Illness is more prevalent than injury in trail runners participating in a mountainous ultra trail race

OBJECTIVES

Trail running is a popular off-road sport involving running in natural environments over various terrains, often in remote locations. This study aims to investigate the epidemiology and risk factors of injuries and illnesses, i.e. medical encounters, on race day among trail runners in a high-altitude ultra trail race.

METHODS

This descriptive cross-sectional study on an ultra trail race (38 km, 65 km and 100 km) in South Africa, included participants 18 years or older. Of the 331 race participants, 285(86.1%) consented to participate in the study. Data collection included demographic details, injuries (body region, specific body area, tissue type, pathology) and illnesses (organ system, symptom cluster, etiology). Risk factor analysis includes sex, age, weight, height, race distance, illness and injury history, training and running experience. Frequency (n, %), prevalence (%) and odds ratios (OR; 95%CI) are reported.

RESULTS

Eighty-nine (31.2%) individuals reported 131 medical encounters [49 injuries (37.4%); 82 illnesses (62.6%)]. Injuries were sustained by 14.7% of athletes, and 22.5% reported illnesses. For injuries, the lower limb was mainly involved (n = 41; 83.7%). Most injuries affected the foot (n = 18; 36.7%), ankle (n = 10; 20.4%) and knee (n = 7; 14.3%). Tissue types mainly involved skin (n = 21; 42.8%), ligament (n = 7; 14.3%) and muscle (n = 7; 14.3%). Multiple (n = 45; 54.9%) and gastrointestinal (n = 17; 20.7%) organ systems were mainly involved in illnesses. Only 100 km runners reported dehydration (n = 28; 31.5%), and one in every six of these runners (n = 5; 17.9%) did not finish. Runners reporting fatigue (n = 21; 23.6%) had a high (n = 8; 38.1%) did not finish rate. Two in every five participants (n = 36; 40.4%) with a medical encounter, did not finish. No medical encounter-associated risk factors were identified.

CONCLUSIONS

Illnesses were more common than injuries during the mountainous ultra trail race. Sustaining a medical encounter increased the chance of not completing the race. Further research on the epidemiology of race day medical encounters in trail running is required.

Gait signatures of endurance runners with low back pain: A case controlled cross sectional study

BACKGROUND

Low back pain (LBP) is an understudied condition among runners, and it is unclear what biomechanical features could be targeted for gait retraining to mitigate pain.

RESEARCH QUESTION

How do running biomechanics differ between healthy individuals and those with running-related LBP?

METHODS

This was a case-controlled, comparative study design of community runners: running-related LBP (n=52) and healthy controls (n=52). All runners completed running history forms and performed a 3-dimensional gait analysis. Kinematic data were collected using a motion capture system and normalized to a gait cycle, while participants ran on a level grade at self-selected speed on an instrumented treadmill. Current running volume, temporal-spatial, kinetic and kinematic features were compared between groups.

RESULTS

The LBP group had 39.5 % lower weekly distance and 15.4 % fewer were currently training for a race (all p<.05). Runners with LBP demonstrated lower cadence (166±10 step/min vs. 171±9 step/min; p=.05), greater center of gravity lateral displacement (1.4±0.5 cm vs. 1.2 ±.3 cm; p=.044) and greater stride width variability (1.3±0.4 cm versus 1.0 ± 0.04 cm; p=.008). Runners with LBP had a greater Vertical Average Loading Rate ([VALR] 67.7±22.2 bodyweights [BW]/s vs. 62.2±21.5 BW/s; p=.022), and higher joint moments (N*m/(kg*m)) at the knee in the sagittal plane (2.13±0.50 vs. 1.87±0.56; p <.001), frontal plane (1.44±0.39 vs. 1.29±0.29; p=.013), and at the hip in the frontal plane (2.04±0.51 vs. 1.84±0.41; p=.024). No differences were found between groups in the pelvis, hip, knee, and ankle joint excursions in any plane of motion during a typical gait cycle.

