Last year I wrote several posts on gardening, and how I really enjoy my two garden boxes. They are each about 10 feet by 3 feet, and raised up about a foot off the ground. Today was the first time this year that I spent much time on them, about 2 hours. I weeded both gardens, used a claw tool to loosen the soil and mix in some fertilizer, and planted seeds for radishes, beets, lavender, snapdragons and zinnias. Sounds like I did alot, and though I am not sore, I did have to take a nap afterwards.
While I was gardening, I was thinking. There are a few things that I might do differently if I were to build new garden boxes. The way the gardens are set up, they are as little awkward to work in. I can sit on the brick edging. This puts my back to the garden, and I have to twist around to work. Another option is to kneel on the ground. This puts me facing the garden, but I need to wear knee pads or use some kind of cushion to kneel on. I could also sit on a low stool, and lean forward. Its a long reach to the back of the bed. I did a combination of sitting on the edge and kneeling today. Keeping myself moving and switching positions often helped decrease any strains on my body.
An ideal arrangement for gardening is to build a raised box garden. There needs to be about 26-27 inches of clearance under the table so a person can sit in a chair, legs under the table. This allows the person to get close enough to work in the garden without straining to reach. The box should be 8-12 inches deep, allowing enough depth of soil for many kinds (but not all kinds) of plants, but not so deep that the sides are too high. If there is access to the garden from just one side, it should be no more than 2 1/2 feet wide, if there is access from all around, it can be as much as 5 feet wide. Here is one site I found with instructions for building such a bed. There were other sites like this as well, I searched for 'raised garden on legs'.
For easy on the hands garden tools, I like Goodgrips, though there are other brands available. This site has info on gardening with arthritis, and a variety of ergonomic gardening tools. They even have a gardening caddy that you can sit on, and it has wheels to move around easily.