Tables 3.1 and 3.2 summarize studies reporting overall (i.e., practice and competition combined) injury rates for girls’ and boys’ sports, respectively. Girls’ incidence rates per 1,000 h and/or per 1,000 athlete-exposures (AEs) are shown for alpine skiing [15], artistic gymnastics [16–21], rhythmic gymnastics [22], soccer [23–30], softball [28], TeamGym [31], and tennis [32]. Incidence rates for boys’ sports are reported for alpine skiing [15], baseball [28], gridiron football [33], artistic gymnastics [17], rugby [34], soccer [26–28, 30, 35, 36], and tennis [32]. Girls participating in artistic gymnastics (range = 0.5–5.3) and soccer (range = 3.7–15.3), and boys participating in rugby (range = 3.4–8.7) and soccer (range = 2.3–5.5) reported the highest rates of injury per 1,000 h exposure. When using AEs, injury rates among girls were highest in soccer (23.0), softball (10.0), and gymnastics (range = 1.3–8.5), while in boys injury rates were highest in baseball (17.0) and soccer (range = 4.3–17.0). Most of these sports involve contact, jumping, sprinting, or pivoting, actions often involved in the mechanism of sports injury.

Some data indicate that injury rates may vary by participation level. For example, advanced-level club female gymnasts may experience greater risk of injury compared to beginning-level counterparts, particularly in competition [18]. Increased daily and accumulated exposure to injury risk among advanced-level gymnasts, and an increased difficulty of skills practiced and performed, may explain this.

Data among girls’ soccer players are mixed. Emery et al. [27] reported lower rates of injuries among U14 soccer players compared to U16 and U18 players (p = .01), whereas McNoe et al. reported higher rates among senior ( > 17 years) vs. junior (< = 17 years) players in matches and training (p < .05) [37]. Soderman et al. reported that the highest incidence was seen in the 16-16.9 age group [29].

In a variety of sports, including football [33], lacrosse [39], rugby [40], and soccer [37], older boys experience higher injury rates than younger boys. In contrast, Brito et al. reported the highest incidence of injury among U17 soccer players followed by U15, U19, and U13 [35]. Older boys are heavier and stronger, and thus generate greater force on contact, enhancing the risk of injury. Other factors, such as maturity- and chronological age-associated variation, as well as intensity and duration of training, may also relate to risk of injury [41].

Gender-based differences in sports injuries are inconsistent. Several studies report higher injury rates for males, yet greater injury severity among females [42–44]. Higher injury rates are reported for females relative to males in skiing [15], gymnastics [17], and soccer [27, 37] (Tables 3.1 and 3.2). By comparison, in tennis, males had higher injury rates than females [32]. In tournament sports, higher taekwondo injury rates were reported for girls in one study and for males in another study [45, 46]. For karate, males had a much higher rate of injury [47].

Minoe et al. [37] found little difference in the incidence rates by playing position for both males and females. However, injury incidence (per 1,000 h) for young female team handball players in practice was highest for goalkeepers (6.7), followed by backs (3.7), wings (3.2), and line (2.9). The highest incidence of injury in games, however, was sustained by backs (54.8) followed by line (54.3), goalkeepers (30.6), and wings (23.6) [48].

Identification of commonly injured anatomical sites is important, as it alerts health-care professionals to sites in need of special attention during pre-participation screenings [49]. Such information is also relevant in considering effective prevention strategies. For example, the impact of neuromuscular training on the incidence of knee injury among adolescent soccer, volleyball, and basketball players revealed that untrained female athletes had a 3.6-fold greater incidence of knee injury than trained female athletes (P < 0.05) [50].

The proportion of injuries by body region may vary by gender within a sport and between sports. Male gymnasts, for example, experience a greater proportion of upper extremity (UE) injuries (e.g., shoulder or wrist) than female gymnasts, likely reflecting the skills practiced and apparatus used in men’s gymnastics [51]. Similarly, variable techniques and competition rules for young martial artists are clearly reflected in the body regions and parts injured. In judo, for example, UEs are more frequently injured, whereas in karate the head/face incur most of the injuries [52].

Comparisons of commonly injured anatomical locations by region, body part, and sport are summarized in recent reviews [50–57]. Across sports, the lower extremity (LE) is most commonly injured, ranging from 21.7–85.1 % of all injuries [16, 23, 37, 50–59]. Adolescents involved in acrobatics [60], alpine skiing [15], and TeamGym [31] also indicate the LE as the most commonly injured body region.

The ankle and/or knee are the most commonly injured LE sites in most sports. Injuries to both joints increase a young athlete’s risk of developing early onset osteoarthritis [61], subsequently creating a societal burden through indirect and direct costs [62]. Exceptions, however, include taekwondo, in which injuries occur primarily to the foot and toes [50]; skiing, where injuries are mainly to the knee and lower leg [15, 54]; rugby, where the thigh is most frequently injured [56]; and track and field where LE injuries primarily affect the lower and upper leg [57].

UE injuries are more common in sports such as baseball, gymnastics, judo, ice hockey, and snowboarding, and likely reflect the sport-specific upper body demands. In baseball, for example, most injuries involve the throwing arm, particularly among pitchers, with the strongest correlation to injury being the number of pitches thrown [63].

Only one sport (karate) reported head and facial injuries, most specifically tooth injuries, as the most common injury site [52]. Rugby injuries are most common to the head and neck [56]. Several studies examining TeamGym [31], soccer [37, 53], and taekwondo [50] indicate the head or head/neck as the second or third most common anatomical location for injury. Chapter 11 in this volume is dedicated to concussions affecting child and adolescent athletes.

In addition, some studies report incidence rates for specific body locations, thus permitting statistical comparison of anatomical location rates across sports, gender, or environmental locations [18, 27, 34, 58, 64, 65]. Lystad et al.’s review in taekwondo revealed that the LE incurred the highest injury rates, with 35.74 injuries per 1,000 AEs (95 % CI: 29.05–43.51), followed by the head and neck (12.65; 95 % CI: 8.80–17.57) and UE (7.22; 95 % CI: 4.41–11.15) [58]. In youth rugby, head injuries had the highest incidence per 1,000 game hours (8.1; 95 % CI: 7.1–9.1), followed by the face (7.8; 95 % CI: 5.1–10.4) and neck (3.3; 95 % CI: 2.7–4.0) [66].

Much of the limited literature on environmental location has focused on injury frequency in practice and competition. Studies reporting practice and competition incidence rates for girls in gymnastics [21], ice hockey [67], martial arts [43–45, 58], lacrosse [38], netball [68], rugby [69], soccer [23, 24, 27–29, 37], softball [28], and team handball [46, 70, 71], and for boys in baseball [28], football [33, 73] ice hockey [67], lacrosse [38], martial arts [43–45, 66], rugby [68, 69, 74, 75], soccer [27, 35, 37, 59], team handball [70, 71], and TeamGym [72] are summarized in Tables 3.3 and 3.4, respectively. As a result of greater exposure time, the proportion of injuries in most girls’ and boys’ sports is greater in practice than in competition. However, incidence rates are typically higher during competition. For example, in gymnastics the vast majority of injuries (71.0–96.6 %) occur in training compared to competition (3.4–21.0 %) [16, 76]. Significantly higher injury rates in competition relative to practice were reported in girls gymnastics (p < .001) [18] and soccer (p = .0009) [24, 27, 36], and in boys baseball (p < .05) [28] and football (p < .05) [28, 33]. Competitors are more likely to be participating at greater intensity and speeds in competition and tournaments than in practice, thus increasing the risk of sustaining injury [27].