there is enough information out there about exercises which are ideal for stimulating bone density, and a google search will give you many options. It would be great if clients could do loaded exercises for the whole body, even dynamic, which have been found to be the best.
What I am finding, though, is that clients who present with osteopenia often have other issues as well which require a more cautious exercise approach. I tend to deal with that client as I would with everybody else; I start with an assessment. More often than not, we have to do foundational exercises which are often corrective in nature.