Epidemiology of insertional and midportion Achilles tendinopathy in runners:A prospective cohort study

Background:Achilles tendinopathy(AT)is a common problem among runners.There is only limited evidence for risk factors for AT,and most studies have not defined the AT subcategories.No study has compared the incidence and risk factors between insertional AT and midportion AT,though they are considered distinct.This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort.The secondary aim was to explore differences in risk factors between insertional and midportion AT.Methods:Participants were recruited from among registered runners at registration for running events.Questionnaires were completed at baseline,1 month before the event,1 week before the event,and 1 month after the event.Information concerning demographics,training load,registered events,and running-related injuries were collected at baseline.The follow-up questionnaires collected information about new injuries.A pain map was used to diagnose midportion and insertional AT.The primary outcome was the incidence of AT.Multivariable logistic regression analysis was applied to identify risk factors for the onset.Results:We included 3379 participants with a mean follow-up of 20.4 weeks.The incidence of AT was 4.2%.The proportion of insertional AT was 27.7%and of midportion AT was 63.8%;the remaining proportion was a combined type of insertional and midportion AT.Men had a significantly higher incidence(5%,95%confidence interval(95%CI):4.1%-6.0%)than women(2.8%,95%CI:2.0%-3.8%).AT in the past12 months was the most predominant risk factor for new-onset AT(odds ratio(OR)=6.47,95%CI:4.27-9.81).This was similar for both subcategories of AT(insertional:OR=5.45,95%CI:2.51-11.81;midportion:OR=6.96,95%CI:4.24-11.40).Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT(OR=0.59,95%CI:0.36-0.97)or midportion AT(OR=0.47,95%CI:0.23-0.93).Higher age had a significant negative association with insertional AT(OR=0.97,95%CI:0.94-1.00).Conclusion:The incidence of new-onset AT among recreational runners was 4.2%.The proportion of insertional and midportion AT was 27.7%and 63.8%,respectively.AT in the past 12 months was the predominant risk factor for the onset of AT.Risk factors varied between insertional and midportion AT,but we could not identify clinically relevant differences between the 2 subtypes.

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 runningrelated 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.