Analysis of Human Whole-Body Joint Torques During Overhead Work With a Passive Exoskeleton

Abstract

Overhead work is classified as one of the major risk factors for the onset of shoulder work-related musculoskeletal disorders and muscle fatigue. Upper-limb exoskeletons can be used to assist workers during the execution of industrial overhead tasks to prevent such disorders. Twelve novice participants have been equipped with inertial and force/torque sensors to simultaneously estimate the whole-body kinematics and the joint torques (i.e., internal articular stress) by means of a probabilistic estimator, while performing an overhead task with a pointing tool. An evaluation has been performed to analyze the effect at the whole-body level by considering the conditions of wearing and not-wearing PAEXO, a passive exoskeleton for upper-limb support during overhead work. Results point out that PAEXO provides a reduction of the whole-body joint effort across the experimental task blocks (from 66% to 86%). Moreover, the analysis along with five different body areas shows that 1) the exoskeleton provides support at the human shoulders by reducing the joint effort at the targeted limbs, and

Influence of the Physical Interface on the Quality of Human–Exoskeleton Interaction

“…Active exoskeletons are promising devices for multiple health and occupational applications and their potential benefits have been examined through numerous studies since the first models of exoskeletons were developed in the late 1960s. In particular, their potential benefits in terms of preventing musculoskeletal disorders [1], [2], [3], [4] and fatigue [5], [6] have been thoroughly investigated in the recent literature. However, exoskeletons are still significantly altering human motor control and these potential benefits are not yet fully achieved.…”

Upper limb modeling and motion extraction based on multi-space-fusion

“…The following simplifications were made in this study: SC is a rotary joint 47 , 60 with two DOFs rotating around the X - and Y -axes (the basal joint of the entire upper limb and serves as a mechanical support). GH is a ball joint 47 , 61 , 62 with three DOFs rotating around the X -, Y - , and Z -axes (the largest range of motion joint in the upper limb and greatly extending upper limb motion). EL is a rotary joint 47 , 62 with one DOF rotating around the Z -axes (the composite joint structure contributes significantly to the stability of forearm motion).…”

“… GH is a ball joint 47 , 61 , 62 with three DOFs rotating around the X -, Y - , and Z -axes (the largest range of motion joint in the upper limb and greatly extending upper limb motion). EL is a rotary joint 47 , 62 with one DOF rotating around the Z -axes (the composite joint structure contributes significantly to the stability of forearm motion). WR is a rotary joint 47 , 63 with two DOFs rotating around the X - and Z -axes (the composite joint structure contributes significantly to the sophisticated motions and stability of the palm).…”

Biomechanical Assessments of the Upper Limb for Determining Fatigue, Strain and Effort from the Laboratory to the Industrial Working Place: A Systematic Review

“…Another group of studies identified ergonomic interventions, such as new ergonomic workstations [ 243 ], tools [ 229 ] or training programs [ 239 ] that could be implemented in order to improve the working postures and reduce FSE. Other studies proposed exoskeletons or supporting devices in order to reduce the FSE, especially in prolonged posture maintenance and overhead working tasks [ 259 , 263 ] that require high loads on the neck, back and shoulder [ 261 ]. Another category included papers that design and validate alternative methods for assessing FSE during working activities, such as marker-less systems [ 286 , 306 ] or EMG measures [ 293 ].…”