In many sports, including golf, the body is called upon to produce movement of the hands or feet at the highest possible velocities to best complete a task. Proximal to distal sequencing has been acknowledged by multiple researchers as a means to achieve these velocities. When using segmental angular velocity components, proximal to distal sequencing has been termed the “kinematic sequence”. Researchers have found that amateur golfers tended to exhibit a more inefficient energy transfer from segment to segment than professional golfers. Physical limitations have been suggested as a source of inefficiency in the kinematic sequence. In the golf swing, a large torque occurs between the moving upper body and the relatively stationary pelvis, which can create a significant amount of stress on the lower back. The lower back is the most common injury site among golfers. Based on the frequency of lower back injuries and the number of people that play golf, conservatively four million people in the United States are affected by lower back injuries.
Physicians, therapists, athletic trainers, and coaches have incorporated aspects of trunk control and core strength training in almost every sport in the hope of preventing or treating injuries and improving performance of the upper and lower extremity. While trunk control and core strength training are popular, at this point it is only speculation as to whether core stability, core strength, and core endurance are important to the production of the proper kinematic sequence, greater clubhead velocity, and presence of lower transverse lumbar spine torques.
Eleven male subjects with a golf handicap index of seven or less participated in this correlational laboratory study. Consisting of two parts, the first part of testing used passive optical motion capture techniques to record the subjects’ golf swings as they hit golf balls with their own driver. The main outcome measures were the number of swings out of 10 that exhibited the proper kinematic sequence, average of the peak clubhead velocity over the 10 swings, and the average of peak transverse lumbar spine torque during those 10 swings. In the second part of testing, subjects performed six lumbopelvic tests specifically targeting core stability, strength, or endurance. Linear regression analysis was used to determine the association between the results of the lumbopelvic tests and the swing outcome measures.
None of the six lumbopelvic tests revealed a significant correlation with proper kinematic sequence production or peak transverse lumbar spine torque. However, peak clubhead angular velocity did significantly correlate with a core stability test measuring pelvic positional control (R=0.72, p=0.012). A sample size estimation analysis for future studies is presented based on the results of this pilot study. Future work should continue to analyze the relationship between core function and golfer performance and injury risk variables. The collective knowledge gained from this and subsequent studies may come in the form of improved training programs that result in performance improvement and reduced injury potential for the golfing population.