Effect of Shoe Cushioning Position and Properties on Running-related Injury Risk

The main purpose of this project is to investigate the influence of cushioning material at both the rear and the forepart of running shoes on musculoskeletal complaints in leisure-time runners. Therefore, the objectives are to investigate if 1. "Extra soft" cushioning materials can reduce injury risk compared to stiffer materials; 2. Cushioning under the forepart of the shoe also influences injury risk, independently of the cushioning at the rear part; 3. Effects of cushioning material and position depend on the runner's body mass; 4. Perception of cushioning is related to both shoe cushioning and injury risk; 5. Other weight-bearing locomotion activities (i.e., number of steps per day besides running practice) represents an independent risk factor for running-related injury. This study consists in a 6-month intervention trial during which leisure-time runners are required to follow their usual training schedule. Before the beginning of the study, the participants will receive a pair of running shoes. The three running shoe models will be exactly the same, except for their foam properties at the rear and forepart of the shoe, which will differ by 33 and 37%, respectively. The study shoes will be administered through random allocation. The participants will be required to use these shoes for all running sessions, and only for running activities. Participants will first fill out a baseline questionnaire. During the intervention, data on running practice will be downloaded from sports watches via their respective app. Information on the use of the study shoes will be collected via a weekly questionnaire. Participants will be asked to fill out a weekly questionnaire on any musculoskeletal complaints experienced during the past 7 days. A questionnaire on the perception of cushioning will be filled in by the participants at three time points (after 5h of running, 25h of running, and at the end of follow-up). Primary hypothesis: \- Greater shock absorption properties at the rear part of running shoes are associated with a lower injury risk in recreational runners. Secondary hypothesis: * Greater shock absorption properties under the forepart of the shoe are also associated with lower injury risk in recreational runners. * Runners with low body mass experience a lower injury risk in shoes with greater shock absorption properties. * Greater perceived cushioning is related to lower injury risk.