Solution Summary: Wearable Devices for Monitoring Ergonomic Risks
Wearable devices for monitoring workers' biomechanical movements to alert them of ergonomic risks via simulated sensations of motion that would be felt by a user interacting directly with physical objects (haptic feedback). Additionally, its real-time monitoring Bluetooth-connected platform offers other features.
Manual material handling risks can be reduced on construction jobsites by an innovative administrative control: wearable devices monitoring workers' physiological movements and providing haptic (vibrational and auditory) feedback for ergonomic risks. The devices provide real-time feedback to workers helping correct mechanics in the moment and collect important data from each user to help provide insight into the risk present at a work site.
SafeWork System & Flex Wearable Sensors by StrongArm Technologies, Inc.
Devices for monitoring physiological movements, such as Flex sensors (figure 1) which are part of the SafeWork System by StrongArm Technologies, Inc., could be worn on the hip (figure 2) or in a harness (figure 3) to monitor ergonomic movements. Each sensor can provide up to 48 hours of operating life when fully charged. Data collected from the sensor is loaded into the cloud-based SafeWork Dashboard for comprehensive safety insight allowing for opportunities to engineer risk out of your operation. Access data for time of day, various job functions, individual safety performance and more in one easy to use interface.
Figure 1. FUSE sensor device for the SafeWork System (Photo courtesy of StrongArm Technologies, Inc.)
Figure 2. Hip Clip for the SafeWork System. (Photo courtesy of StrongArm Technologies, Inc.)
Figure 3. X-Pack for the SafeWork System. (Photo courtesy of StrongArm Technologies, Inc.)
The algorithm programmed into the sensors is based on the Ergonomic Risk Model by Dr. William S Marras of Ohio State University. It uses biotelemetric movement data collected at 125 data points per second to develop a proprietary “Safety Score” that corresponds with the ergonomic safety. This "Safety Score" uses 5 key trunk motions to measure the dynamic nature of movements: Forward Bend (Flexion), Tilt Speed (Lateral Velocity), Twist Speed (Twist Velocity), Lift Rate, and Maximum Moment.
When an ergonomic risk is detected, the device delivers haptic feedback in the form of auditory or vibrational alerts (figure 4).
Figure 4. Measurements of trunk motions to calculate a “Safety Score” for haptic feedback when necessary. (Photo courtesy of StrongArm Technologies, Inc.)
While FUSE sensors can be operated independently, they can also transmit data via Bluetooth to network beacons placed throughout the jobsite, to provide data on positional and environmental risk factors. This data is then processed and displayed onto a cloud-based connected platform (FUSE Management Platform) in real-time to provide continuous insights for injury risks. To learn more about the other safety features, please visit the link on the right.
Heavy lifting or pulling can result in musculoskeletal disorders (MSDs) of the back and shoulders. Heavy lifting is considered 90 lb or more. Repetitive lifting is considered 55 lb or more lifted greater than 10 times per day (Spielholz, 2006). Low back MSDs include disc herniation, which occurs when excessive loads are placed on the spine. Overworking the muscles can also result in back or shoulder strains. Use of wearable devices in monitoring physiological movements may reduce the risk of disc herniation, muscle strains, and other MSDs associated with lifting and pulling.
How Risks are Reduced:
The risk for MSDs can be reduced by alerting workers when their movements are leading to ergonomic risks. The auditory or vibrational alerts allow workers to correct any poor ergonomic behaviors before they lead to permanent musculoskeletal disorders.
As is the case with any construction tool and equipment, users should follow manufacturer safety recommendations and comply with any applicable local, state or federal regulations.
Jean Christophe Le, MPH - CPWR The Center for Construction Research and Training