Influence of the Heel-to-Toe Drop of Standard Cushioned Running Shoes on Injury Risk in Leisure-Time Runners: A Randomized Controlled Trial With 6-Month Follow-up

Maximalist Shoes: Separating Science From Hype

One of the most discussed but misunderstood topics in foot and ankle is shoe wear choices and the purported benefits of each type of shoe versus their actual scientific advantages. All foot and ankle care providers should be familiar with the various shoe wear types available to patients to improve their overall foot health. Recently, mainstream popularity and media coverage of maximalist shoes has created increased interest in the science and potential clinical benefits of maximalist shoes. The purpose of this review is to present the current biomechanical evidence of maximalist shoes and to help inform the foot and ankle community of their potential therapeutic applications.Levels of Evidence: Level V.

Towards functionally individualised designed footwear recommendation for overuse injury prevention: a scoping review

Injury prevention is essential in running due to the risk of overuse injury development. Tailoring running shoes to individual needs may be a promising strategy to reduce this risk. Novel manufacturing processes allow the production of individualised running shoes that incorporate features that meet individual biomechanical and experiential needs. However, specific ways to individualise footwear to reduce injury risk are poorly understood. Therefore, this scoping review provides an overview of (1) footwear design features that have the potential for individualisation; and (2) the literature on the differential responses to footwear design features between selected groups of individuals. These purposes focus exclusively on reducing the risk of overuse injuries. We included studies in the English language on adults that analysed: (1) potential interaction effects between footwear design features and subgroups of runners or covariates (e.g., age, sex) for running-related biomechanical risk factors or injury incidences; (2) footwear comfort perception for a systematically modified footwear design feature. Most of the included articles (n = 107) analysed male runners. Female runners may be more susceptible to footwear-induced changes and overuse injury development; future research should target more heterogonous sampling. Several footwear design features (e.g., midsole characteristics, upper, outsole profile) show potential for individualisation. However, the literature addressing individualised footwear solutions and the potential to reduce biomechanical risk factors is limited. Future studies should leverage more extensive data collections considering relevant covariates and subgroups while systematically modifying isolated footwear design features to inform footwear individualisation.

Simulation of Lower Limb Muscle Activation Using Running Shoes with Different Heel-to-Toe Drops Using Opensim

BACKGROUND

Although numerous studies have been conducted to investigate the acute effects of shoe drops on running kinematics and kinetic variables, their effects on muscle forces remain unknown. Thus, the primary aim of this study was to compare the muscle force, kinematics, and kinetic variables of habitually rearfoot runners with heel-to-toe drops of negative 8 mm shoes (minimalist shoes) and positive 9 mm shoes (normal shoes) during the running stance phase by using musculoskeletal modeling and simulation techniques.

METHODS

Experimental data of lower limb kinematics, ground reaction force, and muscle activation from 16 healthy runners with rearfoot strike patterns were collected and analyzed in OpenSim. Using Matlab, the statistical parameter mapping paired t-test was used to compare the joint angle, moment, and muscle force waveform.

RESULTS

The results revealed differences in the sagittal ankle and hip angles and sagittal knee moments between the different heel-to-toe drops of running shoes. Specifically, it showed that the negative 8 mm running shoes led to significantly smaller values than the positive 9 mm running shoes in terms of the angle of ankle dorsiflexion, ankle eversion, knee flexion, hip flexion, and hip internal and hip external rotation. The peak ankle dorsiflexion moment, ankle plantarflexion moment, ankle eversion moment, knee flexion moment, knee abduction moment, and knee internal rotation also decreased obviously with the minimalist running shoes, while the lateral gastrocnemius, Achilleas tendon, and extensor hallucis longus muscles were obviously greater in the minimalist shoes compared to normal shoes. The vastus medialis, vastus lateralis and extensor digitorum longus muscles force were smaller in the minimalist shoes.

CONCLUSIONS

Runners may shift to a midfoot strike pattern when wearing negative running shoes. High muscle forces in the gastrocnemius lateral, Achilleas tendon, and flexor hallucis longus muscles may also indicate an increased risk of Achilleas tendonitis and ankle flexor injuries.

Effect of Flat Running Shoes on Hip Kinematics in Male Recreational Runners

Patellofemoral joint pain and iliotibial band syndrome are very common running-related injuries. Excessive contralateral pelvic drop, hip adduction, and hip internal rotation have been suggested to be associated with the two injuries. The purpose of this repeated measures and the cross-sectional study was to investigate the effect of flat running shoes on these kinematic variables compared with that of conventional running shoes with a 10 mm drop. Eighteen male recreational runners were recruited to run in flat shoes and conventional shoes with a 10 mm drop, in random order. Impact force data and lower extremity kinematics were synchronously obtained using two Kistler force plates and eight motion infrared cameras, whereas differences in the impact force and hip kinematics were compared using statistical parametric mapping. Regarding hip kinematics, the hip flexion (p = 0.004) and adduction angles (p = 0.004) decreased significantly at 30-70% and 62-85% of the stance phase, respectively, while wearing flat running shoes; the contralateral pelvic drop angle (p = 0.001) decreased significantly at 31-75% of the stance phase while wearing flat running shoes. The knee internal rotation angle (p = 0.035) decreased significantly at 8-17% of the stance phase while wearing flat running shoes compared with conventional running shoes. Given that these kinematic variables are associated with patellofemoral joint pain and iliotibial band syndrome, flat running shoes may have potential benefits for the prevention or treatment of knee injuries.

A escolha do calçado por corredores amadores: caracterização e associação com o histórico de lesão auto reportada

RESUMO O calçado é um elemento importante para a prática de corrida. As evidências sobre os impactos das características do calçado e de sua prescrição nas lesões de corredores são restritas. Dessa forma, os objetivos deste estudo foram investigar o processo de escolha do calçado por corredores e verificar se variáveis relacionadas ao calçado e seu processo de escolha estavam associadas à presença e recorrência de lesão no último ano. Foi realizado um estudo observacional com 254 corredores que responderam um questionário autoadministrado sobre características demográficas, a prática esportiva, o calçado e o processo de sua escolha, e lesões ocorridas nos últimos 12 meses. O teste qui-quadrado foi empregado para verificar se havia diferença na distribuição das respostas de cada questão, enquanto o teste de regressão logística para verificar se as variáveis relacionadas ao calçado e ao processo de escolha predizem a presença e recorrência de lesão no último ano. Os resultados indicaram que a maioria dos corredores possui tênis específico para a prática esportiva e considera algumas características ao adquiri-lo, como o amortecimento intermediário e a diferença na altura do solado entre a parte posterior e a anterior de aproximadamente 10mm. A maioria indica conhecer seu tipo de pisada, mas não a considera na escolha do calçado. Além disso, a maioria não usa palmilha e não recebeu orientação para a escolha do calçado. O modelo obtido com a regressão não foi significativo. Assim, apesar de os corredores considerarem as características do calçado ao adquiri-lo, essas características e o processo de escolha não foram associados à presença e recorrência de lesão nos últimos 12 meses.

