Injury in CrossFit®: A Systematic Review of Epidemiology and Risk Factors

OBJECTIVE

To review the characteristics of the injuries among CrossFit® practitioners, including prevalence and incidence, nature, location, and risk factors.

METHODS

PubMed/MEDLINE, EMBASE, Web of Science, Scopus, and SPORTDiscus databases were searched from inception through August 2020, and English-language articles reporting on CrossFit®-related injuries were included. Data including sample (sex, age, and demographics) and injuries' characteristics (prevalence, incidence rate, nature, location, percentage of injuries requiring surgery and risk factors) were extracted.

RESULTS

Overall, twenty-five studies involving a total of 12,079 CrossFit® practitioners met the inclusion criteria. The mean prevalence of injuries among the included studies was 35.3%, with an incidence rate varying between 0.2 and 18.9 per 1000 hours of training. The most injured areas were shoulder (26%), spine (24%), and knee (18%). Among the studies that reported the injuries requiring surgery, the mean percentage was 8.7%. Regarding the risk factors associated with injuries, older age, male sex, a greater body mass index, the existence of previous injuries, the lack of coach supervision, the experience on CrossFit® and the participation in competitions were reported by the studies.

CONCLUSIONS

CrossFit® training has an injury incidence rate similar to weightlifting and powerlifting. Findings from the studies suggest that the most affected areas are shoulder, spine, and knee. The limited quality of the studies prevents us from drawing solid conclusions about injury risk factors.

Effects of an Injury Prevention Program in CrossFit Athletes: A Pilot Randomized Controlled Trial

The present study aimed to assess the effects of an injury prevention program in CrossFit athletes. Thirty-two CrossFit athletes were randomized to either an intervention group (n=16), that performed mobility and stability exercises during the warm-up of all CrossFit sessions for a 10-week period or to a control group (n=16) that kept performing their usual warm-up. Incidence of injuries (primary outcome) as well as average training loads, fatigue and pain perception were registered during the study. The overall injury incidence rate was 0.04 per 1000 training hours, with no differences between groups (p>0.05). Similarly, no between-group differences were found for injury severity, nor for average training volume, intensity, training load, pain, or fatigue perception during the study (all p>0.05 with trivial-to-small effect sizes). In summary, a 10-week injury prevention program consisting of stability and mobility exercises provided no benefits on injury rates, fatigue and pain perception in recreational CrossFit athletes. Further research might corroborate the preliminary evidence reported here.

Injuries in functional fitness: an updated systematic review

INTRODUCTION

This study aimed to analyze injuries of functional fitness participants through a systematic review.

EVIDENCE ACQUISITION

A systematic search of the literature was conducted in CINAHL, EMBASE, PEDro, PubMed, SCOPUS, SPORTDiscus, and Web of Science, supplemented by searching in the grey literature, from 2017 to November 2020. This systematic review followed the PRISMA guidelines and was documented in the PROSPERO registry (CRD42020201259). Two reviewers independently extracted data including methodological (age, sex, time of practice, location, period, time frame, and completion rate) and injury (definition, diagnosis, prevalence, incidence, severity, mechanism, type, location, risk factors, and treatment) variables, as well as assessing study quality and risk of bias.

EVIDENCE SYNTHESIS

Twenty-six studies were included (10967, range 6-3049, participants). Injury was defined fairly differently across studies. The majority of studies used a retrospective study design and the main variables reported were prevalence, body location, and associated factors of injuries. The mean prevalence of musculoskeletal injuries was 32.8%, ranging from 2.4 to 60.6%, and the injury incidence per 1000 hours ranged from 0.21 to 67 36. The most affected body location in the studies was the shoulder, followed by lumbar spine, and knee. Muscle, joint, and ligament/tendon injuries were the most frequently reported. The majority of studies were of moderate methodological quality. All studies were considered as high risk of bias.

CONCLUSIONS

This review broadened the scope of 75 previous reviews on injuries in functional fitness. There have been few investigations regarding severity, mechanism, and treatment of injuries, so further research is warranted.