To dream of a wheelchair represents emotional or psychological dependency. Something you think you need or feel you can't function without. A situation may have left you feeling lost, powerless, or impotent. Something in your life that you may feel helpless or depressed without. It may also reflect something you have difficulty letting go of believing isn't important.
A wheelchair is a sign that you can't do something on your own or that you are dependent on certain factors in order to function. It may also point to situational requirements in order to feel safe.
Example: A man dreamed of seeing himself in a wheelchair. In real life he felt he couldn't function at work if a woman he liked wasn't going to be working there anymore. The wheelchair may have reflected the man's dependency on the woman to function at work.
Example 2: A woman dreamed of being in a wheelchair that she felt she didn't need. In waking life she was wearing a wig due to side-effects of chemo. She felt she only needed her wig around strangers to feel comfortable. The wheelchair may have reflected her feelings about needing the wig to function socially.
Example 3: A young man dreamed of his girlfriend being in a wheelchair. In waking life he got into a huge argument with his girlfriend. Since she was so angry at him he felt he couldn't have a functioning relationship with her unless he did whatever she wanted to keep her happy. The wheelchair in this case may have reflected his feelings about the need to make enormous efforts to keep his girlfriend happy to make the relationship function at all.