Selection of running shoes by amateur runners: characterization and association with the self-reported history of injury

ABSTRACT Running shoes are an essential element for sports practice. Evidence on the effect of the shoe characteristics and prescription in running injuries are scarce. Thus, this study aimed to investigate runners's process of choosing running shoes and to verify whether the variables related to running shoes and their selection process are associated with the presence and recurrence of injuries in the previous year. An observational study was conducted with 254 runners who answered a self-reported questionnaire about demographics, sports practice, shoe characteristics and selection criteria, and injuries in the last 12 months. The chi-square test evaluated whether there was a difference in the distribution of answers to each question. The logistic regression evaluated whether the variables related to shoes and selection criteria predicted injury’s presence and recurrence in the previous year. The results showed that most runners had specific shoes for sports practice and considered some characteristics of the shoes to choose them, including intermediate cushioning and a difference in the heel-to-toe drop of approximately 10mm. Most respondents indicated knowing their foot type but not considering it when choosing shoes. Besides, most individuals did not use foot orthotics and did not receive guidance to select their shoes. The model obtained with the regression was not significant. Therefore, despite considering shoe characteristics when choosing it, these features and the selection criteria were not associated with the presence and recurrence of injuries in the previous 12 months.

Strategies to prevent and manage running-related knee injuries: a systematic review of randomised controlled trials

OBJECTIVE

To evaluate the effectiveness of interventions to prevent and manage knee injuries in runners.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus up to May 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials (RCTs) with a primary aim of evaluating the effectiveness of intervention(s) to prevent or manage running-related knee injury.

RESULTS

Thirty RCTs (18 prevention, 12 management) analysed multiple interventions in novice and recreational running populations. Low-certainty evidence (one trial, 320 participants) indicated that running technique retraining (to land softer) reduced the risk of knee injury compared with control treadmill running (risk ratio (RR) 0.32, 95% CI 0.16 to 0.63). Very low-certainty to low-certainty evidence from 17 other prevention trials (participant range: 24 -3287) indicated that various footwear options, multicomponent exercise therapy, graduated running programmes and online and in person injury prevention education programmes did not influence knee injury risk (RR range: 0.55-1.06). In runners with patellofemoral pain, very low-certainty to low-certainty evidence indicated that running technique retraining strategies, medial-wedged foot orthoses, multicomponent exercise therapy and osteopathic manipulation can reduce knee pain in the short-term (standardised mean difference range: -4.96 to -0.90).

CONCLUSION

There is low-certainty evidence that running technique retraining to land softer may reduce knee injury risk by two-thirds. Very low-certainty to low-certainty evidence suggests that running-related patellofemoral pain may be effectively managed through a variety of active (eg, running technique retraining, multicomponent exercise therapy) and passive interventions (eg, foot orthoses, osteopathic manipulation).

PROSPERO REGISTRATION NUMBER

CRD42020150630.

Running shoes for preventing lower limb running injuries in adults

BACKGROUND

Lower-limb running injuries are common. Running shoes have been proposed as one means of reducing injury risk. However, there is uncertainty as to how effective running shoes are for the prevention of injury. It is also unclear how the effects of different characteristics of running shoes prevent injury.

OBJECTIVES

To assess the effects (benefits and harms) of running shoes for preventing lower-limb running injuries in adult runners.

SEARCH METHODS

We searched the following databases: CENTRAL, MEDLINE, Embase, AMED, CINAHL Plus and SPORTDiscus plus trial registers WHO ICTRP and ClinicalTrials.gov. We also searched additional sources for published and unpublished trials. The date of the search was June 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs involving runners or military personnel in basic training that either compared a) a running shoe with a non-running shoe; b) different types of running shoes (minimalist, neutral/cushioned, motion control, stability, soft midsole, hard midsole); or c) footwear recommended and selected on foot posture versus footwear not recommended and not selected on foot posture for preventing lower-limb running injuries. Our primary outcomes were number of people sustaining a lower-limb running injury and number of lower-limb running injuries. Our secondary outcomes were number of runners who failed to return to running or their previous level of running, runner satisfaction with footwear, adverse events other than musculoskeletal injuries, and number of runners requiring hospital admission or surgery, or both, for musculoskeletal injury or adverse event.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and performed data extraction and risk of bias assessment. The certainty of the included evidence was assessed using GRADE methodology.

MAIN RESULTS

We included 12 trials in the analysis which included a total of 11,240 participants, in trials that lasted from 6 to 26 weeks and were carried out in North America, Europe, Australia and South Africa. Most of the evidence was low or very low certainty as it was not possible to blind runners to their allocated running shoe, there was variation in the definition of an injury and characteristics of footwear, and there were too few studies for most comparisons. We did not find any trials that compared running shoes with non-running shoes. Neutral/cushioned versus minimalist (5 studies, 766 participants) Neutral/cushioned shoes may make little or no difference to the number of runners sustaining a lower-limb running injuries when compared with minimalist shoes (low-certainty evidence) (risk ratio (RR) 0.77, 95% confidence interval (CI) 0.59 to 1.01). One trial reported that 67% and 92% of runners were satisfied with their neutral/cushioned or minimalist running shoes, respectively (RR 0.73, 95% CI 0.47 to 1.12). Another trial reported mean satisfaction scores ranged from 4.0 to 4.3 in the neutral/ cushioned group and 3.6 to 3.9 in the minimalist running shoe group out of a total of 5. Hence neutral/cushioned running shoes may make little or no difference to runner satisfaction with footwear (low-certainty evidence). Motion control versus neutral / cushioned (2 studies, 421 participants) It is uncertain whether or not motion control shoes reduce the number of runners sustaining a lower-limb running injuries when compared with neutral / cushioned shoes because the quality of the evidence has been assessed as very low certainty (RR 0.92, 95% CI 0.30 to 2.81). Soft midsole versus hard midsole (2 studies, 1095 participants) Soft midsole shoes may make little or no difference to the number of runners sustaining a lower-limb running injuries when compared with hard midsole shoes (low-certainty of evidence) (RR 0.82, 95% CI 0.61 to 1.10). Stability versus neutral / cushioned (1 study, 57 participants) It is uncertain whether or not stability shoes reduce the number of runners sustaining a lower-limb running injuries when compared with neutral/cushioned shoes because the quality of the evidence has been assessed as very low certainty (RR 0.49, 95% CI 0.18 to 1.31). Motion control versus stability (1 study, 56 participants) It is uncertain whether or not motion control shoes reduce the number of runners sustaining a lower-limb running injuries when compared with stability shoes because the quality of the evidence has been assessed as very low certainty (RR 3.47, 95% CI 1.43 to 8.40). Running shoes prescribed and selected on foot posture (3 studies, 7203 participants) There was no evidence that running shoes prescribed based on static foot posture reduced the number of injuries compared with those who received a shoe not prescribed based on foot posture in military recruits (Rate Ratio 1.03, 95% CI 0.94 to 1.13). Subgroup analysis confirmed these findings were consistent between males and females. Therefore, prescribing running shoes and selecting on foot posture probably makes little or no difference to lower-limb running injuries (moderate-certainty evidence). Data were not available for all other review outcomes.

