Association between the Foot Posture Index and running related injuries: A case-control study

      Highlights

      • There is a significant association between running-related injury and foot posture.
      • Running surface type might be associated with injury in novice runners.
      • The use of one pair of shoes might be associated with injury in novice runners.
      • Body mass index might be associated with the presence of injury in novice runners.
      • Running experience might be associated with injury in novice runners.

      Abstract

      Background

      Novice runners are at significantly greater risk of running-related injuries than experienced recreational runners. To develop prevention strategies for this population, it is important to identify predisposing factors that contribute to the incidence of these injuries. This study aims to assess the relationship between running-related injuries, foot posture and other factors in novice runners.

      Methods

      Case-control study in 600 novice runners, classified as cases or controls based on incidence of running-related injuries. Participants' foot posture was measured using the Foot Posture Index, and we performed a descriptive analysis of the explanatory variables, comparing cases and controls. To assess the association between the injury and the presence of exposure and other explanatory variables, we performed a simple logistic regression for each variable and then fit a multivariable regression model.

      Findings

      Our regression model showed that high supination was associated with 76.8 times higher odds of injury than a neutral Foot Posture Index score (P < 0.001). High pronation was associated with 20-fold higher odds of injury than neutral foot posture (P < 0.001). Other variables such as running surface, number of shoes used, and body mass index were also associated with injury. The model showed an acceptable predictive capacity, with an area under the ROC curve of 0.7753.

      Interpretation

      If the association between Foot Posture Index and running-related injury is confirmed in large prospective studies, running programs for beginners should consider foot posture in efforts to prevent running-related injuries.

