Construction of a Musculoskeletal Discomfort Scale for the Lower Limbs of Workers: An Analysis Using the Multigroup Item Response Theory

Musculoskeletal symptoms are a major occupational health problem in workers, and these can affect all professional occupations. Previous studies have proposed metrics capable of evaluating the musculoskeletal discomfort experienced by workers. However, no study has developed a metric that considers professional groups. Thus, this study aimed to develop a scale for musculoskeletal discomfort in the lower limbs to compare self-reported symptoms among education, health, and industry professionals. The sample included 159 teachers, 167 health professionals, and 401 industrial operators who relayed their symptoms using a diagram of the hips, thighs, knees, lower legs, and feet. Factor and multigroup item response theory analyses were used to construct a musculoskeletal discomfort scale consisting of seven levels and to assess and compare the identified symptoms. The results showed that the progressive evolution of discomfort differed for each profession, demonstrating that each context and work environment affects workers differently, which may explain the different patterns of symptom responses among professional groups.

Do men and women have different musculoskeletal symptoms at the same musculoskeletal discomfort level?

Owing to biological and social factors, illness-related musculoskeletal symptoms tend to vary between men and women. However, in the past, conceptualised discomfort metrics were applied uniformly to both genders. This study aimed to develop a scale to measure musculoskeletal discomfort that compares the symptoms between men and women. The scale aimed to determine the gender-based response patterns related to symptoms. A total of 707 men and 1302 women reported their symptoms on a body map. Factor analysis and item response theory were used to differentiate the identified symptoms in the construction of a musculoskeletal discomfort scale. Differences in work exposure appeared to explain the symptom patterns between men and women. The scale had eight levels, and it was found that at the same level of discomfort, men and women reported symptoms in different body regions.Practitioner summary: On this discomfort scale, the response patterns of men and women were categorised into eight levels. Symptoms differed by gender at the same musculoskeletal discomfort level. This is in contrast to previous studies in which scales were devised without considering differences between the genders.Abbreviations: WMSDs: work-related musculoskeletal disorders; BMI: body mass index; FA: factor analysis; IRT: item response theory; KMO: Kaiser-Meyer-Olkin; BST: Bartlett's test of sphericity; F: factor loading; h2: communality; α: Cronbach's alpha; ωt: McDonald's omega; ai: parameters of discrimination of the items; bik: parameters of difficulty of response categories; θj: latent trait; RMSEA: root mean square error of approximation; CFI: comparative fit index; TLI: Tucker-Lewis index; odu: musculoskeletal discomfort units; RA: rarely; OF: often; AL: always.

Evaluation of musculoskeletal discomfort using item response theory: creation of a scale based on the self-reported pain symptoms

This study aims to build a scale for musculoskeletal discomfort based on the self-reported musculoskeletal pain by individuals. For this, methods such as factorial analysis and item response theory were used. A sample of 1821 workers of a footwear industry participated in this study. The scale consists of four levels ranging from mild to maximum discomfort. In mild discomfort (level 60), pain symptoms are rare or frequent in regions such as cervical and trapezoidal area, low back, shoulders, wrists, ankles and feet. At level 70, rare or frequent symptoms affect regions of the upper and lower limbs. At level 80, frequent symptoms become common in the trunk and in most of the upper and lower limbs. At level 90, the symptoms become daily in elbows, thighs and knees. The scale showed signs of validity and proved useful for studies in ergonomics. Practitioner Summary: Methods such as factor analysis and item response theory were used to build a four-level musculoskeletal discomfort scale that can be useful to complement the screening process for workers with musculoskeletal pain. The scale shows signs of accuracy, in addition to validity and reliability. Abbreviations: WMSD: work-related musculoskeletal disorders; CTT: classic test theory; IRT: item response theory; KMO: Kaiser-Meyer-Olkin; PR: pain rarely; PO: pain often; PE: pain everyday; DIF: differential item functioning.

Effects of a worksite physical activities program among men and women: An interventional study in a footwear industry

The study aims to assess the association between various levels of engagement in a worksite physical activities program and variables related to musculoskeletal symptoms, psychophysiological well-being, difficulty to perform tasks, willingness to work, and interpersonal relationships, among men and women in a footwear industry. This program involved 1113 workers. Data were analysed using an ordinal logistic regression model. In women, an increase in the frequency of participation in the worksite physical activities program was associated with less musculoskeletal pain (OR = 3.12; 2.07-4.71), better relationships among colleagues (OR = 2.83; 1.67-4.81), and a higher level of psychophysiological well-being (OR = 1.98; 1.06-3.70). In men, an increase in the frequency participation in the worksite physical activities program was associated with less difficulty in performing occupational tasks (OR = 0.49; 0.27-0.87). Thus, the association between occupational exercises and studied variables differed between genders.