SIGNIFICANCE

These collective motion signature may reflect challenges with control of motion and VALR in the presence of back pain. Cadence training to increase step rate, coupled with core/hip muscle activation, may be an important strategy to reduce motion variability, impact loading rate and pain symptoms while running.

Potential neurophysiological and biomechanical risk factors for sport-related back problems: A scoping review

This scoping review aims (1) to map the literature dealing with neurophysiological and biomechanical aspects of back problems in athletes in order to identify valid risk-factors for their prevention, plus (2) to identify gaps in the existing research and propose suggestions for future studies. A literature search conducted with Scopus, Web of Science, MEDLINE and Cochrane Library was completed by Elsevier, SpringerLink and Google Scholar. The main neurophysiological risk factors identified leading to back problems in athletes are neuromuscular imbalance, increased muscle fatigability, muscle dysfunction and impaired motor control, whilst biomechanical risk factors include maladaptive spinal, spinopelvic and lower limb kinematics, side-to-side imbalances in axial strength and hip rotation range of motion, spinal overloading and deficits in movement pattern. However, most studies focused on back pain in the lumbar region, whereas less attention has been paid to thoracic and cervical spine problems. The range of sports where this topic has been studied is relatively small. There is a lack of research in sports in which the core muscles are highly involved in specific movements such as lifting weights or trunk rotations. A limited number of studies include female athletes and master athletes of both genders. In addition to chronic back pain patients, it is equally important to conduct research on healthy athletes with a predisposition to spine problems. Investigators should focus their empirical work on identifying modifiable risk factors, predict which athletes are at risk for back problems, and develop personalized sport-specific assessment tools and targeted prevention strategies for them. This review was registered using the Open Science Framework Registries (https://osf.io/ha5n7).

Training for shorter ultra-trail races results in a higher injury rate, a more diverse injury profile, and more severe injuries: 2022 Mac ultra races

OBJECTIVES

Determine and compare the epidemiology, clinical characteristics, and injury severity among race entrants training towards different ultra-trail race distances.

DESIGN

Retrospective cross-sectional study.

SETTING

The six months training period before the 2022 Mac Ultra races (46 km, 80 km, 161 km and 322 km).

PARTICIPANTS

Of the 245 race entrants, 162 (66% of Mac ultra-trail runners) consented to analyse their data.

OUTCOME MEASURES

Injury rate (injuries per 1000 h of running), point prevalence (% of currently injured participants), injury severity (time loss), and the frequency (n, %) of injuries reported during pre-race medical screening in the six months before the race. Using inferential statistics, we compared the injury rates between the different race distance categories (46 km, 80 km, 161 km, 322 km). All tests were performed at a 5% level of significance.

RESULTS

We reported a statistically significantly higher injury rate among 46 km study participants (3.09 injuries per 1000 h) compared to the injury rates reported among 80 km (0.68 injuries per 1000 h; p = 0.001) and 161 km (1.09 injuries per 1000 h; p = 0.028) participants. The lower limb (89%) was the most injured anatomical region, with only 46 km study participants reporting upper limb, trunk, and head injuries (11%). Muscle/tendon was the most reported injured tissue type (56%), with muscle injuries (31%) the most reported pathology type. Shorter distance ultra-trail runners reported the highest injury severity.

CONCLUSION

Ultra-trail runners training towards shorter ultra-trail distance races presented with a higher injury rate, more diverse injury profile, and a higher injury severity.

Trail running injury risk factors: a living systematic review

OBJECTIVE

To review and frequently update the available evidence on injury risk factors and epidemiology of injury in trail running.

DESIGN

Living systematic review. Updated searches will be done every 6 months for a minimum period of 5 years.

DATA SOURCES

Eight electronic databases were searched from inception to 18 March 2021.

ELIGIBILITY CRITERIA

Studies that investigated injury risk factors and/or reported the epidemiology of injury in trail running.

