Many of these items can be made at home for a fraction of the cost. Analyze the problem. You might come up with a better solution than the ones normally used. The early cave dwellers probably used assistive devices. A tree limb makes an effective crutch.
Large handles are much easier to use than small handles.
Look for lightweight cutlery and utensils with large handles. Holding and turning a lever is much easier than struggling with a slippery, round doorknob. An 'L' shaped knife requires less wrist movement and less strength. Try shoes with elastic shoe laces and a button. You leave the laces double knotted and simply flip the elastic shoelace over the button to tie the shoe.