Use different techniques in the garden
Employ no-dig methods - Add a layer of well rotted manure, compost, leaf mold, spent mushroom compost, old straw etc to the soil surface as a mulch at least 2 or 3 inches deep. The actions of worms will incorporate the mulch into the soil improving soil structure.
Mulches of bark, plastic or gravel can suppress weed growth and conserve moisture in the soil.
Consider gardening from a seated position – improve seating options or use stools, benches or chairs. Choose long handled tools or tools with adjustable length handles to allow you to garden comfortably from a seated position.
Use long handled pruners and other aids to extend reach, rather than climbing ladders.