Scand J Work Environ Health. 2003 Jun;29(3):197-205
12828389
Spine (Phila Pa 1976). 2001 Aug 15;26(16):1788-92; discussion 1792-3
11493851
Occup Environ Med. 2003 Sep;60(9):649-54
12937185
Scand J Rehabil Med. 1983;15(2):81-8
6223366
Spine (Phila Pa 1976). 1981 Jan-Feb;6(1):93-7
7209680
Scand J Public Health. 2000 Sep;28(3):230-9
11045756
Occup Med. 1999 Jan-Mar;14(1):17-38, iii
9950008
Ergonomics. 1994 Oct;37(10):1623-48
7957019
Am J Ind Med. 1997 Dec;32(6):620-8
9358919
Rheumatol Rehabil. 1975 Aug;14(3):129-43
125914
Pain. 2000 Jun;86(3):305-10
10812260
Scand J Work Environ Health. 2003 Apr;29(2):106-16
12718496
J Occup Environ Med. 2000 Aug;42(8):783-91
10953815
Appl Ergon. 1986 Sep;17(3):162-8
15676580
Am J Ind Med. 1996 Feb;29(2):161-70
8821359
Ergonomics. 1997 Nov;40(11):1255-68
9375538
Appl Ergon. 2001 Dec;32(6):559-71
11703042
Appl Ergon. 1998 Oct;29(5):335-54
9703348
Appl Ergon. 1987 Sep;18(3):233-7
15676628
AIHAJ. 2000 Mar-Apr;61(2):223-30
10782194
J Occup Environ Med. 2000 Aug;42(8):792-7
10953816
Am J Ind Med. 2002 Apr;41(4):236-49
11920967
Int J Occup Saf Ergon. 2001;7(1):103-16
11276268
Scand J Work Environ Health. 2004 Oct;30(5):390-8
15529802
Scand J Work Environ Health. 1993 Aug;19(4):277-83
8235517
Ergonomics. 2004 Feb 5;47(2):119-33
14660208
Ergonomics. 1999 Apr;42(4):535-49
10204419