Injury risk associated with the transition to minimalist footwear in runners: A systematic review and meta-analysis.

BACKGROUND: Running-related injuries have remained relatively stable over recent decades despite advances in athletic footwear design. This has led to a growing interest in minimalist footwear as a strategy for modifying running biomechanics. However, the effects of its use and the optimal characteristics of the transition period remain controversial, particularly regarding injury risk. OBJECTIVE: To analyze the injury prevalence associated with the transition to minimalist footwear and to identify the main biomechanical and musculoskeletal changes associated with injury risk reported in scientific literature. METHOD: A systematic review and meta-analysis were conducted following the PRISMA 2020 guidelines. The literature search included international databases and covered the last 15 years, incorporating randomized controlled trials and prospective cohort studies. Eligibility criteria included a minimum transition period of four weeks in healthy runners with no previous experience with minimalist footwear. The effect size was estimated using a fixed effects model, and heterogeneity was assessed using Cochran's Q test and I2 statistic. RESULTS: A total of 12 studies were included in the qualitative synthesis and 7 in the meta-analysis, with a total of 313 participants. The transition to minimalist footwear was associated with a moderate increase in injury risk, with an overall effect size of 3.529 (95%CI: 2.41-4.646) and low heterogeneity. The most frequently reported injuries were bone marrow edema in the metatarsal region, Achilles tendinopathy and calf pain, related to the adoption of a forefoot strike pattern. CONCLUSIONS: The transition to minimalist footwear is associated with a moderate increase in risk and significant increase in the prevalence of musculoskeletal injuries, related to changes in the foot strike pattern and to forefoot and Achilles tendon overload. Supervised retraining programs of at least 12 weeks may support progressive adaptation of the musculoskeletal system and reduce risk of injury.