Running Technique Alteration: insights into injury prevention and performance

Recreational running is one of the most accessible forms of physical activity and has one of the highest participation rates of any sport worldwide. Over the past century, running performance has markedly improved, with substantial reductions in marathon finishing times. In contrast, these improvements in performance have not been accompanied by a corresponding decrease in running-related injuries. The running technique plays a crucial role in modulating impact forces, tissue loading, and energy transmission throughout the body. The first study of this thesis consisted of a field-based assessment of current knowledge using a questionnaire distributed to athletics coaches in Belgium. This survey highlighted that, despite the absence of scientific evidence, athletics coaches modify the running technique of endurance runners to enhance performance or reduce injury risk. According to coaches, midfoot strike is considered the most effective landing pattern for endurance performance (47%) and injury prevention (36%), while rearfoot strike is perceived as the least favourable (50% and 52%, respectively). These findings may be explained by two main factors: a lack of prospective studies on the topic and limited communication between field practitioners and researchers. Therefore, the overall objective of this thesis was to improve our understanding of the role of running technique alterations in recreational endurance runners, with a particular focus on performance enhancement and injury prevention.
As one of the main focus of interest of the athletes and their coaches is the improvement of performance, the first part of this thesis examined the relationship between running technique modifications and running performance. The second study of this thesis was a one-year prospective randomised controlled trial involving three groups of recreational endurance runners that examined the relationship between running technique alteration and running economy enhancement. The three groups were composed of: 1) a group who transitioned to minimalist footwear, 2) a group who altered their running technique (adopting a non-rearfoot strike and increasing running cadence), and 3) a control group who performed a placebo static stretching programme. Runners were evaluated at four time points throughout the year, with systematic assessments of running economy, running biomechanics, and foot–ankle characteristics. The results revealed significant improvements in running economy in the minimalist and running retraining groups after six and twelve months, by approximately 5% and 10% respectively. Running economy also improved in the control group but only at 12 months, by less than 5%. These results challenged current scientific recommendations that advise runners not to alter their running technique to improve running performance.
However, as the positive effect of altering running technique should not be counterbalanced by an increase in running-related injuries, the second part of this thesis explored the effect of running technique alteration on the incidence rate of running-related injuries. A recent randomised controlled trial has indicated that high-frequency components of impact-related variables may constitute risk factors for running-related injuries in recreational endurance runners. Nevertheless, it remained unclear how running technique alterations influence the high-frequency components of impact-related variables. In the third study of this thesis, we showed that adopting a forefoot strike pattern reduced the high-frequency components of impact-related parameters nearly three times more than increasing running cadence by 10% alone. Additionally, combining a forefoot strike pattern with a 10% increase in running cadence appeared to be the most effective strategy for reducing the high-frequency components of impact-related parameters. This strategy may therefore promising to reduce the incidence of running-related injuries, but should be confirmed through prospective studies as we did in a fourth study. This study was a one-year prospective randomised controlled trial based on the same design as the second study of this thesis. Our results did not show a reduction in overall injury incidence in either intervention group. However, it revealed a higher incidence of hip injuries in the control group (N = 9/46) compared to the running retraining group (N = 0/47) and a greater incidence of foot and ankle injuries in the retraining group (N = 12/47) compared to the control group (N = 5/46). Our study confirmed previous findings that running technique alteration may increase the risk of foot–ankle injuries when a runner follows a running technique alteration programme. However, if adopting a non-rearfoot strike pattern, increasing step rate, or transitioning to minimalist footwear can reduce knee joint loading, it simultaneously increases mechanical demands on the foot and ankle. These load transfers could explain the risk of developing secondary injuries during or following a running technique alteration. Given these considerations, it is essential to better understand the factors that may predispose runners to injury when undergoing such interventions and prepare them for this transition.
The third part of this thesis focuses on the importance of foot–ankle conditioning for safer running technique alteration. In the fifth study, we conducted a retrospective analysis comparing foot–ankle characteristics between rearfoot strikers and non-rearfoot strikers. Interestingly, non-rearfoot strikers demonstrated greater strength in the foot–ankle complex than rearfoot strikers. However, a prospective study was needed to understand whether foot and ankle characteristics constituted risk factors for alterations in running technique. The sixth study included in this thesis consisted of a secondary analysis of the previously described longitudinal randomised controlled trial. This study aimed to determine whether foot–ankle characteristics could be considered risk factors during a transition to minimalist footwear or the implementation of a running retraining programme. The results showed that runners with insufficient hallux flexor strength had an increased risk of sustaining foot and ankle injuries (odds ratio [CI95%]: 0.11 [0.02 –0.53]). This finding highlights the importance of incorporating targeted foot and ankle strengthening exercises during interventions involving changes in running technique. Finally, the seventh study focused on analysing and describing the biomechanical characteristics of commonly used running drills intended to strengthen foot and ankle structures. This study demonstrated the potential of these drills to enhance the foot’s propulsive function and provided athletics coaches with practical recommendations for their application in field settings.