Development of a Closed Kinetic Chain Power Training Device for the Hip Rotators

Abstract

Introduction: Golfers with optimal transverse plane rotational capability, particularly through the hip joints are better able to generate effective golf swing power. Unfortunately, a device that enables controlled, progressively increased training resistance to the hip rotator muscles in a manner that functionally simulates the golf swing does not presently exist. The purpose of this single subject, crossover design study was to compare hip rotator muscle electromyographic (EMG) amplitudes and activation sequences during a golf swing, and during a simulated golf swing on a pneumatic resistance closed kinetic chain exercise device designed specifically to train the muscular rotators of the hips. Methods: A 52-year-old nonimpaired, right handed male (180 cm, 81.9 kg) who had trained on the device for six months served as the test subject. Following static stretching of the low back and extremities, the subject performed a standard warm-up of 10–12 progressively more intense practice golf swings with a standard driver. Following this bilateral hip external rotator/abductor (gluteus maximus) and hip adductor/internal rotator muscle groups were instrumented with surface EMG electrodes and in-shoe plantar pressure sensors (for event timing purposes). Norquest (Noraxon, Scottsdale, AZ) EMG and Pedar (Novel, Minneapolis, MN) pressure sensor systems triggered from side-by-side laptop computers were used for both data collection and analysis. Each trial consisted of three complete movements for the given condition with alternating order to control for potential order effects. Although the device can also provide eccentric resistance, only minimal (35–40 psi) and moderate (75–80 psi) concentric resistances were evaluated. Results: Both minimal (MIN) and moderate (MOD) device resistances displayed similar muscle activation duration, timing of peak EMG amplitudes, and muscle activation sequencing (relative to peak left foot plantar force onset) compared to the golf swing for the right and left gluteus ▭ maximus (GM) and hip adductor (HA) muscles (Fig. 1). As the device was set with increasing concentric resistance, progressive and predictable increases in right (17%, 37%) and left (9%, 28%) peak GM (Fig. 2) and right (5%, 33%) and left (25%, 30%) HA (Fig. 3) muscle activation amplitudes were observed.Fig. 1Fig. 2Fig. 3Discussion: The pneumatic resistance closed kinetic chain exercise device provided an effective and safe method of progressively increasing concentric resistance to increase hip rotator power during transverse plane movement. By applying resistance in functionally similar movement patterns and velocities, the hip rotators can be trained to facilitate greater crossover to golf performance. Comparative training effect studies on specific golf performance parameters and with other sport movements that require hip rotator muscle power are being planned.