Date Presented 04/05/19
A longitudinal multicohort study was conducted to evaluate the impact of task training on upper-extremity musculoskeletal discomfort in health professional students. Differential effects on pain and grip strength were noted in dental hygiene students as compared to OT students. This study validates that repetitive task training has a negative impact on health and illuminates a need for development and implementation of preventive interventions for dental hygiene students.
Primary Author and Speaker: Shawn Roll
Contributing Authors: Naoko Kono, Jane Forrest, Wendy Mack
PURPOSE: Nearly 70% of dental hygienists report experiencing discomfort in their upper extremities at some point during their career (Åkesson, Balogh, & Hansson, 2012); conditions that have been attributed to static postures and repetitive hand motions required to complete dental scaling tasks (Dong, Loomer, Villanueva, & Rempel, 2007; La Delfa, Grondin, Cox, Potvin, & Howarth, 2016). Although prevalence has been well-established in retrospective and cross-sectional data collection, prospective examination of the epidemiologic progression of disorders has not been conducted. The purpose of this study was to investigate the early development of upper extremity musculoskeletal disorders in dental hygienists at the outset of training to inform a model for evaluating risk factors and identifying need for preventive interventions.
DESIGN: A longitudinal, multi-cohort study with repeated measures was conducted. Dental hygiene (DH) and occupational therapy (OT) students were simultaneously recruited to serve as an exposed, study cohort and non-exposed, control cohort. Students were selected for this study due to the minimal retrospective and controlled prospective exposure to work-related tasks, which provided a clean detection framework to track changes in symptoms related to task exposure. Individuals with previous history of upper extremity trauma or peripheral nerve injury were excluded.
METHODS: Data were obtained from at the outset of training (baseline) and at the end of the first and second year, which included provocative tests for carpal tunnel syndrome, grip/pinch strength, self-rated pain in the neck, shoulder, hand, and wrist using a visual analogue scale (VAS), and symptom/function ratings on the Boston Carpal Tunnel Questionnaire (BCTQ). All measures were compared between the two groups at baseline using t-tests, and at each follow-up timepoint using Wilcoxon signed-rank tests due to non-normal distribution of data. Group comparisons for provocative test results were conducted using Fishers exact test.
RESULTS: 104 participants were enrolled, of which 100 completed all data collection (i.e., 47 DH, 53 OT). No significant differences were noted between the groups at baseline, and no differences were noted in provocative tests or BCTQ scores at 2-years. There was no change in the frequency of OT students reporting pain, nor was there any change in pain severity in any region. In contrast, DH students had significantly higher and increased frequency of pain in the neck, shoulder, wrist, and hand from baseline to 2-years, with greatest increases noted in the dominant hand (i.e., 16.7% to 42.6%). DH students also reported significantly greater increases in pain severity across all regions, with average pain increasing by approximately 1 point in most regions. A significant decrease in grip strength (-1.7kg, SE=0.4) was also noted in the DH group.
CONCLUSION: DH and OT students are similar at entry to their respective educational training – both groups presenting as healthy individuals with minimal symptoms and full function. Significant increases in the prevalence and severity of upper extremity discomfort, along with decreased grip strength in DH students may be due to highly repetitive, hand-specific task training components of the educational program.
IMPACT: By validating that repetitive, task training has a negative impact on health, this study provides a preliminary foundation upon which the exposure-response relationship and risk factors in early development of upper extremity disorders in hygienists can be explored. Moreover, the study illuminates a need for development and implementation of preventive interventions in DH students to reduce early contributions to the development of work-related musculoskeletal injuries.
References
Åkesson, I., Balogh, I., & Hansson, G. Å. (2012). Physical workload in neck, shoulders and wrists/hands in dental hygienists during a work-day. Applied Ergonomics, 43(4), 803–811. doi:10.1016/j.apergo.2011.12.001
Dong, H., Loomer, P., Villanueva, A., & Rempel, D. (2007). Pinch forces and instrument tip forces during periodontal scaling. Journal of Periodontology, 78(1), 97–103. doi:10.1902/jop.2007.060171
La Delfa, N. J., Grondin, D. E., Cox, J., Potvin, J. R., & Howarth, S. J. (2016). The biomechanical demands of manual scaling on the shoulders & neck of dental hygienists. Ergonomics, 1–11. doi:10.1080/00140139.2016.1171402
