Does a relationship exist between the number of training or competition hours and the presence of sonographic alterations in the shoulder of CrossFit athletes?

Abstract

Introduction CrossFit is a sport that is on the rise and has a known injury rate thanks to studies that have affirmed that the shoulder is the area that suffers the most damage. To date, no objective tool has been used to evaluate this. The aim of the present study was to determine the frequency of structural sonographic alterations in CrossFit athletes and its relationship with accumulated hours of practice and/or competition in the sport and shoulder pain. Material and Methods A cross-sectional descriptive study was conducted with sonographic assessments performed on 208 shoulders of 104 participants at official CrossFit gyms in Barcelona, between April and May 2017. The participants were requested to complete a specific questionnaire on CrossFit sports practice that included demographic data, the existence of pain, data on training routines, and clinical history. Ultrasound (US) examinations were made on the supraspinatus tendons (SST), on the long head of the biceps (LHB), and on the acromioclavicular (AC) joint. Results The presence of focal hypoechoic areas (FHAs) in the LHB (48.1%) and in the SST (60.6%) were the most common alterations in this sample, whereas, at the level of the AC joint, the most common disorder was the presence of cortical defects (30.3%). Shoulder pain was present in 37.5% of the participants. The probability of experiencing pain increased when the athletes accumulated > 1,000 hours of training (odds ratio [OR] = 2.0). In these athletes, the probability of presenting a focal hypoechoic area (FHA) decreased in the LHB (OR = 0.3), and the width of the SST increased a mean of 0.5 mm (p < 0.01). In athletes who participated in competitions, the sonographic pattern also presented an increased width of the SST and LHB tendons; however, this was not related with an increased probability of experiencing pain. Conclusions The sonographic pattern of the shoulder of CrossFit athletes presented structural changes in the SST and LHB tendons when subjects accumulated > 1,000 hours of training or when they participated in competitions. It is essential to relate the sonographic findings with the clinical findings of a patient to define whether these findings are, indeed, pathological. The probability of experiencing pain in the shoulder doubles when > 1,000 hours of CrossFit training are accumulated. This finding bears no relation with competing.