en Musculoskeletal مقاله اصیل Original Article <div style="text-align: justify;"><strong>Background. </strong>Rugby is a high-intensity sport that involves strength, power, agility, and speed. The shoulder has been reported as the second-most-injured site in rugby union players. Muscle strength imbalances have been reported to increase the injury risk to the shoulder.<br> <strong>Objectives. </strong>This study aimed to measure and evaluate the isometric strength differences by arm dominance differences in isometric shoulder strength measurements and the incidence of previous injuries in amateur rugby union players.<br> <strong>Methods. </strong>This descriptive, cross-sectional design examines Sharks Academy rugby players in KwaZulu-Natal, South Africa. Sixty-one players between the ages of 18 and 23 participated in the study. All participants completed an injury-prevalence questionnaire, anthropometric (height and weight), and selected isometric shoulder strength tests. These specific tests were performed using the Pressure Air Biofeedback (PAB&reg;) device. Descriptive and inferential statistics were used.<br> <strong>Results.</strong> The mean age of participants was 19.1 years. The only significant difference was between the maximum shoulder flexion strength in the non-dominant and dominant arm strength (p=0.024). No significant differences were found between the mean isometric strength values and player position, either a back or a forward. More than one-third of the participants had sustained a previous shoulder injury within the past six months. No significant differences were found between the mean isometric strength values and previous shoulder injury.<br> <strong>Conclusions.</strong> Structured preseason upper-body strength testing and subsequent conditioning programs are recommended to help minimize shoulder injuries in amateur rugby union players.</div> Isometric Strength, Shoulder Injuries, Pressure Air Biofeedback (PAB®) 0 0 http://aapjournal.com/browse.php?a_code=A-10-29-1&slc_lang=en&sid=1 Vincent Bertolotti vinnybert1995@gmail.com 100319475328460079 100319475328460079 No College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa Tarryn Stening-Smith tazsteningsmith@gmail.com 100319475328460080 100319475328460080 No College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa Benjamin van Zyl benjivz@hotmail.com 100319475328460081 100319475328460081 No College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa Andre Pienaar andre@pressurebio.co.za 100319475328460082 100319475328460082 No College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa Rowena Naidoo naidoor3@ukzn.ac.za 100319475328460083 100319475328460083 Yes College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa