CF & CP Release

CP/CF release is usually associated with hitting and swinging.  Let’s take a slightly different view and assume CF release as one where the main input in the downswing is delivered before impact, hence free wheeling through impact, and CP release as one where most effort is primarily produced close to and during impact.

Note: below, ‘left side figures’ refer to CF releases, whereas ‘right side figures’ refer to CP release.

In the present analysis will look at the torques generated at the joint (wrists) during the downswing for both releases to learn a bit more what they might possible have in common or have as distinguishable features.

For an Iron Byron golfer this can be readily arranged by modulating appropriately the torques A and B, Fig2a,  Fig2b.  In Fig2a both torques are reduced to zero well before impact to allow free wheeling of the club through impact, hence simulating a CF release type swing. In Fig2b the two torques are initially quite small but increasing during the down swing and kept going full throttle trough impact to simulate a CP release.

The two torque patterns were adjusted to produce the same speed for the clubhead at impact. The spatial time histories for the two segments are shown in Fig3a and Fig3b.  Notice for the CF release the hands to be more ‘pinned through impact as there is appreciable slowing of the hands, due to the transfer of angular momentum from upper to lower segment, but very little for a CP release type swing.

Fig4a and Fig4b show the torques acting on the lower segment. There is the externally applied wrist torque by the golfer (brown), some torque due to gravity (green), and two inertial torques, respectively due to the centripetal force (red) and the tangential force (blue) exerted by the upper segment on the lower segment, Fig5.

Immediately it is clear that in both types of release it is the centripetal torque (red) which is dominant. The gravity torque (green) and the torque due to the tangential force exerted by the upper segment (blue) only play a minor role in the release action.

It might come as a surprise to some but the biggest inertial release torque is developed during the free wheeling action, (Fig5a, red) in a CF type release, i.e., when the golfer feels he is doing nothing other than simple holding on to the club.  Sweet paradox!

Moreover interesting to note is that for a hitter’s action, CP release, the total torque close to impact tends to go nevertheless (Fig4b) to zero. Again this is counter intuitive as the hitter feels that he is pouring it on definitely through impact. Feel and real are not quite playing the same game here.

Typically a golfer will feel to be doing very different actions when swinging or hitting.  Analyzing the matter however they seem to have in common the same dominant releases action due to the centripetal acceleration of the upper segment.

There are two inertial forces exerted by the upper segment on the lower segment, i.e., tangential and centripetal. The tangential force initially creates speed but very soon leaves the stage for the centripetal force, Fig6.  The latter produces the bulk of the release torque prior to and through impact.  

The centripetal release torque is proportional to the angular velocity squared of the upper segment (arms). In  golf there are auto-regulating mechanisms which make golf possible. Produce more velocity and automatically there will be a greater release torque.

mandrin