AUTHORS' CONCLUSIONS

Most evidence demonstrates no reduction in lower-limb running injuries in adults when comparing different types of running shoes. Overall, the certainty of the evidence determining whether different types of running shoes influence running injury rates was very low to low, and as such we are uncertain as to the true effects of different types of running shoes upon injury rates. There is no evidence that prescribing footwear based on foot type reduces running-related lower-limb injures in adults. The evidence for this comparison was rated as moderate and as such we can have more certainty when interpreting these findings. However, all three trials included in this comparison used military populations and as such the findings may differ in recreational runners.  Future researchers should develop a consensus definition of running shoe design to help standardise classification. The definition of a running injury should also be used consistently and confirmed via health practitioners. More researchers should consider a RCT design to increase the evidence in this area. Lastly, future work should look to explore the influence of different types or running shoes upon injury rates in specific subgroups.

Effect of the Innovative Running Shoes With the Special Midsole Structure on the Female Runners’ Lower Limb Biomechanics

The study aimed to research the effects of innovative running shoes (a high heel-to-toe drop and special structure of midsole) on the biomechanics of the lower limbs and perceptual sensitivity in female runners. Fifteen healthy female runners were recruited to run through a 145-m runway with planted force plates at one peculiar speed (3.6 m/s ± 5%) with two kinds of shoe conditions (innovative running shoes vs. normal running shoes) while getting biomechanical data. The perception of shoe characteristics was assessed simultaneously through a 15-cm visual analog scale. The statistical parametric mapping technique calculated the time-series parameters. Regarding 0D parameters, the ankle dorsiflexion angle of innovative running shoes at touchdown was higher, and the peak dorsiflexion angle, range of motion, peak dorsiflexion velocity, and plantarflexion moment on the metatarsophalangeal joint of innovative running shoes during running were significantly smaller than those of normal running shoes (all p < 0.001). In addition, the braking phase and the time of peak vertical force 1 of innovative running shoes were found to be longer than those of normal running shoes (both p < 0.05). Meanwhile, the average vertical loading rate 1, peak vertical loading rate 1, peak braking force, and peak vertical force 1 in the innovative running shoes were lower than those of the normal running shoes during running (both p < 0.01). The statistical parametric mapping analysis exhibited a higher ankle dorsiflexion angle (0–4%, p < 0.05), a smaller knee internal rotation angle (0–6%, p < 0.05) (63–72%, p < 0.05), a decreased vertical ground reaction force (11–17%, p = 0.009), and braking anteroposterior ground reaction force (22–27%, p = 0.043) for innovative running shoes than normal running shoes. Runners were able to perceive the cushioning of innovative running shoes was better than that of normal running shoes. These findings suggested combining the high offset and structure of the midsole would benefit the industrial utilization of shoe producers in light of reducing the risk of running injuries for female runners.

Running Footwear and Impact Peak Differences in Recreational Runners

Simple Summary

Running is a physical activity practiced by many people to maintain good levels of movement. Recreational runners commonly strike the ground with the postero–lateral zone of the foot, which may be associated with a higher biomechanical load on the lower limb, called impact peak. Different running shoes with specific cushioning are available to overcome the biomechanical load, e.g., shoes with a thickness difference between the forefoot and heel parts of the sole, called heel-to-toe drop. Analyzing the running pattern of recreational runners may be challenging because biomechanics laboratories mainly analyze these characteristics in individuals with visible alterations. To overcome these limitations, we employed a 3D markerless system; furthermore, we investigated footwear use. These parameters were studied to understand the behavior of those runners with and without a higher impact peak. Thirty participants underwent a running analysis and a questionnaire about their footwear. The study’s main finding highlighted kinematic and spatiotemporal differences between the runners presenting a higher impact peak and those without it. Furthermore, we observed that runners without an impact peak prefer shoes with a lower heel-to-toe drop, while the other group prefers shoes with a higher heel-to-toe drop. Investigating biomechanics characteristics is essential to reduce possible injury.

Abstract

Running is a physical activity and the investigation of its biomechanical aspects is crucial both to avoid injuries and enhance performance. Recreational runners may be liable to increased stress over the body, particularly to lower limb joints. This study investigates the different running patterns of recreational runners by analyzing characteristics of the footwear impact peak, spatiotemporal, and kinematic parameters among those that present with a peak impact and those that do not, with a 3D markerless system. Thirty recreational runners were divided into two groups: impact peak group (IP) (n = 16) and no impact peak group (n = 14) (n-IP). Kinematic and spatiotemporal parameters showed a large Cohen’s d effect size between the groups. The mean hip flexion was IP 40.40° versus n-IP 32.30° (d = −0.82). Hip extension was IP 30.20° versus n-IP 27.70° (d = −0.58), and ankle dorsiflexion was IP 20.80°, versus n-IP 13.37° (d = −1.17). Stride length was IP 117.90 cm versus n-IP 105.50 cm (d = −0.84). Steps per minute was IP group 170 spm, versus n-IP 163 spm (d = −0.51). The heel-to-toe drop was mainly 10–12 mm for the IP group and 4–6 mm for the n-IP group. Recreational runners whose hip extension is around 40°, ankle dorsiflexion around 20°, and initial foot contact around 14°, may be predisposed to the presence of an impact peak.