RESULTS

Nineteen eligible studies were included, of which 10 studies investigated injury risk factors among 2 785 participants. Significant intrinsic factors associated with injury are: more running experience, level A runner and higher total propensity to sports accident questionnaire (PAD-22) score. Previous history of cramping and postrace biomarkers of muscle damage is associated with cramping. Younger age and low skin phototypes are associated with sunburn. Significant extrinsic factors associated with injury are neglecting warm-up, no specialised running plan, training on asphalt, double training sessions per day and physical labour occupations. A slower race finishing time is associated with cramping, while more than 3 hours of training per day, shade as the primary mode of sun protection and being single are associated with sunburn. An injury incidence range 0.7-61.2 injuries/1000 hours of running and prevalence range 1.3% to 90% were reported. The lower limb was the most reported region of injury, specifically involving blisters of the foot/toe.

CONCLUSION

Limited studies investigated injury risk factors in trail running. Our review found eight intrinsic and nine extrinsic injury risk factors. This review highlighted areas for future research that may aid in designing injury risk management strategies for safer trail running participation.PROSPERO registration numberCRD42021240832.

Injury Prevention, Safe Training Techniques, Rehabilitation, and Return to Sport in Trail Runners

This current concept, narrative review provides the latest integrated evidence of the musculoskeletal injuries involved with trail running and therapeutic strategies to prevent injury and promote safe participation. Running activities that comprise any form of off-road running (trail running, orienteering, short-long distance, different terrain, and climate) are relevant to this review. Literature searches were conducted to 1) identify types and mechanisms of acute and chronic/overuse musculoskeletal injuries in trail runners, 2) injury prevention techniques most relevant to running trails, 3) safe methods of participation and rehabilitation timelines in the sport. The majority of acute and chronic trail running-related musculoskeletal injuries in trail running occur in the lower leg, primarily in the knee and ankle. More than 70% are due to overuse, and ankle sprains are the most common acute injury. Key mechanisms underlying injury and injury progression include inadequate neuromotor control-balance-coordination, running through fatigue, and abnormal kinematics on variable terrain. Complete kinetic chain prehabilitation programs consisting of dynamic flexibility, neuromotor strength and balance, and plyometrics exercise can foster stable, controlled movement on trails. Patient education about early musculoskeletal pain symptoms and training adjustment can help prevent injury from progressing to serious overuse injuries. Real-time adjustments to cadence, step length, and knee flexion on the trail may also mitigate impact-related risk for injury. After injury occurs, rehabilitation will involve similar exercise components, but it will also incorporate rest and active rest based on the type of injury. Multicomponent prehabilitation can help prevent musculoskeletal injuries in trail runners through movement control and fatigue resistance.

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.

Knowledge and management of low back pain as running-related injuries among Italian physical therapists: findings from a national survey

OBJECTIVES

To investigate the beliefs, knowledge, attitudes, behavior, and the clinical management procedures of the Italian physical therapists specialized in orthopedic manipulative physical therapy (OMPT) toward running and its correlation with low back pain (LBP).Design: A cross-sectional online survey was conducted in 2019, according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.Setting: Italy.Participants: One thousand two hundred and eighteen Italian OMPTs.

METHODS

Survey Monkey software was used to administer the survey. The questionnaire was self-reported and included 26 questions. Descriptive statistics were used and related to the effective respondents for each question.

RESULTS

One thousand two hundred and eighteen questionnaires (60.9%) were included in the analysis. A considerable cohort of OMPTs working in private practice clinical settings (n = 845; 69.4%; 95% CI 66.7-71.9) has indicated running not to be a relevant risk factor for the onset of LBP (n = 806; 66.2%; 95% CI 63.4-68.8). Moreover, most of the participants (n = 679; 55.7%; 95% CI 52.9-58.5) adopted a combination of manual therapy techniques and therapeutic exercise for the management of runners with LBP.

CONCLUSIONS

Widespread knowledge of clinical and theoretical management of LBP in runners-patients has emerged among Italian OMPTs. The OMPTs' academic background agrees with the recent literature and therefore highlights the paucity of studies related to LBP as running-related injuries.

