Clearly there are differences, but many of the same conditions apply, such as low pressure on the bones, so that it can still be useful in /most/ studies relate

Clearly there are differences, but many of the same conditions apply, such as low pressure on the bones, so that it can still be useful in /most/ studies related to microgravity. It's a little like using an animal to test medicine -- there are differences, but the initial work can often be completed because of the overwhelming similarities.