Excessive progression in weekly running distance and risk of running-related injuries: an association which varies according to type of injury

Risk factors associated with a history of iliotibial band syndrome (hITBS) in distance runners: a cross-sectional study in 76 654 race entrants - a SAFER XXXIII study

BACKGROUND

Despite the numerous health benefits of distance running, it is also associated with the development of 'gradual onset running-related injuries' (GORRIs) one of which is Iliotibial Band Syndrome (ITBS). Novel risk factors associated with a history of ITBS (hITBS) have not been described in a large cohort of distance runners.

OBJECTIVE

To identify risk factors associated with hITBS in distance runners.

DESIGN

Descriptive cross-sectional study.

SETTING

21.1 km and 56 km Two Oceans Marathon races (2012-2015).

PARTICIPANTS

106 743 race entrants completed the online pre-race medical screening questionnaire. A total of 1 314 runners confirmed an accurate hITBS diagnosis.

METHODS

Selected risk factors associated with hITBS explored included: demographics (race distance, sex, age groups), training/running variables, history of existing chronic diseases (including a composite chronic disease score) and history of any allergy. Prevalence (%) and prevalence ratios (PR; 95% CI) are reported (uni- & multiple regression analyzes).

RESULTS

1.63% entrants reported hITBS in a 12-month period. There was a higher (p < 0.0001) prevalence of hITBS in the longer race distance entrants (56 km), females, younger entrants, fewer years of recreational running (PR = 1.07; p = 0.0009) and faster average running speed (PR = 1.02; p = 0.0066). When adjusted for race distance, sex, age groups, a higher chronic disease composite score (PR = 2.38 times increased risk for every two additional chronic diseases; p < 0.0001) and a history of allergies (PR = 1.9; p < 0.0001) were independent risk factors associated with hITBS.

CONCLUSION

Apart from female sex, younger age, fewer years of running and slower running speed, two novel independent risk factors associated with hITBS in distance runners are an increased number of chronic diseases and a history of allergies. Identifying athletes at higher risk for ITBS can guide healthcare professionals in their prevention and rehabilitation efforts.

Clinical and exercise professional opinion of return-to-running readiness after childbirth: an international Delphi study and consensus statement

Female athletes have identified a lack of guidance as a barrier to successfully returning to running postpartum, and existing guidelines are vague. Our aim was to define the current practice of determining postpartum run-readiness through a consensus survey of international clinicians and exercise professionals in postpartum exercise to assist clinicians and inform sport policy changes.A three-round Delphi approach was used to gain international consensus from clinicians and exercise professionals on run-readiness postpartum. Professionals who work with postpartum runners participated in an online survey to answer open-ended questions about the following postpartum return-to-running topics: definitions (runner and postpartum), key biopsychosocial milestones that runners need to meet, recommended screening, timeline to initiate running, support items, education topics and factors that contribute to advising against running. Consensus was defined as ≥75% participant agreement.One hundred and eighteen professionals participated in round I, 107 participated in round II (response rate 90.6%) and 95 participated in round III (response rate 80.5%). Responses indicated that, following a minimum 3-week period of rest and recovery, an individualised timeline and gradual return to running progression can be considered. Screening for medical and psychological concerns, current physical capacity, and prior training history is recommended prior to a return to running.This study proposes recommendations for the initial guidance on return-to-running postpartum, framed in the context of current research and consensus from professionals. Future research is needed to strengthen and validate specific recommendations and develop guidelines for best practice when returning-to-running after childbirth.

Clinical and exercise professional opinion on designing a postpartum return-to-running training programme: an international Delphi study and consensus statement

Returning to running postpartum presents challenges such as musculoskeletal pain and pelvic floor dysfunction for some females, but there is little guidance on developing and progressing postpartum training programmes. This study aims to establish expert consensus recommendations on designing and modifying a postpartum return-to-running training programme, highlight costs and access to qualified professionals as potential barriers and discuss clinical, research and sports policy implications.A three-round Delphi survey of clinical and exercise professionals working with postpartum runners was conducted. Round I consisted of open-ended questions related to designing the training plan, modifications based on biopsychosocial factors, key muscle groups to train and referral and payment sources. Rounds II and III involved Likert-scale voting to identify consensus (≥75% agreement).118 participants completed Round I, 107 completed Round II (response rate 90.6%) and 95 completed Round III (response rate 80.5%). Consensus was reached in 42/47 (89%) statements, including recommendations for a period of relative rest, gradual increases in duration and intensity, starting with a walk-run protocol and incorporating strength training. Training should be modified based on musculoskeletal or pelvic symptoms, sleep, mental health, lactation or energy availability concerns. Cost and access to experienced postpartum running professionals were identified as potential barriers for runners to receive care.Consensus recommendations for a postpartum return-to-running programme include an individualised exercise prescription, gradual increases in physical activity, walk-run protocols and targeted muscle strengthening. Further research and improved access to clinical and exercise professionals are needed to inform and facilitate best practices.

Risk Factors for Running-Related Injury in High School and Collegiate Cross-country Runners: A Systematic Review

OBJECTIVE: To summarize and describe risk factors for running-related injuries (RRIs) among high school and collegiate cross-country runners. DESIGN: Descriptive systematic review. LITERATURE SEARCH: Four databases (Scopus, SPORTDiscus, CINAHL, Cochrane) were searched from inception to August 2023. STUDY SELECTION CRITERIA: Studies assessing RRI risk factors in high school or collegiate runners using a prospective design with at least 1 season of follow-up were included. DATA SYNTHESIS: Results across each study for a given risk factor were summarized and described. The NOS and GRADE frameworks were used to evaluate quality of each study and certainty of evidence for each risk factor. RESULTS: Twenty-four studies were included. Overall, study quality and certainty of evidence were low to moderate. Females or runners with prior RRI or increased RED-S (relative energy deficiency in sport) risk factors were most at risk for RRI, as were runners with a quadriceps angle of >20° and lower step rates. Runners with weaker thigh muscle groups had increased risk of anterior knee pain. Certainty of evidence regarding training, sleep, and specialization was low, but suggests that changes in training volume, poorer sleep, and increased specialization may increase RRI risk. CONCLUSION: The strongest predictors of RRI in high school and collegiate cross-country runners were sex and RRI history, which are nonmodifiable. There was moderate certainty that increased RED-S risk factors increased RRI risk, particularly bone stress injuries. There was limited evidence that changes in training and sleep quality influenced RRI risk, but these are modifiable factors that should be studied further in this population. J Orthop Sports Phys Ther 2024;54(2):1-13. Epub 16 November 2023. doi:10.2519/jospt.2023.11550.

Running-Related Injuries Among More Than 7000 Runners in 87 Different Countries: The Garmin-RUNSAFE Running Health Study

OBJECTIVE: To describe the cumulative injury proportion after 1000 and 2000 km of running among runners from 87 countries worldwide using wearable devices. Secondly, examine if the cumulative injury proportion differed between runners from different countries. DESIGN: Cohort study with an 18-month follow-up. METHODS: Runners aged ≥18 years who were familiar with the English language, and who were using a Garmin sports watch that supported tracking of running were eligible for inclusion. The exposure was residential country; self-reported running-related injury was the primary outcome. A generalized linear model was used to estimate the cumulative injury proportion for each country and the cumulative risk difference between the countries (country with the lowest risk used as reference). Data were analyzed at 1000 and 2000 km. RESULTS: The proportions of injured runners among the 7605 included runners from 87 different countries were 57.6% [95% CI: 56.9%, 59.0%] at 1000 km and 69.8% [95% CI: 68.3%, 71.4%] at 2000 km. Runners from the Czech Republic (40.3% [95% CI: 28.7%, 51.9%]), Austria (41.1% [95% CI: 25.9%, 52.2%]), and Germany (41.9% [95% CI: 36.0%, 47.9%]) had the lowest cumulative injury proportions at 1000 km, whereas Ireland (75.4% [95% CI: 60.4%, 90.4%]), Great Britain and Northern Ireland (73.2% [95% CI: 69.3%, 77.1%]), and Finland (67.5% [95% CI: 47.2%, 87.7%]) had the highest proportions. At 2000 km, Poland (47.7% [95% CI: 36.0%, 59.4%]), Slovenia (52.2% [95% CI: 28.5%, 75.8%]), and Croatia (54.2% [95% CI: 35.6%, 72.7%]) had the lowest proportions of injured runners. The highest cumulative injury proportions were reported in Great Britain and Northern Ireland (83.6% [95% CI: 79.6%, 87.6%]) and the Netherlands (78.3% [95% CI: 70.6%, 85.9%]). CONCLUSION: More than half of the population of adult runners from 87 countries using wearable devices sustained a running-related injury during follow-up. There were considerable between-country differences in injury proportions. J Orthop Sports Phys Ther 2024;54(2):1-9. Epub 16 November 2023. doi:10.2519/jospt.2023.11959.

