Risk Factors For Running-related Injuries Research Articles

One in Five Trail Running Race Entrants Sustained an Injury in the 12 Months Training Period before the 2021 Mac Mac Ultra Race

Background: Trail running is characterised by large elevation gains/losses and varying uneven running surfaces. Limited literature is available to help guide injury prevention strategies among trail runners. The purpose of this study was to determine the epidemiology, clinical characteristics, and related risk factors for running-related injuries (RRIs) amid trail runners who entered the 2021 Mac Mac Ultra races. Methods: Design: Descriptive cross-sectional study. Setting: 2021 Mac Mac Ultra Race. Participants: Consent for data analysis was given by 251 of 330 (76%) race entrants. Main outcome measures: Point prevalence (%), frequency (n, %), retrospective annual incidence (RRIs/100 athlete-years), characteristics (pathology type, tissue type, body area, anatomical region), and associated injury risk factors (training and demographic variables) of RRIs. Results: In the sample, the retrospective annual incidence was 19.92/100 athlete-years. The point prevalence was 4%. Injuries mostly appeared in the lower limb (95%), with the lower leg (26%), thigh (22%), ankle and foot (13%) described as the highest injured body areas. Of tissue type injuries, muscle/tendon comprised 60%. Muscle injury (36%), tendinopathy (24%), and joint sprain (9%) were the most reported pathology types. No related injury risk factors were discovered in this study. Conclusions: One in five trail runners reported one or more RRI during the 12 months before a competitive event. RRIs commonly involved the lower limb, especially the lower leg, thigh, foot, and ankle. More studies are needed to establish injury risk factors.

Recruitment and Retention of Recreational Runners in Prospective Injury Research: A Qualitative Study

Purpose Continuous and long-term prospective monitoring of athletes in natural training environments is essential to provide further clarity on the risk factors for running-related injuries. However, participant recruitment and retention can be problematic. This study aimed to identify factors for facilitating the recruitment and retention of recreational runners in prospective, longitudinal running-related injury research involving running technologies. Methods Twenty-seven recreational runners (14 female, 13 male) participated across nine semi-structured focus groups. Focus groups were audio and video recorded and transcribed verbatim. A reflexive thematic analysis was undertaken, with a critical friend approach taken to enhance reliability. Results Incentives, recruiting suitable participants, ease of use of running technologies, an appropriate research design, and good communication practices will facilitate recruitment and retention. Conclusion Receiving study outputs, evidence-based information and undergoing laboratory testing were identified as incentives, however, researchers need to consider whether these may influence participant behaviour and adversely bias the findings of their study. Researchers should offer participants an option with regard to the type, content, frequency and mode of delivery of incentives and communication. Appealing to potential participants’ personal interests will facilitate initial recruitment, while attempts to ‘feed’ this interest throughout the course of a study will enhance retention. Employing a user-friendly smartphone app and unobtrusive sensor(s), and a research study that can work with runners’ training schedules and technology usage habits, will further facilitate their recruitment and retention.

Comparison of impact accelerations between injury-resistant and recently injured recreational runners.

Previous injury has consistently been shown to be one of the greatest risk factors for running-related injuries (RRIs). Runners returning to participation following injury may still demonstrate injury-related mechanics (e.g. repetitive high impact loading), potentially exposing them to further injuries. The aim of this study was to determine if the magnitude (Peakaccel) and rate of loading (Rateaccel) at the tibia and sacrum differ between runners who have never been injured, those who have acquired injury resistance (runners who have not been injured in the past 2 years) and those who have been recently injured (RRI sustained 3-12 months ago). Runners completed an online survey capturing details of their RRI history over the previous 2 years. Never injured runners were matched by sex, quarterly annual mileage and typical training speed to runners who had acquired injury resistance and to runners who had been recently injured. Differences in Peakaccel and Rateaccel of the tibia and sacrum were assessed between the three groups during a treadmill run at a set speed, with consideration for sex. A total of 147 runners made up the three injury status groups (n: 49 per group). There was a significant main effect of injury status for Peakaccel and Rateaccel at the sacrum, with recently injured runners demonstrating significantly greater Rateaccel than never injured and acquired injury resistant runners. There was also a significant main effect for sex, with females demonstrating greater tibial Peakaccel, sacrum Peakaccel and Rateaccel than males. Rateaccel at the sacrum distinguishes recently injured runners from never injured runners and runners who may have acquired injury resistance, potentially highlighting poor impact acceleration attenuation in recently injured runners.

