How could you strengthen your now healed broken wrist?

Wrist injury. Physical therapy and occupational therapy are useful following a wrist injury. A simple exercise is squeezing a rubber ball or a tennis ball. Your primary care physician can provide you with more exercises and resources for further therapy.
Wrist rehab . After an injury is often not linear it takes time and it starts with trying to use your hand normally in normal activities as well as squeeze in a ball and other hand strengthening devices what you should avoid however are weights in the early phase of recovery as it often can be too much for healing wrist instead do Isometric strengthening and maintain motion .
Participate in life. Use you hand for all activities you can and it will strengthen automatically. Physical therapy is often not necessary.