ORIGINAL ARTICLE Nr 2021;11 (1):118-127 118 CORRESPONDING AUTHOR: Ayoola Aiyegbusi Department of Physiotherapy Faculty of Clinical Sciences College of Medicine University of Lagos Lagos, Nigeria E-mail: aaiyegbusi@unilag.edu.ng DOI: 10.32098/mltj.01.2021.13 LEVEL OF EVIDENCE: 2B SUMMARY Background. Achilles tendinopathy (AT) is a major foot and ankle overuse injury which has been reported to be prevalent in running and jumping sporting activities, especial- ly football which has witnessed increased participation in recent times. However, there are no epidemiological data on tendinopathy in footballers in Nigeria. The aim of this study was to determine the prevalence of Achilles tendinopathy and associated intrin- sic risk factors among Nigerian footballers. Methods. Participants were 151 registered football players recruited from various foot- ball clubs in Lagos State, Nigeria. Selected intrinsic factors of age, gender, body mass index (BMI), random blood glucose and bilateral ankle dorsifexion and plantarfexion were evaluated. AT was determined with the Royal London Hospital Test and ultraso- nography. Principal Component Analysis (PCA) was used to determine the association between AT and selected intrinsic risk factors and signifcance set at p < 0.05. Results. The prevalence of AT was 15.9%. There were signifcant associations between elevated BMI (p = 0.027), left ankle dorsifexion (p = 0.035) and right ankle plantar- fexion (p = 0.008) with Achilles tendinopathy. No signifcant association (p > 0.05) was found between Achilles tendinopathy and blood glucose level. Conclusions. Elevated body mass index, reduced ankle dorsifexion and plantarfexion are risk factors for Achilles tendinopathy. KEY WORDS Prevalence; Achilles tendinopathy; intrinsic risk factors; Nigerian footballers. Prevalence of Achilles Tendinopathy and Associated Selected Intrinsic Risk Factors among Nigerian Footballers A. I. Aiyegbusi 1 , I. O. Owoeye 2 , O. J. Balogun 3 , O. O. Fapojuwo 1 , O. A. Akinloye 4 1 Department of Physiotherapy, Faculty of Clinical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria 2 Medical Rehabilitation Therapist Board of Nigeria 3 Department of Biomedical Engineering, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria 4 Department of Medical Laboratory Sciences, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria INTRODUCTION Exposure of the Achilles tendon to excessive mechanical loadings during vigorous exercises such as running and jumping result in tendinopathy and subsequent tendon rupture (1). A prevalence of 21% was reported for Achilles tendinopathy among recreational sports (2) participants in Nigeria (3). The aetiology of Achilles tendinopathy has been reported to be multi-factorial, which could be due to intrin- sic and extrinsic factors (4). The intrinsic factors include intra-tendinous degeneration, aging, genetic factors, diabe- tes, body mass index (BMI) and kinematics and biomechan- ical abnormalities such as limited range of motion (ROM) and leg length discrepancy (4, 5). Some of the extrinsic factors on the other hand are training frequency, trauma, training errors and mechanical overload which all play some role in the development of Achilles tendinopathy (6). Overweight and obesity as determined by the body mass index (BMI), has been on the increase over the years and it has been reported that both may be associated with poorer ftness in terms of strength and endurance (7, 8). This results in lower levels of neuromuscular control including balance and coordination, which could place those with elevated BMI at greater risk for injury (1). A systematic review on running related musculoskeletal injuries found that Achil- les tendinopathy presented as the second highest injury incidence at 9.1-10.9% (7) Saunders et al. (9) reported a