Isokinetic Evaluation of Hip Flexors and Extensors Muscles in Athletes of Rhythmic Gymnastics

Rhythmic Gymnastics (RG) is a competitive sport that due to its aesthetic and technical requirements makes athletes seek to maximize their technical performance. Elements inherent to the sport are based on movements of hip extension, flexion and abduction, which explain the need for producing considerable levels of strength in different muscle lengths and speeds. The aim of the study was to evaluate the capacity of strength in flexors and extensors of the hip joint in a Brazilian team of GR. Five international level athletes of RG from 15 to 22 years old, participated in this study. Strenght of hip extensor and flexor muscles was evaluated from the peak torque measured using Biodex System 4 Pro isokinetic dynamometer Torque was evaluated during maximal concentric isokinetic voluntary contraction at six different angular velocities (30o/s, 60o/s, 120o/s, 180o/s, 240o/s and 300o/s) and during three maximal isometric voluntary contractions at eight different hip angles (15o, 30o, 45o, 60o, 75o, 90o, 105o and 120o). The widespread use of hip flexion and extension in RG seems to influence the muscle mechanical properties, resulting in a functional adaptation that tends to render homogeneous force production capacity in different joint angles and angular velocities. This homogenization is most evident in hip flexion, since this movement is trained extensively, either in larger or smaller lenghts and high or low speeds.