Does choice of athletic footwear affect musculoskeletal injury risk in US Coast Guard recruits? A retrospective cohort study.

Context: Musculoskeletal injuries (MSKIs) are ubiquitous during initial entry military training, with overuse injuries in the lower extremities the most frequent. A common mechanism for overuse injuries is running, an activity that is an integral part of United States Coast Guard (USCG) training and a requirement for graduation. Objective: Assess the effects of athletic footwear choice on lower quarter MSKI risk in USCG recruits. Design: Descriptive Epidemiological Study Setting: USCG Training Center, Cape May, NJ Participants: A retrospective cohort study was performed in which 1229 recruits (1038 males, 191 females) were allowed to self-select athletic footwear during training. A group of 2876 recruits (2260 males, 616 females) who trained under a policy that required obligatory wear of prescribed athletic shoes served as a control. Main Outcome Measures: Demographic data and physical performance were derived from administrative records. Injury data were abstracted from a medical tracking database. Multivariable logistic regression was used to assess group, age, sex, height, body mass, and run times on MSKI outcomes. Results: Ankle-foot, leg, knee and lumbopelvic-hip complex diagnoses were ubiquitous in both groups (experimental: 20.37 to 29.34 per 1000 recruits; control: 18.08 to 25.59 per 1000 recruits). Group was not a significant factor for any of the injuries assessed. Sex was a significant factor in all injury types, with female recruits demonstrating ~2.00 greater odds of experiencing running-related injuries (RRIs), overuse injuries, or any MSKI in general. When considering ankle-foot or bone stress injuries, the risk in female recruits was 3.73 to 4.11 greater odds than their male counterparts. Run time was a significant predictor in RRI, all overuse injuries, and for any MSKI in general. Conclusion: While footwear choice did not influence MSKI risk in USCG recruits, female sex was a primary, nonmodifiable intrinsic risk factor.

Global Value Chains, Industrial Hubs, and Economic Development in the Twenty-first Century

This chapter uses the global value chain (GVC) framework to analyse the shifting strategies of key lead firms and first-tier suppliers in the athletic footwear and electronics industries. Growing cost pressures for labour and raw materials, as well as the potential political disruption from the escalating ‘trade war’ between the United States and China and the accelerating technological disruption sparked by the digital economy on both the demand side (e.g. e-commerce) and the supply side (e.g. automation) of GVCs, are encouraging brand leaders and major suppliers in both GVCs (such as Adidas and Nike in footwear, and Apple and Foxconn in electronics) to pursue automation in select factories in their supply chains. However, the industrial hubs where athletic footwear and electronics production is concentrated remain overwhelmingly labour-intensive, both in China and elsewhere in Asia (such as Vietnam and Indonesia) where big suppliers are moving to diversify their options.

A Biomechanical Investigation of Athletic Footwear Traction Performance: Integration of Gait Analysis with Computational Simulation

Evaluations are vital to quantify the functionalities of athletic footwear, such as the performance of slip resistance, shock absorption, and rebound. Computational technology has progressed to become a promising solution for accelerating product development time and providing customized products in order to keep up with the competitive contemporary footwear market. In this research, the effects of various tread pattern designs on traction performance in a normal gait were analyzed by employing an approach that integrated computational simulation and gait analysis. A state-of-the-art finite element (FE) model of a shoe was developed by digital sculpting technology. A dynamic plantar pressure distribution was automatically applied to interpret individualized subject conditions. The traction performance and real contact area between the shoe and the ground during the gait could be characterized and predicted. The results suggest that the real contact area and the structure of the outsole tread design influence the traction performance of the shoe in dry conditions. This computational process is more efficient than mechanical tests in terms of both cost and time, and it could bring a noticeable benefit to the footwear industry in the early design phases of product development.