Female Speaker: Swimming free style the primary muscle groups involved in Freestyle swimming are anterior deltoids, posterior deltoids, pectorals and anterior uveitis, hip, hamstring, quadriceps, latissimus dorsi, triceps and the Gluteus Maximus. The support muscles used are the Trapezius, biceps, upper abdominals, lower abdominals and the calves. There are no ancillary muscles used in Freestyle swimming.