  Occupational exoskeletons promise to alleviate musculoskeletal injuries among
industrial workers. Knowledge of the usability of the exoskeleton designs with
respect to the user device interaction points, and the problems in design
features, functions and parts, evaluated and rated using design principles is
still limited. Further, the usability of exoskeletons when assembling, donning,
doffing and disassembling them, tasks that can be considered pre and post use
tasks are also critical to evaluate, especially from a device design
standpoint. We conducted a heuristic evaluation of the usability of three
popular exoskeletons, a back support device, a shoulder support device, and a
sit stand exoskeleton when assembling, donning, doffing and disassembling them.
Seven evaluators used Nielsen and Shneiderman usability heuristics to evaluate
the devices. Results indicate that none of the three exoskeletons had any
catastrophic usability problems, but all three had major usability problems
including accommodating diverse users, the assembly, donning and doffing being
a two person operation, poor documentation, a lack of sequence indicators
during assembly of the devices, presence of safety hazards while donning and
doffing the devices, and manual strength requirements. Further, the assembly
task is the most difficult task resulting in the most violations of usability
heuristics. The exoskeleton human factors research community should include
diverse users in their evaluations and conduct usability, accessibility, and
safety evaluations of these devices to provide design feedback to device
designers.
