What an interesting question! Many people with a variety of different
disabilities talk about similar issues. As some conditions exacerbate,
functioning can decrease. Obviously this affects all parts of peoples'
lives including their sexual interactions with others.
There are a couple of ways to approach this change in physical ability.
First, prepare yourself to feel a bit discouraged. Some people who lose
physical ability go through a period of time where they feel down on
themselves. This could decrease your interest in sex. Or, it may make
you feel like you want to fight against it. Either way, go easy on
yourself as you adjust to the changes.
Second, try experimenting with different positions. Lay on a bed or couch
with your arms resting upon cushions and attempt to masturbate this way.
You can first try with your hands and then also experiment with holding a
vibrator. Some vibrators and sex toys are easier to hold than others. In
fact, some toys can be modified by attaching a Velcro strap. You can
investigate these strategies by yourself or with your partner.
Third, see if different positions help with easing the weakness in your
hands when you are being sexual with your partner. If you are unable to
find a position that is right for you, ask you partner to assist you.
He/she can place his/her hand over your hand and move it across his/her
body. This way, you continue to have direct contact with your partner's
skin and you are simply getting a helpful nudge of momentum.
Some people with significant disabilities do choose to ask for assistance
from others with masturbation. That is, you could ask your partner to
assist you with getting a vibrator in your hand so that you could masturbate.
In fact, people who do not have partners often times ask their personal
assistants (sometimes called personal care attendants) to assist them
with self-stimulation.
Basically, my advice to you is to continue communicating with your partner
and have fun experimenting!