I have arthritic bits too in my back, shoulders and starting now in my hands.
I find the best thing is to water thoroughly and leave it to soak for an hour or two. Weeds are then much easier to grub out either by hand or with a cultivator tool. Wolf do exchangeable tool heads in different sizes and different length handles so you can have a hand tool and kneel or a full length handle to avoid bending.
You then need to fill the gaps, either with ground cover plants, more plants that will spread such as hardy geraniums or a good mulch of grit, pebbles or chipped bark to suppress weeds whilst allowing your real plants to spread happily.