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.)

Risk Mapping

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.

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