Psychology of Sport Injury Course 1_Part3.pdf

Antecedents of Sport Injury   25 vocated expanding that component to include affective and behavioral aspects. More specifically, they noted that chronic, prolonged, or repeated stress—in the form of a history of stressors from life events, training, and competition—can increase general muscle tens...

Antecedents of Sport Injury   25 vocated expanding that component to include affective and behavioral aspects. More specifically, they noted that chronic, prolonged, or repeated stress—in the form of a history of stressors from life events, training, and competition—can increase general muscle tension and narrow the visual field (which overlaps with the cognitive and attentional components of the stress response). It can also increase activation of the body’s short-term (i.e., sympathoadrenal medullary, or SAM) and long-term (i.e., hypothalamic–pituitary–adrenal, or HPA) stress-response systems. These changes, when followed by the release of stress hormones (e.g., cortisol), are thought to raise the risk of illness, injury, and other deleterious health consequences by suppressing the immune system, disrupting the tissue-repair process, and interfering with the restorative effects of sleep. Model Integration On the surface, although the multifactorial model and the stress–injury model are both intended to explain the process by which athletes sustain injuries, they appear to differ greatly not only in their terminology but also in their depictions of the process of sport injury occurrence. A closer look, however, reveals that the two models are wholly compatible and that the stress–injury model represents a specific pathway within the more general multifactorial model. Specifically, the stress– injury model’s personality component, as well as the cognitive and behavioral aspects of its coping-resources component, can be viewed as internal risk factors (or, more accurately, internal risk mitigators) in the multifactorial model. Similarly, the history of stressors in the stress–injury model dovetails nicely with the category of external risk factors in the multifactorial model. The biggest question in this integration is whether the stress-response component of the stress–injury model is part of the susceptibleathlete phase of the multifactorial model— “where the intrinsic and extrinsic risks and the interactions between all the risks accumulate” (Meeuwisse et al., 2007)—or if it occurs after, or as part of, an inciting or other event immediately before the injury and when there are no injury outcomes. In other words, is the heightened stress response that confers an elevated risk of injury on athletes a relatively chronic state experienced by individuals made susceptible by their personality, history of stressors, and coping resources? Or is it an acute state manifested only by individuals under stressful circumstances? The answer is not as straightforward as it may seem. The stress–injury model clearly indicates that a “potentially stressful athletic situation” triggers the stress response that places athletes at increased risk for injury. For example, research has shown that a stressful sport situation (e.g., playing in an important game) causes a narrowing of the peripheral visual field (T.J. Rogers, Alderman, & Landers, 2003), which is positively associated with sport injury (T.J. Rogers & Landers, 2005). These findings might seem to support the view that a stressful situation beyond an athlete’s history of stressors is needed in order to elicit the stress response that heightens injury risk. However, the vast majority of studies that have found components of the stress–injury model to predict the occurrence of sport injury (for a review, see J.M. Williams & Andersen, 2007) have not included measures of the stress response under stressful conditions. Therefore, it may not be necessary for an athlete to encounter a stressful sport situation over and above the ones experienced in his or her history of stressors (which includes the physical training stressors described by Petrie & Perna, 2004) in order to experience a maladaptive stress response sufficient to contribute to injury occurrence. Instead, as suggested by the physiological responses to chronic stress identified by Petrie and Perna (2004), the independent and interactive influences of personality, history of stressors, and coping resources may be sufficient in combination to create a state of vulnerability—corresponding with the multifactorial model’s susceptible-athlete phase— that needs only an inciting event or series of inciting events. This event or series of events could involve a stressful sport situation and B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. 26 Psychology of Sport Injury subsequent exacerbated stress response that bring about injury. Removing the “potentially stressful athletic situation” as a necessary condition for the occurrence of sport injury better reconciles the stress–injury and multifactorial models. It also allows for the occurrence of overuse injuries and acute injuries in seemingly nonstressful circumstances such as training sessions and friendly competitions. Psychosocial Predictors of Sport Injury More than four decades’ worth of research has identified numerous psychological and social factors that are predictive of sport injury outcomes, such as injury occurrence and time lost from sport participation due to injury. Many of these factors were specified by the developers of the stress–injury and multifactorial models, and predictive factors that are not explicitly mentioned in the two models can invariably be placed in an appropriate component of one or both of the models. Some of the psychosocial