I do not have physical handicaps - however, an ex of mine has CP, and she and I had the opportunity to participate in a panel about sexuality and disabilities. The panelists with disabilities included another woman with CP, a man who'd been partially paralyzed in a skiing accident, and another man paralized from the neck down due to a gang-related shooting. All of them were there with their partners. The panel was presented for college students, and they had the predictable questions: Can you get it up? Can you get aroused? How can you enjoy sex if you can't feel anything? HOW do you do it? It was absolutely fascinating to listen to the panelists' responses and for my gf and I to share our own.
Long story short? People with disabilities can have wonderfully fulfilling sex lives. Shocker, I know! If your body doesn't move as freely as others, work with your partner to find ways around it. Loss of sensation may limit the enjoyment of being whipped, say, just as paralysis can make it impossible to DO the whipping. The simple trick is to be creative. Exploit the mental elements of BDSM and participate in the physical elements to the best of your ability. Dominate your sub through verbal commands if you have difficulty with physical activity. Adapt your submissive behavior to what your body is able to do. If someone tells you that you can't do something you know you can do, wish them well, sigh at their ignorance, and move on.
Call BDSM clubs ahead of time to ask whether they are handicap-accessible (particularly if you use a wheelchair or other movement aids). Make a point of smiling, being friendly, and initiating conversations - sometimes the very person who's afraid to talk to you because they don't want to cause offense will turn out to be the person that opens up readily when they see that you're genuine. There aren't many people already familiar with folks with disabilities, and while it's not your job to be The Embassador For The Disabled, you can still present yourself in a way that lets people respond positively. Become a regular attendee at clubs or munches, if you have the time and transportation. Have a good time and let people see that you're enjoying yourself. These ways of building connections and friendships work for everyone!