Preinjury Knee and Ankle Mechanics during Running Are Reduced among Collegiate Runners Who Develop Achilles Tendinopathy

INTRODUCTION

Achilles tendinopathies (AT) are common in runners, but prospective data assessing running mechanics associated with developing AT are limited. Asymmetry in running mechanics is also considered a risk factor for injury, although it is unknown if the problematic mechanics occur on the injured limb only or are present bilaterally.

PURPOSE

This study aimed to prospectively identify differences in preinjury running biomechanics in collegiate runners who did and did not develop AT and determine if between-limb asymmetries were associated with which limb developed AT.

METHODS

Running gait data were obtained preseason on healthy collegiate cross-country runners, and AT incidence was prospectively recorded each year. Spatiotemporal, ground reaction forces, and joint kinematics and kinetics were analyzed. Linear mixed-effects models assessed differences in biomechanics between those who did and did not develop AT during the subsequent year. Generalized linear mixed-effects models determined if the asymmetry direction was associated with which limb developed an AT, with odds ratios (OR) and 95% confidence intervals (95% CI) reported.

RESULTS

Data from 106 runners were analyzed and 15 developed AT. Preinjury biomechanics of runners who developed AT showed less peak knee flexion (noninjured: 45.9° (45.2°-46.6°), injured: 43.2° (41.5°-44.9°), P < 0.001), ankle dorsiflexion (noninjured: 28.7° (28.0°-30.2°), injured: 26.0° (23.8°-28.3°), P = 0.01), and knee extensor moment (noninjured: -2.18 (N·m)·kg -1 (-2.24 to -2.12 (N·m)·kg -1 ), injured: -2.00 (N·m)·kg -1 (-2.17 to -1.84 (N·m)·kg -1 ), P = 0.02). The limb demonstrating less peak knee flexion had greater odds of sustaining an AT (OR, 1.29 (1.00-1.65), P = 0.05).

CONCLUSIONS

Knee and ankle kinematics, in addition to knee kinetics, were associated with developing an AT. Monitoring these mechanics may be useful for prospectively identifying runners at risk of developing AT.

Aetiological Factors of Running-Related Injuries: A 12 Month Prospective "Running Injury Surveillance Centre" (RISC) Study

BACKGROUND

Running-related injuries (RRIs) are a prevalent issue for runners, with several factors proposed to be causative. The majority of studies to date are limited by retrospective study design, small sample sizes and seem to focus on individual risk factors in isolation. This study aims to investigate the multifactorial contribution of risk factors to prospective RRIs.

METHODS

Recreational runners (n = 258) participated in the study, where injury history and training practices, impact acceleration, and running kinematics were assessed at a baseline testing session. Prospective injuries were tracked for one year. Univariate and multivariate Cox regression was performed in the analysis.

RESULTS

A total of 51% of runners sustained a prospective injury, with the calf most commonly affected. Univariate analysis found previous history of injury < 1 year ago, training for a marathon, frequent changing of shoes (every 0-3 months), and running technique (non-rearfoot strike pattern, less knee valgus, greater knee rotation) to be significantly associated with injury. The multivariate analysis revealed previous injury, training for a marathon, less knee valgus, and greater thorax drop to the contralateral side to be risk factors for injury.

CONCLUSION

This study found several factors to be potentially causative of injury. With the omission of previous injury history, the risk factors (footwear, marathon training and running kinematics) identified in this study may be easily modifiable, and therefore could inform injury prevention strategies. This is the first study to find foot strike pattern and trunk kinematics to relate to prospective injury.

Running Marathons in High School: A 5-Year Review of Injury in a Structured Training Program

OBJECTIVE

The aim in this study was to quantify the number, nature, and severity of injuries sustained by male and female high school students who took part in a running training program that culminated in the completion of a half or full marathon.

DESIGN

This study is a retrospective clinical audit.

METHODS

Injury reports from high school students (grades 9-12) who participated in a half or full marathon 30-week progressive training program comprising four training days per week (three running days and one cross-training day) were reviewed. The number of runners completing a marathon, together with the number, nature, severity of injuries, and treatment types, as reported to the program physiotherapist, were the main outcome measures.

RESULTS

Program completion was 96% (n = 448/469). Of all participants, 186 (39.6%) were injured, with 14 withdrawing from the program due to injury. For those who completed a marathon, 172 (38%) reported 205 musculoskeletal injuries (age of injured runners: 16.3 ± 1.1 years; 88 girls (51.2%) and 84 boys (48.8%)). More than half (n = 113, 55.1%) of the reported injuries were soft tissue injuries. Most injuries were localized to the lower leg (n = 88, 42.9%) and were of a minor nature (n = 181, 90%), requiring only 1-2 treatments.

CONCLUSIONS

There was a low number of relatively minor injuries for high school participants taking part in a graduated and supervised marathon training program. The injury definition was conservative (i.e., any attendance to physiotherapist) and the relative severity of injuries was minor (i.e., requiring 1-2 treatment sessions). Overall, these results do not support a need to restrict high school students from taking part in marathon running, though continued emphasis on graduated program development and close supervision of young participants is recommended.

Characteristics of return to running programs following an anterior cruciate ligament reconstruction: A scoping review of 64 studies with clinical perspectives

OBJECTIVE

To (1) describe return to running (RTR) programs used during rehabilitation after anterior cruciate ligament reconstruction (ACLR); and (2) provide clinical guidelines for RTR program after ACLR.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched the MEDLINE (Pubmed), EMBASE, Web of Science and PEDro databases.

STUDY SELECTION CRITERIA

We included randomized controlled trial (RCT), cases series, meta-analyses, both scoping and systematic reviews including a rehabilitation program after ACLR with a specific RTR program. A "Running program checklist" (RPC) was elaborated based on the Template for Intervention Description and Replication (TIDieR), and on the Consensus on Exercise Reporting Template (CERT) checklist.

DATA SYNTHESIS

The percentage and number of studies specifying each of the running program checklist items in their RTR program were reported. Number of items reported in each study and specific analysis item-by-item were also proposed.

RESULTS

The "When (2)" item was the most frequently found (92.19%) and, conversely, the "Who (1)" item appeared only in four studies (6.2%). One-third of the studies presented only one item of the RPC, and 48 of the 64 articles discussed less than three items. Two studies described in detail their RTR program by reporting 8 and 9 items out of the 10, respectively. No study presented 10 of the PRC items.

CONCLUSION

There is a serious lack of information concerning RTR program following ACLR in the literature and further studies are needed to establish a program based on the best evidence.

Endoscopy-related injury among gastroenterology trainees

Background and study aims  Endoscopy-related injury (ERI) is widespread among practicing gastroenterologists. However, less is known about the incidence among trainees. This study assesses the rate of self-reported ERI occurrence, patterns of injury, and knowledge of preventive strategies in a nationally representative sample of gastroenterology fellows. Methods  A 38-item electronic survey was sent to members of the American College of Gastroenterology. One hundred and sixty-eight gastroenterology fellows were included in analyses. Descriptive and univariate analyses evaluated the likelihood of ERI by workload parameters and gender. Results  ERI was reported by 54.8 % of respondents. ERI was most common in the thumb (58.7 %), hand/finger (56.5 %), and wrist (47.8 %). There was no significant difference in the reported occurrence of ERI between male and female gastroenterology fellows. However, female fellows were significantly more likely to report a greater number of body areas affected by ERI, and male fellows were more likely to report elbow pain. Most respondents (85.1 %) reported discussion about, or training in, ergonomic strategies during gastroenterology fellowship. Conclusions  ERI is reported to occur as early as gastroenterology fellowship. Results of this study support this finding and highlight the need for ongoing implementation and monitoring of a formal ergonomics training program as well as development of ergonomically appropriate instruments. Implications of these findings likely extend to trainees in other procedural related specialties like orthopedics and general surgery, though further research is required. Ergonomics training in gastroenterology fellowship and monitoring of its impact on trainees reported ERI is important due to negative effects on productivity and career longevity.