Independent Risk Factors Predicting Gradual Onset Injury in 2824 Trail Running Race Entrants: SAFER XVIII Study

INTRODUCTION

Trail running is characterized by elevation changes, with uneven and varying running surfaces. Risk factors that may predict gradual-onset running-related injuries (GORRIs) in short-distance trail running have not been explored. The objective was to determine risk factors that predict GORRIs in trail running race entrants who entered mass community-based trail running events.

METHODS

In this descriptive cross-sectional study, data were collected prospectively from a prerace medical screening questionnaire over 4 trail run events held annually. Using a Poisson regression model, runner demographics, race distance, running training/racing variables, history of chronic diseases (number of chronic diseases reported as a cumulative "chronic disease composite score"), and allergies were investigated to determine factors predicting self-reported GORRI history in the previous 12 mo.

RESULTS

This study included 2824 race entrants (80% of entrants). The retrospective annual incidence for GORRIs was 13%. Independent risk factors predicting GORRIs were longer race distance (P<0.0001), increasing chronic disease composite score (P=0.0012), and a history of allergies (P=0.0056). The lower limb (94%) was the main anatomic region of GORRIs, and soft tissue injuries accounted for most (83%) GORRIs. Common specific GORRIs were iliotibial band syndrome (22%), Achilles tendon injury (10%), and hamstring injury (9%).

CONCLUSIONS

Independent risk factors predicting GORRIs among trail running entrants included longer race distance, a higher chronic disease composite score, and a history of allergies. This study has highlighted trail running race entrants at risk for sustaining GORRIs who could be targeted for future injury prevention interventions.

Musculoskeletal Injuries in Ultra-Endurance Running: A Scoping Review

Ultra-endurance running (UER) has seen an important increase in participation over the last few decades. Long hours of UER can lead to excessive stress on the body, resulting in musculoskeletal injuries (MSKI). UER is not a uniform sport and events can differ considerably in distance (over 42.195 km), time (e.g., events over 6 h) and multi-day or multi-stage events on various surfaces (e.g., track, on-road, off-road). The aims of this scoping review were therefore: (1) to examine the current evidence of MSKI, providing a synthesis of the most common MSKI by anatomical region and specific diagnosis; (2) categorize MSKI by type of UER activity (competition: time-limited; multi-stage; continuous UER events and training); (3) describe knowledge gaps in the literature and provide advice on potential further research. Our electronic literature search (PubMed, SPORTDiscus, Web of Science) identified a total of 13 studies (9 in competition, and 4 in training). Anatomical site, diagnosis and rate of injuries differ between competition and training as well as between different UER types. MSKI are observed in 18% of multi-stage events (0.7-1.8 injuries/runner and 7.2 injuries/1000 h). Most MSKI involve the lower leg (35.0%), ankle (16.8%), knee (13.1%) and foot (12.6%), with main diagnosis of medial tibial stress syndrome (30.1%) and patella femoral pain syndrome (PFPS; 7.2%). Single, continuous UER events differ between a 1005 km road race with almost all of the injuries due to overuse, with the main anatomical site of the knee (31%), ankle (28%) and lower leg (14%) and main diagnosis of PFPS (15.6%), compared to a 65 km trail race, with 32.8% of MSKI, mainly on the foot [plantar fasciitis (28.6%)], ankle [sprain (28.6%)] and knee. Timed-UER events (injury rate of 2.1 injuries/athlete) observed most injuries on the ankle (36%) and knee (19%), with the main diagnosis of tendinitis of the foot dorsiflexors (30%). Injuries during training most commonly affect, the back (42%), and knee (40%) and bone stress injuries (22%). Main diagnoses include ankle sprain (18%), iliotibial band injury (16%) and Achilles tendinopathy (11%). Future considerations include examining MSKI in different UER events, environments and surfaces, and on larger study populations. Establishing risk factors, examining sex differences and using a standard reporting system of MSKI in UER are also important.

Low back pain among Italian runners: A cross-sectional survey

BACKGROUND

Low Back Pain (LBP) is commonly reported as a very frequent disorder in sports, but its prevalence in runners remains unclear.

