The time history of measured torques are complex patterns and seem to be rather characteristic for each golfer. However it is interesting, using a 2D math model, to analyze the effect of some specific time histories for the inner torque.

Fig0a shows the starting postion for the down swing, whereas Fig0c shows the position for which the 'club head hits the ball', hence impact postion. The time and angle corresponding to this position is indicated with a green line in the various diagrams below. From the starting postion the wrist angle is maintained till the postion shown in Fig0b, where the innner segment makes an angle of 60 deg with the negative vertical axis. From that moment on there is no torque applied at the 'wrists', which are hence free wheeling through the impact zone.

In the two sequences above the torques are shown respectively as a function of the angle from the top and as a function of time. They represent three types of golfers: a) those who start slowly and peak at impact. b) those who keep an even effort during the down swing and c) those who are impulsive early on and let the arms coast through impact.

Notice in the sequence above how, from a to b to c, the arms (red) acquire both more kinetic energy and additionaly transfer more of it to the club. This indicates that in swing c) the arms are used as an efficient kinetic link between shoulders and club. On the other hand, sequence a) indicates a swing where the emphasis is more on 'muscles' to create club head speed.

Figs 5a,b,c show the increasing efficiency when the effort is applied progressively earlier in the down swing. This is actually the overall conclusion of this analysis - For an efficient swing, apply effort early on in the down swing, allowing the arms time and space to act efficiently as an accumulator/distributor for the kinetic energy.

The power curves are interesting in that they shows the most pronounced difference between the three golf swings analyzed. Observe that swing c) has hardly any power input at impact and that the power input is earlier on in the down swing.

mandrin