I came across this ergonomics video produced in the UK. It's a bit dated but does cover the fundamentals of ergonomic design in several situations. At the 11:30 point there is a discussion about proper ergonomic design of can openers.
Robb Godshaw and Instructables Developer Will Doenlen designed and constructed the Hamster Wheel Workstation at San Francisco based Pier 9.
There are a couple of nice features with this station. If it is combined with a 72inch wide height adjustable platform the worker can transition to standing or sitting position by moving to the side and pulling up a chair. Also the wheel does not require electricity and would use less energy than a treadmill. The hamster wheel could also be set up to generate electricity.
24 hour project for hamster wheel workstation - less than 1 minute
For those of you on a limited budget, combining a New Balance stepper
with a height adjustable workstation will provide a similar workout.