Evaluation of a passive exoskeleton for static upper limb activities.

Area of Science:

• Ergonomics
• Human Factors Engineering
• Biomechanics

Background:

• Overhead static tasks can lead to significant musculoskeletal strain.
• Exoskeletons are being developed to mitigate physical exertion in occupational settings.
• Evaluating the efficacy of passive upper body exoskeletons for reducing muscle load is crucial.

Purpose of the Study:

• To assess the impact of a passive upper body exoskeleton on muscle activity.
• To evaluate perceived musculoskeletal effort, pressure, and usability during a static overhead task.
• To determine the exoskeleton's effect on arm, trunk, and leg musculature.

Main Methods:

• Eight participants performed a 30-second static overhead task with and without an exoskeleton, holding 0 kg and 2 kg loads.
• Electromyography (EMG) measured muscle activity in the Biceps Brachii, Medial Deltoid, and trunk/leg muscles.
• Perceived effort, local pressure, and device usability were assessed using rating scales.

Main Results:

• The exoskeleton significantly reduced Biceps Brachii (49%) and Medial Deltoid (62%) muscle activity for the 2 kg load.
• Perceived arm effort decreased by 41% with the exoskeleton for the 2 kg load.
• No significant effects on trunk or leg muscle activity or perceived effort were observed; local pressure was low, and usability was rated acceptable by 50% of participants.

Conclusions:

• Passive upper body exoskeletons can effectively reduce muscle activity and perceived effort in the arms during static overhead tasks.
• The evaluated exoskeleton demonstrated no adverse effects on trunk or lower body musculature or comfort.
• Findings suggest potential ergonomic benefits of passive exoskeletons for specific occupational demands.