OBJECTIVES

To determine the prevalence of LBP in a wide sample of Italian runners.

DESIGN

A cross-sectional online survey.

SETTING

A national survey, according to the CHERRIES and STROBE guidelines, was performed in 2019.

PARTICIPANTS

2539 Italian runners.

METHODS

A sample of Italian runners registered with national running associations was recruited. The survey was conducted using an online survey development platform. The questionnaire was self-reported and included 38 questions.

MAIN OUTCOME MEASURES

Descriptive statistics and frequencies were used to analyze results. Relationships between demographics, daily habits and running characteristics and the responses given was calculated with Cramer's V. Only correlation values higher >0.60 were deemed of interest.

RESULTS

2539 questionnaires (63.5%) were valid for analysis. In total, 22.6% of runners reported having experienced LBP in the past year. Most participants (77.0%) reporting episodes of LBP believed it was not caused by running. No significant correlations (Cramer's V < 0.60) were found between LBP and demographics, training characteristics or lifestyle habits.

CONCLUSION

The prevalence of LBP among Italian runners was 22,57%. LBP was not associated with training, equipment or lifestyle.

Common Running Musculoskeletal Injuries and Associated Factors among Recreational Gorge Marathon Runners: An Investigation from 2013 to 2018 Taroko Gorge Marathons

Many studies exist on the incidence and related risk factors of running injuries, such as those obtained during marathons. However, in gorge-terrain marathons, an insufficient number of reports exist in the relevant literature. Therefore, this study aimed to explore the incidence of musculoskeletal injuries occurring in participants in the 2013 to 2018 Taroko Gorge Marathons in Taiwan and the distribution of running injuries and related influencing factors. A total of 718 runners who entered the physiotherapy station presented with records of treatment and injuries and filled out a running-related injury and self-training questionnaire for further statistical analysis. The association between risk factors and injury were evaluated by logistic regression. The injured areas on the lower extremities after the gorge marathon were as follows: 28% in the knees, 20% in the posterior calves, 13% in the thighs, 10% in the ankles, and 8% in the feet. The analysis of injury-related risk factors showed that male athletes demonstrated a higher risk of thigh injury than female athletes (OR = 2.42, p = 0.002). Underweight runners exhibited a higher risk of thigh injury (OR = 3.35, p = 0.006). We conclude that in the gorge marathon the rates of knee, calf, thigh, and foot injuries are significantly increased. Medical professionals, coaches, and runners may use the findings of this study to reduce the potential risk of running injuries in marathons.

Running-related injuries in Portuguese trail runners: a retrospective cohort study

BACKGROUND

The purpose of this study was to characterize trail running injuries within a cohort of Portuguese male and female recreational trail running athletes.

METHODS

The study was retrospective (12 months), with data collected through an online survey. A total of 719 athletes participated (529 male and 190 female, average age: 38.01±7.78 years). A valid questionnaire was used to collect: 1) demographic information; 2) general information; 3) training typology; 4) physical information; 5) injuries (body location, number, type, reason, treatment, time without practice); and 6) general information concerning the effects of injuries on respondents' daily lives.

RESULTS

The results revealed that 87.8% of the sample contracted an injury resulting from this practice, with the toenails (24.8%), knees (17.5%), and ankles (14.5%) being the most-often reported locations of injuries and blisters (20%), irritation (chafing) (14%), superficial wounds (12%), sprains (11%), and iliotibial band syndrome (7%) being the most common injuries. The result of 10.0 injuries per 1000 h was found, with a negative and medium correlation (r=-0.344; P=0.000) between total exposure time and injuries per 1000 h. It was also found that those who do not perform warm-up have a significantly increased injury rate (P<0.05).

CONCLUSIONS

The gathered evidence demonstrated a large number of dermatological and musculoskeletal injuries, and these tended to have higher incidences in athletes with less exposure time and who devalue warm-up exercises.