A machine learning approach to identify risk factors for running-related injuries: study protocol for a prospective longitudinal cohort trial

BackgroundRunning is a very popular sport among both recreational and competitive athletes. However, participating in running is associated with a comparably high risk of sustaining an exercise-related injury. Due to the often multifactorial and individual reasons for running injuries, a shift in thinking is required to account for the dynamic process of the various risk factors. Therefore, a machine learning approach will be used to comprehensively analyze biomechanical, biological, and loading parameters in order to identify risk factors and to detect risk patterns in runners.MethodsThe prospective longitudinal cohort study will include competitive adult athletes, running at least 20 km per week and being free of injuries three months before the start of the study. At baseline and the end of the study period, subjective questionnaires (demographics, injury history, sports participation, menstruation, medication, psychology), biomechanical measures (e.g., stride length, cadence, kinematics, kinetics, tibial shock, and tibial acceleration) and a medical examination (BMI, laboratory: blood count, creatinine, calcium, phosphate, parathyroid hormone, vitamin D, osteocalcin, bone-specific alkaline phosphatase, DPD cross-links) will be performed. During the study period (one season), continuous data collection will be performed for biomechanical parameters, injuries, internal and external load. Statistical analysis of the data is performed using machine learning (ML) methods. For this purpose, the correlation of the collected data to possible injuries is automatically learned by an ML model and from this, a ranking of the risk factors can be determined with the help of sensitivity analysis methods.DiscussionTo achieve a comprehensive risk reduction of injuries in runners, a multifactorial and individual approach and analysis is necessary. Recently, the use of ML processes for the analysis of risk factors in sports was discussed and positive results have been published. This study will be the first prospective longitudinal cohort study in runners to investigate the association of biomechanical, bone health, and loading parameters as well as injuries via ML models. The results may help to predict the risk of sustaining an injury and give way for new analysis methods that may also be transferred to other sports.Trial registration: DRKS00026904 (German Clinical Trial Register DKRS), date of registration 18.10.2021.

Effects of Foot-Core Training on Foot-Ankle Kinematics and Running Kinetics in Runners: Secondary Outcomes From a Randomized Controlled Trial.

This study investigated the effectiveness of an 8-week foot-core exercise training program on foot-ankle kinematics during running and also on running kinetics (impact loads), with particular interest in biomechanical outcomes considered risk factors for running-related injuries in recreational runners. A single-blind, randomized, controlled trial was conducted with 87 recreational runners randomly allocated to either the control (CG) or intervention (IG) group and assessed at baseline and after 8 weeks. The IG underwent foot-core training 3 times/week, while the CG followed a placebo lower-limb stretching protocol. The participants ran on a force-instrumented treadmill at a self-selected speed while foot-segment motion was captured simultaneously with kinetic measurements. After the intervention, there were statistically significant changed in foot biomechanics, such as: IG participants strike the ground with a more inverted calcaneus and a less dorsiflexed midfoot than those in the CG; at midstance, ran with a less plantarflexed and more adducted forefoot and a more abducted hallux; and at push-off, ran with a less dorsiflexed midfoot and a less adducted and more dorsiflexed hallux. The IG runners also had significantly decreased medial longitudinal arch excursion (p = 0.024) and increased rearfoot inversion (p = 0.037). The 8-week foot-core exercise program had no effect on impact (p = 0.129) and breaking forces (p = 0.934) or on vertical loading rate (p = 0.537), but it was positively effective in changing foot-ankle kinematic patterns.”

Epidemiology, Clinical Characteristics, and Risk Factors for Running-Related Injuries among South African Trail Runners.