Factors Influencing Runner's Choices of Footwear

Until the mid-2000s, qualitative research has been virtually absent from running injury research. A handful of studies have been recently published regarding the attitudes and perceptions of runners and coaches toward injury development. Footwear is frequently perceived as a risk factor for running related injuries, but empeirical evidence fails to support such beliefs. The reasons why runners choose specific footwear warrants formal investigation to further understand the links between footwear and running related injuries. This study aimed to investigate the factors influencing runners choices of footwear. Interviews were conducted with 12 runners. Recordings from the interviews were transcribed verbatim and themes were developed using thematic analysis. Findings revealed 15 unique factors that influence runner's choices of footwear for running. These factors were grouped into three main themes: personal footwear characteristic preferences, other people and economic considerations. Runners largely gather information about their footwear choices from past experiences and people they trust and admire. They also emphasized the complexity of footwear choices due to availability and the constant changes preset within the footwear industry. This research adds to the growing body of knowledge to better understand the wider running injury system. Further studies are needed to establish how runners perceptions of their footwear impact injury rates and to develop effective injury prevention strategies.

The effect of heel-to-toe drop of running shoes on patellofemoral joint stress during running

BACKGROUND

Traditional running shoes with heel-to-toe drops is thought to be a contributor to increased patellofemoral joint stress, which is proposed as a mechanism of patellofemoral pain.

RESEARCH QUESTION

Is there an increase in patellofemoral joint stress when running in shoes with drops compared to running in shoes without a drop?

METHODS

Lower limbs kinematics and ground reaction force were collected from eighteen healthy runners during over-ground running in shoes with 15 mm, 10 mm, 5 mm drops, and without a drop. Patellofemoral joint force and stress were calculated from the kinematic and kinetic data using a biomechanical model of the patellofemoral joint.

RESULTS

The peak patellofemoral joint stress was increased by more than 15% when running in shoes with 15 mm and 10 mm drops compared to running in shoes without a drop (p = 0.003, p = 0.001). The knee flexion angle was significantly increased when running in shoes with 15 mm, 10 mm and 5 mm drops (p = 0.014, p = 0.003, p = 0.002), the knee extension moment (p = 0.009, p = 0.002) and patellofemoral joint force (p = 0.003, p = 0.001) were increased when running in shoes with 15 mm and 10 mm drops, compared to running in shoes without a drop.

SIGNIFICANCE

Compared to running in shoes without a drop, running in shoes with drops > 5 mm increase the peak patellofemoral joint stress significantly, which is mainly due to the increased knee extension moment.

Acute Effects of Heel-to-Toe Drop and Speed on Running Biomechanics and Strike Pattern in Male Recreational Runners: Application of Statistical Nonparametric Mapping in Lower Limb Biomechanics

With the increased popularity of running, many studies have been conducted into footwears that are highly related to running performance and running-related injuries. Previous studies investigated different shoe types and running shoes with different heel-to-toe drops (HTDs). However, no research was found in investigating shoes with negative values with HTD. Therefore, the aim of this study was to determine the acute effect of HTD and running speed on lower limb biomechanics and strike pattern in recreational runners. Thirteen male recreational runners wearing shoes with two different HTDs (−8 and 8 mm) performed running at three different speeds (preferred speed [PS], 90% of PS, 110% of PS). Lower extremity kinematics and ground reaction forces were synchronously captured via Vicon motion analysis system and AMTI force platform. Strike index (SI), vertical average loading rate (VALR), vertical instantaneous loading rate (VILR), excursion, eversion duration, joint angles, and range of motion (ROM) of metatarsophalangeal (MTP), ankle, knee, and hip joints were calculated. Joint angles during the entire stance phase were analyzed applying the statistical nonparametric mapping (SnPM) method. SI and VILR in shoes with −8 mm HTD significantly increased by 18.99% and 31.836 BW/s compared to those with 8 mm HTD (SI: p = 0.002; VILR: p < 0.001). Significant alterations of ROM occurred in the MTP, ankle, and knee joints (p < 0.05), and HTD factor primarily accounted for these changes. Joint angles (MTP, knee, and hip) during the entire stance phase altered due to HTD and speed factors. Running speed primarily influenced the kinematics parameters of knee and hip joints, increasing knee angles in the frontal plane and hip angle in the horizontal plane at PS (p > 0.05). Compared to shoes with 8 mm HTD, shoes with −8 mm HTD may be useful to storage and return energy because of the increased ROM of MTP in the sagittal plane. Besides, forefoot strike gait retraining was recommended before transition from normal running shoes to running shoes with −8 mm HTD.

Evolution of distance running shoes: performance, injuries, and rules

Over the last 50 years, the development of running shoes has been mainly focused on improving the protection and comfort of the runner and her/his foot. Although there have been tentative attempts by companies to make shoes a tool for improving athletic performance, this goal has only recently been achieved. Indeed, the year 2016 was a real turning point when Nike launched its first shoe benefiting from the advanced footwear technology. Advanced footwear technology (AFT) mostly consists of an increased sole thickness, a curved and stiff plate embedded or below the shoe midsole, and an outsole with a marked concave shape. This innovation turned to a game changer in the world of distances running performance. Indeed, between 2016 and 2019, many male and female runners broke personal best times, national records, area, and world records in distance from 5 km to the marathon. The present article aimed at describing the magnitude of these performance enhancements in distance running as well as and the possible underlying performance-enhancement mechanisms associated with the advanced footwear technology. It also reviewed the existing literature on the safety aspects of "classical" construction shoes and AFT shoes. It concluded on a possible shoe mechanical tests-based protocol to maintain fair distance running competitions while not totally preventing manufacturers to innovate, and some thoughts on the nature and goals of further studies to be conducted to assess the safety (macro- and micro-traumatic) AFT in both elite and recreational runner populations.

