Being a keen allotmenteer and lover of the therapeutic effects of all aspects of "digging" a recent spate of working on my allotment has caused an old injury to flare up (there's a story for another blogpost in this) to have a painful, left thumb. Every time I grip the spade handle or secateurs, the joint "gives way" and by the end of the day is achey.
To give support and aid recovery I used some Kinesio tape strapping across the joint and exercised the thumb. The strapping is placed along the tendons, allowing exercise and movement with support. This helps the brain and joint to reconnect so movement is improved across the painful joint.
In the beginning, exercise with the strapping on so you know how it should "feel".
When not gardening, practice "release motion"....