Biomechanical and neural changes evaluation induced by prolonged use of non-stable footwear: a systematic review

The aim of this review is to collect and discuss the current best evidence published in literature about the effect of the Masai Barefoot Technology(MBT) shoes on gait and muscle activation and try to draw conclusions on the possible benefits. We searched Medline, CINAHL, Embase and the Cochrane Central Registry of Controlled Trials. The reference lists of the previously selected articles were then examined by hand. Only studies comparing biomechanical and clinical outcomes were selected. Review, anatomical studies, letter to editor and instructional course were excluded. Finally, all the resulting articles were reviewed and discussed by all the authors to further confirm their suitability for this review: in the end, 22 articles were included. A total of 532 patients presenting a mean age of 34.3 years were studied. All patients evaluated were healthy or amateur sports except in two studies where only obese subjects and knee osteoarthritis patients were involved. Seven studies evaluated only male subjects, whereas four studies evaluated only female. Twelve of twenty-two studies performed electromyographic analyses. Weight was reported in 19 studies, whereas body mass index were reported only in a five studies. All studies reported kinematic analysis of shoe effects and compared the relationship between muscle recruitment and electromyographic activity. Unstable footwears were shown to immediately alter the stability in gait during daily-life activities. The center of body pressure is moved posteriorly with a consequent posterior displacement of the upper part of body in order to regain an appropriate body balance, and these postural changes are associated with an overall increase in the activity of lumbar erector spine muscles, as well as certain lower limb muscles. Current literature provides enough cues to conclude for a beneficial role of MBT shoes in the postural and proprioceptive recovery, but from the same literature cannot be drown clear and appropriate guidance to determine more in detail their indication for specific pathological conditions or for particular phases of the musculoskeletal recovery process.