factors presented in this section have been linked to sport injury in a single study, whereas others have been repeatedly associated with sport injury in research investigations. The quality of the studies varies widely. Some are retrospective (i.e., measuring psychosocial factors after injury occurrence), but most are prospective (i.e., measuring factors before the injury). Because almost all of the studies are correlational, it cannot be concluded that any of the psychosocial factors is causally related to sport injury. Indeed, if a positive correlation is found between a given personality factor and the number of days lost to injury during the season after personality was measured, it is possible that the personality factor caused the time lost due to injury, that another variable caused both the personality factor and the time loss, or, more likely, that the relationship between the personality factor and the time loss is mediated by one or more other variables. For example, in studies finding a relationship between trait anxiety and time loss, the tendency to be anxious across situations may elevate other risk factors (e.g., muscle tension, distracted attention) that are more proximal to injury occurrence in the stress–injury and multifactorial models. For more on injury-prediction research, see this chapter’s Focus on Research box. Having acknowledged the limitations of the research base on sport injury prediction, we now turn to an overview of psychosocial factors associated with sport injury outcomes. Particular attention is given to personality, history of stressors, coping resources, mood states, miscellaneous factors, and interactive relationships. Personality As one of three categories of psychosocial variables proposed to affect the stress response in the stress–injury model, personality has been the focus of numerous investigations aimed at identifying predictors of sport injury. However, no “injury-prone” personality has been documented, and the association between individual personality characteristics and injury outcomes has generally been weak at best (for reviews, see Prieto, Labisa, & Olmedilla [2014] and J.M. Williams & Andersen [2007]). In the initial description of the stress–injury model (M.B. Andersen & Williams, 1988), five personality characteristics were hypothesized as potential contributors to the stress response: hardiness, locus of control, sense of coherence, competitive trait anxiety, and achievement motivation. Of the five characteristics, competitive trait anxiety has shown the most consistent association with sport injury outcomes; specifically, higher levels of competitive trait anxiety are related to more or longer-lasting injuries. This finding, which seems to hold only when competitive trait anxiety is assessed with a measure specific to the sport environment (J.M. Williams & Andersen, 2007; Yang, Cheng, et al., 2014), makes sense in that athletes who tend to be anxious about sport competition in general would be expected to enter particular sport settings with elevated anxiety that could exacerbate the stress response and heighten the risk of B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. Research on the general causes and precise mechanisms of sport injury is not likely to yield a smoking gun—not now, and not ever! This is not merely the opinion of guarded, appropriately skeptical scientists; it is an accurate reflection of the limitations of research on the etiology of sport injury. Under ideal circumstances, researchers would manipulate variables hypothesized to cause injury in athletes and then observe the effects on athletes’ injury status. However, although this approach might be desirable from a scientific standpoint, it is impermissible on ethical grounds. Besides, who would sign up to participate in a study like that? This is not to say that experimental studies are never carried out in which sport injury occurrence is the dependent variable; they are. It’s just that those studies typically involve experimental manipulations proposed to decrease the occurrence of sport injury. Therefore, they are covered in chapter 3, which pertains to the prevention of sport injury. With experimental methods essentially off the table, investigators interested in the etiology of sport injury have relied heavily on correlational research designs that examine associations between sport injury and purported risk factors. Correlational studies do not enable researchers to draw causal inferences, but they can increase one’s confidence that the hypothesized risk factors might exert a causal influence on sport injury occurrence—if the research design is not retrospective but prospective. In retrospective studies, proposed injury-risk factors are measured after the occurrence of sport injury. For instance, in a typical retrospective study, a group of athletes with injuries and a group of athletes without injuries complete a series of risk-variable measures. Comparisons between the two groups will reveal little about the causes of the athletes’ injuries, because any differences between the two groups could just as easily be the consequence of sport injury as they could be the cause. In contrast, prospective studies administer measures of risk variables to asymptomatic athletes before the occurrence of injury, thereby making it less likely that the proposed risk factors are the effects rather than the causes of injury (Petrie & Falkstein, 1998). The inability to conduct experimental etiological research with injury as the primary dependent variable has made it exceedingly difficult for investigators to identify the mechanisms by which sport injury occurs. Even if a researcher happened to observe an