Can the "Appropriate" Footwear Prevent Injury in Leisure-Time Running? Evidence Versus Beliefs

Leisure-time running is one of the most popular forms of physical activity around the world. It can be practiced almost everywhere and requires mainly a pair of "appropriate" running shoes. However, the term appropriate is ambiguous, and the properties of running footwear have always generated hot debates among clinicians, coaches, and athletes, whatever the level of practice. As the main interface between the runner's foot and the ground, the shoe potentially plays an important role in managing repetitive external mechanical loads applied to the musculoskeletal system and, thus, in injury prevention. Consequently, over the last decades, running shoes have been prescribed based on matching shoe features to foot morphology. This strategy aligns with the popular belief that footwear is one of the main extrinsic factors influencing running-related injury risk. Despite a seemingly sound strategy for shoe prescription and constant progress in running-footwear technology, the injury rate remains high. Therefore, our aim in this narrative literature review is to clarify whether the prescription of appropriate footwear to prevent injury in running is evidence based, the result of logical fallacy, or just a myth. The literature presented in this review is based on a nonsystematic search of the MEDLINE database and focuses on work investigating the effect of shoe features on injury risk in runners. In addition, key elements for a proper understanding of the literature on running footwear and injury risk are addressed. In this literature review, we outline (1) the main risk factors and the mechanisms underlying the occurrence of running-related injury, (2) important methodologic considerations for generating high-level evidence, (3) the evidence regarding the influence of running-shoe features on injury risk, (4) future directions for research, and (5) final general recommendations.

What are the Benefits and Risks Associated with Changing Foot Strike Pattern During Running? A Systematic Review and Meta-analysis of Injury, Running Economy, and Biomechanics

BACKGROUND

Running participation continues to increase. The ideal strike pattern during running is a controversial topic. Many coaches and therapists promote non-rearfoot strike (NRFS) running with a belief that it can treat and prevent injury, and improve running economy.

OBJECTIVE

The aims of this review were to synthesise the evidence comparing NRFS with rearfoot strike (RFS) running patterns in relation to injury and running economy (primary aim), and biomechanics (secondary aim).

DESIGN

Systematic review and meta-analysis. Consideration was given to within participant, between participant, retrospective, and prospective study designs.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and SPORTDiscus.

RESULTS

Fifty-three studies were included. Limited evidence indicated that NRFS running is retrospectively associated with lower reported rates of mild (standard mean difference (SMD), 95% CI 3.25, 2.37-4.12), moderate (3.65, 2.71-4.59) and severe (0.93, 0.32-1.55) repetitive stress injury. Studies prospectively comparing injury risk between strike patterns are lacking. Limited evidence indicated that running economy did not differ between habitual RFS and habitual NRFS runners at slow (10.8-11.0 km/h), moderate (12.6-13.5 km/h), and fast (14.0-15.0 km/h) speeds, and was reduced in the immediate term when an NRFS-running pattern was imposed on habitual RFS runners at slow (10.8 km/h; SMD = - 1.67, - 2.82 to - 0.52) and moderate (12.6 km/h; - 1.26, - 2.42 to - 0.10) speeds. Key biomechanical findings, consistently including both comparison between habitual strike patterns and following immediate transition from RFS to NRFS running, indicated that NRFS running was associated with lower average and peak vertical loading rate (limited-moderate evidence; SMDs = 0.72-2.15); lower knee flexion range of motion (moderate-strong evidence; SMDs = 0.76-0.88); reduced patellofemoral joint stress (limited evidence; SMDs = 0.63-0.68); and greater peak internal ankle plantar flexor moment (limited evidence; SMDs = 0.73-1.33).

CONCLUSION

The relationship between strike pattern and injury risk could not be determined, as current evidence is limited to retrospective findings. Considering the lack of evidence to support any improvements in running economy, combined with the associated shift in loading profile (i.e., greater ankle and plantarflexor loading) found in this review, changing strike pattern cannot be recommended for an uninjured RFS runner.

PROSPERO REGISTRATION

CRD42015024523.

Shoe feature recommendations for different running levels: A Delphi study

Providing runners with footwear that match their functional needs has the potential to improve footwear comfort, enhance running performance and reduce the risk of overuse injuries. It is currently not known how footwear experts make decisions about different shoe features and their properties for runners of different levels. We performed a Delphi study in order to understand: 1) definitions of different runner levels, 2) which footwear features are considered important and 3) how these features should be prescribed for runners of different levels. Experienced academics, journalists, coaches, bloggers and physicians that examine the effects of footwear on running were recruited to participate in three rounds of a Delphi study. Three runner level definitions were refined throughout this study based on expert feedback. Experts were also provided a list of 20 different footwear features. They were asked which features were important and what the properties of those features should be. Twenty-four experts, most with 10+ years of experience, completed all three rounds of this study. These experts came to a consensus for the characteristics of three different running levels. They indicated that 12 of the 20 footwear features initially proposed were important for footwear design. Of these 12 features, experts came to a consensus on how to apply five footwear feature properties for all three different running levels. These features were: upper breathability, forefoot bending stiffness, heel-to-toe drop, torsional bending stiffness and crash pad. Interestingly, the experts were not able to come to a consensus on one of the most researched footwear features, rearfoot midsole hardness. These recommendations can provide a starting point for further biomechanical studies, especially for features that are considered as important, but have not yet been examined experimentally.

What are the perceptions of runners and healthcare professionals on footwear and running injury risk?

Objectives

There is a gap in research exploring perceptions of runners and healthcare professionals (HCPs) about running footwear and injury risk. The objectives of this study were: (1) to document factors considered by runners when selecting footwear; (2) to compare perceptions on footwear and injury risk in runners and HCPs; and (3) to evaluate the perceived usefulness of an online educational module.

Methods

Using an online survey, we collected information on demographics and perceptions about footwear and injury risk. Runners reported their footwear selection strategy, and HCPs their typical recommendations. An evidence-based educational module was presented, and participants rated its usefulness.

Results

The survey was completed by 2442 participants, of which 1035 completed the optional postmodule questions. Runners reported relying mostly on comfort and advice from retailers when selecting shoes. Perceptions regarding the effects of specific footwear types (minimalist, maximalist), characteristics (softness, drop) and selection strategy (foot type, transition) on biomechanics and injury risk were different between HCPs and runners. Overall, runners perceived footwear as more important to prevent injury than did HCPs (7.6/10, 99% CI 7.4 to 7.7 vs 6.2/10, 99% CI 6.0 to 6.5; p<0.001). Both runners (8.1/10, 99% CI 7.9 to 8.3) and HCPs (8.7/10, 99% CI 8.6 to 8.9) found the educational module useful. A majority of respondents indicated the module changed their perceptions.

Conclusion

Footwear is perceived as important in reducing running injury risk. This online module was deemed useful in educating about footwear evidence. Future studies should evaluate if changes in perceptions can translate to behaviour change and, ultimately, reduced injury risk.

