Biomechanical analysis of lower limbs based on unstable condition sports footwear: a systematic review

The purpose of this paper is to summarize the functional arguments for unstable footwear in the recent research literature and to explore the different effects of various unstable designs of footwear in enhancing muscle strength training, improving stability and loss prevention. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria, to find all the relevant studies for this systematic review, a comprehensive electronic search was conducted. The following keyword combinations were used as part of a standardized electronic literature search strategy: ‘unstable OR bionic OR MBT’ AND ‘shoe OR shoes OR footwear’ AND ‘biomechanics OR kinetics OR kinematics OR muscle force’ from 2000 until November 2021 using the following databases: ScienceDirect, Web of Science and PubMed online. There were 17 articles included in this review, eight consisting of anterior-posterior (AP) unstable condition studies and nine consisting of medial-lateral (ML) unstable condition studies. It was also uncovered that AP unstable footwear is more suitable for fully developed adults, while for ML unstable footwear is perhaps more suitable for children and adolescents.