Trail running involves running on varying natural terrains, often including large elevation gains/losses. Trail running has a high risk of injury, and runners often participate in remote regions where medical support is challenging. The aim of this study was to determine the epidemiology, clinical characteristic, and associated injury risk factors among trail runners. A modified Oslo Sports Trauma Research Center Questionnaire for Health Problems (OSTRC-H) was used biweekly to collect running-related injury (RRI) and training history data prospectively, among 152 participants (males n = 120, females n = 32) over 30 weeks. We report an overall injury rate of 19.6 RRIs per 1000 h and an RRI mean prevalence of 12.3%. The leading anatomical site of RRIs was the lower limb (82.9%), affecting the knee (29.8%), shin/lower leg (18.0%), and the foot/toes (13.7%). A history of previous RRI in the past 12 months (p = 0.0032) and having a chronic disease (p = 0.0188) are independent risk factors for RRIs among trail runners. Two in three trail runners sustain an RRI mainly affecting the knee, shin/lower leg, and foot/toes. A history of previous RRI in the past 12 months and a having chronic disease is independently associated with RRI among trail runners. These results could be used to develop future RRI prevention strategies, combined with clinical knowledge and experience.

The Running Readiness Scale as an Assessment of Kinematics Related to Knee Injury in Novice Female Runners.

Frontal- and transverse-plane kinematics have been prospectively identified as risk factors for running-related injuries in females. The Running Readiness Scale (RRS) may allow for clinical evaluation of these kinematics. To determine the reliability and validity of the RRS as an assessment of frontal- and transverse-plane running kinematics. Cross-sectional study. University research laboratory. A total of 56 novice female runners (median [interquartile range] age = 34 years [26-47 years]). We collected 3-dimensional kinematics during running and RRS tasks: hopping, plank, step-ups, single-legged squats, and wall sit. Five clinicians assessed RRS performances 3 times each. Interrater and intrarater reliabilities of the total RRS score and individual tasks were calculated using the intraclass correlation coefficient and Fleiss κ, respectively. Pearson product moment correlation coefficients between peak joint angles measured during running and the same angles measured during RRS tasks were computed. Peak joint angles of high- and low-scoring participants were compared. Interrater and intrarater reliabilities of assessment of the total RRS scores were good (intraclass correlation coefficients = 0.75 and 0.80, respectively). Reliability of assessing individual tasks was moderate to almost perfect (κ = 0.58-1.00). Peak hip adduction, contralateral pelvic drop, and knee abduction during running were correlated with the same angles measured during hopping, step-ups, and single-legged squats (r = 0.537-0.939). Peak knee internal rotation during running was correlated with peak knee internal rotation during step-ups (r = 0.831). Runners who scored high on the RRS demonstrated less knee abduction during running (P ≤ .01). The RRS may effectively assess knee abduction in novice runners, but evaluation criteria or tasks may need to be modified to effectively characterize pelvic and transverse-plane knee kinematics.

Predictive Effect of Well-Known Risk Factors and Foot-Core Training in Lower Limb Running-Related Injuries in Recreational Runners: A Secondary Analysis of a Randomized Controlled Trial

Background: Running carries the risk of several types of running-related injuries (RRIs), especially in the lower limbs. The variety of risk factors and the lack of strong evidence for several of these injury risks hinder the ability to draw assertive conclusions about them, hampering the implementation of effective preventive strategies. Because the etiology of RRIs seems to be multifactorial, the presence of RRI risk factors might influence the outcome of therapeutic strategies in different ways. Thus, further investigations on how risk and protective factors influence the incidence and prevention of RRIs should be conducted. Purpose: To investigate the predictive effect of well-known risk factors and 1 protective factor—foot-core training—on the incidence of lower limb RRIs in recreational runners. Study Design: Cohort study; Level of evidence, 2. Methods: Middle- and long-distance recreational runners (N = 118) were assessed at baseline and randomly allocated to either an intervention group (n = 57) or a control group (n = 61). The intervention group underwent an 8-week (3 times/wk) foot-core training program. Participants were followed for a year after baseline assessment for the occurrence of RRIs. Logistic regression with backward elimination of variables was used to develop a model for prediction of RRI in recreational runners. Candidate predictor variables included age, sex, body mass index, years of running practice, number of races, training volume, training frequency, previous RRI, and the foot-core exercise training. Results: The final logistic regression model included 3 variables. As previously shown, the foot-core exercise program is a protective factor for RRIs (odds ratio, 0.40; 95% CI, 0.15-0.98). In addition, older age (odds ratio, 1.07; 95% CI, 1.00-1.14) and higher training volume (odds ratio, 1.02; 95% CI, 1.00-1.03) were risk factors for RRIs. Conclusion: The foot-core training was identified as a protective effect against lower limb RRI, which can be negatively influenced by older age and higher weekly training volume. The predictive model showed that RRIs should be considered a multivariate entity owing to the interaction among several factors. Registration: NCT02306148 (ClinicalTrials.gov identifier).