      Keywords

      1. Introduction

      Running has long been one of the most popular recreational sports worldwide (
      • Janssen M.
      • Scheerder J.
      • Thibaut E.
      • Brombacher A.
      • Vos S.
      Who uses running apps and sports watches? Determinants and consumer profiles of event runners' usage of running-related smartphone applications and sports watches.
      ), and in recent years the number of runners has only increased. However, this sport is not free of risk; according to one systematic review by
      • van Gent R.N.
      • Siem D.
      • van Middelkoop M.
      • van Os A.G.
      • Bierma-Zeinstra S.M.
      • Koes B.W.
      Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review.
      , the incidence of lower extremity running injuries can range anywhere from 19% to 79%. This variation is largely a product of the multifactorial (and incompletely elucidated) etiology of running-related injuries (RRIs), which have been associated with diverse variables, including older age, higher body mass index (BMI), previous musculo-skeletal complaints unrelated to sports, and lack of running experience, among others (
      • Buist I.
      • Bredeweg S.W.
      • Bessem B.
      • van Mechelen W.
      • Lemmink K. a P.M.
      • Diercks R.L.
      Incidence and risk factors of running-related injuries during preparation for a 4-mile recreational running event.
      ;
      • Buist I.
      • Bredeweg S.W.
      • Lemmink K.A.P.M.
      • van Mechelen W.
      • Diercks R.L.
      Predictors of running-related injuries in novice runners enrolled in a systematic training program: a prospective cohort study.
      ;
      • Gijon-nogueron G.
      • Sanchez-rodriguez R.
      • Lopezosa-reca E.
      • Cervera-marin J.A.
      • Martinez-quintana R.
      • Martinez-nova A.
      Normal values of the Foot Posture Index in a young adult Spanish population.
      ;
      • Kluitenberg B.
      • van Middelkoop M.
      • Smits D.W.
      • Verhagen E.
      • Hartgens F.
      • Diercks R.
      • van der Worp H.
      The NLstart2run study: incidence and risk factors of running-related injuries in novice runners.
      ;
      • Saragiotto B.T.
      • Yamato T.P.
      • Hespanhol Junior L.C.
      • Rainbow M.J.
      • Davis I.S.
      • Lopes A.D.
      What are the main risk factors for running-related injuries?.
      ). In this context, novice runners are a key subgroup, as they often take up the sport without any previous preparation or professional advice and are at significantly higher risk of RRIs than other, more experienced recreational runners (
      • Videbæk S.
      • Bueno A.M.
      • Nielsen R.O.
      • Rasmussen S.
      Incidence of running-related injuries per 1000 h of running in different types of runners: a systematic review and meta-analysis.
      ).
      Among runners themselves,
      • Saragiotto B.T.
      • Yamato T.P.
      • Lopes A.D.
      What do recreational runners think about risk factors for running injuries? A descriptive study of their beliefs and opinions.
      reported that foot posture is widely believed to be a risk factor that is directly related to injury. One of the most widely used methods to assess this variable is the Foot Posture Index (FPI) (
      • Redmond A.C.
      • Crosbie J.
      • Ouvrier R.A.
      Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index.
      ), which has revealed strong associations with sports-related foot injuries (
      • Neal B.S.
      • Griffiths I.B.
      • Dowling G.J.
      • Murley G.S.
      • Munteanu S.E.
      • Franettovich Smith M.M.
      • et al.
      Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis.
      ;
      • Tong J.W.K.
      • Kong P.W.
      Association between foot type and lower extremity injuries: systematic literature review with meta-analysis.
      ). Research specific to running has shown that the musculature of the leg and foot is subject to a process of fatigue, generating changes in posture over the course of the run (
      • Escamilla-Martínez E.
      • Martínez-Nova A.
      • Gómez-Martín B.
      • Sánchez-Rodríguez R.
      • Fernández-Seguín L.M.
      The effect of moderate running on foot posture index and plantar pressure distribution in male recreational runners.
      ). Although foot pronation is thought to be a risk factor for injury (
      • Hreljac A.
      Etiology, prevention, and early intervention of overuse injuries in runners: a biomechanical perspective.
      ), and different authors have suggested that footwear based on the runner's foot type could be an effective prevention measure (
      • Gojanovic B.
      Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study.
      ;
      • Richards C.E.
      • Magin P.J.
      • Callister R.
      • Richards C.
      Is your prescription of distance running shoes evidence-based?.
      ), previous studies have reported contradictory results on this research question.
      • Malisoux L.
      • Chambon N.
      • Delattre N.
      • Gueguen N.
      • Urhausen A.
      • Theisen D.
      Injury risk in runners using standard or motion control shoes: a randomised controlled trial with participant and assessor blinding.
      reported that runners classified as having pronated feet on the FPI were at higher risk for injury when using neutral shoes than runners with neutral feet. In contrast,
      • Gojanovic B.
      Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study.
      concluded that foot pronation was not associated with increased injury risk in novice runners wearing a neutral shoe.
      RRIs have considerable physical and psychological impacts (
      • Von Rosen P.
      Injuries, Risk Factors, Consequences and Injury Perceptions in Adolescent Elite Athletes.
      ), and they may lead to a temporary or permanent suspension of physical activity. Moreover, they often incur important medical costs, estimated at EUR 1300 per injury, as well as indirect costs due to work absenteeism (
      • Hespanhol Junior L.C.
      • Costa L.O.P.
      • Carvalho A.C.a.
      • Lopes A.D.
      A description of training characteristics and its association with previous musculoskeletal injuries in recreational runners: a cross-sectional study.
      ). Thus, developing effective preventive interventions is a priority, but this requires knowledge of the incidence, etiology, mechanisms of injury (
      • van Mechelen W.
      • Hlobil H.
      • Kemper H.C.
      Incidence, severity, aetiology and prevention of sports injuries. A review of concepts.
      ), and risk factors that predispose individuals to injury (
      • Van Der Worp M.P.
      • Ten Haaf D.S.M.
      • Van Cingel R.
      • De Wijer A.
      • Nijhuis-Van Der Sanden M.W.G.
      • Bart Staal J.
      Injuries in runners; a systematic review on risk factors and sex differences.
      ). The increasing numbers of runners, the higher risk of RRI among beginners, and the controversy regarding the relationship between foot posture and RRIs led to the present study. Our aim was to assess the relationship between RRIs and foot posture in novice runners.

