No it will hurt your arm little buddy
It depends which way he is throwing the ball. If he is twisting his wrist he could hurt his elbow and end up seriously injured. Only adults should twist their wrist when throwing a curve ball. There is a way to throw a curve ball without hurting your arm though. What you do is you get your grip on the baseball and throw the ball like a football. I throw my curves this way and they are pretty nasty.
12 year olds shouldn't throw curve balls. Too hard on the elbow. Stick to the change up. Palm the ball, use the same arm angle and wait until after puberty for throwing junk. If you can teach him the knuckle ball, that might be useful.
Pitching a fast ball at 69 mph will not harm a 13 year old. A 13 year old should not be allowed to pitch a curve ball or any other pitch that may hurt his pitching arm. Curve balls should never be pitched by any boy under the age of 16.
Unless there is a physical problem, 8-12 year olds should have fully developed gross motor skills. They should be able to throw and catch balls, pick up things, etc.
The average 14 year old should be able to throw around 55-65 miles per hour.
Im 14 to and I throw 75
they can throw one maybe 3 times a game but not for every batter
about 3-4 feet.
Between 55 and 75 MPH
Balls? your choise but only start to shave when you have to start iching, that's why people shave :P:P
a 12 year old boy should be able to throw anywhere between 55-65mph