Background: A colonoscopy is a medical procedure that uses an endoscope to assess the colon for abnormalities. It has been established in the literature that performing this procedure frequently is associated with operator musculoskeletal injury of the distal upper extremity. However, it is less understood whether this procedure contributes to pain and injury of the low back, an exceedingly common workplace injury that often results in time off.
Objectives: To investigate the effects of patient posture (left lateral decubitus [LL, right lateral decubitus [RL], and supine) on biomechanical and psychological outcome measures (muscle activity, perceived pain, exertion, and posture) in endoscopists during a simulated colonoscopy.
Methods: Eighteen practicing endoscopists performed three 10-minute trials of a simulated colonoscopy with varying patient positions: LL, RL, and supine. Surface electromyography (sEMG) sensors recorded muscle activity, and an ergonomic assessment tool assessed posture and injury risk. Perceived exertion and discomfort were measured before and after each trial using the BORG-CR10 and Visual Analog Scales. Descriptive statistics, Shapiro-Wilk tests, and one-way repeated measures ANOVA were used to analyze normally distributed data. Nonparametric data were assessed using the Wilcoxon signed-rank test. Tukey's post hoc tests were used where necessary, and Pearson correlations examined trends in height, weight, and BMI. Significance was accepted at p < 0.05.
Results: This study found that patient position did not result in significant differences in muscle activity, perceived discomfort, or perceived exertion during a short exposure to simulated colonoscopy. Specifically, average muscle activity levels across positions were low and not significantly different (F(2, 32) = 3.415, p = 0.068, η² = 0.176). Perceived discomfort and exertion showed similar patterns with no significant differences observed (discomfort: F(2, 32) = 2.686, p = 0.110, η² = 0.144; exertion: F(2, 34) = 1.045, p = 0.342). However, Rapid Upper Limb Assessment scores indicated a significantly lower ergonomic risk in LL position compared to the RL and supine positions (LL vs. RL: median 4 vs. 6.5, p < 0.03; LL vs. supine: median 4 vs. 6, p < 0.03). While no significant differences were found in muscle activity or perceived discomfort, ergonomic assessment scores suggest that all positions have elevated injury risk, particularly if exposures would be prolonged. Future research should examine longer durations and real-world scenarios to better understand the impact of patient positioning on injury risk.
Limitations: This study faced several limitations. The sample size was small, with only 18 participants who were predominantly right-handed, healthy, and of Caucasian ethnicity, limiting generalizability. The study used a high-fidelity simulation with a dummy patient, which may have reduced the procedural challenge and variability. Additionally, participant bias could have influenced subjective reports of strain, as more experienced endoscopists may have perceived the procedure differently. Future research should involve larger, more diverse samples and real-world settings inclusive of full workloads to address these limitations and provide more comprehensive insights into the impact of patient position on musculoskeletal demands.
Conclusion: In conclusion, this study finds that patient position does not significantly affect muscle activity or perceived pain and exertion scores during a short exposure to simulated colonoscopy. As such, endoscopists may not need to adjust patient positioning to mitigate musculoskeletal strain in brief procedures. Future research should investigate the impact of longer procedure durations and real-world settings to further explore factors that may influence injury risk.