Yoda.. when discussing accumulator #4 I am a bit surprised at the lack of Latissimus Dorsi (Lats) muscle emphasis as per 2-M-3. As per the equation for a Class 3 Lever
-Fe x De = Fr x Dr
the greater the effort, the greater the force. In particular accumulator 4 has the greatest Dr or resistance arm. The radius being greater than the other 3 accumulators would put accumulator 4 as a premium speed inducer. So it could be said that either the Pivot is essencial, or the movement of the Latissimus Dorsi of the left side is the key generator of speed.
The Right Shoulder drives the #4 Accumulator (the Left Arm) Downplane. Since the 'lats' pull the Shoulders backward, not forward, I would suspect they contribute little to the action. Can anybody add something here?
Isn't it a valid choice to pull up with the left shoulder, rather than drive
down with the right, in a 3-barrel swing? One time I asked Bill Glasson how
he had just hit a 220 yd 3 iron approach onto a tree guarded green. He said
he just pulled up with his left shoulder.
As the Right Shoulder Thrusts Down Plane, its Rotation returns the Left
Shoulder to its higher Impact Fix Location. Since the Right Shoulder Turn
Thrust (a Push) 'cranks the Gyroscope' and thereby creates the
Swinger's Centrifugal Pull, it is not surprising that Mr. Glasson
interpreted his Motion as a Pull of the Left Shoulder, rather than a Push of
the Right. But...he described the effect and not the cause. The
'cause' was the Right Shoulder Turn Acceleration through Pressure Point #4.