Here is a quote from the book Par Bowling, by Tom Kouros (highly recommended):
"In the beginning, the ball is placed (not pushed) into an arc by means of control and, if held at waist level or lower, with some force. It is controlled (not pushed) in order to accommodate the initial relationship and movements of the feet and ball. When the ball in the stance is held at waist level or below, force is used in order to effect an arc in the ball placement. Once placed, the ball moves down into the backswing by means of gravitational acceleration. At the bottom of the backswing, kinetic energy (stored energy) takes over, and is employed until the ball reaches the height of the backswing.
After a momentary pause at the height of the backswing, the ball moves into the downswing, once again under the influence of gravitational acceleration. In the delivery, the ball reaches a point where its gravitational force begins to compromise with kinetic energy (at the point of release). At this time, acceleration (force) is applied, and the release and the follow-through ensue.
To better accommodate various techniques and to effect more leverage, the following modifications can be made. When a ball is under gravitational acceleration, control can be used to slow the swing down, but NOT to the extent that it eliminates more than 50% of the pendulum effect (this undue force is referred to as "muscling the ball"). Also, force (acceleration) is NEVER applied when the ball is in a state of gravitational acceleration, for this will also remove too much of the pendulum's effect (the exception being...a slight, steady pull in the downswing).
On the other hand, when the ball is in a state of kinetic energy, force (acceleration) can be applied to lengthen the backswing, and should always be applied to effect a strong release and follow-through. Finally, control in the swing should never be used when the ball is in a state of kinetic energy."
Mr. Kouros is a very deep and knowledgeable individual in our sport, thus I type this in deference to his bowling wisdom.
Not knowing your style, nor the problems you are expiriencing with your swing, I hope that this excerpt will somehow help.
Regards,
BowlingWolf
