Saskia Baltrusch

86 Chapter 4 Abstract The objective of this study was to assess how wearing a passive trunk exoskeleton affects metabolic costs, movement strategy, and muscle activation during repetitive lifting and walking. We measured energy expenditure, kinematics, and muscle activity in 11 healthy men during 5 minutes of repetitive lifting and 5 minutes of walking with and without exoskeleton. Wearing the exoskeleton during lifting, metabolic costs decreased as much as 17%. In conjunction, participants tended to move through a smaller range of motion, reducing mechanical work generation. Walking with the exoskeleton, metabolic costs increased up to 17%. Participants walked somewhat slower with shortened steps, while abdominal muscle activity slightly increased when wearing the exoskeleton. Wearing an exoskeleton during lifting decreased metabolic costs and hence may reduce the development of fatigue and low back pain risk. During walking metabolic costs increased, stressing the need for a device that allows disengagement of support depending on activities performed.