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

BACKGROUND

Running 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.

METHODS

The 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.

DISCUSSION

To 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.

Quantification method influences training load change in high school cross-country runners across a competitive season

CONTEXT

Running programs traditionally monitor external loads (e.g., time, distance). There has been a recent movement to encompass a more comprehensive approach to also monitor training loads that account for internal loads (e.g., intensity, measured as session rating of perceived exertion [sRPE]). The combination of an external and internal load accounts for the potential interaction between these loads. While differences in weekly change in training loads have been reported between external loads and the combination of an external and internal load during 2- and 4-week training cycles, there are no reports whether these differences are apparent during an entire cross-country season in high school runners.

OBJECTIVE

To compare change in training loads, as measured by external loads and combinations of an external and internal load, in high school runners during an interscholastic cross-country season.

DESIGN

Case-series.

SETTING

Community-based with daily online surveys.

PARTICIPANTS

Twenty-four high school cross-country runners (female=14, male=10, age=15.9±1.1 years, running experience=9.9±3.2 years).

MAIN OUTCOME MEASURE(S)

Week-to-week percent change in training load when measured by external loads (time, distance) and the combination of an external and internal load (timeRPE, distanceRPE).

RESULTS

Overall, the average weekly change was 7.1% greater for distanceRPE compared to distance (p=.04, d=0.18). When decreasing weekly running duration, the average weekly change was 5.2% greater for distanceRPE compared to timeRPE (p=.03, d=0.24). When maintaining or increasing weekly running duration, the average weekly change was 10-15% greater when an external load was combined with an internal load compared to external loads alone, but these differences were non- significant (p=.11-.22, d=0.19-0.34).

CONCLUSIONS

Our results demonstrate that progression in training load may be underestimated when relying solely on external loads. The interaction between internal loads (sRPE) and external loads (distance or time) appears to provide a different measure of training stresses experienced by runners than external loads alone.

Dance Exposure, Individual Characteristics, and Injury Risk over Five Seasons in a Professional Ballet Company

PURPOSE

This study aimed to describe the relationships between dance exposure, dancer characteristics, and injury risk across five seasons in a professional ballet company.

METHODS

Dance exposure time and clinician-reported time-loss and medical attention injury data were prospectively collected from 118 professional dancers of The Royal Ballet between 2015/2016 and 2019/2020. Cox proportional hazards and shared frailty models were fitted to overuse and traumatic injuries; individualized robust Z-scores for 7- and 28-d accumulated exposure, and week-to-week change in exposure, age, sex, company rank, and injury history were included as time-varying covariates.

RESULTS

Across 381,710 h of exposure, 1332 medical attention and 427 time-loss injuries were observed. Positive relationships were observed between week-to-week change in exposure and overuse time-loss (+1 Z-score hazard ratio (HR), 1.27; 95% confidence interval (CI), 1.06-1.53) and medical attention injury risk (+1 Z-score HR, 1.17; 95% CI, 1.06-1.28). A negative relationship was observed between 7-d accumulated exposure and overuse medical attention injury risk (+1 Z-score HR, 0.74; 95% CI, 0.66-0.84). Overuse time-loss injury risk was greater in soloists compared with the corps de ballet (HR, 1.47; 95% CI, 1.01-2.15) and in dancers with a higher previous injury rate (+1 injury per 1000 h HR, 1.06; 95% CI, 1.02-1.10). Only age was associated with traumatic time-loss (+1-yr HR, 1.05; 95% CI, 1.01-1.09) or medical attention injury risk (+1-yr HR, 1.04; 95% CI, 1.01-1.07).

CONCLUSIONS

Professional ballet companies should implement training principles such as periodization and progression, particularly in the case of senior-ranking dancers, older dancers, and dancers with high rates of previous injury. These findings provide a basis for future prospective investigations into specific causal injury pathways.

Interactions between running volume and running pace on injury occurrence in recreational runners: A secondary analysis

Context The combination of an excessive increase in running pace and volume is essential to consider when investigating associations between running and running-related injury. Objectives The purpose of the present study was to complete a secondary analysis on a dataset from a randomized trial, to investigate the interactions between relative or absolute weekly changes in running volume and running pace on running injury occurrence among a cohort of injury-free recreational runners in Denmark. Design Prospective cohort study Setting Running volume and pace were collected during a 24-week follow-up using global positioning systems (GPS) data. Training data was used to calculate relative and absolute weekly changes in running volume and pace. Patients or Other Participants A total of 586 recreational runners were included in the analysis. All participants were injury-free at inclusion. Main Outcome Measure(s) Running-related injury was the outcome. Injury data were collected weekly using a modified version of the OSTRC questionnaire. Risk difference (RD) was the measure of injury risk. Results A total of 133 runners sustained a running-related injury. A relative weekly change of progression >10% in running volume and progression in running pace (RD=8.1%, 95%CI: - 9.3;25.6%) and an absolute weekly change of progression >5km in running volume and progression in running pace (RD=5.2%, 95%CI: -12.0;22.5%), were not associated with a statistically significant positive interaction. Conclusions As coaches, clinicians and athletes may agree that excessive increase in running pace and excessive increase in running volume are important contributors to injury development, we analyzed the interaction between them. Although a statistically significant positive interaction on an additive scale in runners who progressed both running pace and running volume were not identified in the present study, readers of scientific articles should be aware that interaction is an important analytical approach that could be applied to other datasets in future publications.

The association between running injuries and training parameters: A systematic review

OBJECTIVE

To synthesise the current evidence on the incidence of running-related injuries (RRI) and their association with training parameters (distance, duration, frequency, intensity), as well as recent changes in training parameters.

DATA SOURCES

Searches were conducted in Medline/Ovid, CINAHL, Embase and SportDiscus up to July 7, 2020.

STUDY SELECTION

Included articles had to report prospective data on RRIs and training parameters, or any changes in parameters, and be published in English or French. Two reviewers independently screened titles, abstracts and full-texts.

DATA EXTRACTION

Data extraction and quality assessment (QualSyst) were performed by two independent raters.

DATA SYNTHESIS

Thirty-six articles totaling 23,047 runners were included. Overall, 6,043 runners (26.2%) sustained an RRI (incidence range: 8.8% to 91.3%). The incidence of RRI was 14.9% in novice runners (range: 9.4 to 94.9%), 26.1% in recreational runners (range: 17.9 to 79.3%) and 62.6% in competitive runners (range: 52.6 to 91.3%). The three most frequently injured body parts were the knee (25.8%), foot/ankle (24.4%) and lower leg (24.4%). Overall, there was conflicting evidence about the association between weekly running distance, duration, frequency, intensity or specific changes in training parameters and the onset of RRIs.

CONCLUSIONS

Despite high rates of RRIs, current evidence does not consistently link RRIs with specific training parameters or recent changes in training parameters. Therefore, caution should be taken when recommending optimal parameters or progressions. Given the multifactorial nature of RRIs, future studies also need to consider the interaction between training parameters, as well as psychosocial, hormonal, lifestyle and recovery outcomes to better understand the onset of RRIs.

Changes in health promoting behavior during COVID-19 physical distancing: Utilizing wearable technology to examine trends in sleep, activity, and cardiovascular indicators of health

The COVID-19 pandemic incited unprecedented restrictions on the behavior of society. The aims of this study were to quantify changes to sleep/wake behavior and exercise behavior, as well as changes in physiological markers of health during COVID-19 physical distancing. A retrospective analysis of 5,436 US-based subscribers to the WHOOP platform (mean age = 40.25 ± 11.33; 1,536 females, 3,900 males) was conducted covering the period from January 1st, 2020 through May 15th, 2020. This time period was separated into a 68-day baseline period and a 67-day physical distancing period. To provide context and allow for potential confounders (e.g., change of season), data were also extracted from the corresponding time periods in 2019. As compared to baseline, during physical distancing, all subjects fell asleep earlier (-0.15 hours), woke up later (0.29 hours), obtained more sleep (+0.21 hours) and reduced social jet lag (-0.13 hours). Contrasting sleep behavior was seen in 2019, with subjects falling asleep and waking up at a similar time (-0.01 hours; -0.03 hours), obtaining less sleep (-0.14 hours) and maintaining social jet lag (+0.06 hours) in corresponding periods. Individuals exercised more intensely during physical distancing by increasing the time spent in high heart rate zones. In 2020, resting heart rate decreased (-0.90 beats per minute) and heart rate variability increased (+0.98 milliseconds) during physical distancing when compared to baseline. However, similar changes were seen in 2019 for RHR (-0.51 beats per minute) and HRV (+2.97 milliseconds), suggesting the variation may not be related to the introduction of physical distancing mandates. The findings suggest that individuals improved health related behavior (i.e., increased exercise intensity and longer sleep duration) during physical distancing restrictions. While positive changes were seen to cardiovascular indicators of health, it is unclear whether these changes were a direct consequence of behavior change.