      2. Methods

      2.1 Study design, setting and participants

      An observational, analytical nested case-control study was conducted in four different physiotherapy and podiatry clinics in Alicante (Spain). This study was approved by the ethical committee of the University Hospital of San Juan de Alicante, and all participants provided informed consent. This study was reported following the STROBE guidelines for reporting observational studies.
      From January 2013 to January 2015, recreational runners who attended one of the clinics for any reason were offered a biomechanical assessment of gait and footprint. A database was created to store all the information acquired from 1150 runners visiting the physiotherapist.
      In 2016 the principal investigator reviewed this database of runners and contacted with all those who met inclusion criteria by phone to ask them to use of their data in this study. Principal investigator obtained the informed consent of those runners who accepted to participate in the study, and asked for any information that was required to include in the study. Inclusion criteria were: aged 30–50 years, novice runner, body mass index (BMI) <28 kg/m2, running 2–3 days/week, and using neutral running shoes. Exclusion criteria were: previous or current status as a professional athlete in any sporting discipline, previous surgery on lower limbs, previous injury on lower limb leaving sequalae, and use of tailor-made insoles. We defined novice runners as those who had not been running on a regular basis the previous year, according to the definition used by
      • Buist I.
      • Bredeweg S.W.
      • Lemmink K.A.P.M.
      • et al.
      No effect of a graded training program on the number of running-related injuries a randomized controlled trial.
      .
      We included a total of 600 study participants, who were classified into cases (N = 300) or controls (N = 300). Cases were patients who met the inclusion criteria and presented in the clinic with an RRI. Controls were defined as patients who met the inclusion criteria and attended the clinic without any musculoskeletal injury on a lower limb, who had presented at the clinic for another injury on an upper limb or to undergo a study of their foot strike pattern to prevent injury and find out their foot type. We used the definition proposed by
      • Yamato T.P.
      • Saragiotto B.T.
      • Lopes A.D.
      A consensus definition of running-related injury in recreational runners: a modified Delphi approach.
      to define RRI, that is, a running-related (training or competition) musculoskeletal pain in the lower limbs that causes a restriction or suspension running activity (distance, speed, duration, or training) for at least seven days or three consecutive scheduled training sessions, or which requires the runner to consult a physician or other health professional.

      2.2 Study variables

      We extracted the following study variables from the initial database: age, sex, height, weight, running surface (asphalt, dirt, both), usual distance for competition (<10 km, 10–22 km, >22 km), experience running (months), average time spent on each run, usual pace (min/km), number of days/week spent training, average distance run each week, number of races per year, use of more than one pair of running shoes, and average cost of running shoes. If any data were missing, we collected the information during the phone call for study inclusion.
      A podiatrist assessed foot posture during the biomechanical assessment of gait and footprint, based on the six-item criterion reference tool (FPI) (
      • Redmond A.C.
      • Crosbie J.
      • Ouvrier R.A.
      Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index.
      ;
      • Redmond A.C.
      • Crane Y.Z.
      • Menz H.B.
      Normative values for the Foot Posture Index.
      ). The FPI consists of six validated, criterion-based observations of the rearfoot and forefoot of a person standing in a relaxed position. The rearfoot was assessed via palpation of the head of the talus, observation of the curves above and below the lateral malleoli, and evaluation of the extent of the inversion/eversion of the calcaneus. The observations of the forefoot consist of assessing the bulge in the region of the talo-navicular joint, the congruence of the medial longitudinal arch and the extent of abduction/adduction of the forefoot on the rearfoot (
      • Tweed J.L.
      • Campbell J.A.
      • Avil S.J.
      Biomechanical risk factors in the development of medial tibial stress syndrome in distance runners.
      ). We recorded the posture of a single foot. In the control group, we chose the foot presenting with the FPI score furthest from normal. In the cases, we chose the foot from the injured limb. We divided participants according to their FPI values for the included foot, using a five-category FPI classification. For the five-category analysis, the cut points were −12 to −5 (highly supinated), −4 to −1 (supinated), 0 to 5 (neutral), 6 to 9 (pronated), and 10 to 12 (highly pronated). The results were collected in the initial database.
      Selection bias may occur when control participants are not representative of the population that produced the cases. In the present study both cases and controls were recruited from the same setting; they have similar characteristics, and controls can suffer a RRI in the future.
      Estimating a 26% prevalence of exposure (supinated or pronated foot posture) in controls (
      • Saragiotto B.T.
      • Yamato T.P.
      • Hespanhol Junior L.C.
      • Rainbow M.J.
      • Davis I.S.
      • Lopes A.D.
      What are the main risk factors for running-related injuries?.
      ), a significance level of P = 0.05 and a power of 80%, we calculated a sample size of 260 participants per group, using a design with a balanced case-control ratio of 1:1. Anticipating a dropout rate of 15% (40 participants), two groups of 300 participants each (a total of 600 participants) were needed. One control per RRI case was randomly selected from the control population.

      2.3 Statistical analysis

      We performed a descriptive analysis of the control and case groups, calculating absolute and relative frequencies for categorical variables and comparing them by means of the Chi2 test. We also calculated the minimum, maximum, mean and standard deviation (SD) values for quantitative variables using the Student's t-test. To estimate the magnitude of association between the RRI and the presence of exposure and other explanatory variables, we performed a simple logistic regression for each variable. We then fit a multivariable regression model, selecting variables to be included using a manual step-by-step procedure, based on the Akaike Information Criterion (AIC), and calculating goodness of fit and predictive indicators. We then estimated the adjusted odds ratio (OR) of the lesion along with the 95% confidence interval (CI). All analyses were undertaken using SPSS v.18 statistical software.