Injury Prevention in Recreational Runners

Apply It! After reading this article, fitness professionals will be able to: • appreciate the relatively high injury prevalence in recreational runners and share this information with their clients; • understand and share the major risk factors for running-related injuries; • guide clients through functional balance and hip strengthening exercises to help prevent running-related injuries.

Most Military Runners Report Recent Changes in Running Parameters Before Lower Limb Injury Onset.

While running is a popular activity because of the health and fitness benefits it provides, the yearly incidence of running-related injuries (RRI) is high across all populations of runners, including military members. The etiology of RRI is multifactorial, and despite the numerous studies on risk factors for RRI, there is no clear consensus in the literature on the relative contribution of several intrinsic or extrinsic risk factors to the development of RRI. Furthermore, little is known on RRI profile and running parameters among Canadian military members. The objectives of this study were to (1) describe the clinical presentation of lower limb RRI and running profile among military members and (2) explore any association between recent changes in running parameters (volume or intensity) and specific RRI diagnoses. This cross-sectional study was conducted in 107 military members from the Canadian Armed Forces (Valcartier Military Base) who presented with a restriction or interruption of running because of lower limb running-related pain. The following variables were collected during a physiotherapy evaluation: injury location and diagnosis, running kinematics (foot strike pattern and step rate), degree of minimalism of running shoes, running parameters in the last 3 months before consultation (volume, duration, frequency, and intensity), and recent changes in training before pain onset. Descriptive statistical analyses were conducted to describe the clinical presentation and running profile, while chi-square tests and multiple correspondence analysis were used to explore the association between recent changes in running parameters and diagnosis. This study was approved by the institutional ethics committee, and participants signed a detailed consent form. Among the 107 participants included in the study (mean age: 30.7 ± 8.9 years; 13 females), the most common diagnoses were patellofemoral pain (26.2%), medial tibial stress syndrome (11.2%), plantar fasciopathy (9.3%), and sciatica (9.3%). The average Minimalist Index of running shoes was 27.6 ± 18.5%. Step rate was 161.7 ± 10.3 steps per minute, and 73.3% of the participants used a rearfoot strike pattern. The majority of military runners reported previous RRI, gradual onset of symptoms, and recent changes in their training parameters (75.7%) before injury onset. No association was found between recent changes in running volume ((χ2(4) = 2.849; P = .606)) or intensity ((χ2(4) = 1.381; P = .855)) and diagnosis. This is the first study to specifically investigate RRI and running profile among Canadian military members. The most common injuries were located at the knee, and the most frequent diagnosis was patellofemoral pain. The majority of military runners reported previous RRI as well as recent changes in their running parameters before injury onset, but unique types of recent changes were not associated with specific diagnoses. This study illustrates the need to further investigate the impact of training loads on the development of RRI.

Fatigue-Induced Hip-Abductor Weakness and Changes in Biomechanical Risk Factors for Running-Related Injuries.

