michaelcheng1991
commented
9 years ago - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3362989/
- http://v1.aroundhawaii.com/lifestyle/health_and_fitness/2007-01_k-vest_ultra_hi-tech_golf_analysis.html
Open michaelcheng1991 opened 9 years ago
michaelcheng1991
commented
9 years ago michaelcheng1991
commented
8 years ago The concepts of the kinematic sequence, coiling, and the X-factor stretch have proven to be very useful in golf swing analysis.1,2,3,4,5,7,9 The rotation of the pelvis initiates the kinematic sequence as well as plays a vital role in creating power during the X-factor stretch.1,2,3,4,5,7 Peak pelvis rotation velocity was included in Cheetham's study which compared the kinematic sequence parameters between amateur and professional golfers.3 The professional golfers had an average peak pelvic rotation velocity of 477 ± 53 degrees/second while the mean for the amateurs was only 395 ± 53 degrees/second.3 These results indicated that a significant difference (p = 0.011) existed in peak pelvis rotation velocity between golfers of two skill levels.3 Cheetham proposed that ideally a 1.5 transfer ratio should exist between the pelvis to thorax and thorax to arm. A slightly higher transfer ratio of 2.2-2.4 is optimal for the transfer of energy between the lead arm to club.2 In other words, each segment should increase in speed (degrees/sec) to 150% of the proximal connecting segment.2 Assuming that this transfer ratio holds true, it is easy to see how an increase in peak pelvic rotation can greatly increase club head speed and in turn, power.
If you look at the Transfer Ratios, his hip to shoulder ratio (dividing the max shoulder speed by the max hip speed) is 1.63 and his shoulder to arm ratio (dividing the max arm speed by the max shoulder speed) is a large 2.37. A double, double would elucidate the ideal 2.00 transfer ratio in each linkage. So while he is not perfect in obtaining the double, double, he does have a pretty good level of synchronicity.