      3. Results

      Overall, there were more men than women in the study population (429/600, 71.5%), and participants' mean age was 38.6 years (SD6.8). Table 1 shows the anthropometric and training-related characteristics of the two groups. The variables that presented a statistically significant difference between cases and controls in univariable analysis (P < 0.05) were: BMI, running surface, use of more than one pair of shoes, and months of running experience. The mean time of running experience was higher in controls than in cases (7.4 [SD 3.2] months vs 6.9 [SD 2.9] months).
      Table 1Anthropometric description and training characteristics of case and control groups.
      Cases

      (N = 300)
      Controls

      (N = 300)
      P value
      Sex, n (%)Male217 (50.6)212 (49.4)0.651
      Female83 (48.5)88 (51.5)
      Age (years), mean (SD)38.8 (6.9)38.3 (6.8)0.392
      Height (cm), mean (SD)174.7 (8.5)174.8 (9.8)0.887
      Weight (kg), mean (SD)69.2 (9.2)68.6 (9.7)0.415
      BMI (kg/m2), mean (SD)22.6 (1.5)22.3 (1.5)0.046
      Foot studied, n (%)Right150 (46.6)172 (53.4)0.072
      Left150 (54.0)128 (46.0)
      Running experience (months), mean (SD)6.9 (2.9)7.4 (3.2)0.030
      Usual running surface, n (%)Asphalt249 (53.0)221 (47.0)0.003
      Dirt34 (47.2)38 (52.8)
      Both17 (29.3)41 (70.7)
      Length of training sessions (min), mean (SD)51.0 (18.1)53.2 (20.3)0.158
      Pace (min/km), mean (SD)5.5 (0.7)5.4 (0.8)0.119
      Training days/week, mean (SD)2.8 (0.4)2.7 (0.5)0.228
      Km/week, mean (SD)27.7 (13.3)29.5 (16.5)0.137
      Racing events/year, n (%)2.6 (1.9)2.8 (2.0)0.350
      Distance run in competitions, n (%)<10 km110 (52.1)101 (47.9)0.128
      10–22 km146 (51.8)136 (48.2)
      >22 km44 (41.4)63 (58.9)
      Pairs of running shoes, n (%)≥263 (42.9)84 (57.1)0.046
      1237 (52.3)216 (47.7)
      Cost of running shoes (EUR), mean (SD)117.0 (31.3)116.9 (32.5)0.969
      BMI: body mass index; SD: standard deviation.
      Table 2 presents the proportion of cases and controls according to FPI classification. We detected a significant association between foot posture and incidence of RRI, with a greater proportion of the supinated feet (60.0%), highly supinated feet (96.3%), pronated feet (60.8%) and highly pronated feet (86.6%) presenting in cases and a greater proportion of patients with normal FPI (74.9%) among controls (P < 0.001).
      Table 2Proportion of cases and controls according to 5-category FPI classification.
      CaseControlP value
      n%n%
      FPIHighly supinated2696.313.7<0.001
      Supinated4260.02840.0
      Normal6425.119174.9
      Pronated11060.87139.2
      Highly pronated5886.6913.4
      FPI: Foot Posture Index.
      In the multivariable analysis, significant associations between RRI and selected variables included FPI categories, running surface, and BMI. Our regression model with FPI (Table 3) showed that high supination was associated with 76.8 times higher odds of injury than a neutral FPI score. High pronation was associated with 20.0-fold higher odds of injury than a neutral foot posture. For each point increase in BMI, the risk of injury rose by 15.9%. The model showed an acceptable predictive capacity, with an area under the ROC curve (AUC) of 0.7753, and good fit with the data (Chi2 test 166.68; P < 0.001).
      Table 3Multivariable logistic regression model demonstrating the relationship of RRI with the 5-category FPI classification and other variables.
      VariablesOR95% CIP value
      Neutral FPI1
      Highly supinated FPI76.87(10.14–582.40)<0.001
      Supinated FPI4.23(2.41–7.43)<0.001
      Pronated FPI4.80(3.15–7.30)<0.001
      Highly pronated FPI20.02(9.28–43.10)<0.001
      Surface both1
      Surface dirt2.57(1.32–5.02)0.044
      Surface asphalt2.22(0.98–5.06)0.004
      BMI1.16(1.03–1.31)0.018
      BMI: body mass index; CI: confidence interval; FPI: Foot Posture Index; OR: odds ratio.

