Tweet
The frame on the left shows the hips open and the shoulders still closed and the bat still up behind the head. This is separation between the lower and upper halves. This separation creates body torque that provides much of the energy for the swing.
Separation is 'seen' as the angle between the shoulder line and the hip line. But it actually occurs INSIDE the rear hip socket. THAT is the POINT of separation. It starts when the rear hip coils back around the ball of the rear femur....and the rear femur begins to internally rotate. That action is enhanced, and stretch is increased, when your lower back and scap area pull back WITH the hip....against the rear leg....creating an upward spiral-like twist in the back....against the internal rotation of the leg.