My forehand sailed deep — not just behind-the-baseline deep, but over-the-fence deep. I’ve played tennis for more than four decades, yet I was staring at my right hand as if it had never swung a racket, which was sort of true.

I am left-handed, and in recent years I’ve been plagued by one injury after another. Adding more topspin led to tendon and cartilage damage in my left wrist, requiring three months in a brace and physical therapy. Hitting and pitching thousands of baseballs while coaching my sons’ teams left me with constant elbow pain. An old injury returned with a vengeance, leading to strains in the rotator cuff and trapezius with a mild scapular dyskinesis.

I decided to give my left arm the summer to recuperate by learning to play tennis right-handed.

“There’s a huge percentage of players in their 50s and 60s struggling with this issue,” said Brad Gilbert, a former pro player and coach. “Most just change their strings or their swing. If you’re aspiring to be pain-free, then this may be worthwhile, but you are looking at a long journey.”

Retraining my brain would not be simple. Check out Destin Sandlin’s Backwards Brain Bicycle video online. It took two months for him to undo a lifetime of habits and learn to ride an inverted bicycle, with the handlebar turning the opposite way from the wheel.