Thank you for your mouse cold shoulder advice. With my extended keyboard I noticed I had a problem with positioning my mouse directly in front of my right side. However, I solved that problem immediately I started serious work because I have typed for years with my keyboard on my knees ( I’m a translator so I type all day). Years ago I experienced pain in my wrists with my hands held at what gradually became an excruciating unnatural angle of 90° or less to my body. My niece, a qualified and practising physiotherapist working in the NHS, once saw me working and I remember her look of approval at my keyboard on my knees.
I hope this recommendation of mine might be of use to others.
Jim Davis ~ July 2, 2019
Computer Posture comment: Thanks Jim for your useful comments. Some people find themselves in compromised environments and his suggestion is helpful for these. We still believe the best permanent workstation ergonomics involve appropriate height adjustable desks, chairs and monitors, compact keyboards and ergonomic mice. Jim’s suggestion would reduce tendon strain at the shoulder in compromised environments.