Pull-ups can be done just about anywhere. They are great for preventing shoulder injuries and are very functional. Thus, it's no wonder why the military and many top MMA athletes include pull-ups on a regular basis in their training. The really fun part is that they can be performed in a bunch of challenging and different ways.
1. If you can not handle your own bodyweight, place a chair behind you to put your feet on. This will reduce the weight load.
2. To avoid shoulder injury, never have your hands wider than shoulder width.
3. Vary your grips often to increase different muscles activated