Sport Specialization and Quality of Life among Middle- and High-School Long-Distance Runners of Different Injury Status: A Retrospective Study

Running-related injuries are prevalent in adolescent long-distance runners. The aim of our retrospective study was to compare differences in sport specialization, running habits,quality of life, and sleep habits among middle-and high-school long-distance runners of different injury statuses. Middle- and high-school long-distance runners across the United States were recruited via cross-country coaches and athletic directors between January and May 2020. Participants completed an online survey with questions related to demographics, sport specialization, running habits, quality of life, sleep, and self-reported injury history. Overall, 306 participants completed the survey (male = 107, female = 176, unspecified = 23; age = 15.7 ± 1.1 years). Of the participants, 178 (58.2%) reported no history of injury, 101 (33.0%) reported a previous injury, and 27 (8.8%) reported a current injury. Middle- and high-school runners with a current injury reported significantly lower overall health (p= .01) and average distance per run (p = .05) than uninjured runners. No significant differences were found among injury status and sport specialization level, quality of life, sleep habits, or running volume (p> .05). Runners with a self-reported previous or current injury do not appear to be classified as high-specialized runners more frequently than uninjured runners.

Frequency of Injury and Illness in the Final 4 Weeks before a Trail Running Competition

We aimed to (i) determine self-reported injury and illness frequency in trail runners 4 weeks preceding competition; (ii) compare athletes with and without injury/illness by sex, age, body mass index (BMI) and competition distance; (iii) describe mechanism of injury, anatomical region (injury)/organ system (illness) involved, consequences of injury on preparation and self-perception of injury severity; (iv) compare anatomical region (injury) and organ system (illness) by sex. A total of 654 trail runners (age 36.2, IQR 30.6-43.0; 36.9% females) participated in this retrospective cross-sectional study by completing a self-reported questionnaire. Injury and illness frequency rates were 31.3% (n = 205, CI: 27.7-35.0%) and 22.3% (n = 146, CI: 19.1-25.7%), respectively. No significant difference was found between injured vs. non-injured or ill vs. non-ill study participants by sex, age, BMI and competition distance. Regarding injuries, gradual onset (41.6%) and knee (33.2%) were the most indicated mechanism and anatomical region of injury. At least 85.4% of trail runners changed their training following injury and 79% indicated that their injury would affect their competition performance. Regarding illness, the respiratory tract was the most frequent organ system involved (82.9%). Male and female participants reported similar proportions of anatomical regions (injury) and organ systems (illness) affected. These results could help to generate education strategies and appropriate medical support before and during these competitions.

Session Rating of Perceived Exertion Combined With Training Volume for Estimating Training Responses in Runners

CONTEXT

Historically, methods of monitoring training loads in runners have used simple and convenient metrics, including the duration or distance run. Changes in these values are assessed on a week-to-week basis to induce training adaptations and manage injury risk. To date, whether different measures of external loads, including biomechanical measures, provide better information regarding week-to-week changes in external loads experienced by a runner is unclear. In addition, the importance of combining internal-load measures, such as session rating of perceived exertion (sRPE), with different external-load measures to monitor week-to-week changes in training load in runners is unknown.

OBJECTIVE

To compare week-to-week changes in the training loads of recreational runners using different quantification methods.

DESIGN

Case series.

SETTING

Community based.

PATIENTS OR OTHER PARTICIPANTS

Recreational runners in Vancouver, British Columbia.

MAIN OUTCOME MEASURE(S)

Week-to-week changes in running time, steps, and cumulative shock, in addition to the product of each of these variables and the corresponding sRPE scores for each run.

RESULTS

Sixty-eight participants were included in the final analysis. Differences were present in week-to-week changes for running time compared with timeRPE (d = 0.24), stepsRPE (d = 0.24), and shockRPE (d = 0.31). The differences between week-to-week changes in running time and cumulative shock were also significant at the overall group level (d = 0.10).

CONCLUSIONS

We found that the use of an internal training-load measure (sRPE) in combination with external load (training duration) provided a more individualized estimate of week-to-week changes in overall training stress. A better estimation of training stress has significant implications for monitoring training adaptations, resulting performance, and possibly injury risk reduction. We therefore recommend the regular use of sRPE and training duration to monitor training load in runners. The use of cumulative shock as a measure of external load in some runners may also be more valid than duration alone.

Injury Prediction in Competitive Runners With Machine Learning

PURPOSE

Staying injury free is a major factor for success in sports. Although injuries are difficult to forecast, novel technologies and data-science applications could provide important insights. Our purpose was to use machine learning for the prediction of injuries in runners, based on detailed training logs.

METHODS

Prediction of injuries was evaluated on a new data set of 74 high-level middle- and long-distance runners, over a period of 7 years. Two analytic approaches were applied. First, the training load from the previous 7 days was expressed as a time series, with each day's training being described by 10 features. These features were a combination of objective data from a global positioning system watch (eg, duration, distance), together with subjective data about the exertion and success of the training. Second, a training week was summarized by 22 aggregate features, and a time window of 3 weeks before the injury was considered.

RESULTS

A predictive system based on bagged XGBoost machine-learning models resulted in receiver operating characteristic curves with average areas under the curves of 0.724 and 0.678 for the day and week approaches, respectively. The results of the day approach especially reflect a reasonably high probability that our system makes correct injury predictions.

CONCLUSIONS

Our machine-learning-based approach predicts a sizable portion of the injuries, in particular when the model is based on training-load data in the days preceding an injury. Overall, these results demonstrate the possible merits of using machine learning to predict injuries and tailor training programs for athletes.

Non-operative Management of Anterior Knee Pain: Patient Education

PURPOSE OF REVIEW

Anterior knee pain is a multifactorial, often chronic condition, which can lead to long-term pain and disability. The purpose of this review is to examine the latest research on patient education for anterior knee pain. We will focus on how we might use patient education to increase the adoption of other efficacious treatment modalities and offer some suggestions for content and form of effective patient education.

RECENT FINDINGS

New research suggests that patient education, alone, or in combination with targeted exercise therapy, can be effective in reducing pain and improving function in patients with patellofemoral pain. Addressing non-physical or psychological factors may also be an important component of patient education in many patients with chronic pain. Incorporation of new technologies into patient education, such as those available online, or through phone- or tablet-based apps, is likely to be helpful in the future, as we move more towards connecting with patients virtually. Patient education has been shown to be effective in decreasing pain and improving activity in patients with patellofemoral pain. Patient education should be individualized to the patient, focus on the latest effective treatments, and emphasize those treatments that can be self-managed by the patient. Emphasis should also be placed on patient understanding of risk factors and patterns of movement that may lead to, or exacerbate, anterior knee pain. Future research should continue to further characterize the elements of patient education that offer the most efficient treatment benefit.

Are hip and knee kinematics and training load characteristics relate to pain intensity and physical function level in runners with Patellofemoral Pain?

BACKGROUND

Patellofemoral pain (PFP) is the most common running-related injury. Altered hip and knee kinematics and increases in weekly distance and running pace are often associated with PFP development and exacerbation.

RESEARCH QUESTION

Are altered movements and training load characteristics (weekly distance and running pace) relate to pain intensity or physical function level in runners with PFP?

METHODS

Forty recreational runners with PFP (20 males and 20 females) participated in this cross-sectional observational study. Three-dimensional hip and knee kinematics were quantified during the stance phase of running. Weekly distance was defined as the average weekly kilometers of running and running pace as the average pace of the activity measured as minutes per kilometer. A visual analogue scale was used to evaluate worst knee pain during the last week. The anterior knee pain scale (AKPS) was used to evaluate knee functional score. A Pearson correlation matrix was used to investigate the association between each dependent variable (worst pain in the last week and AKPS score) and the independent variables (knee and hip kinematics, weekly distance and running pace).

