First let me congratulate you on taking up PhD in ergonomics. From which university you are doing. To which country you belong. There are many factors which have their implications on office productivity. May be i shall give you some inputs after knowing details from you.
How did you decide on the topic? You must have done some literature review and formulated some objectives. Please tell us your objectives, and who would be your study groups? Also, a bit of clarity is required on "ergonomic implications".