      4. Discussion

      Our findings show a significant association between the occurrence of RRI and the presence of a supinated or pronated foot, which was associated with high and significant risks compared to feet with a neutral standing position. Other variables with significant associations were the running surface, the use of more than one pair of shoes, BMI, and prior running experience.
      The literature describes disparate results regarding the association of foot posture with RRIs. It is important to keep in mind the difficulty of comparing studies on prevalence or risk of RRIs due to the lack of consensus around a definition for RRIs.
      • Tweed J.L.
      • Campbell J.A.
      • Avil S.J.
      Biomechanical risk factors in the development of medial tibial stress syndrome in distance runners.
      and
      • Ryan M.
      • Grau S.
      • Krauss I.
      • Maiwald C.
      • Taunton J.
      • Horstmann T.
      Kinematic analysis of runners with Achilles mid-portion tendinopathy.
      found that pronation was significantly associated with tibial stress syndrome and Achilles tendinopathy. Systematic reviews have also reported strong evidence of an association between non-neutral foot types and lower extremity injuries, although the magnitude of effect seems to be low (
      • Neal B.S.
      • Griffiths I.B.
      • Dowling G.J.
      • Murley G.S.
      • Munteanu S.E.
      • Franettovich Smith M.M.
      • et al.
      Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis.
      ;
      • Tong J.W.K.
      • Kong P.W.
      Association between foot type and lower extremity injuries: systematic literature review with meta-analysis.
      ). For
      • Burns J.
      • Keenan A.-M.
      • Redmond A.
      Foot type and overuse injury in triathletes.
      , triathletes with a supinated foot posture had four times greater risk of injury due to overuse during competition season.
      • Neal B.S.
      • Griffiths I.B.
      • Dowling G.J.
      • Murley G.S.
      • Munteanu S.E.
      • Franettovich Smith M.M.
      • et al.
      Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis.
      suggested that the evaluation of static foot posture should be included in a multifactorial assessment for medial tibial stress syndrome and patellofemoral pain, although only as a part of the potential injury risk profile. Authors who did not observe significant associations between foot posture and RRIs include
      • Ramskov D.
      • Jensen M.L.
      • Obling K.
      • Nielsen R.O.
      • Parner E.T.
      • Rasmussen S.
      No association between q-angle and foot posture with running-related injuries: a 10 week prospective follow-up study.
      , who concluded that static foot posture as quantified by FPI did not seem to affect the risk of injury among novice runners. However, these results should be interpreted with caution due to a small sample size and the low count in the supinated and highly pronated groups compared to the neutral foot posture group. Other authors found similar results (
      • Gojanovic B.
      Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study.
      ). One clear area of consensus was on the need for further studies to determine the relationship between RRIs and dynamic foot function.
      In general, previous findings are in line with the results of the present study, which show that in novice runners, a highly supinated foot according to the 5-category FPI is associated with the highest risk of RRI compared to a neutral foot. Moderate supination and pronation were associated with a similarly increased risk of RRI compared to a neutral foot.
      Other potential confounders that were measured in the present study showed a statistically significant association with RRI. Compared with runners without RRI (control group), we observed that a significantly higher proportion of runners with RRI (case group) used asphalt as a running surface (P = 0.003). This result is consistent with studies by
      • Tessutti V.
      • Ribeiro A.P.
      • Trombini-Souza F.
      • Sacco I.C.N.
      Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.
      ,
      • Tessutti V.
      • Trombini-Souza F.
      • Ribeiro A.P.
      • Nunes A.L.
      • Sacco I de C.N.
      In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners.