RESULTS

There was no significantly correlation between kinematic variables, pain and functional score for both males and females separately and combined. Weekly distance (km/week) was found to positively correlate to pain intensity (r = 0.452; p < 0.05) in females with PFP. A simple linear regression revealed that weekly distance was significant predictor emerged of pain in females with PFP. Females exhibited significantly greater peak hip adduction and hip adduction ROM than the males and males had significantly greater running pace compared to females.

SIGNIFICANCE

Weekly distance should be considered in the clinical context during rehabilitation of PFP in females runners aiming at pain reduction.

Sex-Specific Differences in Running Injuries: A Systematic Review with Meta-Analysis and Meta-Regression

BACKGROUND

Running is a popular sport with high injury rates. Although risk factors have intensively been investigated, synthesized knowledge about the differences in injury rates of female and male runners is scarce.

OBJECTIVE

To systematically investigate the differences in injury rates and characteristics between female and male runners.

METHODS

Database searches (PubMed, Web of Science, PEDro, SPORTDiscus) were conducted according to PRISMA guidelines using the keywords "running AND injur*". Prospective studies reporting running related injury rates for both sexes were included. A random-effects meta-analysis was used to pool the risk ratios (RR) for the occurrence of injuries in female vs. male runners. Potential moderators (effect modifiers) were analysed using meta-regression.

RESULTS

After removal of duplicates, 12,215 articles were screened. Thirty-eight studies were included and the OR of 31 could be pooled in the quantitative analysis. The overall injury rate was 20.8 (95% CI 19.9-21.7) injuries per 100 female runners and 20.4 (95% CI 19.7-21.1) injuries per 100 male runners. Meta-analysis revealed no differences between sexes for overall injuries reported per 100 runners (RR 0.99, 95% CI 0.90-1.10, n = 24) and per hours or athlete exposure (RR 0.94, 95% CI 0.69-1.27, n = 6). Female sex was associated with a more frequent occurrence of bone stress injury (RR (for males) 0.52, 95% CI 0.36-0.76, n = 5) while male runners had higher risk for Achilles tendinopathies (RR 1. 86, 95% CI 1.25-2.79, n = 2). Meta-regression showed an association between a higher injury risk and competition distances of 10 km and shorter in female runners (RR 1.08, 95% CI 1.00-1.69).

CONCLUSION

Differences between female and male runners in specific injury diagnoses should be considered in the development of individualised and sex-specific prevention and rehabilitation strategies to manage running-related injuries.

Training and technique choices predict self-reported running injuries: An international study

OBJECTIVES

The aim of this study was to describe the self-reported injury, training, and running technique choices of regular runners in four international regions.

DESIGN AND SETTING

756 participants began an expert derived self-report online survey in Ireland, USA, Hong Kong and Australia.

PARTICIPANTS

325 participants completed the survey (age = 38 ± 10 years; weight = 68.0 ± 13.1 kg; height = 1.70 ± 0.10 m).

MAIN OUTCOME MEASURES

Descriptive statistics are reported examining injury incidence and location; shoe and orthosis choices; and training and technique practices. A backwards logistic regression was implemented to examine associations between injury and training choices.

RESULTS

68.3% reported having an injury in the last year. 81.45% of these injuries were believed to be running related. A large variation in training and footwear choices were observed for respondents. The regression (P ≤ 0.001) explained 20% of the variance in injury selection (Nagelkerke R²) and was able to identify 73% of cases accurately. Associated injury factors included competitive running, running on more than one surface, younger age, having a lower running age, and a higher proportion of running at an easy intensity.

CONCLUSIONS

The high amount of variability in runner's choices highlights the lack of consistent information being presented to them and may be the reason for the high injury incidence.

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

PURPOSE

The 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).

METHODS

Electronic 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.

RESULTS

A 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.

CONCLUSION

Several 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.

A Contemporary Approach to Patellofemoral Pain in Runners

Patellofemoral pain (PFP) is among the most common injuries in recreational runners. Current evidence does not identify alignment, muscle weakness, and patellar maltracking or a combination of these as causes of PFP. Rather than solely investigating biomechanics, we suggest a holistic approach to address the causes of PFP. Both external loads, such as changes in training parameters and biomechanics, and internal loads, such as sleep and psychological stress, should be considered. As for the management of runners with PFP, recent research suggested that various interventions can be considered to help symptoms, even if these interventions target biomechanical factors that may not have caused the injury in the first place. In this Current Concepts article, we describe how the latest evidence on education about training modifications, strengthening exercises, gait and footwear modifications, and psychosocial factors can be applied when treating runners with PFP. The importance of maintaining relative homeostasis between load and capacity will be emphasized. Recommendations for temporary or longer-term interventions will be discussed. A holistic, evidence-based approach should consist of a graded exposure to load, including movement, exercise, and running, while considering the capacity of the individual, including sleep and psychosocial factors. Cost, accessibility, and the personal preferences of patients should also be considered.

Impact of COVID-19 Social Distancing Restrictions on Training Habits, Injury, and Care Seeking Behavior in Youth Long-Distance Runners

Purpose: The COVID-19 pandemic impacted the sporting and exercise activities of millions of youth. Running is an activity that could be maintained while social distancing restrictions were implemented during the pandemic. If running-related injuries do occur, these restrictions may also influence the access to care or care seeking behavior of this population. Therefore, the purpose of this study was to determine if the social distancing restrictions during the 2020 COVID-19 pandemic influenced training habits, injury, and care seeking behavior in youth long-distance runners. Methods: A customized, open online questionnaire was provided to runners 9-19 years of age who participated in long-distance running activities including team/club cross-country, track and field (distances ≥800 m), road races, or recreational running. Participants responded to questions about demographics, running habits, RRIs, and health care provider visits 6-months before as well as during social distancing restrictions due to COVID-19. Wilcoxon signed rank tests compared differences for ratio data and Chi-square tests were used to compare proportions before and during COVID-19 social distancing restrictions. Statistical significance was set at p ≤ 0.05. Results: A total of 287 youth long-distance runners (male = 124, female = 162, unspecified = 1; age = 15.3 ± 1.7 years; running experience = 5.0 ± 2.3 years) participated. Compared to their pre-COVID-19 responses, youth long-distance runners reported lower distances run per week (p < 0.001), fewer runs per week (p < 0.001), fewer hard runs per week (p < 0.001), fewer number of injuries (p < 0.001), and fewer injuries per 1,000 km (p = 0.002) during the COVID-19 social distancing restrictions. A lower proportion of participants reported in-person health care provider visits (p < 0.001) and a lower proportion of visits were made to an athletic trainer during COVID-19 social distancing restrictions compared to prior to COVID-19 (p < 0.001). Conclusion: The COVID-19 pandemic resulted in significant decreases in both training and injuries which were different compared to previous reports in an adult population. Many of the runners who sustained an injury during COVID-19 social distancing restrictions did not seek care, with the most prominent reduction in visits to an athletic trainer. This could impact future injury and chronic pain.

Strength Training Habits in Amateur Endurance Runners in Spain: Influence of Athletic Level

This study determined the strength training (ST) habits of amateur endurance runners in Spain regarding athletic level. A sixteen-item online questionnaire comprised of (i) demographic information, (ii) performance, and (iii) training contents was completed by 1179 athletes. Five group levels were determined according to the personal best times of the athletes in a 10-km trial (LG1: level group 1, 50–55 min; LG2: level group 2, 45–50 min; LG3: level group 3, 40–45 min; LG4: level group 4, 35–40 min; LG5: level group 5, 30–35 min). Most athletes (n = 735, 62.3%) perceived ST as being a key component in their training program. Resistance training (RT) was reported as a ST type used by 63.4% of the athletes, 66.9% reported using bodyweight exercises, 46.8% reported using plyometric training, 65.6% reported using uphill runs, and 17.8% reported using resisted runs. The prevalence of runners who excluded ST from their training programs decreased as the athletic performance level increased (18.2% in lower-level athletes vs. 3.0% in higher-level), while the inclusion of RT, bodyweight exercises, plyometric training, and uphill and resisted runs was more frequent within higher-level groups. Most athletes included ST using low-to-moderate loads and high a number of repetitions/sets comprised of RT, plyometric training, resisted runs, and core, respiratory, and foot muscles training.