Review of Terms and Definitions Used in Descriptions of Running Shoes

OBJECTIVE

Our study aim is to identify and describe the definitions used for different types of running shoes. In addition, we highlight the existence of gaps in these concepts and propose possible new approaches. Methods: This review was undertaken in line with the guidelines proposed by Green et al., based on a literature search (until December 2019) of the PubMed, Web of Science, Scopus, SPORTDiscus and Google Scholar databases. A total of 23 papers met the inclusion criteria applied to identify the definition of running shoes.

RESULTS

Although there is a certain consensus on the characteristics of minimalist footwear, it is also described by other terms, such as barefoot-style or barefoot-simulating. Diverse terms are also used to describe other types of footwear, and in these cases, there is little or no consensus regarding their characteristics.

CONCLUSIONS

The terms barefoot-simulated footwear, barefoot-style footwear, lightweight shoes and full minimalist shoes are all used to describe minimalist footwear. The expressions partial minimalist, uncushioned minimalist and transition shoes are used to describe footwear with non-consensual characteristics. Finally, labels such as shod shoes, standard cushioned running shoes, modern shoes, neutral protective running shoes, conventional, standardised, stability style or motion control shoes span a large group of footwear styles presenting different properties.

Shoe Cushioning Influences the Running Injury Risk According to Body Mass: A Randomized Controlled Trial Involving 848 Recreational Runners

BACKGROUND

Shoe cushioning is expected to protect runners against repetitive loading of the musculoskeletal system and therefore running-related injuries. Also, it is a common belief that heavier runners should use footwear with increased shock absorption properties to prevent injuries.

PURPOSE

The aim of this study was to determine if shoe cushioning influences the injury risk in recreational runners and whether the association depends on the runner's body mass.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Healthy runners (n = 848) randomly received 1 of 2 shoe prototypes that only differed in their cushioning properties. Global stiffness was 61.3 ± 2.7 and 94.9 ± 5.9 N/mm in the soft and hard versions, respectively. Participants were classified as light or heavy according to their body mass using the median as a cut-off (78.2 and 62.8 kg in male and female runners, respectively). They were followed over 6 months regarding running activity and injury (any physical complaint reducing/interrupting running activity for at least 7 days). Data were analyzed through time-to-event models with the subhazard rate ratio (SHR) and their 95% confidence interval (CI) as measures of association. A stratified analysis was conducted to investigate the effect of shoe cushioning on the injury risk in lighter and heavier runners.

RESULTS

The runners who had received the hard shoes had a higher injury risk (SHR, 1.52 [95% CI, 1.07-2.16]), while body mass was not associated with the injury risk (SHR, 1.00 [95% CI, 0.99-1.01]). However, after stratification according to body mass, results showed that lighter runners had a higher injury risk in hard shoes (SHR, 1.80 [95% CI, 1.09-2.98]) while heavier runners did not (SHR, 1.23 [95% CI, 0.75-2.03]).

CONCLUSION

The injury risk was higher in participants running in the hard shoes compared with those using the soft shoes. However, the relative protective effect of greater shoe cushioning was found only in lighter runners.

REGISTRATION

NCT03115437 (ClinicalTrials.gov identifier).

A Randomized Study of a Strength Training Program to Prevent Injuries in Runners of the New York City Marathon

BACKGROUND

Lower extremity overuse injuries are common among runners, especially first-time marathoners. Hip abductor and quadriceps strengthening is often recommended to reduce running-related injuries.

HYPOTHESIS

A 12-week strength training program would decrease the rate of overuse injuries resulting in marathon noncompletion and improve race finishing time.

STUDY DESIGN

Randomized trial.

LEVEL OF EVIDENCE

Level 2.

METHODS

Twelve weeks before the New York City Marathon, first-time marathon runners age 18 years and older were randomized into a strength training group or an observation group. The strength training group was instructed to perform a 10-minute program 3 times weekly using written and video instruction. This program targeted the quadriceps, hip abductor, and core muscle groups. Injuries were self-reported through biweekly surveys, with major injuries being those that resulted in marathon noncompletion and minor injuries being those that impaired training or race performance.

RESULTS

A total of 720 runners were enrolled (mean age, 35.9 ± 9.4 years; 69.4% female), of whom 583 runners started the marathon and 579 completed it. The incidence of major injury was 8.9% and minor injury was 48.5%. Fifty two of 64 major injuries were overuse, of which 20 were bone stress injuries. The incidence of overuse injury resulting in marathon noncompletion was 7.1% in the strength training group and 7.3% in the observation group (risk ratio, 0.97; 95% CI, 0.57-1.63; P = 0.90). The mean finishing time was 5 hours 1 ± 60 minutes in the strength training group and 4 hours 58 ± 55 minutes in the observation group (P = 0.35).

CONCLUSION

There is a high prevalence of injury among first-time marathon runners, but this self-directed strength training program did not decrease overuse injury incidence resulting in marathon noncompletion.

CLINICAL RELEVANCE

Prevention strategies such as strength training need to be developed and evaluated through clinical trials to reduce the high prevalence of overuse injuries in runners, especially for high-risk populations such as first-time marathon runners.

Opinions, Barriers, and Facilitators of Injury Prevention in Recreational Runners

BACKGROUND

Effective injury prevention measures for running-related injuries (RRIs) have not yet been identified. More insight into the opinions of runners about injury prevention might help to develop effective injury prevention programs that are supported by the target population.

OBJECTIVES

To describe the opinions of recreational runners on different components of injury prevention, and to identify the barriers to and facilitators of injury prevention in adult recreational runners.

METHODS

In this comparative cross-sectional study, a single questionnaire was sent to 2378 recreational runners. The questionnaire contained questions about their interests, actions undertaken, and perceived barriers to and facilitators of injury prevention. Descriptive analyses were used to examine differences with regard to sex, age, and previous RRIs.

RESULTS

One thousand thirty-four adult recreational runners (43.5%) responded to the questionnaire. Runners with previous RRIs were more likely to rate injury prevention as very useful than runners who had never sustained an RRI (76.8% versus 63.6%, P<.001). In total, 81.8% of the participants indicated that they already performed preventive measures, including changes to training schedules (65.4%) and warming up and cooling down (57.8%). Most frequently reported barriers to injury prevention were "not knowing what to do" (45.2%) and "no history of RRI" (34.6%). The most important facilitator was an injury (60.1%). Women more often preferred information via a trainer or running store than did men, while men more frequently preferred websites or e-mail.

