PURPOSE/OBJECTIVES: This study examined the relationship between environmental factors (e.g., working position, patient position, and scaling instruments) and poor posture in dental hygiene students.

METHODS

A longitudinal cohort study was conducted from 2017 to 2019 to observe dental hygiene students' clinical rotation performance at two undergraduate universities. Samples of video observations (n = 1487) of dental hygiene students performing scaling activities during oral care sessions were evaluated using the Rapid Upper Limb Assessment (RULA). Descriptive analysis and exploratory prediction modeling were performed to assess clinical environmental factors that predicted higher risks of developing WMSDs.

RESULTS

RULA scores (mean = 4.8, median = 5, range = 2-7) indicate dental hygiene students are at high risk of developing upper extremity MSDs. The type of scaling instrument, clock positioning relative to the patient, and sitting versus standing had statistically significant associations (p < 0.001) with the RULA outcome. In univariate analyses, clock positions 7 and 8 were the worst, having an increased risk of poor RULA outcomes (scores 5-7) by nearly nine times over working in clock position 12 (odds ratio [OR] 9.11, 95% CI 5.48-15.60). Multivariate predictive modeling indicated that the riskiest combination of factors is using a manual scaling instrument (OR 1.67, 95% CI 1.28-2.18), standing (OR 1.42, 95% CI 1.03-1.96), and working clock positions 7 and 8 (OR 8.4, 95% CI 5.02-14.50).

CONCLUSIONS

There is a need to consider the combined contribution of multiple environmental factors on working positions to optimize ergonomic training during dental hygiene and protect emerging dental health professionals from the negative health impacts of prolonged awkward postures.