The efficacy and incorporation of biofeedback in medical professionals’ ergonomic awareness
Creators: name: Tuken, Demir
Publisher: name: University of Iowa
Year: 2024
Subjects: Wearable Sensors
Biofeedback
Biomechanics
Ergonomics

description: Introduction: Healthcare workers, primarily those in the surgical field and dentistry, have a high risk of developing musculoskeletal disorders (MSD) due to maintaining prolonged awk- ward or unsafe postures induced by environmental working conditions that have generated few new worker safety regulations throughout the decades. The associated chronic, debilitating pain significantly impacts their careers and lives, and it frequently leads to early retirement and, ergo, a critical loss of talent and productivity that required years of expensive training to obtain. Previous work has provided a wealth of subjective data, which indicates a certain level of negation of the prevalence and impact of these medical conditions. Although a problem has been identified, an ob- jective, quantifiable method of determining the key factors contributing toward injury or tracking improvements resulting from interventions is missing. This thesis provides an in depth approach to developing a wearable sensor based system that acquires muscle activation and spinal orientation and use the acquired data to employee haptic biofeedback. To accomplish this goal a two separate research studies were conducted. The purpose of the first study was to evaluate if the wearable sensors, inertial measurement units (IMUs) and surface electromyography (EMG) sensors, can quantify differences in spine orientations and muscle activity, respectively, for different postures that were constrained with haptic biofeedback. The purpose of the second study was to implement a novel haptic real-time biofeedback system with the usage of IMU and EMG data guidance to train dental students to develop more mechanically advantageous working postures.Methods: For the feasability study, 35 healthy adults were recuited to complete simple typ- ing tasks. For each participant, five postural test conditions distributed in a randomized order were conducted. Each condition had 6 trials, 3 with haptic biofeedback and 3 without biofeedback. Muscle activation from shoulder muscles [left descending trapezius (LT), right descending trapez- ius (RT), left infraspinatus (LI), and right infraspinatus (RI)] were collected using surface EMGs. Posture analysis for the back and neck was conducted using lightweight, wireless IMUs (SageMo- tion). The IMUs also include vibrotactile motors capable of providing haptic biofeedback. The average normalized moving RMS for each muscle was evaluated for each condition and compares to the neutral average normalised moving RMS. Orientation differences between trials with and without feedback were compared for the average angle deviation from desired test condition. For the dental ergnomic study, 4 participants were recruited to complete 6 cast metal crown procedures. Each participant completed 3 trials with biofeedback and 3 without biofeedback. Muscle activa- tion from the LT, RT, right lower erector spinae ( RLES) and left lower erector spinae (LERS) were collected via EMG. Posture analysis was carried out the same way as the feasibility study. EMG analysis was the same as the feasibility study. No postural conditions were imposed so orientation analysis assessed average angle per trial.
description: Results: Study one used a linear mixed effects regression model to assess muscle activy, orietnation, and cognition. There were significant changes in muscle activity across the LT, LI, and RI with biofeedback (p &lt; 0.05). There were significant changes in both head and back angles with and without biofeedback (p &lt; 0.05). Biofeedback induced a signifcant decrease in average words per minute compared to trials without biofeedback (p&lt;0.05). For the dental ergnomics study there were significant decreases in muscle acticity for the LT and the RLES with biofeedback (p &lt;0.05). Furthermore, there was a signifcant increase in muscle activity in the LT for trials without biofeedback (p&lt;0.05). The back angle without biofeedback prodcued significant increases in average angle compared to trials without biofeedback. When assessing individual distribution of muscle activity there was a shift in muscle activity to lower head and back angles for trials with biofeedback in participants one and two.
description: Discussion: Both studies aid in providing quantitative sensor-based data for improved un- derstanding of the relationships between biomechanical variables on the development of MSDs. The feasibility study showed that using IMUs and sEMG sensors in combination is a viable ap- proach for detecting postural conditions and the muscle activation effects of maintaining those conditions. The dental ergnomic study suggests that biofeedback can induce a significant decrease in muscle activity, while the absence of biofeedback leads to a significant increase in average back angles throughout a standard dental procedure. The results from both studies suggest that biofeed- back is a viable option as a preventative measure as well as for ergonomic training within dentistry.