What proportion of athletes sustained an injury during a prospective study? Censored observations matter

The Effect of Wearable-Based Real-Time Feedback on Running Injuries and Running Performance: A Randomized Controlled Trial

BACKGROUND

Running technique and running speed are considered important risk factors for running injuries. Real-time feedback on running technique and running speed by wearables may help reduce injury risk.

PURPOSE

To investigate whether real-time feedback on spatiotemporal metrics and relative speed by commercially available pressure-sensitive insoles would reduce running injuries and improve running performance compared with no real-time feedback.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 220 recreational runners were randomly assigned into the intervention and control groups. Both groups received pressure-sensitive insoles, but only the intervention group received real-time feedback on spatiotemporal metrics and relative speed. The feedback aimed to reduce loading on the joint/segment estimated to exhibit the highest load. Injury rates were compared between the groups using Cox regressions. Secondary outcomes compared included injury severity, the proportion of runners with multiple injuries, changes in self-reported personal best times and motivation (Behavioral Regulation in Exercise Questionnaire-2), and interest in continuing wearable use after study completion.

RESULTS

A total of 160 participants (73%) were included in analyses of the primary outcome. Intention-to-treat analysis showed no significant difference in injury rate between the groups (Hazard ratio [HR], 1.11; P = .70). This was expected, as 53 of 160 (33%) participants ended up in the unassigned group because they used incorrect wearable settings, nullifying any interventional effects. As-treated analysis showed a significantly lower injury rate among participants receiving real-time feedback (HR, 0.53; P = .03). Similarly, the first-time injury severity was significantly lower (-0.43; P = .042). Per-protocol analysis showed no significant differences in injury rates, but the direction favored the intervention group (HR, 0.67; P = .30). There were no significant differences in the proportion of patients with multiple injuries (HR, 0.82; P = .40) or changes in running performance (3.07%; P = .26) and motivation. Also, ~60% of the participants who completed the study showed interest in continuing wearable use.

CONCLUSION

Real-time feedback on spatiotemporal metrics and relative speed provided by commercially available instrumented insoles may reduce the rate and severity of injuries in recreational runners. Feedback did not influence running performance and exercise motivation.

REGISTRATION

NL8472 (Dutch Trial Register).

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.

A CHecklist for statistical Assessment of Medical Papers (the CHAMP statement): explanation and elaboration

Misuse of statistics in medical and sports science research is common and may lead to detrimental consequences to healthcare. Many authors, editors and peer reviewers of medical papers will not have expert knowledge of statistics or may be unconvinced about the importance of applying correct statistics in medical research. Although there are guidelines on reporting statistics in medical papers, a checklist on the more general and commonly seen aspects of statistics to assess when peer-reviewing an article is needed. In this article, we propose a CHecklist for statistical Assessment of Medical Papers (CHAMP) comprising 30 items related to the design and conduct, data analysis, reporting and presentation, and interpretation of a research paper. While CHAMP is primarily aimed at editors and peer reviewers during the statistical assessment of a medical paper, we believe it will serve as a useful reference to improve authors' and readers' practice in their use of statistics in medical research. We strongly encourage editors and peer reviewers to consult CHAMP when assessing manuscripts for potential publication. Authors also may apply CHAMP to ensure the validity of their statistical approach and reporting of medical research, and readers may consider using CHAMP to enhance their statistical assessment of a paper.

Recreational Runners With a History of Injury Are Twice as Likely to Sustain a Running-Related Injury as Runners With No History of Injury: A 1-Year Prospective Cohort Study

OBJECTIVES

To investigate (1) the cumulative incidence proportion and the most common anatomical locations of running-related injuries in recreational runners, and (2) the associations between running-related injuries and previous injury, running experience, weekly running distance, age, sex, and body mass index.

DESIGN

A 1-year prospective cohort study.

METHODS

Two hundred twenty-four recreational runners (average weekly running distance for the past 12 months, 15 km) were included (89 women, 135 men). Pain information was reported weekly for 1 year, and all running-related injuries that resulted in time loss or medical consultation were recorded. We accounted for censoring when calculating cumulative incidence proportion, and used crude Cox proportional hazards regression to evaluate whether the variables of interest were associated with running-related injuries.

RESULTS

The 1-year cumulative incidence proportion of running-related injuries was 45.9% (95% confidence interval [CI]: 38.4%, 54.2%). The most common anatomical locations were the knee (20/75, 27%) and Achilles tendon/calf (19/75, 25%). Previous injury was associated with a higher injury rate (hazard rate ratio = 1.9; 95% CI: 1.2, 3.2), while the other variables had no statistically significant association with injury.

CONCLUSION

There were 75 running-related injuries during the 1-year surveillance period, for a cumulative incidence proportion of 46%. The most common injuries were to the knee and Achilles tendon/calf. Recreational runners with a previous injury were twice as likely to sustain a running-related injury as runners with no previous injury. J Orthop Sports Phys Ther 2021;51(3):144-150. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9673.

Associations between biomechanical and clinical/anthropometrical factors and running-related injuries among recreational runners: a 52-week prospective cohort study

BACKGROUND

The purpose of this exploratory study was to investigate whether runners with certain biomechanical or clinical/anthropometrical characteristics sustain more running-related injuries than runners with other biomechanical or clinical/anthropometrical characteristics.

METHODS

The study was designed as a prospective cohort with 52-weeks follow-up. A total of 224 injury-free, recreational runners were recruited from the Gothenburg Half Marathon and tested at baseline. The primary exposure variables were biomechanical and clinical/anthropometrical measures, including strength, lower extremity kinematics, joint range of motion, muscle flexibility, and trigger points. The primary outcome measure was any running-related injury diagnosed by a medical practitioner. Cumulative risk difference was used as measure of association. A shared frailty approach was used with legs as the unit of interest. A total of 448 legs were included in the analyses.

RESULTS

The cumulative injury incidence proportion for legs was 29.0% (95%CI = 24.0%; 34.8%). A few biomechanical and clinical/anthropometrical factors influence the number of running-related injuries sustained in recreational runners. Runners with a late timing of maximal eversion sustained 20.7% (95%CI = 1.3; 40.0) more injuries, and runners with weak abductors in relation to adductors sustained 17.3% (95%CI = 0.8; 33.7) more injuries, compared with the corresponding reference group.

CONCLUSIONS

More injuries are likely to occur in runners with late timing of maximal eversion or weak hip abductors in relation to hip adductors.

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

Background

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

Methods

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

Results

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

Conclusion

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