CONCLUSION

The majority of runners rated injury prevention as important. To increase effectiveness, future prevention programs should be developed with an awareness of the barriers and facilitators experienced by adult runners. J Orthop Sports Phys Ther 2019;49(10):736-742. Epub 23 Aug 2019. doi:10.2519/jospt.2019.9029.

Randomised controlled trials (RCTs) in sports injury research: authors—please report the compliance with the intervention

Background

In randomised controlled trials (RCTs) of interventions that aim to prevent sports injuries, the intention-to-treat principle is a recommended analysis method and one emphasised in the Consolidated Standards of Reporting Trials (CONSORT) statement that guides quality reporting of such trials. However, an important element of injury prevention trials—compliance with the intervention—is not always well-reported. The purpose of the present educational review was to describe the compliance during follow-up in eight large-scale sports injury trials and address compliance issues that surfaced. Then, we discuss how readers and researchers might consider interpreting results from intention-to-treat analyses depending on the observed compliance with the intervention.

Methods

Data from seven different randomised trials and one experimental study were included in the present educational review. In the trials that used training programme as an intervention, we defined full compliance as having completed the programme within ±10% of the prescribed running distance (ProjectRun21 (PR21), RUNCLEVER, Start 2 Run) or time-spent-running in minutes (Groningen Novice Running (GRONORUN)) for each planned training session. In the trials using running shoes as the intervention, full compliance was defined as wearing the prescribed running shoe in all running sessions the participants completed during follow-up.

Results

In the trials that used a running programme intervention, the number of participants who had been fully compliant was 0 of 839 (0%) at 24-week follow-up in RUNCLEVER, 0 of 612 (0%) at 14-week follow-up in PR21, 12 of 56 (21%) at 4-week follow-up in Start 2 Run and 8 of 532 (1%) at 8-week follow-up in GRONORUN. In the trials using a shoe-related intervention, the numbers of participants who had been fully compliant at the end of follow-up were 207 of 304 (68%) in the 21 week trial, and 322 of 423 (76%), 521 of 577 (90%), 753 of 874 (86%) after 24-week follow-up in the other three trials, respectively.

Conclusion

The proportion of runners compliant at the end of follow-up ranged from 0% to 21% in the trials using running programme as intervention and from 68% to 90% in the trials using running shoes as intervention. We encourage sports injury researchers to carefully assess and report the compliance with intervention in their articles, use appropriate analytical approaches and take compliance into account when drawing study conclusions. In studies with low compliance, G-estimation may be a useful analytical tool provided certain assumptions are met.

The Garmin-RUNSAFE Running Health Study on the aetiology of running-related injuries: rationale and design of an 18-month prospective cohort study including runners worldwide

INTRODUCTION

Running injuries affect millions of persons every year and have become a substantial public health issue owing to the popularity of running. To ensure adherence to running, it is important to prevent injuries and to have an in-depth understanding of the aetiology of running injuries. The main purpose of the present paper was to describe the design of a future prospective cohort study exploring if a dose-response relationship exists between changes in training load and running injury occurrence, and how this association is modified by other variables.

METHODS AND ANALYSIS

In this protocol, the design of an 18-month observational prospective cohort study is described that will include a minimum of 20 000 consenting runners who upload their running data to Garmin Connect and volunteer to be a part of the study. The primary outcome is running-related injuries categorised into the following states: (1) no injury; (2) a problem; and (3) injury. The primary exposure is change in training load (eg, running distance and the cumulative training load based on the number of strides, ground contact time, vertical oscillation and body weight). The change in training load is a time-dependent exposure in the sense that progression or regression can change many times during follow-up. Effect-measure modifiers include, but is not limited to, other types of sports activity, activity of daily living and demographics, and are assessed through questionnaires and/or by Garmin devices.

ETHICS AND DISSEMINATION

The study design, procedures and informed consent have been evaluated by the Ethics Committee of the Central Denmark Region (Request number: 227/2016 - Record number: 1-10-72-189-16).

Online multifactorial prevention programme has no effect on the number of running-related injuries: a randomised controlled trial

Objective

To examine the effect of a multifactorial, online injury prevention programme on the number of running-related injuries (RRIs) in recreational runners.

Methods

Adult recreational runners who registered for a running event (distances 5 km up to 42.195 km) were randomised into the intervention group or control group. Participants in the intervention group were given access to the online injury prevention programme, which consisted of information on evidence-based risk factors and advices to reduce the injury risk. Participants in the control group followed their regular preparation for the running event. The primary outcome measure was the number of self-reported RRIs in the time frame between registration for a running event and 1 month after the running event.

Results

This trial included 2378 recreational runners (1252 men; mean [SD] age 41.2 [11.9] years), of which 1196 were allocated to the intervention group and 1182 to the control group. Of the participants in the intervention group 37.5% (95% CI 34.8 to 40.4) sustained a new RRI during follow-up, compared with 36.7% (95% CI 34.0 to 39.6) in the control group. Univariate logistic regression analysis showed no significant difference between the intervention and control group (OR 1.08; 95% CI 0.90 to 1.30). Furthermore, the prevention programme seemed to have a negative impact on the occurrence of new RRIs in the subgroup of runners with no injuries in the 12 months preceding the trial (OR 1.30; 95% CI 0.99 to 1.70).

Conclusion

A multifactorial, online injury prevention programme did not decrease the total number of RRIs in recreational runners.

Trial registration number

NTR5998.

Time-to-event analysis for sports injury research part 2: time-varying outcomes

BACKGROUND

Time-to-event modelling is underutilised in sports injury research. Still, sports injury researchers have been encouraged to consider time-to-event analyses as a powerful alternative to other statistical methods. Therefore, it is important to shed light on statistical approaches suitable for analysing training load related key-questions within the sports injury domain.

CONTENT

In the present article, we illuminate: (i) the possibilities of including time-varying outcomes in time-to-event analyses, (ii) how to deal with a situation where different types of sports injuries are included in the analyses (ie, competing risks), and (iii) how to deal with the situation where multiple subsequent injuries occur in the same athlete.

