Lacrosse is a violent full-contact sport played by youth and adults all over the world. The game has origins in Native American culture and was first adapted by Europeans in the early 1800s. Since then, the game has exploded, especially in North America. Much like other full contact sports, lacrosse players are prone to many types of trauma. Some of these traumas include major ligament tears in the knee such as the anterior cruciate ligament (ACL) and medial collateral ligament (MCL))(Mihata, Beutler, Boden, 2006), pulled or torn muscles in the hamstrings and gluteus muscles (McCulloch & Bach, 2007). Concussions are also present in lacrosse (Kerr, Caswell, Lincoln, Djoko, Dompier, 2016), as are bone breaks (McCulloch & Bach, 2007). The most common types of bone trauma are muscle or ligament strains, but overuse injuries can also lead to specialized injuries (McCulloch & Bach, 2007). While lacrosse is known as a violent sport, it actually rates fairly low in injuries when compared to other college sports. Lacrosse is listed as seventh in game injury rate in the NCAA (McCulloch & Bach, 2007). These rankings are topped by sports such as football, wrestling, and soccer. In 2004 the injury rate of college lacrosse players was only 4.7 per 1000 athletic exposures (McCulloch & Bach, 2007).While this number is relatively low, it can be argued that injuries occurring from playing lacrosse are usually violent and damaging. According to Yard and Comstock (2006), lacrosse injuries are more than doubled by those seen in hockey players. This paper will explore the most common traumas seen in lacrosse players, the types of trauma and the patterns seen across the population of lacrosse players.

The most common type of trauma is a ligament strain or tear (McCulloch & Bach, 2007). Most tears happen in the knee, a part of the body that accounts for 10-15% of all lacrosse injuries, although the literature is split on this debate. According to Xian, Collins, Liu, McKenzie, and Comstock (2014), the knee only makes up 12% of all injuries, with injuries to the head and neck more than doubling the amount of injuries to the knee. Of the four major ligaments that cross the knee joint, the ACL and MCL are most likely to be strained or torn. Both of these ligaments are usually season ending when torn, requiring surgery in order to be repaired (Mihata, et al., 2006). While many injuries in lacrosse are a direct result of its full contact rules, ligament tears in the knee normally occur from non-contact reasons (McCulloch & Bach, 2007). Players attempting to pivot or dodge at high intensity, such as in a game, are at high risk of a ligament tear. This could be due to players having to hold a stick in their hands while performing explosive movements. Something as simple as arm position has been found to increase the load on the knee that is planting, leading to higher risk of ACL injury (Chaudhari, Hearn & Andriacchi, 2005). Having the arms free to increase balance is a simple way to avoid ACL injuries, unfortunately, the sport of lacrosse requires players to hold a stick in their hands. Finally, there is no significant difference between men and women’s lacrosse with regards to ACL injury rate (Mihata, et al., 2006). This is surprising, especially when compared to other sports. Basketball and soccer athletes are at much less risk of ACL injury, women athletes are also less likely to injure the ACL in basketball and soccer when compared to men (Mihata, et al., 2006).

Another form of trauma that lacrosse players face are muscle strains. As with any running sport, the legs are especially prone to muscle strains. Strains occur in the hamstring and quadricep muscles the most because these muscles cross two joints (McCulloch & Bach, 2007). Long muscles also perform multiple functions such as contraction and extension when running leaving them prone to strains. The most likely time a hamstring strain will occur is when the foot lands during a sprint. During this movement, the hamstring is completely extended and must contract and load very quickly when the foot makes contact. (Seen in fig. 1)

Fig. 1 Source: Michaud, 2014

The running movement depicted in fig. 1 is the most likely time that a hamstring strain will occur. During this phase of running the hamstring is fully elongated, meaning it is especially at risk of a strain or tear. Although not as common, the shoulder is also susceptible to muscle tears and subluxations. However, these muscles are usually torn or strained as a result of contact or a shot motion, not running. Lacrosse is unique as it is an overhead collision sport combined with intense bouts of running. This uniqueness creates plenty of opportunities for athletes to pull or strain muscles in their legs due to running or shoulder due to a collision.

Collisions are an integral part of lacrosse. As a result, many players suffer traumatic injuries due to hits to the head, or shoulder. Typically, lacrosse players suffer from concussions or Acromioclavicular (AC) joint injuries due to the high rate of collisions. While McCulloch and Bach (2007), report that concussions only make up 11% of injuries in men’s collegiate lacrosse, other authors have found that concussions make up 10-28% of injuries seen in lacrosse players (Xiang, et al., 2014; Kerr, et al., 2016; Yard & Comstock, 2006). Although these studies use different age groups for their data, it is surprising to find such a wide range. Overall these studies show that youth are more likely to suffer from concussions and that this type of injury seems to lessen as players become older. One possible reason for this finding may be the use of older data. Old data may account for more concussions due to inadequate protective equipment. Players in the 1990-2000s were using far less advanced protective equipment than what is available now. As a result, Yard & Comstock’s (2006) data pulled from the years 1990-2003 may explain the higher concussion rate. There could be a correlation between an advance in head protection technology and a decrease in concussions, although there are many spurious factors that may also have an effect. Another major impact trauma is shoulder separation or AC joint injuries. Often, this injury is a direct result of a collision with another player or a fall onto the ground. Athletes with AC joint injuries can expect pain on the distal end of their clavicle and will likely be inhibited from playing for multiple weeks. Normally AC joint injuries are not seen until age thirty, but athletes have been found to have five times more risk of an AC joint injury during intercollegiate sports (Pallis, Cameron, Svoboda, Owens, 2012). AC joint injuries are classified into grades, from least severe to requiring surgery (I-VI). Nearly 90% of AC joint injuries are in the I-II range and do not require surgery, although physical therapy is recommended (Pallis, et al., 2012).

