Effects of Vehicle Size on Pedestrian Injury Pattern and Severity: Prospective Study Essa M. AlEassa • Hani O. Eid • Fikri M. Abu-Zidan Published online: 27 September 2012 Ó Socie ´te ´ Internationale de Chirurgie 2012 Abstract Background The type of injuries caused by sport utility vehicles may be different from those caused by small passenger cars. We studied prospectively the effects of the offending vehicle type and design on severity and pattern of pedestrian injuries. Methods All injured pedestrians admitted to the two major trauma centers of Al-Ain city were studied pro- spectively during the period of April 2006 to October 2007. Patients were classified into two groups according to the offending vehicle type: small vehicle and sport utility vehicle. These two groups were compared regarding the distribution of injury and its severity. Results The anatomical distribution of injury in a descending order were the lower extremities (56.3, 67 %), head (53.8, 57.1 %), face (37.5, 57.1 %), and upper extremities (32.5, 28.6 %) in small vehicle and sport utility vehicle groups, respectively. No significant statistical dif- ference has been found between the two groups regarding the anatomical distribution and severity. Conclusions The vehicle size and design did not affect the anatomical injury distribution and severity in our set- ting. High-impact speed may overcome the vehicle type when it comes to injury severity and pattern of distribution. Introduction The United Arab Emirates (UAE) is a rapidly developing country. Within 40 years, it became a country with metropolitan cities and well-developed infrastructure. Tolls came along with these developments; injuries due to road traffic collisions (RTC) in the UAE are reported to be among the highest in the world [1]. RTC is the second leading cause of death in the country [2]. The Statistics Center of Abu Dhabi Emirate reported more than 5,000 RTC causalities that occurred in 2009 having a mortality of 7.9 %. Twenty percent of these were pedestrian injuries [3]. Al-Ain city is the largest city in the eastern region of the Emirate of Abu Dhabi and had a population of 568,221 in 2010; with a male to female ratio of 2:1 and a non-national to national ratio of 2.2:1. It extends over a large area of 30 9 20 km with an internal length of roads of 1,227 km [3]. A recent study looking at the driving behavior of road users in UAE indicated that 5 % of the drivers never yielded for pedestrians and *11 % occasionally yielded for them [4]. This puts pedestrians at a high risk of injury when crossing these lengthy roads. A study from Al-Ain City showed that 13 % of RTC-injured patients who were treated at hospitals were pedestrians [5]. Furthermore, pedestrian injuries accounted for 28.5 % of road traffic mortality in UAE [6]. Different aspects of pedestrian road traffic injury have been studied; an important aspect is the biomechanics of pedestrian injury. During collision, energy is transferred between objects. Energy is calculated as  mass times velocity squared (E =  mv 2 ). It is worth noting that the velocity is exponential; thus, every kilometer per hour increase in velocity actually highly increases the energy that the vehicle possesses and, therefore, the higher the E. M. AlEassa Á H. O. Eid Á F. M. Abu-Zidan (&) Trauma Group, Department of Surgery, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al-Ain, United Arab Emirates e-mail: fabuzidan@uaeu.ac.ae E. M. AlEassa e-mail: e.aleassa@uaeu.ac.ae H. O. Eid e-mail: hani2003@hotmail.com 123 World J Surg (2013) 37:136–140 DOI 10.1007/s00268-012-1797-4