      , which characterized asphalt as the surface with the greatest contact time, the highest peak pressure and the highest pressure-time integral. Running on asphalt may increase the total stress on the musculoskeletal system compared with other sufaces, causing the most overload (
      • Dixon S.J.
      • Collop A.C.
      • Batt M.E.
      Surface effects on ground reaction forces and lower extremity kinematics in running.
      ;
      • Tessutti V.
      • Ribeiro A.P.
      • Trombini-Souza F.
      • Sacco I.C.N.
      Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.
      ). In our study, we also observed that there were more runners who used a single pair of shoes for training in the case group compared to the control group. This result is consistent with
      • Malisoux L.
      • Ramesh J.
      • Mann R.
      • Seil R.
      • Urhausen A.
      • Theisen D.
      Can parallel use of different running shoes decrease running-related injury risk?.
      BMI was another statistically significant factor for the risk of injury. For each point increase in BMI, risk of injury rose by nearly 16%.
      • Nielsen R.O.
      • Buist I.
      • Parner E.T.
      • et al.
      Predictors of running-related injuries among 930 novice runners: a 1-year prospective follow-up study.
      also reported a higher risk of injury for people with a BMI of >30 kg/m2 and a protective effect associated with a BMI of <20 kg/m2; in fact, these findings prompted us to use high BMI (≥28 kg/m2) as an exclusion criterion. Thus, our data has to be interpreted taking into account the BMI parameters we used in the study; the positive correlation we found for risk of injury and BMI applies up to BMI of 28 kg/m2.
      More consensus exists in terms of the impact of running experience on the risk of injury, with novice runners at greater risk than their more experienced counterparts (
      • Buist I.
      • Bredeweg S.W.
      • Lemmink K.A.P.M.
      • van Mechelen W.
      • Diercks R.L.
      Predictors of running-related injuries in novice runners enrolled in a systematic training program: a prospective cohort study.
      ;
      • Hespanhol Junior L.C.
      • Costa L.O.P.
      • Carvalho A.C.a.
      • Lopes A.D.
      A description of training characteristics and its association with previous musculoskeletal injuries in recreational runners: a cross-sectional study.
      ). Although in our study all of the participants had fewer than 12 months of experience, the control group had an average of 7.4 months of experience, compared to 6.9 months in the case group; this difference was statistically significant.
      One of the variables most commonly identified as a risk factor for injury in runners was previous injury. In the definition of injury proposed by
      • Yamato T.P.
      • Saragiotto B.T.
      • Lopes A.D.
      A consensus definition of running-related injury in recreational runners: a modified Delphi approach.
      the authors recommended that in retrospective studies, investigators should determine whether participants suffered an injury over the previous six months. In light of this recommendation, one or our exclusion criteria was a recent (<1 year) lesion in a lower limb.
      This study has some limitations. First, there were few runners with highly supinated foot posture in the control group; results for this subgroup should be interpreted with caution, and further research is needed on runners with this foot type. Another potential limitation could be that some explanatory variables are self-reported; however, both the identification of the injury and the foot posture were analyzed objectively in each participant. In addition, the missing data were collected at the time of inclusion, putting some data at risk for recall bias. On the other hand, one strength of this study is the use of the
      • Yamato T.P.
      • Saragiotto B.T.
      • Lopes A.D.
      A consensus definition of running-related injury in recreational runners: a modified Delphi approach.
      definition of RRI, which was proposed as a standard for the field, enabling future comparisons with other studies. Future research should likewise use the standardized definition of RRI. Despite the inherent bias involved in case-control studies, this study allowed analysis of a large number of cases and multiple exposures.

