Relationships between strength and activation of the gluteal muscles and dynamic stabilization of the knee: a systematic review

Abstract

The knee undergoes, absorbs and dissipate important part of the forces imposed by daily activities such as walking, climbing and going down stairs, and jumping. Given the great demands imposed on this joint, knee dysfunctions are very common. The ability to respond to this demand seems to be related to the functions of the hip muscles, which seems to play an important biomechanical role in certain aspects, as the dynamic stability of the knee joint. Objective: To conduct a systematic review of the literature to identify possible characteristics and actions of gluteal muscles in dynamic knee stabilization and to investigate the effectiveness of interventional programs that focus on the gluteal muscles in improving the functional or symptomatologic outcomes associated with the knee joint. Methods: This is a systematic review performed according to PRISMA protocol (Preferred Report Items for Systematic Reviews and Meta-Analyses). Electronic databases (MEDLINE, SCIELO, COCHRANE, LILACS and PEDro) were searched under a strategy of different combinations of terms related to the study goals. Inclusion criteria were: studies published up to March 2016, of subjects aging 18-60 years, with unrestricted language of publication, involving assessment or treatment of any feature of the hip muscles in relation to dynamic knee stabilization. Results: Of the 109 studies found, eleven met inclusion criteria and were included. Of these, eight (73%) were observational exploratory studies and three (27%) were randomized controlled trials (RCTs) (5≤PEDro≤8). All RCTs included young female adults with patellofemoral pain syndrome and assessed the gluteus medius muscle. According to the results of the most part of the included studies, gluteal muscles are involved in maintaining frontal plane lower limb alignment that reduces dynamic valgus during functional activities, therefore revealing the great importance of magnitude of muscle activation rather than only time of activation. The RCTs provided evidence of the importance of gluteal muscle interventions in knee rehabilitation programs: in symptomatic subjects with patellofemoral pain syndrome, there was significant improvement in function and symptoms after this kind of intervention, which was performed in association with conventional knee or trunk treatment. Conclusion: Magnitude of activation and gluteal muscle strength play an important role in dynamic knee stability. Gluteal muscle interventions, associated with conventional treatment, effectively improved functional and symptomatologic outcomes related to the knee joint.