Accelerometer Based Data Can Provide a Better Estimate of Cumulative Load During Running Compared to GPS Based Parameters

Running is a popular way to become or stay physically active and to maintain and improve one's musculoskeletal load tolerance. Despite the health benefits, running-related injuries affect millions of people every year and have become a substantial public health issue owing to the popularity of running. Running-related injuries occur when the musculoskeletal load exceeds the load tolerance of the human body. Therefore, it is crucial to provide runners with a good estimate of the cumulative loading during their habitual training sessions. In this study, we validated a wearable system to provide an estimate of the external load on the body during running and investigated how much of the cumulative load during a habitual training session is explained by GPS-based spatiotemporal parameters. Ground reaction forces (GRF) as well as 3D accelerations were registered in nine habitual runners while running on an instrumented treadmill at three different speeds (2.22, 3.33, and 4.44 m/s). Linear regression analysis demonstrated that peak vertical acceleration during running explained 80% of the peak vertical GRF. In addition, accelerometer-based as well as GPS-based parameters were registered during 498 habitual running session of 96 runners. Linear regression analysis showed that only 70% of the cumulative load (sum of peak vertical accelerations) was explained by duration, distance, speed, and the number of steps. Using a wearable device offers the ability to provide better estimates of cumulative load during a running program and could potentially serve as a better guide to progress safely through the program.

Common musculoskeletal impairments in postpartum runners: an international Delphi study

Background

Postpartum runners report musculoskeletal pain with running. Because of inadequate research, little is known about the origin and pain-related classification. Through expert consensus, this study is the first attempt to understand the musculoskeletal impairments that these runners present with. The objective of this survey was to gather expert consensus on characteristics of reported impairments in postpartum runners that have musculoskeletal pain.

Methods

A web-based Delphi survey was conducted and was composed of five categories: strength, range of motion, alignment and flexibility impairments, as well as risk factors for pain in postpartum runners.

Results

A total of 117 experts were invited. Forty-five experts completed round I and forty-one completed rounds II and III. The strength impairments that reached consensus were abdominal, hip and pelvic floor muscle weakness. The range of motion impairments that reached consensus were hip extension restriction, anterior pelvic tilt and general hypermobility. The alignment impairments that reached consensus were a Trendelenburg sign, dynamic knee valgus, lumbar lordosis, over-pronation and thoracic kyphosis. The flexibility impairments that reached consensus were abdominal wall laxity, and tightness in hip flexors, lumbar extensors, iliotibial band and hamstrings. The risk factors for pain in postpartum runners were muscular imbalance, poor lumbopelvic control, too much too soon, life stressors, pain during pregnancy and pelvic floor trauma.

Conclusion

This study presents a framework for clinicians to understand pain in postpartum runners and that can be investigated in future cohort studies.

Level of evidence

5.

Medial Tibial Stress Syndrome in Novice and Recreational Runners: A Systematic Review

This systematic review evaluates the existing literature about medial tibial stress syndrome (MTSS) in novice and recreational runners. PubMed/MEDLINE, EMBASE, Web of Science, Scopus, SPORTDiscus and CINAHL databases were searched until July 2020. Studies covering risk factors, diagnostic procedures, treatment methods and time to recovery of MTSS in novice and recreational runners were selected. Eleven studies met the inclusion criteria and were included. The risk factors of MTSS are mainly intrinsic and include higher pelvic tilt in the frontal plane, peak internal rotation of the hip, navicular drop and foot pronation, among others. Computed tomography (CT) and pressure algometry may be valid instruments to corroborate the presence of this injury and confirm the diagnosis. Regarding treatment procedures, arch-support foot orthoses are able to increase contact time, normalize foot pressure distribution and similarly to shockwave therapy, reduce pain. However, it is important to take into account the biases and poor methodological quality of the included studies, more research is needed to confirm these results.

How Has Workload Been Defined and How Many Workload-Related Exposures to Injury Are Included in Published Sports Injury Articles? A Scoping Review

OBJECTIVE

To describe how workload-related exposure variables have been defined in sports injury articles, and to identify the number of workload-related exposure variables included in comparative analyses.

DESIGN

Scoping review.

LITERATURE SEARCH

PubMed, SPORTDiscus, and Scopus were systematically searched on March 13, 2020. Two reviewers independently screened the retrieved literature and selected articles for inclusion.

STUDY SELECTION CRITERIA

Prospective cohort studies using workload-related variables as the primary exposure to sports injury were eligible for inclusion.

DATA SYNTHESIS

The type (eg, distance, balls bowled) and construct of workload-related exposure variables (eg, acute-chronic workload ratio) were extracted and summarized in frequency tables.

RESULTS

A total of 648 articles were identified, and 45 were eligible for inclusion. Workload definition differed greatly, as sports- and workload-related exposure variables could be, but were not limited to, distance, balls bowled, session rating of perceived exertion, accelerations, soreness, and sleep. Within and across articles, authors used different constructs for workload-related exposure variables. For example, distance was represented as total distance, distance per week, distance per 2 weeks, and acute-chronic workload ratio. The number of workload-related exposure variables included in comparative analyses ranged from 1 to 336.

CONCLUSION

Studies used different definitions of workload-related exposure variables. The number of workload-related exposure variables in a single study ranged from 1 to 336. J Orthop Sports Phys Ther 2020;50(10):538-548. doi:10.2519/jospt.2020.9766.

Enhanced injury prevention programme for recreational runners (the SPRINT study): design of a randomised controlled trial

Introduction

Running-related injuries (RRIs) are frequent, but no effective injury prevention measures have been identified yet. Therefore, we have set up the INSPIRE trial in 2017, in which the effectiveness of an online injury prevention programme was tested. Although this programme was not effective in reducing the number of RRIs, we gained new insights from this study, which we used to design an enhanced, online multidisciplinary injury prevention programme. The aim of this study is to test the effectiveness of this enhanced injury prevention programme in a group of recreational runners.

Methods and analysis

For this randomised controlled trial, we aim to include 3394 recreational runners aged 18 years or older who register for a running event (distances 10 to 42.2 km). During the preparation for the running event, runners in the intervention group get access to the enhanced online injury prevention programme. This online programme consists of 10 steps, all covering separate items of RRI prevention. Runners in the control group will follow their regular preparation. With three follow-up questionnaires (1 month before, 1 week before and 1 month after the running event), the proportions of self-reported RRIs in the intervention group and the control group are compared.

Ethics and dissemination

An exemption for a comprehensive application has been obtained by the Medical Ethical Committee of the Erasmus MC University Medical Center, Rotterdam, the Netherlands. The results of the study will be disseminated among the running population, published in peer-reviewed international journals and presented on international conferences.

Trial registration number

NL7694

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.

Training for a (half-)marathon: Training volume and longest endurance run related to performance and running injuries

OBJECTIVE

Examine the associations of training volume and longest endurance run with (half-)marathon performance and running-related injuries (RRIs) in recreational runners.

MATERIALS AND METHODS

During the preparation for and directly after the running event, 556 participants of a half marathon and 441 participants of a marathon completed three questionnaires on RRIs, average weekly training volume and the longest endurance run. With finish time, decline in pace during the running event and RRIs as dependent variables, linear and logistic regression analyses were performed to test the associations with weekly training volume and the longest endurance run.

RESULTS

In half-marathon runners, a high training volume (>32 km/wk) (β -4.19, 95% CI: -6.52;-1.85) and a long endurance run (>21 km) (β -3.87, 95% CI: -6.31;--1.44) were associated with a faster finish time, while a high training volume (β -1.81, 95% CI: -3.49;-0.12) and a long endurance run (β -1.89, 95% CI: -3.65;-0.12) were also related to less decline in pace. In marathon runners, a low training volume (<40 km/wk) was related to a slower finish time (β 6.33, 95% CI: 0.18;12.48) and a high training volume (>65 km/wk) to a faster finish time (β -14.09, 95% CI: -22.47;-5.72), while a longest endurance run of <25 km was associated with a slower finish time (β 13.44, 95% CI: 5.34;21.55). No associations between training characteristics and RRIs were identified.

CONCLUSIONS

Preparation for a (half-)marathon with a relatively high training volume and long endurance runs associates with a faster finish time, but does not seem related to an increased injury risk.

