Many years ago, a neighbor had a stroke, and lost the strength in his right hand, wrist, & arm. He could no longer remove the lids from any jars or bottles -- large (e.g., mayonnaise), medium (cranberry juice), or small (plastic soda-pop). A physical therapist had him do simple isometric exercises that required no equipment or expense, and they worked like a charm:
- To simulate opening larger lids, hold your left hand in a tight fist, wrap the finger-tips of your right hand around the fist, and try to twist your hand off...of course, you can't, but it really exercise the right muscle-groups.
- For medium-size lids, the exercise is almost the same, but open your left thumb away from the fist, then grip down on the first two fingers of your left hand with your right thumb under the finger-tips, and the right index finger against the palm-knuckles of the left hand, try to twist the fingers open. Again, you can't, but the attempt closely resembles removing a juice bottle lid.
- For smaller bottle-tops, just wrap your right hand around the base of your left thumb, and once again, try to twist it off. On this one, be careful to grip the BASE of the thumb...farther out will be painful to the left thumb.
I realize that you could do the exercises with real bottles of mayo, juice, or pop, but if you want to do these exercises many times each day, sometimes you simply don't have immediate access to the real bottles...but it seems like you always take your left hand with you.
What surprised my neighbor, he didn't even have to squeeze or twist really hard. He'd just do each exercise for about ten seconds each, then repeat them. He went through this routine four or five times a day for a month, and regained most of the strength in his right arm/hand. He had no trouble opening bottles and jars.