One of the biggest myths about people with disabilities is that they are not sexually desirable or that they’re not sexual beings. Not true. All humans are sexual.
Lesbians who are disabled or chronically ill may have to make some adaptations in order to have sex. They might need to take breaks to rest. For someone with arthritis or carpal tunnel stimulating your partner digitally may be difficult, but they might be able to hold a sex toy that can give the same pleasure.
Some lesbians might use pillows to prop themselves up and give support where they need it. Someone with heart disease may need to watch her excursion level and take breaks from time to time. A woman in a wheelchair may need help getting into bed, but once she is there, she needs no help getting her partner off.
Are you are your partner disabled? Share your stories. What accommodations, if any, have you made to enjoy sex?
Corey Silverberg, About.com's Sexuality Guide has some great resources about sex and disability.