      4.1 Conclusions

      We observed a significant association between foot posture (according to the FPI) and the occurrence of an RRI, where highly supinated and pronated feet were associated with more RRIs in novice runners. In addition, the type of running surface, the use of more than one pair of running shoes, previous running experience and BMI might be associated with the presence of RRI in novice runners. If these associations are confirmed in large prospective studies, running programs for beginners should consider the role of foot posture measured by the FPI in order to prevent injuries. Individualized program of muscle strength for each runner might avoid overuse injuries caused by the foot posture and which may lead the runner to stop the sport activity or even leave running.

      Funding

      This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

      References

        • Buist I.
        • Bredeweg S.W.
        • Lemmink K.A.P.M.
        • et al.
        No effect of a graded training program on the number of running-related injuries a randomized controlled trial.
        Am. J. Sports Med. 2008; 36: 33-39
        • Buist I.
        • Bredeweg S.W.
        • Bessem B.
        • van Mechelen W.
        • Lemmink K. a P.M.
        • Diercks R.L.
        Incidence and risk factors of running-related injuries during preparation for a 4-mile recreational running event.
        Br. J. Sports Med. 2010; 44: 598-604https://doi.org/10.1136/bjsm.2007.044677
        • Buist I.
        • Bredeweg S.W.
        • Lemmink K.A.P.M.
        • van Mechelen W.
        • Diercks R.L.
        Predictors of running-related injuries in novice runners enrolled in a systematic training program: a prospective cohort study.
        Am. J. Sports Med. 2010; 38: 273-280https://doi.org/10.1177/0363546509347985
        • Burns J.
        • Keenan A.-M.
        • Redmond A.
        Foot type and overuse injury in triathletes.
        J. Am. Podiatr. Med. Assoc. 2005; 95: 235-241
        • Dixon S.J.
        • Collop A.C.
        • Batt M.E.
        Surface effects on ground reaction forces and lower extremity kinematics in running.
        Med. Sci. Sports Exerc. 2000; 32: 1919-1926https://doi.org/10.1097/00005768-200011000-00016
        • Escamilla-Martínez E.
        • Martínez-Nova A.
        • Gómez-Martín B.
        • Sánchez-Rodríguez R.
        • Fernández-Seguín L.M.
        The effect of moderate running on foot posture index and plantar pressure distribution in male recreational runners.
        J Am Podiatr Med Assoc [Internet]. 2013; 103: 121-125
        • van Gent R.N.
        • Siem D.
        • van Middelkoop M.
        • van Os A.G.
        • Bierma-Zeinstra S.M.
        • Koes B.W.
        Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review.
        Br. J. Sports Med. 2007 Aug; 41: 469-480
        • Gijon-nogueron G.
        • Sanchez-rodriguez R.
        • Lopezosa-reca E.
        • Cervera-marin J.A.
        • Martinez-quintana R.
        • Martinez-nova A.
        Normal values of the Foot Posture Index in a young adult Spanish population.
        J. Am. Podiatr. Med. Assoc. 2015; 105: 42-46https://doi.org/10.7547/8750-7315-105.1.42
        • Gojanovic B.
        Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study.
        Schweiz. Zeitschrift Sport. Sport. 2013; 61: 52-53https://doi.org/10.1136/bjsports-2013-092202
        • Hespanhol Junior L.C.
        • Costa L.O.P.
        • Carvalho A.C.a.
        • Lopes A.D.
        A description of training characteristics and its association with previous musculoskeletal injuries in recreational runners: a cross-sectional study.
        Rev. Bras. Fis. 2012; 16: 46-53https://doi.org/10.1590/S1413-35552012005000005
        • Hreljac A.
        Etiology, prevention, and early intervention of overuse injuries in runners: a biomechanical perspective.
        Phys. Med. Rehabil. Clin. N. Am. 2005 Aug; 16 (vi): 651-667
        • Janssen M.
        • Scheerder J.
        • Thibaut E.
        • Brombacher A.
        • Vos S.
        Who uses running apps and sports watches? Determinants and consumer profiles of event runners' usage of running-related smartphone applications and sports watches.
        in: Guilhem G. PLoS ONE. 12. 2017https://doi.org/10.1371/journal.pone.0181167 (7):e0181167
        • Kluitenberg B.
        • van Middelkoop M.
        • Smits D.W.
        • Verhagen E.
        • Hartgens F.
        • Diercks R.
        • van der Worp H.
        The NLstart2run study: incidence and risk factors of running-related injuries in novice runners.
        Scand. J. Med. Sci. Sports. 2015 Oct; 25: e515-e523https://doi.org/10.1111/sms.12346
        • Malisoux L.
        • Ramesh J.
        • Mann R.
        • Seil R.
        • Urhausen A.
        • Theisen D.
        Can parallel use of different running shoes decrease running-related injury risk?.
        Scand. J. Med. Sci. Sports. 2015; 25: 110-115https://doi.org/10.1111/sms.12154
        • Malisoux L.
        • Chambon N.
        • Delattre N.
        • Gueguen N.
        • Urhausen A.
        • Theisen D.
        Injury risk in runners using standard or motion control shoes: a randomised controlled trial with participant and assessor blinding.