CONCLUSION

Time-to-event analyses can handle time-varying outcomes, competing risk and multiple subsequent injuries. Although powerful, time-to-event has important requirements: researchers are encouraged to carefully consider prior to any data collection that five injuries per exposure state or transition is needed to avoid conducting statistical analyses on time-to-event data leading to biased results. This requirement becomes particularly difficult to accommodate when a stratified analysis is required as the number of variables increases exponentially for each additional strata included. In future sports injury research, we need stratified analyses if the target of our research is to respond to the question: 'how much change in training load is too much before injury is sustained, among athletes with different characteristics?' Responding to this question using multiple time-varying exposures (and outcomes) requires millions of injuries. This should not be a barrier for future research, but collaborations across borders to collecting the amount of data needed seems to be an important step forward.

Effects of footwear midsole thickness on running biomechanics

Shoe manufacturers launch running shoes with increased (e.g., maximalists) or decreased (e.g., minimalists) midsole thickness and claim that they may prevent running injury. Previous studies tested footwear models with different midsole thicknesses on the market but the shoe construct was not strictly comparable. Therefore, in the present study, we examined the effect of midsole thickness, from 1-mm to 29-mm, in a standard test shoe prototype on the vertical loading rates, footstrike angle and temporal spatial parameters in distance runners. Fifteen male habitual rearfoot strikers were recruited from local running clubs. They were asked to run on an instrumented treadmill in shoes with different midsole thicknesses. We found significant interactions between midsole thickness with vertical loading rates (p < 0.001), footstrike angle (p = 0.013), contact time (p < 0.001), cadence (p = 0.003), and stride length (p = 0.004). Specifically, shoes with thinner midsole (1- and 5-mm) significantly increased the vertical loading rates and shortened the contact time, when compared with thicker midsole shoes (25- and 29-mm). However, we did not observe any substantial differences in the footstrike angle, cadence and stride length between other shod conditions. The present study provides biomechanical data regarding the relationship between full spectrum midsole thicknesses and running biomechanics in a group of rearfoot strikers.

Design of ProjectRun21: a 14-week prospective cohort study of the influence of running experience and running pace on running-related injury in half-marathoners

BACKGROUND

Participation in half-marathon has been steeply increasing during the past decade. In line, a vast number of half-marathon running schedules has surfaced. Unfortunately, the injury incidence proportion for half-marathoners has been found to exceed 30% during 1-year follow-up. The majority of running-related injuries are suggested to develop as overuse injuries, which leads to injury if the cumulative training load over one or more training sessions exceeds the runners' load capacity for adaptive tissue repair. Owing to an increase of load capacity along with adaptive running training, the runners' running experience and pace abilities can be used as estimates for load capacity. Since no evidence-based knowledge exist of how to plan appropriate half-marathon running schedules considering the level of running experience and running pace, the aim of ProjectRun21 is to investigate the association between running experience or running pace and the risk of running-related injury.

METHODS

Healthy runners using Global Positioning System (GPS) watch between 18 and 65 years will be invited to participate in this 14-week prospective cohort study. Runners will be allowed to self-select one of three half-marathon running schedules developed for the study. Running data will be collected objectively by GPS. Injury will be based on the consensus-based time loss definition by Yamato et al.: "Running-related (training or competition) musculoskeletal pain in the lower limbs that causes a restriction on or stoppage of running (distance, speed, duration, or training) for at least 7 days or 3 consecutive scheduled training sessions, or that requires the runner to consult a physician or other health professional". Running experience and running pace will be included as primary exposures, while the exposure to running is pre-fixed in the running schedules and thereby conditioned by design. Time-to-event models will be used for analytical purposes.

DISCUSSION

ProjectRun21 will examine if particular subgroups of runners with certain running experiences and running paces seem to sustain more running-related injuries compared with other subgroups of runners. This will enable sport coaches, physiotherapists as well as the runners to evaluate their injury risk of taking up a 14-week running schedule for half-marathon.

Shoe cushioning, body mass and running biomechanics as risk factors for running injury: a study protocol for a randomised controlled trial

INTRODUCTION

Repetitive loading of the musculoskeletal system is suggested to be involved in the underlying mechanism of the majority of running-related injuries (RRIs). Accordingly, heavier runners are assumed to be at a higher risk of RRI. The cushioning system of modern running shoes is expected to protect runners again high impact forces, and therefore, RRI. However, the role of shoe cushioning in injury prevention remains unclear. The main aim of this study is to investigate the influence of shoe cushioning and body mass on RRI risk, while exploring simultaneously the association between running technique and RRI risk.

METHODS AND ANALYSIS

This double-blinded randomised controlled trial will involve about 800 healthy leisure-time runners. They will randomly receive one of two running shoe models that will differ in their cushioning properties (ie, stiffness) by ~35%. The participants will perform a running test on an instrumented treadmill at their preferred running speed at baseline. Then they will be followed up prospectively over a 6-month period, during which they will self-report all their sports activities as well as any injury in an internet-based database TIPPS (Training and Injury Prevention Platform for Sports). Cox regression analyses will be used to compare injury risk between the study groups and to investigate the association among training, biomechanical and anatomical risk factors, and injury risk.

ETHICS AND DISSEMINATION

The study was approved by the National Ethics Committee for Research (Ref: 201701/02 v1.1). Outcomes will be disseminated through publications in peer-reviewed journals, presentations at international conferences, as well as articles in popular magazines and on specialised websites.

TRIAL REGISTRATION NUMBER

NCT03115437, Pre-results.

Preventing running-related injuries using evidence-based online advice: the design of a randomised-controlled trial

Introduction

Running-related injuries (RRIs) are frequent and can lead to cessation of health promoting activities. Several risk factors for RRIs have been identified. However, no successful injury prevention programme has been developed so far. Therefore, the aim of the present study is to investigate the effect of an evidence-based online injury prevention programme on the number of RRIs.

Methods and analysis

The INSPIRE trial is a randomised-controlled trial with a 3-month follow-up. Both novice and more experienced runners, aged 18 years and older, who register for a running event (distances 5 km up to 42.195 km) will be asked to participate in this study. After completing the baseline questionnaire, participants will be randomised into either the intervention group or control group. Participants in the intervention group will get access to the online injury prevention programme. This prevention programme consists of information on evidence-based risk factors and advices to reduce the injury risk. The primary outcome measure is the number of self-reported RRIs in the time frame between registration for a running event and 1 month after the running event. Secondary outcome measures include the running days missed due to injuries, absence of work or school due to injuries, and the injury location.

Ethics and dissemination

An exemption for a comprehensive application is obtained by the Medical Ethical Committee of the Erasmus University Medical Centre Rotterdam, Netherlands. The results of the study will be published in peer-reviewed journals and presented on international congresses.

Trial registration number

NTR5998. Pre-results