Despite overlap between hip-abductor (HABD) weakness and fatigue-induced changes in running, the interaction of these theorized contributors to running injuries has been underevaluated. To assess the effects of a fatiguing run on HABD torque and evaluate the correlation between HABD torque and previously identified running-related injury pathomechanics while participants were rested or fatigued. Crossover study. Laboratory. A total of 38 healthy, physically active males (age = 21.61 ± 4.02 years, height = 1.78 ± 0.08 m, body mass = 76.00 ± 12.39 kg). Data collection consisted of rested-state collection, a fatiguing treadmill-run protocol, and fatigued-state collection. For the HABD measures, side-lying handheld-dynamometer isometric tests were performed and converted to torque using femur length. For the gait analysis, kinematic (240 Hz) and kinetic (960 Hz) running (4.0 m/s) data were collected for 3 trials. The fatigue protocol involved a graded exercise test and 80% o2max run to exhaustion. Immediately after the run, fatigued-state measures were obtained. Variables of interest were HABD torque and peak angles, velocities, and moments for hip and knee adduction and internal rotation. Differences between conditions were compared using paired t tests. Pearson correlation coefficients were calculated to evaluate relationships between HABD torque and biomechanical variables. Fatigue decreased HABD torque and increased hip-adduction angle, knee-adduction velocity, and hip and knee internal-rotation velocities and moments (all P values < .05). In the rested state, HABD torque was correlated with hip-adduction velocity (r = -0.322, P = .049). In the fatigued state, HABD torque was correlated with hip-adduction velocity (r = -0.393, P = .015), hip internal-rotation velocity (r = -0.410, P = .01), and knee-adduction angle (r = 0.385, P = .017) and velocity (r = -0.378, P = .019). Changes in joint velocities due to fatigue and correlations between HABD torque and hip- and knee-joint velocities highlight the need to consider not only the quantity of HABD strength but also the rate of eccentric control of HABDs.

Risk factors for overuse injuries in short- and long-distance running: A systematic review

PurposeThe aim of this study was to review information about risk factors for lower extremity running injuries in both short-distance (mean running distance ≤20 km/week and ≤10 km/session) and long-distance runners (mean running distance >20 km/week and >10 km/session). MethodsElectronic databases were searched for articles published up to February 2019. Prospective cohort studies using multivariable analysis for the assessment of individual risk factors or risk models for the occurrence of lower extremity running injuries were included. Two reviewers independently selected studies for eligibility and assessed risk of bias with the Quality in Prognostic Studies Tool. The GRADE approach was used to assess the quality of the evidence. ResultsA total of 29 studies were included: 17 studies focused on short-distance runners, 11 studies focused on long-distance runners, and 1 study focused on both types of runners. A previous running-related injury was the strongest risk factor for an injury for long-distance runners, with moderate-quality evidence. Previous injuries not attributed to running was the strongest risk factor for an injury for short-distance runners, with high-quality evidence. Higher body mass index, higher age, sex (male), having no previous running experience, and lower running volume were strong risk factors, with moderate quality evidence, for short-distance runners. Low-quality evidence was found for all risk models as predictors of running-related injuries among short- and long-distance runners. ConclusionSeveral risk factors for lower extremity injuries have been identified among short- and long-distance runners, but the quality of evidence for these risk factors for running-related injuries is limited. Running injuries seem to have a multifactorial origin both in short- and long-distance runners.

Fatigue matters: An intense 10 km run alters frontal and transverse plane joint kinematics in competitive and recreational adult runners

BackgroundFatigue is an essential component of distance running. Still, little is known about the effects of running induced fatigue on three-dimensional lower extremity joint movement, in particular in the frontal and transverse planes of motion. Research questionHow are non-sagittal plane lower extremity joint kinematics of runners altered during a 10 km treadmill run with near-maximum effort? MethodsIn a cross-sectional study design, we captured three-dimensional kinematics and kinetics at regular intervals throughout a 10 km treadmill run in 24 male participants (subdivided into a competitive and recreational runner group) at a speed corresponding to 105 % of their season-best time. We calculated average and peak joint angles at the hip, knee and ankle during the stance phase. ResultsWe observed peak deviations of 3.5°, 3° and 5° for the hip (more adduction), knee (more abduction) and ankle (more eversion) in the frontal plane when comparing the final (10 km) with the first (0 km) measurement. At the end of the run peak knee internal rotation angles increased significantly (up to 3° difference). Running with a more abducted knee joint and with a higher demand for hip abductor muscles in the unfatigued state was related to greater fatigue-induced changes of joint kinematics at the knee and hip. SignificanceThe fatigue related change of non-sagittal joint kinematics needs to be considered when addressing risk factors for running-related injuries, when designing shoe interventions as well as strengthening and gait retraining protocols for runners. We speculate that strengthening ankle invertors and hip abductors and monitoring the dynamic leg axis during running appear to be promising in preventing fatigue induced alterations of non-sagittal joint kinematics.

