First up, ensure you set the backdrop on, give it a distinct colour or better yet, create an inversed cube or sphere and give it a texture... with a pattern... create a plane for a floor, move the camera around and point it to your object, make your object/limb reflecting and see the magic
As soon as you set reflection shading on, if everything around the objects is two tone, you will just see through the object... try moving the camera around to get the reflection to change or better yet, rotate your object
[still moving the camera too..]