Analysis of Running-Related Injuries: The Vienna Study

Background: This study aimed to provide an extensive and up-to-date analysis of running-related injuries (RRI) and analyze a broad range of contributing factors for a large heterogeneous and non-selected running population from Central Europe. Methods: Anthropometric, training, footwear, anatomic malalignment, and injury data from 196 injured runners were assessed case-controlled and retrospectively. Univariate and multivariate regression models were developed to identify associated factors for specific injury locations and diagnoses. Results: The majority of patients were female (56%). Three most frequently observed malalignments included varus knee alignment, pelvic obliquity, and patellar squinting. The most common injuries were the patellofemoral pain syndrome (PFPS), the iliotibial band friction syndrome (ITBFS), patellar tendinopathy, spinal overload, and ankle instability. A number of contributing factors were identified. Previous injury history was a contributing factor for knee injuries and ITBFS. Lower training load was reported with a higher incidence of PFPS, while a higher training load was positively associated with injuries of the lower leg. Runners with a higher body mass index (BMI) were at a significantly higher risk for lower back injuries. Conclusions: Running-related injuries are multifactorial associated with a combination of variables including personal data, training load, anatomic malalignments, and injury history. They can furthermore result from a lack of experience/training as well as from overuse. Suffering a specific RRI of high risk could be defined based on individual predispositions and help to induce appropriate training balance.

A Multifactorial Approach to Overuse Running Injuries: A 1-Year Prospective Study

BACKGROUND

Because of the complex and multifaceted nature of running injuries, a multifactorial approach when investigating running injuries is required.

HYPOTHESIS

Compared with uninjured runners, injured runners would exhibit different running biomechanics, display more fatigue changes, and would run a greater weekly running volume; more injured runners would also report having a previous injury.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 4.

METHODS

At commencement of the study, data were collected on demographics, anthropometrics, training history, previous injury history, and center-of-mass accelerations during a long-distance overground run. Participants completed weekly training diaries and were monitored for 1 year for an injury.

RESULTS

A total of 76 runners completed the study, with 39 (22 male; 17 female) reporting an injury. Compared with male uninjured runners, male injured runners were heavier and ran a greater weekly distance. Male runners (injured and uninjured) exhibited increases in mediolateral center-of-mass accelerations during the run. Compared with female uninjured runners, female injured runners were heavier, ran with longer flight times and lower step frequencies, and more of them had reported an injury in the previous year and had increased speed training in the weeks prior to injury. Over 60% of male injured runners and over 50% of female injured runners had increased their weekly running distance by >30% between consecutive weeks at least once in the 4 weeks prior to injury.

CONCLUSION

Factors that may be related to injury for male runners include being heavier, running a greater weekly distance, and exhibiting fatigue changes in mediolateral center-of-mass accelerations. Factors that may be related to injury for female runners include being heavier, having an injury in the previous year, running with longer flight times and lower step frequencies, and increasing speed training prior to injury. Increases in weekly running distance in 1 consecutive week (particularly >30%) needs to be monitored in training, and this along with the other factors found may have contributed to injury development.

CLINICAL RELEVANCE

This study found that multiple factors are related to running injuries and that some factors are sex specific. The findings can aid in injury prevention and management.

Does glucocorticoid exposure explain the association between metabolic dysfunction and tendinopathy?

BACKGROUND

While metabolic health is acknowledged to affect connective tissue structure and function, the mechanisms are unclear. Glucocorticoids are present in almost every cell type throughout the body and control key physiological processes such as energy homeostasis, stress response, inflammatory and immune processes, and cardiovascular function. Glucocorticoid excess manifests as visceral adiposity, dyslipidaemia, insulin resistance, and type 2 diabetes. As these metabolic states are also associated with tendinopathy and tendon rupture, it may be that glucocorticoids excess is the link between metabolic health and tendinopathy.

OBJECTIVE

To synthesise current knowledge linking glucocorticoids exposure to tendon structure and function.

METHODS

Narrative literature review.

RESULTS

We provide an overview of endogenous glucocorticoid production, regulation, and signalling. Next we review the impact that oral glucocorticoid has on risk of tendon rupture and the effect that injected glucocorticoid has on resolution of symptoms. Then we highlight the clinical and mechanistic overlap between tendinopathy and glucocorticoid excess in the areas of visceral adiposity, dyslipidaemia, insulin resistance and type 2 diabetes. In these areas, we highlight the role of glucocorticoids and how these hormones might underpin the connection between metabolic health and tendon dysfunction.

CONCLUSIONS

There are several plausible pathways through which glucocorticoids might mediate the connection between metabolic health and tendinopathy.

The effects of marathon running on three-dimensional knee kinematics during walking and running in recreational runners

BACKGROUND

Running-related musculoskeletal injuries are common. Knee injuries are most frequent, and often occur during or shortly after marathons.

RESEARCH QUESTION

The effects of a marathon on runners' knee kinematics remain unclear. No studies have shown comprehensive three-dimensional (3D) knee kinematic changes following a marathon. This study aimed to observe the effects of running a marathon on 3D knee kinematics and identify the phases of walking and running gait in which significant changes occur.

METHODS

Based on an electronic survey, 10 healthy, recreational runners (20 knees) with similar running experience were included. Their 3D knee kinematics (during treadmill walking and running) were collected using a portable, optical motion capture system within 24 h before and within 6 h after running a marathon.

RESULTS

All measurements after the marathon were compared with pre-marathon measurements. (1) For walking post-marathon: varus rotation increased by 1.8° [95% confidence interval (CI) 0.1-3.4, P = 0.036] at peak knee extension during stance; anterior translation increased by 2.2 mm (95% CI 0.3-4.1, P = 0.025) at initial contact; range of motion (ROM) in internal-external rotation increased less than 1°, P = 0.023; ROM in anteroposterior translation increased by 3.8 mm, P = 0.048. (2) For running post-marathon: flexion rotation increased by 1.6° (95% CI 0.2-2.9, P = 0.025) at initial contact; varus rotation increased by 2.0° (95% CI 0.2-3.8, P = 0.031) at peak knee extension during stance.

SIGNIFICANCE

Significant differences in varus rotation and anterior translation were identified following a marathon, which could potentially contribute to injury. These results provide important information for runners and coaches about knee kinematic alterations following a marathon.

A 10% Increase in Step Rate Improves Running Kinematics and Clinical Outcomes in Runners With Patellofemoral Pain at 4 Weeks and 3 Months

BACKGROUND

Aberrant frontal-plane hip and pelvis kinematics have been frequently observed in runners with patellofemoral pain (PFP). Gait retaining interventions have been shown to improve running kinematics and may therefore be beneficial in runners with PFP.

PURPOSE

To investigate whether a 10% increase in the running step rate influences frontal-plane kinematics of the hip and pelvis as well as clinical outcomes in runners with PFP.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Runners with PFP underwent a 3-dimensional gait analysis to confirm the presence of aberrant frontal-plane hip and/or pelvis kinematics at baseline. A total of 12 participants with frontal-plane hip and/or pelvis kinematics 1 standard deviation above a reference database were invited to undergo the gait retraining intervention. Running kinematics along with clinical outcomes of pain and functional outcomes were recorded at baseline, 4 weeks after retraining, and 3 months. Gait retraining consisted of a single session where step rate was increased by 10% using an audible metronome. Participants were asked to continue their normal running while self-monitoring their step rate using a global positioning system smartwatch and audible metronome.

RESULTS

After gait retraining, significant improvements in running kinematics and clinical outcomes were observed at 4-week and 3-month follow-up. Repeated-measures analysis of variance with post hoc Bonferroni correction (P < .016) showed significant reductions in peak contralateral pelvic drop (mean difference [MD], 3.12° [95% CI, 1.88°-4.37°]), hip adduction (MD, 3.99° [95% CI, 2.01°-5.96°]), and knee flexion (MD, 4.09° [95% CI, 0.04°-8.15°]) as well as significant increases in self-reported weekly running volume (MD, 13.78 km [95% CI, 4.62-22.93 km]) and longest run pain-free (MD, 6.84 km [95% CI, 3.05-10.62 km]). Friedman test with a post hoc Wilcoxon signed-rank test showed significant improvements on a numerical rating scale for worst pain in the past week and the Lower Extremity Functional Scale.

