Bilateral back extensor exosuit (BBEX) for multidimensional force assistance and prevention of spinal overuse injuries during lifting

Lumbar spine injuries resulting from heavy or repetitive lifting remain a
prevalent concern in workplaces. Back-support devices have been developed
to mitigate these injuries by aiding workers during lifting tasks.
However, existing devices often fall short in providing multidimensional
force assistance for asymmetric lifting - an essential feature for
practical workplace use. Additionally, validation of device safety across
the entire human spine has been lacking. This paper introduces the
Bilateral Back Extensors Exosuit (BBEX), a robotic back-support device
designed to address both functionality and safety concerns. The design of
the BBEX draws inspiration from the anatomical characteristics of the
human spine and back extensor muscles. Employing a multi-degree-of-freedom
architecture and serially connected linear actuators, the device's
components are strategically arranged to closely mimic the biomechanics of
the human spine and back extensor muscles. To establish the efficacy and
safety of the BBEX, a series of human-subject experiments were conducted.
Eleven healthy male participants engaged in symmetric and asymmetric
lifting tasks while wearing the BBEX. The results confirm the ability of
the BBEX to preserve the natural range of motion of the back and to
provide effective multidimensional force assistance. Moreover,
comprehensive safety validation was achieved through analyses of muscle
fatigue in the upper and the lower erector spinae muscles, as well as
mechanical loading on spinal joints during both lifting scenarios. By
seamlessly integrating functionality inspired by human biomechanics with a
focus on safety, this study offers a promising solution to address the
persistent challenge of preventing lumbar spine injuries in demanding work
environments.