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.

Context: Two-dimensional (2D) video-based analysis is often used by clinicians to examine the foot strike pattern (FSP) and step rate in runners. Reliability and validity of 2D video-based analysis have been questioned. Objective: To synthesize the psychometric properties of 2D video-based analysis for assessing runners’ FSP and step rate while running. Data Sources: Medline/PubMed, Science Direct, Embase, EBSCOHost/CINAHL, and Scielo were searched from their inception to August 2018. Study Selection: Studies were included if (1) they were published in English, French, Portuguese or Spanish; (2) they reported at least 1 psychometric property (validity and/or reliability) of 2D video-based analysis to assess running kinematics; and (3) they assessed FSP or step rate during running. Study Design: Systematic review. Level of Evidence: Level 2. Data Extraction: Studies were screened for methodological (MacDermid checklist) and psychometric quality (COSMIN checklist) by 2 independent raters. Results: Eight studies, with a total of 702 participants, were included. Seven studies evaluated the reliability of 2D video to assess FSP and found very good to excellent reliability (0.41 ≤ κ ≤ 1.00). Two studies reported excellent reliability for the calculation of step rate (0.75 ≤ intraclass correlation coefficient [ICC] ≤ 1.00). One study demonstrated excellent concurrent validity between 2D and 3D (gold standard) motion capture systems to determine FSP (Gwet agreement coefficient [AC] > 0.90; ICC > 0.90), and another study found excellent concurrent validity between 2D video and another device to calculate step rate (0.84 ≤ ICC ≤ 0.95). Conclusion: Strong evidence suggests that 2D video-based analysis is a reliable method for assessing FSP and quantifying step rate, regardless of the experience of the assessor. Limited evidence exists on the validity of 2D video-based analysis in determining FSP and calculating step rate during running.