Shoulder kinematics during cyclic overhead work are affected by a passive arm support exoskeleton

Area of Science:

• Biomechanics
• Human-robot interaction
• Ergonomics

Background:

• Overhead cyclic tasks pose ergonomic risks.
• Arm-support exoskeletons (ASE) may mitigate these risks.
• Understanding ASE influence on upper arm movement is crucial.

Purpose of the Study:

• To evaluate the effect of passive arm-support exoskeleton (ASE) torque levels on upper arm osteokinematics.
• To analyze how different ASE torque settings influence joint angles and acceleration during overhead tasks.

Main Methods:

• Twenty participants performed a cyclic overhead drilling task.
• The study compared performance with and without ASE at 50%, 75%, and 100% torque.
• Upper arm osteokinematics, including joint angles and angular acceleration peaks, were measured.

Main Results:

• Increased ASE torque significantly decreased peak arm acceleration during both ascent and descent phases.
• Task duration remained consistent across all conditions.
• Higher torque levels resulted in increased arm flexion and internal rotation, with minor changes in abduction.

Conclusions:

• Passive arm-support exoskeletons effectively reduce arm acceleration during overhead cyclic tasks.
• The observed osteokinematic changes at maximum support levels do not preclude ASE use.
• This ASE is suitable for supporting overhead cyclic tasks, even at the highest torque settings.