CONCLUSION

A single session of gait retraining using a 10% increase in step rate resulted in significant improvements in running kinematics, pain, and function in runners with PFP. These improvements were maintained at 3-month follow-up. It is important to assess for aberrant running kinematics at baseline to ensure that gait interventions are targeted appropriately.

REGISTRATION

NCT03067545 (ClinicalTrials.gov identifier).

Update of Risk Factors, Diagnosis, and Management of Patellofemoral Pain

PURPOSE OF REVIEW

Patellofemoral pain is the most common cause of anterior knee pain. The purpose of this review is to examine the latest research on risk factors, physical examination, and treatment of patellofemoral pain to improve accuracy of diagnosis and increase use of efficacious treatment modalities.

RECENT FINDINGS

The latest research suggests patellofemoral pain pathophysiology is a combination of biomechanical, behavioral, and psychological factors. Research into targeted exercise therapy and other conservative therapy modalities have shown efficacy especially when used in combination. New techniques such as blood flow restriction therapy, gait retraining, and acupuncture show promise but require further well-designed studies. Patellofemoral pain is most commonly attributed to altered stress to the patellofemoral joint from intrinsic knee factors, alterations in the kinetic chain, or errors in training. Diagnosis can be made with a thorough assessment of clinical history and risk factors, and a comprehensive physical examination. The ideal treatment is a combination of conservative treatment modalities ideally individualized to the risk factors identified in each patient. Ongoing research should continue to identify biomechanical risk factors and new treatments as well as look for more efficient ways to identify patients who are amenable to treatments.

Effects of medially wedged insoles on the biomechanics of the lower limbs of runners with excessive foot pronation and foot varus alignment

BACKGROUND

Excessive foot pronation during running in individuals with foot varus alignment may be reduced by medially wedged insoles.

RESEARCH QUESTION

This study investigated the effects of a medially wedged insole at the forefoot and at the rearfoot on the lower limbs angles and internal moments of runners with excessive foot pronation and foot varus alignment.

METHODS

Kinematic and kinetic data of 19 runners (11 females and 8 males) were collected while they ran wearing flat (control condition) and medially wedged insoles (insole condition). Both insoles had arch support. We used principal component analysis for data reduction and dependent t-test to compare differences between conditions.

RESULTS

The insole condition reduced ankle eversion (p = 0.003; effect size = 0.63); reduced knee range of motion in the transverse plane (p = 0.012; effect size = 0.55); increased knee range of motion in the frontal plane in early stance and had earlier knee adduction peak (p = 0.018; effect size = 0.52); reduced hip range of motion in the transverse plane (p = 0.031; effect size = 0.48); reduced hip adduction (p = 0.024; effect size = 0.50); reduced ankle inversion moment (p = 0.012; effect size = 0.55); and increased the difference between the knee internal rotation moment in early stance and midstance (p = 0.012; effect size = 0.55).

SIGNIFICANCE

Insoles with 7˚ medial wedges at the forefoot and rearfoot are able to modify motion and moments patterns that are related to lower limb injuries in runners with increased foot pronation and foot varus alignment with some non-desired effects on the knee motion in the frontal plane.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

Maintaining motivation and health among recreational runners: Panel study of factors associated with self-rated performance outcomes at competitions

OBJECTIVES

To investigate health-related factors associated with self-rated race performance outcomes among recreational long-distance runners.

DESIGN

Panel study.

METHODS

Data were collected from runners one month before and after a community-level race event including distances from 8 to 42.2 km. The primary outcome measure was self-rated race performance outcome. The explanatory variables represented health complaints suffered during the build-up year, the pre-race month, and the race and among full marathon runners predicted objective performance outcome (mean pace equal to training pace or faster). Multiple logistic regression was used to determine factors associated with the self-rated performance outcome.

RESULTS

Two-hundred forty-five runners (29%) provided complete data sets. Seventy-four percent of the runners reached their desired race performance outcome. Achievement of the performance outcome was more likely when having avoided illness during the build-up and pre-race periods (OR = 3.8; 95% CI:1.8-8.0, p < 0.001), having avoided per-race injury (OR=3.0; 95% CI:1.2-7.4, p = 0.02) and avoided per-race illness (OR = 4.1; 95% CI:1.3-15, p = 0.020). Having obtained the self-rated performance outcome was also associated with running a shorter distance (OR=3.6; 95% CI: 1.7-8.0, p = 0.001) and being younger than 50 years of age (OR = 2.4; 95% CI:1.1-5.3-8.3, p = 0.03). Having met the predicted objective performance outcome predisposed marathon runners to also obtain the self-rated performance outcome (OR = 4.7, 95% CI: 1.5-16, p < 0.01).

CONCLUSIONS

Having avoided illness during build-up and pre-race was positively associated with self-rated race performance outcome among recreational runners. Adjusting the desired performance outcomes with regard to recent illness and age may help recreational runners to more often achieve their goals and thereby prevent them from leaving the sport.

Running Themselves Into the Ground? Incidence, Prevalence, and Impact of Injury and Illness in Runners Preparing for a Half or Full Marathon

OBJECTIVE

To describe the incidence, prevalence, and impact of running-related injuries (RRIs) and illness symptoms in half marathon and marathon runners during the 16-week period before the Utrecht Marathon.

METHODS

In this prospective cohort study, we used the Oslo Sports Trauma Research Center questionnaire to register RRIs and illness symptoms every 2 weeks during the 16-week study period. When an injury or illness occurred, questions were added regarding its nature. We calculated the incidence proportion (the number of new cases divided by the number of runners at risk) and the period prevalence (the number of existing and new cases within a 2-week period, divided by the total number of runners at risk during that period).

RESULTS

Of the 161 included runners, 9 out of 10 reported an RRI or illness symptom at some time during the study period. In any 2-week period, 5.6% to 14.8% of the runners reported a new RRI, and 6.3% to 13.8% of the runners reported a new illness symptom. The prevalence of RRIs ranged from 29.2% to 43.5%, and the prevalence of illness symptoms ranged from 28.3% to 71.2%. The most prevalent RRIs were in the lower leg (prevalence range, 5.4%-12.3%) and knee (prevalence range, 2.7%-9.3%). The most prevalent illness symptoms were rhinorrhea/sneezing (prevalence range, 3.9%-12.7%) and coughing (prevalence range, 3.9%-11.9%). The incidence and prevalence of illness symptoms peaked at the same time as the influenza-like illness epidemic of the winter of 2015-2016.

CONCLUSION

Nine out of every 10 runners reported an RRI or illness symptom in the lead-up to a half or full marathon. In any 2-week period, up to 1 in 7 runners reported a new RRI or illness symptom.

LEVEL OF EVIDENCE

2b. J Orthop Sports Phys Ther 2019;49(7):518-528. doi:10.2519/jospt.2019.8473.

Musculoskeletal Injuries Are Commonly Reported Among Gastroenterology Trainees: Results of a National Survey

BACKGROUND

Endoscopy-related musculoskeletal injuries are increasingly recognized among gastroenterologists. While injury rates and risk factors have been studied among practicing gastroenterologists, little is known about rates among trainees during fellowship.

AIMS

This study analyzes the prevalence of endoscopy-related overuse injuries and risk factors for injuries among a national sample of gastroenterology (GI) fellows. We also surveyed GI fellowship program directors and fellows about perceptions of overuse injuries during GI training.

METHODS

We distributed a 29-item electronic survey to GI fellows at accredited programs in the USA in April 2016. Survey items included demographic information, questions pertaining to injuries, and level of agreement on the importance of ergonomics training in GI fellowship. Additionally, we distributed a 7-item electronic survey to fellowship program directors evaluating perception of overuse injuries and prevention during fellowship training. Fisher's exact test determined factors associated with sustaining an injury.

RESULTS

An estimated 1509 fellows received the survey. Eleven percent (n = 165) of gastroenterology fellows completed the survey. Twenty percent reported having a musculoskeletal injury. Female gender was the only factor associated with a higher rate of reported injury (p < 0.01). The most common injuries reported were thumb and other hand-related pain (n = 28 [64%]).

CONCLUSIONS

Musculoskeletal injuries may affect up to 20% of GI fellows. Female fellows more frequently report injuries and may be at particularly high risk which has not been found in previously reported surveys of practicing gastroenterologists. Standardized curricula on ergonomic considerations and injury prevention are needed to enhance GI fellowship training and reduce injury rates.