Kinematic Correlates of Kinetic Outcomes Associated With Running-Related Injury.

High magnitudes and rates of loading have been implicated in the etiology of running-related injuries. Knowledge of kinematic variables that are predictive of kinetic outcomes could inform clinic-based gait retraining programs. Healthy novice female runners ran on a treadmill while 3-dimensional biomechanical data were collected. Kinetic outcomes consisted of vertical impact transient, average vertical loading rate, instantaneous vertical loading rate, and peak braking force. Kinematic outcomes included step length), hip flexion angle at initial contact, horizontal distance from heel to center of mass at initial contact, shank angle at initial contact, and foot strike angle. Stepwise multiple linear regression was used to evaluate the amount of variance in kinetic outcomes explained by kinematic outcomes. A moderate amount of variance in kinetic outcomes (vertical impact transient = 46%, average vertical loading rate = 37%, instantaneous vertical loading rate = 49%, peak braking force = 54%) was explained by several discrete kinematic variables-predominantly speed, horizontal distance from heel to center of mass, foot strike angle, and step length. Hip flexion angle and shank angle did not contribute to any models. Decreasing step length and transitioning from a rearfoot strike may reduce kinetic risk factors for running-related injuries. In contrast, clinical strategies such as modifying shank angle and hip flexion angle would not appear to contribute significantly to the variance of kinetic outcomes after accounting for other variables.

LEG-LENGTH INEQUALITY AND RUNNING-RELATED INJURY AMONG HIGH SCHOOL RUNNERS

Participation in high school cross-country continues to increase with over 492,000 participants during the 2016-17 cross-country season. Several studies have indicated a high incidence of running-related injuries (RRI) in high school cross-country runners. Risk factors for RRI can be divided between intrinsic and extrinsic risk factors. Intrinsic risk factors such as structural asymmetries have received less attention in recent years. The primary purposes of the current study were to (1) describe the prevalence of leg-length inequality among female and male high school cross-country runners, and (2) to determine whether leg-length inequality was associated with increased RRI in female and male high school cross-country runners. Prospective observational cohort study. Three hundred ninety-three (222 males, 171 females) athletes competing in high school cross-country running were followed, prospectively. The runners' right and left leg-lengths were measured with a standard cloth tape measure in a supine position. Incidence of low back/lower extremity RRI during practices or competitive events was monitored using the Daily Injury Report. A similar percentage of leg-length inequality greater than 0.5 cm was found among female (19.3%) and male (22.1%) runners. No statistically significant associations were found between leg-length inequality and (RRI) for female or male runners, with the exception that after adjusting for BMI, males with a leg-length inequality > 1.5 cm were over seven times more likely to incur a lower leg RRI (Adjusted Odds Ratio = 7.47; 95%CI: 1.5, 36.9; p = 0.01) than males with a leg-length inequality < 0.5 cm. Side of RRI was not associated with side of longer limb length. While leg-length inequality was not associated with RRI, in general, males with a leg-length inequality > 1.5 cm were at greater likelihood of sustaining a lower leg RRI. 2b.

Examination of fundamental movement patterns and likelihood of injury in amateur runners from Opole region in Poland

Background: The most common risk factors for running-related injuries are mistakes, such as insufficient warm-up and stretching exercises, during training. Good preparation and proper training reduces the risk of sport-related injuries. Aim of the study: To examine fundamental movement patterns and likelihood of injury in amateur runners. Material and methods: Twenty-four amateur long-distance runners from Opole region (Poland) were divided into two groups. The first group comprised 12 runners from the club “Kotwica Brzeg”, who did a proper warmup before training and stretching exercises after training. The second group comprised 12 runners from other clubs who did not undertake any warm-up or stretching exercises (control group). Fundamental movement patterns were tested by the Functional Movement Screen test (FMS). Results: The mean FMS test score was higher in “Kotwica Brzeg” runners (17.08 points) than in the control group (15.50 points), but this was not statistically significant. The “Kotwica Brzeg” runners performed better in five of the FMS tests, but this was only significant for the rotational stability test. Conclusions: Runners who did a proper warm-up and stretching exercises achieved better results in the FMS test, which may reduce the risk of running-related injuries.

