Understanding the role of shaft stiffness in the golf swing

A three-dimensional forward dynamic model of the golf swing optimized for ball carry distance

“…Peak clubhead speed is reached slightly before impact and the clubhead speed at impact is 41.5 m s −1 (92.8 mph). This clubhead speed is similar to that observed by Mackenzie, 41.9 m s −1 [16], for a similar model and observed experimentally by Milne & Davis [24]. The clubhead speed at impact is slightly slower than the peak clubhead speed to achieve better impact conditions with the ball.…”

“…This pattern also matches the observations of Mackenzie [16] using a similar model. At impact, Table 9 compares the clubhead speeds at impact of our model to those found in [16]. The velocity in the x-direction is very similar, but our velocities in the y and z-directions are quite a bit lower.…”

“…The inside-out pattern is suggested by many golf professionals as the best way to hit long straight drives [36]. This pattern also matches the observations of Mackenzie [16] using a similar model. At impact, Table 9 compares the clubhead speeds at impact of our model to those found in [16].…”

“…The mass and inertia properties for the torso and arm of the golfer were taken from the work of MacKenzie [14] and are shown in Table 1. The mass and moment of inertia of the hand also takes into account the mass of the grip of the shaft and is also shown in Table 1.…”

“…The input torques for the golfer model were defined by the same functions used by MacKenzie [16], taking into account both the activation and force-velocity curves Table 3. The arm generator provides supination/pronation torques about the long axis of the arm while the shoulder generator provides torque to rotate the arm in the swing plane.…”