How much getting involved in the ‘doing’ of the project is acceptable? I tend to work on the Path of Least Resistance. I don’t code and I’m no Graphic Designer but I can produce mock ups, write copy, review work and test.
There are certain tasks in a Project that could add significant delay to the production of a good product that are being pushed to the back of the queue because of more pressing concerns. Basic Mock ups and wireframes are easy to produce and take little time, basic site copy is easy to add and testing processes can take up time but be productive, it will also make you far more intimate with the system that you are Project Managing.
By taking simple yet significant jobs that are not being done due to time constraints you can certainly help the team achieve a greater burn down over a sprint.
The team will see you not only removing blockers within the business to help them move forwards but also some of the more technical tasks.