THE INFLUENCE OF THE TIME SCALE USED IN TIME-TO-EVENT ANALYSES ON THE IDENTIFICATION OF TRAINING-RELATED RISK FACTORS IN RUNNING

BackgroundTraining errors are considered as one of the main causes of running-related injuries, although few of them have been identified. Time-to-event analysis is a useful tool for researchers within sports...

Risk Factors for Running-Related Injuries in Trailrunners

Risk Factors for Running-Related Injuries in Trailrunners

The 5- or 10-km Marikenloop Run: A Prospective Study of the Etiology of Running-Related Injuries in Women.

Study Design Prospective cohort. Background The popularity of running events is still growing, particularly among women; however, little is known about the risk factors for running-related injuries in female runners. Objectives The aims of this study were to determine the incidence and characteristics (site and recurrence) of running-related injuries and to identify specific risk factors for running-related injuries among female runners training for a 5- or 10-km race. Methods Four hundred thirty-five women registered for the Marikenloop run of 5 or 10 km were recruited. Follow-up data were collected over 12 weeks using questionnaires, starting 8 weeks before the event and ending 4 weeks after the event. Two orthopaedic tests (navicular drop test and extension of the first metatarsophalangeal joint) were performed in the 8 weeks before the event. Running-related injuries, defined as running-related pain of the lower back and/or the lower extremity that restricted running for at least 1 day, were assessed at 1-, 2-, and 3-month follow-ups. Results Of 417 female runners with follow-up data (96%), 93 runners (22.3%) reported 109 running-related injuries, mainly of the hip/groin, knee, and lower leg. Multivariable Cox regression analysis showed that a weekly training distance of more than 30 km (hazard ratio = 3.28; 95% confidence interval [CI]: 1.23, 8.75) and a previous running injury longer than 12 months prior (hazard ratio = 1.88; 95% CI: 1.03, 3.45) were associated with the occurrence of running-related injuries. Conclusion Hip/groin, knee, and lower-leg injuries were common among female runners. Only weekly training distance (greater than 30 km) and previous running injury (greater than 12 months prior) were associated with running-related injuries in female runners training for a 5- or 10-km event. Level of Evidence Etiology, 2b. J Orthop Sports Phys Ther 2016;46(6):462-470. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6402.

What are the main risk factors for running-related injuries?

Despite several studies that have been conducted on running injuries, the risk factors for running-related injuries are still not clear in the literature. The aim of this study was to systematically review prospective cohort studies that investigated the risk factors for running injuries in general. We conducted electronic searches without restriction of language on EMBASE (1980 to Dec 2012), PUBMED (1946 to Dec 2012), CINAHL (1988 to Dec 2012) SPORTDiscus (1977 to Dec 2012), Latin American and Caribbean Centre on Health Sciences Information (1985 to Dec 2012) and Scientific Electronic Library Online (1998 to Dec 2012) databases, using subject headings, synonyms, relevant terms and variant spellings for each database. Only prospective cohort studies investigating the risk factors for running-related musculoskeletal injuries were included in this review. Two independent reviewers screened each article and, if they did not reach a consensus, a third reviewer decided whether or not the article should be included. Year of publication, type of runners, sample size, definition of running-related musculoskeletal injury, baseline characteristics, reported risk factors and the statistical measurement of risk or protection association were extracted from the articles. A scale adapted by the authors evaluated the risk of bias of the articles. A total of 11 articles were considered eligible in this systematic review. A total of 4,671 pooled participants were analysed and 60 different predictive factors were investigated. The main risk factor reported was previous injury (last 12months), reported in 5 of the 8 studies that investigated previous injuries as a risk factor. Only one article met the criteria for random selection of the sample and only six articles included a follow-up of 6months or more. There was no association between gender and running injuries in most of the studies. It is possible that eligible articles for this review were published in journals that were not indexed in any of the searched databases. We found a great heterogeneity of statistical methods between studies, which prevented us from performing a meta-analysis. The main risk factor identified in this review was previous injury in the last 12months, although many risk factors had been investigated in the literature. Relatively few prospective studies were identified in this review, reducing the overall ability to detect risk factors. This highlights the need for more, well designed prospective studies in order to fully appreciate the risk factors associated with running.