The effects of gluteus medius strengthening and video feedback on hip adduction angle in female runners

Lower-limb injuries in recreational runners account for a large number of patients presenting at physiotherapy departments in the United Kingdom (Buist et al., 2010, British Journal of Sports Medicine, 44, 598–604). Females have been shown to be more prone to injury, and evidence suggests that a main contributing factor is increased hip adduction (Crowell and Davis, 2011, Clinical Biomechanics, 26, 78–83). Numerous studies have suggested that an increase in hip adduction is related to weakness of the gluteus medius muscle (Reiman et al., 2009, Physiotherapy Theory and Practice, 28, 257–268); however, there is disagreement whether strengthening the gluteus medius alone is sufficient to alter a person’s running pattern. The purpose of this study was to investigate the effects of a combined gluteus medius strength training and video feedback intervention and a gluteus medius strength training alone on hip adduction during running. Following institutional ethics approval, 12 uninjured female participants (age = 31.3 ± 4.6 years, height = 1.66 ± 0.07 m, mass = 64.2 ± 7.4 kg) who demonstrated abnormal frontal plane hip mechanics (hip adduction >10° on one-legged squat) were randomly assigned into two groups: group 1 received a 6-week gluteus medius strengthening programme and group 2 received a 6-week gluteus medius strengthening programme and video analysis feedback of their running technique which they were instructed to view prior to each running session they completed. The gluteus medius strength training intervention consisted of performing two sets of 12 repetitions of four exercises (side-lying abduction, single-leg squat, crook lying with abduction against resistance band and lateral step up) with a 60-s rest between each set, three times per week. Peak hip adduction angle during the stance phase of treadmill running at 2.5 m · s−1 was assessed before and after the 6-week intervention period through 2D video analysis (120 Hz) of the anterior superior iliac spine and tibial tuberosity in the frontal plane using Kinovea motion analysis software. Paired samples t-tests found a significant decrease in peak hip adduction angle during running in both the groups (P < 0.01) but independent samples t-tests found no significant difference in peak hip adduction angle between the two groups (P = 0.191) (group 1, pre-intervention = 12.8° ± 1.4, post-intervention = 12.0° ± 1.0; group 2, pre-intervention = 12.9° ± 1.8, post-intervention = 11.2° ± 1.0). These results suggest that a 6-week gluteus medius strength training programme may reduce hip adduction angle during running which is thought to be a contributory factor in lower-limb running injuries. However, there appears to be no increased benefit with the use of video analysis feedback