A pilot study to precisely quantify forces applied by sonographers while scanning: A step toward reducing ergonomic injury.

BACKGROUND There is a significantly high rate of work-related musculsokeletal injuries in sonography professionals. To date, assessment of risk factors for work- related injuries in sonographers has been based primarily on surveys, subjective reports, and observational methods. There is a need to develop quantitative techniques to better understand risk factors and develop preventive interventions. OBJECTIVE We pilot tested a high-resolution force-measuring probe capable of precisely measuring forces applied through the transducer by sonographers and used this novel direct measurement technique to evaluate forces during abdominal imaging. METHODS Twelve sonographers with varied experience, ranging from 1-33 years, performed routine abdominal scans on 10 healthy volunteers who had varied body mass indices (BMI). Imaging was conducted using the force-measuring probe, which provided real-time measurement of forces, and angles. Data were compared by sonographer years of experience and subject BMI. RESULTS In total, 47 abdominal examinations were performed as part of this study, and all images met standards for clinical diagnostic quality. The mean contact force applied across all exams was 8.2±4.3 Newtons (N) (range: 1.2-36.5 N). For subjects in the high BMI group (BMI>25, n = 4) the mean force was 10.5 N (range: 8.9-13.2 N) compared to 7.9 N (range: 5.9-10.9 N) for subjects with normal BMI (BMI = 18.5-25, n = 6). Similarly, the mean maximum force applied for subjects with high BMI (25.3 N) was significantly higher than force applied for subjects with normal BMI (17.4 N). No significant difference was noted in the amount of force applied by sonographers with more than 5 years of experience (n = 6) at 8.2 N (Range: 5.1-10.0 N) compared to less experienced sonographers (n = 6), whose forces averaged 8.1 N (Range: 5.8-10.0 N). CONCLUSIONS It is feasible to directly measure forces applied by sonographers using a high-resolution force measurement system. Forces applied during abdominal imaging vary widely, are significantly higher when scanning subjects with high BMI, and are not related to sonographer years of experience. This force measurement system has the potential to provide an additional quantitative data point to explore the impact of applied forces on sonographer related musculoskeletal injury, particularly in conjunction with various body positions, exam types and force durations.