You're refering to a high topspin backhand?
Harder to rotate the waist and shoulders from a "closed" to a more chest facing forward position, I suspect.
Think about it - when you cream a high forehand, your shoulders and waist rotate from a neutral or open stance until on your followthrough, your upper body if not your whole body is facing the court. Much harder to do that on the backhand side because a 1HBH is usually hit with a closed stance with both feet planted.
On top of that, when hitting high forehands, you also have the large chest muscles helping to bring the racquet round. On the 1HBH you don't have that luxury - your largest shoulder and back muscles are not designed to contract (i.e. exert "pull") in that direction. Same thing for the arm and wrist muscles, too, I suspect.
An easy way to understand this is to try pushing in the forehand and backhand directions with your arm fully or nearly fully extended. You'll find that you can exert more strength in the forehand (to the front) direction. And if you do it hard enough, you'll feel exactly which muscles are involved because they'll ache. Of course, if you're a 5.5 with a 150 mph serve and a 90 mph backhand like so many members here, then you won't need to worry about any of this at all...
I could just be wrong, of course, since I'm not a doctor, but that's my limited understanding. Perhaps someone with more knowledge could help out?
That's why I prefer to hit a flat slice semi-backhand smash on a high backhand. It just feels easier - probably because my upper back and shoulder muscles towards my back are contracting in the direction for which they were designed, i.e. like a karate chop.
Sorry I don't know the names of the muscles involved.
5' 10". 56. Fat. No talent. I'm ONLY 2.5 no matter what anybody else says! And GOATS have horns, eat grass and go "Meh eh eh eh!"
Last edited by winstonlim8; 12-04-2013 at 07:19 AM.