The epidemiology of non-traumatic injuries in road cyclists participating in the Cape Town tour

Abstract

Cycling is a popular form of transportation, recreation, fitness and sporting activity worldwide and South Africa. There are over 450 annual cycling events in South Africa and approximately 600 000 cyclists participate in at least one of these events annually. In spite of the popularity of road cycling, literature is rather scarce on the epidemiology of non-traumatic injury in cyclists. The study aimed to describe the epidemiology, clinical characteristics and severity of non-traumatic cycling injuries (NTCIs), and determine the independent risk factors associated with NTCIs in recreational cyclists that registered for the Cape Town Cycle Tour (CTCT). All cycle race entrants from the 2016 CTCT were required to complete an online medical screening questionnaire, at the time of registration, developed to provide clinical information for medical staff on race day. The screening questions considered: cycling training / racing history, medical history and general medication use for chronic disease and medication use before and during racing. A total of 35914 cyclists entered the 2016 CTCT, and 27349 completed the questionnaire with 21902 providing written informed consent for their data to be used. The final study population was 21824 (60.8% of all cycle race entrants) as 78 cyclists had missing / incomplete data. NTCIs were reported by 617 cyclists and 29 cyclists reported more than one NTCI. The epidemiology of NTCIs is reported for the 617 cyclists with NTCI, while the clinical characteristics and severity of NTCIs is reported for the 646 NTCIs. NTCIs, and their risk factors in recreational cyclists have not been well studied. This study shows that 1 in 40 recreational cyclists report ever suffering from a NTCI that was severe enough to interfere with cycling, require treatment or seek medical advice from a health professional. These NTCIs affect mostly the knee, lower back and shoulder and more than 37% of the injuries were severe enough to affect training and competition. The multi-variate analysis of the independent risk factors associated with NTCIs shows novel findings, namely: an association between NTCIs and cycling training/racing history [increased years of participation in distance cycling events >2 hours, and increased average weekly training / racing frequency in the last 12 months (times per week)], a history of chronic disease [any symptoms of CVD, any respiratory disease, any GIT disease, and any nervous system / psychiatric disease], and a history of medication use [any regular prescribed medication use for chronic disease, and any analgesic / anti-inflammatory medication (AAIM) used in the week before or during racing]. Of importance is that clinicians should consider NTCIs are not associated with a single aetiology, but rather a more complex interaction of a variety of intrinsic and extrinsic factors requiring careful and systematic clinical assessment. Clinicians should explore the possibility that NTCIs may be associated with underlying chronic disease and / or side effects of medications that are used by cyclists. Although data is self-reported and a potential for recall bias exists, the large sample size mitigates these study limitations. Future research should determine the cause-effect relationship between NTCIs and the factors identified in this research, and explore possible pathophysiological mechanisms that may link NTCIs to underlying chronic disease and medication use.