ORIGINAL RESEARCH Upper Extremity Sports Injury: Risk Factors in Comparison to Lower Extremity Injury in More Than 25 000 Cases Renee Sytema, MD,* Rienk Dekker, MD, PhD,*† Pieter U. Dijkstra, PhD,*† Hendrik J. ten Duis, MD, PhD,‡ and Corry K. van der Sluis, MD, PhD*† Objective: To analyze differences in sports injury characteristics of the upper and lower extremity and to identify factors that contribute to the risk of sustaining an upper extremity injury compared with the risk of sustaining a lower extremity injury. Design: Retrospective cohort study. Setting: An emergency department of a large European level I trauma center. Patients: A total of 25 120 patients with a simple sports injury, attending during 1990-2005. Assessment of Risk Factors: Independent variables used to as- sess risk factors were extracted from a local database. These include age, sex, type of injury, site and side of the injury, type of sport, injury mechanism, and data on admission. Main Outcome Measures: Main outcome measure was the re- lation of various risk factors to the occurrence of either upper or lower extremity injury. Logistic regression analysis was used to identify predictors for upper extremity injury. Results: Thirty-five percent upper and 53% lower extremity injuries were recorded. Most injuries were sustained when playing soccer (36%). Fractures were more frequently diagnosed in the upper than in the lower extremities (44% and 14%, respectively), especially in children. Falling was the main cause of upper extremity injury. Further risk factors were young age and playing individual sports, no- contact sports, or no-ball sports. Women were at risk in speed skating, inline skating, and basketball, whereas men mostly got injured during skiing and snowboarding. Conclusions: A high percentage of sports injuries are sustained to the upper extremity. Different risk factors were identified for both sexes. These risk factors should be taken into account when designing preventive measures. Key Words: athletic injuries, sports, upper extremity, lower extremity, epidemiology, risk factors (Clin J Sport Med 2010;20:256–263) INTRODUCTION Participation in sports is generally held to be a source of fun and beneficial to health, but it can also have major negative consequences. In the Netherlands, approximately 1.5 million sports injuries occur every year, of which 50% need medical attention. 1 After domestic accidents, sport is the second cause of injury seen at the emergency departments in the Nether- lands. 1,2 This is consistent with data from other European countries and the United States. 3,4 In the literature, most attention has been paid to sports injuries of the lower extremity in comparison to upper extre- mity injuries, probably because injuries of the ankle and knee are the most frequently sustained injuries. 3,5–10 However, some studies show that injuries in the upper extremity occur as frequently as, or even more frequently than, injuries in other body regions. 5–8,11,12 In particular, hand injuries are com- mon. 3,6,10,13,14 In our opinion, upper extremity sport injuries need more attention because these injuries may lead to severe disability. 15 In the light of the unique and refined coordination and grasp function of the hand, more attention is needed to prevent disturbance of its functions. 15 The aim of this study was to analyze differences in characteristics of sports injuries of the upper and lower extremity and to identify those factors that contribute to the risk of sustaining an upper extremity injury relative to the risk of suffering a lower extremity injury. METHODS Setting and Population All consecutive patients treated at the Emergency Department of the University Medical Center Groningen (UMCG) in the Netherlands because of a sports injury were eligible for the study. The UMCG is a level I trauma center that plays a major role as an emergency care center for trauma victims in the city of Groningen and the surrounding region. Design Data on sports injuries were obtained from the Registry of Injuries and Accidents Groningen (RIAG), a database that holds data on all injuries seen at the Emergency Department of Submitted for publication November 20, 2009; accepted May 5, 2010. From the *Centre for Rehabilitation, University Medical Centre Groningen, Groningen, the Netherlands; †Share Graduate School for Health Research, University of Groningen, Groningen, the Netherlands; and ‡Department of Traumatology, University Medical Centre Groningen, Groningen, the Netherlands. The authors declare that they have no conflicts of interest. Reprints: Corry K. van der Sluis, MD, PhD, Center for Rehabilitation, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, the Netherlands (e-mail: C.K.van.der.Sluis@rev.umcg.nl). Copyright Ó 2010 by Lippincott Williams & Wilkins 256 | www.cjsportmed.com Clin J Sport Med  Volume 20, Number 4, July 2010