Many of the bone breaks seen in lacrosse players are a direct result of its full contact nature. Players use sticks made of metal alloy and repeatedly strike opposing players in an effort to dislodge the ball. This can come in the form of a cross-check or a stick check(swinging the stick much like a sword). While fractures are less common than previously mentioned injuries, they do makeup 6-17% of injuries in lacrosse players (McCulloch & Bach, 2006; Yard & Comstock, 2006). Bone fractures are most commonly seen in the upper limbs as a result of cross-checks and stick checks by other players. Phalangeal fractures happen relatively frequently because players wrap their fingers around their own sticks, while opposing players are frequently stick checking at the hands in order to dislodge the ball. Goalies are also susceptible to phalangeal breaks, although the cause is usually from a ball that has been shot. The thumb is the most common finger to break, probably due to the malleable and flexible nature of lacrosse gloves. Compared to hockey gloves, lacrosse gloves have much less hard protection to allow players to grip their sticks with more control. Unfortunately, this adaptation leaves them at a higher risk of hand fractures. Another high-risk area for fractures are the ribs (McCulloch & Bach, 2007). While it is required by rule to wear shoulder pads, most pads only sit directly on top of the shoulders and do not protect the back or sides of the torso. This leaves the ribs susceptible to injury from cross checks or collisions as well as the lacrosse ball. Notably, even with the lack of protective gear around the lateral and posterior side of the body, it is very rare for players to get abdominal injuries (McCulloch & Bach, 2007).

Injuries can also occur because of direct contact with a lacrosse ball. In younger cohorts, players are more likely to be injured by a lacrosse ball than with contact from another player (Kerr, et al., 2016). However, these injuries are usually less severe than contact injuries. Contusions, concussions, and fractures can all occur to nearly every body part. Goalies are especially prone to these types of injuries as they face shots in excess of 40m/s in high-level lacrosse. Fractures to the hand are common and shots to head region can lead to concussions. The most common injury type caused by a lacrosse ball are contusions (Kerr, et al., 2016). Defensive players routinely block shots with their body in order to prevent goals leading to ruptured blood capillaries and injured soft tissues. As players advance to higher levels of lacrosse they see less injury from ball contact and more from body contact. This could be due to the increase in muscle mass and size and an increase in hitting as players get older. There have also been isolated cases of death from players blocking a shot with their chest (McCulloch & Bach, 2007). This happens if the ball hits the sternum of a player during a specific phase of cardiac repolarization. These events are extremely rare and have become even less frequent with the advent of improved shoulder pads that also protect the sternum.

Elite level athletes may also suffer from injuries not directly caused by lacrosse, but by the associated lifestyle of elite athletes. Many athletes at this level are also required to weight lift and run outside of practices and games in order to perform at their best. While there is no direct research on this topic there are definitely injuries caused by weightlifting and overuse that could cause a player to miss playing time. Usually, injuries stemming from overuse and weightlifting include muscle and ligament sprains or tears. At the extreme end some athletes may suffer from specific overuse injuries such as distal clavicular osteolysis (weightlifters shoulder). This injury is caused by overuse of the shoulder joint whether through weight lifting or repetitive lacrosse movements. It also inhibits an athlete’s movement of the shoulder and causes immense pain when performing physical activities (Schwarzkopf, Ishak, Elman, Gelber, Strauss, Jazrawi, 2008). Athletes with distal clavicular osteolysis can expect degradation of the clavicle and should rest and modify activity.

There are also differences between men and women’s lacrosse injury patterns. This subject is generally overlooked but some studies have found that women’s lacrosse usually has less injury rate when compared to men’s lacrosse (Matz & Nibbelink, 2004; Xiang, et al., 2014). Some confounding variable could be that less women play lacrosse or the fact that hitting is against the rules, which is strictly enforced. Women’s lacrosse also has a lower injury rate when compared women’s soccer and hockey at the collegiate level (Matz & Nibbelink, 2004). Overall the pattern of injury does not change significantly between genders. Many of the injuries we see in men’s lacrosse translate to women’s lacrosse. The rate of concussions and muscle sprains are relatively stable across both genders. However, the cause of injury is slightly different. Women are more prone to injury due to overuse (17%) and no contact (26%), while men’s injuries are caused by contact with another player (40%)(Xiang, et al., 2014). These causes may be different due to other rules between the men’s and women’s lacrosse game. These rules allow the men’s game to be much more physical while women’s lacrosse is focused more on skill.

Finally, the injury rate amongst lacrosse players changes depending on when they are playing. For example, injury rates are much higher during games than during practices (Xiang, et al., 2014; Kerr, et al., 2016). However, these statistics can be misleading. Injuries during practice do have a lower rate when compared to competition, but the amount of athletic exposure each athlete gets is also much higher during practice than during competition. This means that overall, injuries are more likely to happen during practice simply due to the fact that players have higher athletic exposures during that time.

Overall, lacrosse provides some unique trauma patterns to areas all over the body. The most common injuries are to the muscles and ligaments, however, bone fractures are not unheard of. Figure 2 is a chart adapted from McCulloch and Bach (2007) and clearly summarizes the number of injuries to men’s collegiate lacrosse athletes in 2004.

Fig. 2 Adapted from: McCulloch & Bach, 2007

This chart is a good representation of the types of injuries seen across all lacrosse players. The differences in rates of injury between sexes is insignificant, but the cause of injuries do differ. There also seems to be a difference in the rate of injury between younger players when compared to collegiate athletes. This may be due to higher intensity of play in collegiate lacrosse. Finally, it should be noted that injury rates are more frequent during games, however with increased athletic exposures, athletes are more likely to be injured during practice.

