The role of circadian rhythm stability and amplitude in musculoskeletal disorder prevalence and work-family conflict

Clinical physiology of circadian rhythms: A systematic and hierarchized content analysis of circadian questionnaires

Circadian rhythms are near-24 h patterns of physiology and behavior associated with several physical and mental health outcomes. Self-report questionnaires are routinely used and practical tools to assess circadian rhythms. However, the extent to which these questionnaires capture the relevant parameters and can be used interchangeably is unknown. We investigated different types of circadian manifestations using 14 circadian self-report questionnaires for adults. A systematic and hierarchical content analysis was combined with a visualization method. Jaccard indices were calculated to quantify the degree to which the questionnaires overlapped. Content analysis revealed 40 distinct manifestations, which we classified into five dimensions ("circadian phase," "circadian amplitude and stability," "nycthemeral timing," "nycthemeral regularity," and "circadian complaints"). The average Jaccard index was 0.150, indicating very weak content overlap. None of the 14 questionnaires explored all five dimensions. The Composite Scale of Morningness and the Morningness-Eveningness Questionnaire exhibited greater, but still limited, overlap with the other questionnaires (Jaccard indices of 0.255 and 0.251, respectively), and are the best instruments for assessing the circadian phase. Nycthemeral timing, which must be analyzed to measure the circadian misalignment in clinical and research settings, is only explored by the Munich Chronotype Questionnaire, but that instrument does not evaluate circadian amplitude and stability and only partially assesses nycthemeral regularity. Based on our preliminary analysis, we make recommendations regarding the circumstances in which some circadian questionnaires could prove more useful than the others. The results might also aid the definition and investigation of circadian health at the crossroads of physiology and behavior.

The role of circadian rhythm stability and amplitude in musculoskeletal disorder prevalence and work-family conflict

Aim

This study aimed to investigate the effect of circadian rhythm stability and amplitude on musculoskeletal disorder prevalence and work–family conflict among nurses.

Design

This cross‐sectional study was conducted on 386 nurses working in three hospitals, in Shahroud, Iran.

Method

The data were collected using the Circadian Rhythm Inventory, Nordic Musculoskeletal Disorders, and Carlson Work‐Family Conflict questionnaires.

Results

The highest prevalence of musculoskeletal disorders was reported in the lower back (68.4%), upper back (65.5%) and shoulders (53.6%), respectively. No significant relation was found between circadian rhythm stability and amplitude, and musculoskeletal disorders prevalence. The nurses who could not overcome drowsiness reported more Work Interference with Family (WIF), Family Interference with Work (FIW) (time‐based) and FIW (strain‐based) compared to the nurses who overcame drowsiness. In addition, the appropriate nurses for shift work experienced less WIF, FIW (behavioural‐based) and WIF (strain‐based) compared to the nurses who could not work overtime or at night.

Prevalence of musculoskeletal discomfort among female cabin crew in Taiwan

OBJECTIVES

This study investigated the prevalence of musculoskeletal discomfort among female cabin crew through cabin tasks and demographic factors, including age and seniority.

METHODS

This study conducted an online questionnaire survey targeted at female cabin crew in Taiwan and ensured that the sample size was with a statistical power of 0.95. This study evaluated the work intensity by ranking six common cabin tasks and examined musculoskeletal discomfort with Cornell Musculoskeletal Discomfort Questionnaire. Descriptive statistics were used to learn the work intensity and discomfort conditions. In addition, the Chi-square test of independence and multivariate adjustment were applied to clarify the impact of age and occupation on musculoskeletal discomfort in the neck, shoulders, and lower back.

RESULTS

This study enrolled 88 female cabin crew members. Handling carry-on baggage was voted as the highest intensity cabin task (40%), which was also ranked as the strongest intensity on shoulders. Meanwhile, the upper trunk was more prevalent in musculoskeletal discomfort. Moreover, after multivariate adjustment with controlling the effect of age, this study found a marginal significant association (p = .09) between seniority and right shoulder discomfort for younger staff.

CONCLUSION

This study found that handling carry-on baggage was associated with musculoskeletal complaints in the shoulders. Therefore, this study suggested that shoulders, especially for the right side might be related to the occupational injury, which was prevalent along with seniority among the younger crew. Overall, this study provided the preliminary findings to improve occupational training for preventive health.