A Hip Active Assisted Exoskeleton That Assists the Semi-Squat Lifting

Abstract

(1) Background: In the case of quick picking and heavy lifting, the carrying action results in a much more active myoelectric signal in the lower back than in an upright stationary one, and there is a high risk of back muscle injury without proper handling skills and equipment. (2) Methods: To reduce the risk of LBP during manual handing tasks, a hip active exoskeleton is designed to assist human manual lifting. A power control method is introduced into the control loop in the process of assisting human transportation. The power curve imitates the semi-squat movement of the human body as the output power of the hip joint. (3) Results: According to the test, the torque can be output according to the wearer’s movement. During the semi-squat lifting process, the EMG (electromyogram) signal of the vertical spine at L5/S1 was reduced by 30–48% and the metabolic cost of energy was reduced by 18% compared the situation of without EXO. (4) Conclusion: The exoskeleton joint output torque can change in an adaptive manner according to the angular velocity of the wearer’s joint. The exoskeleton can assist the waist muscles and the hip joint in the case of the reciprocating semi-squat lifting movement.

The Effects of Upper-Body Exoskeletons on Human Metabolic Cost and Thermal Response during Work Tasks—A Systematic Review

“…Table 1 shows an overview of the main characteristics of the nine considered studies [ 26 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ], following the PICO model and highlighting the type of exoskeleton used. All the articles that met the eligibility criteria are very recent—eight were published between 2019 and 2020 and one, the oldest, in 2014.…”

“…All the studies were carried out in the laboratory. Most of them (six out of nine, [ 38 , 40 , 41 , 42 , 44 , 45 ]), chose a repetitive lifting task to be performed in the experimental trial, two out of nine [ 26 , 39 ] selected an overhead working task and one considered a static holding posture of the trunk [ 43 ]. All the studies were based on the comparison between the “with exoskeleton condition (WEC)” and “without exoskeleton condition (WOEC)”.…”

“…In total, eight different UBEs were investigated: seven BSEs [ 38 , 40 , 41 , 42 , 43 , 44 , 45 ] and one ULSE [ 26 , 39 ]. Among them, seven were passive assistive devices and one [ 45 ] was an active device.…”

“…Seven studies [ 26 , 40 , 41 , 42 , 43 , 44 , 45 ] had a moderate risk of bias due to confounding, since they recruited only male subjects. Considering that the subjects performing trials in WEC and in WOEC were the same and given the nature of the experimental setup, the authors assigned to all studies a low risk of bias due to the selection of participants, classification of the interventions, deviation from the intended interventions, missing data and measurements of outcomes.…”

“…All the studies, in fact, carried out measurements. Four of them [ 38 , 40 , 42 , 45 ] provided results in terms of the energy expenditure rate (EER) or M . This implies that they also collected, as they stated, data on the carbon dioxide production rate ( ).…”