Variations of Workload Indices Prior to Injuries: A Study in Trail Runners

The purpose of this study was to compare the variations of weekly workload indices of internal and external load measures across the three weeks prior to injury occurrences in trail runners. Twenty-five trail runners (age: 36.23 ± 8.30 years old; body mass: 67.24 ± 5.97 kg; height: 172.12 ± 5.12 cm) were monitored daily for 52 weeks using global positioning systems (GPSs) to determine the total distance covered. Additionally, a rate of perceived exertion (RPE) scale was applied to determine session-RPE (sRPE: RPE multiplied by training time). The accumulated load (AL), acute: chronic workload ratio (ACWR), training monotony (TM), and training strain (TS) indices were calculated weekly for each runner. During the period of analysis, the injury occurrences were recorded. The differences were observed in AL and ACWR for sRPE and training time were significantly greater during the injury week when compared to the previous weeks. Similar evidence was found in TM and TS indices for sRPE, training time, and total distance. Furthermore, no meaningful differences were observed in AL and ACWR for total distance in the weeks prior to injury occurrence. Nevertheless, significant between-subjects variability was found, and this should be carefully considered. For that reason, an individualized analysis of the workload dynamics is recommended, avoiding greater spikes in load by aiming to keep a progressive increment of load without consequences for injury risk.

Prevalence and incidence of low back pain among runners: a systematic review

Background

Running is one of the most popular sports worldwide. Despite low back pain (LBP) represents the most common musculoskeletal disorder in population and in sports, there is currently sparse evidence about prevalence, incidence and risk factors for LBP among runners. The aims of this systematic review were to investigate among runners: prevalence and incidence of LBP and specific risk factors for the onset of LBP.

Methods

A systematic review has been conducted according to the guidelines of the PRISMA statement. The research was conducted in the following databases from their inception to 31st of July 2019: PubMed; CINAHL; Google Scholar; Ovid; PsycINFO; PSYNDEX; Embase; SPORTDiscus; Scientific Electronic Library Online; Cochrane Library and Web of Science. The checklists of The Joanna Briggs Institute Critical Appraisal tools were used to investigate the risk of bias of the included studies.

Results

Nineteen studies were included and the interrater agreement for full-text selection was good (K = 0.78; 0.61–0.80 IC 95%). Overall, low values of prevalence (0.7–20.2%) and incidence (0.3–22%) of LBP among runners were reported. Most reported risk factors were: running for more than 6 years; body mass index > 24; higher physical height; not performing traditional aerobics activity weekly; restricted range of motion of hip flexion; difference between leg-length; poor hamstrings and back flexibility.

Conclusions: Prevalence and incidence of LBP among runners are low compared to the others running related injuries and to general, or specific population of athletes. View the low level of incidence and prevalence of LBP, running could be interpreted as a protective factor against the onset of LBP.

Systematic review registration

PROSPERO CRD42018102001.

A narrative review of potential measures of dynamic stability to be used during outdoor locomotion on different surfaces

Dynamic stability of locomotion plays an important role in running injuries, particularly during trail running where ankle injuries occur frequently. Several studies have investigated dynamic stability of locomotion using wearable accelerometer measurements. However, no study has reviewed how dynamic stability of locomotion is quantified using accelerometry. Therefore, the present review aims to synthetise the methods and findings of studies investigating stability related parameters measured by accelerometry, during locomotion on various surfaces, and among asymptomatic participants. A systematic search of studies associated with locomotion was conducted. Only studies including assessment of dynamic stability parameters based on accelerometry, including at least one group of asymptomatic participants, and conditions that occur during trail running were considered relevant for this review. Consequently, all retrieved studies used a non-obstructive portable accelerometer or an inertial measurement unit. Fifteen studies used a single tri-axial accelerometer placed above the lumbar region allowing outdoor recordings. From trunk accelerations, a combination of index of cycle repeatability and signal dispersion can adequately be used to assess dynamic stability. However, as most studies included indoor conditions, studies addressing the biomechanics of trail running in outdoor conditions are warranted.