        Br. J. Sports Med. 2016; 50: 481-487https://doi.org/10.1136/bjsports-2015-095031
        • van Mechelen W.
        • Hlobil H.
        • Kemper H.C.
        Incidence, severity, aetiology and prevention of sports injuries. A review of concepts.
        Sports Med. 1992; 14: 82-99
        • Neal B.S.
        • Griffiths I.B.
        • Dowling G.J.
        • Murley G.S.
        • Munteanu S.E.
        • Franettovich Smith M.M.
        • et al.
        Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis.
        J. Foot Ankle Res. [Internet]. 2014; 7: 1-13
        • Nielsen R.O.
        • Buist I.
        • Parner E.T.
        • et al.
        Predictors of running-related injuries among 930 novice runners: a 1-year prospective follow-up study.
        Orthop. J. Sport Med. 2013; 1: 1-7https://doi.org/10.1177/2325967113487316
        • Ramskov D.
        • Jensen M.L.
        • Obling K.
        • Nielsen R.O.
        • Parner E.T.
        • Rasmussen S.
        No association between q-angle and foot posture with running-related injuries: a 10 week prospective follow-up study.
        Int. J. Sports Phys. Ther. 2013; 8: 407-415
        • Redmond A.C.
        • Crosbie J.
        • Ouvrier R.A.
        Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index.
        Clin. Biomech. 2006; 21: 89-98
        • Redmond A.C.
        • Crosbie J.
        • Ouvrier R.A.
        Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index.
        Clin. Biomech. 2006; 21: 89-98
        • Redmond A.C.
        • Crane Y.Z.
        • Menz H.B.
        Normative values for the Foot Posture Index.
        J. Foot Ankle Res. 2008; 1: 6https://doi.org/10.1186/1757-1146-1-6
        • Richards C.E.
        • Magin P.J.
        • Callister R.
        • Richards C.
        Is your prescription of distance running shoes evidence-based?.
        BJSM. 2009; 43: 159-162https://doi.org/10.1136/bjsm.2008.046680
        • Von Rosen P.
        Injuries, Risk Factors, Consequences and Injury Perceptions in Adolescent Elite Athletes.
        (Doctoral dissertation). Available from:
        https://openarchive.ki.se/xmlui/handle/10616/45942
        Date: 2017
        Date accessed: April 27, 2018
        • Ryan M.
        • Grau S.
        • Krauss I.
        • Maiwald C.
        • Taunton J.
        • Horstmann T.
        Kinematic analysis of runners with Achilles mid-portion tendinopathy.
        Foot Ankle Int./Am. Orthop. Foot Ankle Soc. [and] Swiss Foot Ankle Soc. 2009; 30: 1190-1195
        • Saragiotto B.T.
        • Yamato T.P.
        • Hespanhol Junior L.C.
        • Rainbow M.J.
        • Davis I.S.
        • Lopes A.D.
        What are the main risk factors for running-related injuries?.
        Sports Med. 2014 Aug; 44: 1153-1163https://doi.org/10.1007/s40279-014-0194-6
        • Saragiotto B.T.
        • Yamato T.P.
        • Lopes A.D.
        What do recreational runners think about risk factors for running injuries? A descriptive study of their beliefs and opinions.
        J. Orthop. Sports Phys. Ther. 2014; 44: 733-738https://doi.org/10.2519/jospt.2014.5710
        • Tessutti V.
        • Trombini-Souza F.
        • Ribeiro A.P.
        • Nunes A.L.
        • Sacco I de C.N.
        In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners.
        J. Sci. Med. Sport. 2010; 13: 151-155https://doi.org/10.1016/j.jsams.2008.07.008
        • Tessutti V.
        • Ribeiro A.P.
        • Trombini-Souza F.
        • Sacco I.C.N.
        Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.
        J. Sports Sci. 2012; 30: 1545-1550https://doi.org/10.1080/02640414.2012.713975
        • Tong J.W.K.
        • Kong P.W.
        Association between foot type and lower extremity injuries: systematic literature review with meta-analysis.
        J. Orthop. Sport Phys. Ther. [Internet]. 2013; 43: 700-A8
        • Tong J.W.K.
        • Kong P.W.
        Association between foot type and lower extremity injuries: systematic literature review with meta-analysis.
        J Orthop. Sport Phys. Ther. 2013; 43700-A8
        • Tweed J.L.
        • Campbell J.A.
        • Avil S.J.
        Biomechanical risk factors in the development of medial tibial stress syndrome in distance runners.
        J. Am. Podiatr. Med. Assoc. 2008; 98: 436-444
        • Van Der Worp M.P.
        • Ten Haaf D.S.M.
        • Van Cingel R.
        • De Wijer A.
        • Nijhuis-Van Der Sanden M.W.G.
        • Bart Staal J.
        Injuries in runners; a systematic review on risk factors and sex differences.
        in: Zadpoor A.A. PLoS One. 10. 2015https://doi.org/10.1371/journal.pone.0114937 (2):e0114937
        • Videbæk S.
        • Bueno A.M.
        • Nielsen R.O.
        • Rasmussen S.
        Incidence of running-related injuries per 1000 h of running in different types of runners: a systematic review and meta-analysis.
        Sports Med. (Auckland, NZ). 2015; 45: 1017-1026https://doi.org/10.1007/s40279-015-0333-8
        • Yamato T.P.
        • Saragiotto B.T.
        • Lopes A.D.
        A consensus definition of running-related injury in recreational runners: a modified Delphi approach.
        J. Orthop. Sport Phys. Ther. 2015; 45: 375-380