unfortunate athlete in the act of being injured, the occurrence would likely be uninformative unless the researcher had been monitoring relevant etiological parameters for a period of time before the injury was sustained. However, rather than throw their hands in the air and surrender to these difficulties, resourceful researchers have devised creative strategies to explore mechanisms of sport injury occurrence. Specifically, Krosshaug, Andersen, Olsen, Myklebust, and Bahr (2005) indicated that researchers have examined the inciting events of sport injury in the following ways: • Interviewing athletes about the circumstances under which they were injured • Conducting clinical studies to analyze the pathology of an injury and related damage • Systematically analyzing video representations of athletes incurring injuries Focus on Research How We Know What We Know About Sport Injury Occurrence (continued) injury. It is possible that an even more pertinent form of anxiety—“sport injury trait anxiety”— may fare even better than competitive trait anxiety in predicting injury, but researchers have not yet ascertained the relationship between the first scale to assess the construct (Sport Injury Trait Anxiety Scale; Kleinert, 2002) and injury. In addition, two studies have found negative associations between hardiness and sport injury occurrence outcomes (Ford, Eklund, & Gordon, 2000; Wadey, Evans, Hanton, & Neil, 2012a). Empirical support for the other three personality characteristics is either weak or nonexistent, whether because they have not B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. 27 Focus on Research How We Know What We Know About Sport Injury Occurrence (continued) 28 • Performing laboratory motion analyses in which typical injury situations are mimicked and loading patterns are assessed Although these methods do not fully replace live human experimentation, they do shed an abundance of light on a critical part of the process of sport injury occurrence. In sport injury prediction research, as in much of life, timing can be everything. In a typical study of sport injury prediction, risk factors for injury are assessed at the beginning of the season, and athletes’ injury outcomes are recorded over the course of the season. Given the increased recognition that susceptibility to injury is a dynamic condition, researchers have recommended moving away from the standard preseason assessment and making more measurements of injury risk factors that can change during the study period (Meeuwisse et al., 2007; Petrie & Falkstein, 1998). Repeated assessment of such factors (e.g., history of stressors; social support; environmental conditions; and cognitive, affective, and behavioral responses to stress) at regular intervals enables more accurate representation of the risk for injury and therefore should enhance the predictive power of models of sport injury occurrence. Of course, the ability to manipulate the timing of data collection about risk factors may be limited by practical considerations, such as the willingness of athletes and coaches to participate. been tested or because they have not shown consistent results when they have been tested. M.B. Andersen and Williams (1988) also recognized that sport injury occurrence might be related to personality characteristics other than the five noted in their initial presentation of the stress–injury model. Of particular note, manifestations of the type A personality pattern—characterized by driven, hostile, hypercompetitive, hurried, and impatient behavior—has been positively associated with the occurrence of overuse injuries in runners in multiple studies (Diekhoff, 1984; Ekenman, Hassmén, Koivula, Rolf, & Fellander-Tsai, 2001; K.B. Fields, Delaney, & Hinkle, 1990). Similar results were reported by McClay, Appleby, and Plascak (1989), who found that young cross country runners who scored high on self-motivation were more likely than those who scored low to incur severe injuries. In addition, Kazarian, Thompson, and Clark (1995) showed that the positive association between type A behavior and both number of injuries and time lost due to injury extended beyond overuse injuries incurred by runners to more acute injuries experienced by American football players. The generalizability of the positive relationship between type A behavior and number of injuries was further demonstrated in a study of 2,164 collegiate athletes in Japan (Nigorikawa et al., 2003). Associations with sport injury occurrence have also been documented for many other personality characteristics, but some of these associations seem to be contradictory, and most were reported in single, isolated studies and have not been replicated. For instance, a negative correlation was found between optimism and injury occurrence for athletes in a variety of sports (Wadey, Evans, Hanton, & Neil, 2013). Factors found to correlate positively with sport injury occurrence include dominance (W. van Mechelen et al., 1996), ego orientation (Steffen, Pensgaard, & Bahr, 2009), external locus of con- • Measuring in vivo strain or force of muscles, tendons, or other tissues • Documenting accidental injuries that occur during biomechanical experiments • Simulating the effects of potential inciting events on cadavers and dummies • Developing mathematical models that estimate what is likely to happen in situations with high risk for injury B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. Antecedents of Sport Injury   29 trol (Pargman & Lunt, 1989), internal locus of control (Kolt & Kirkby, 1996; Plante & Booth, 1997), narcissism (Plante & Booth), perfectionism (Krasnow, Mainwaring, & Kerr, 1999), stress susceptibility (Ivarsson & Johnson, 2010), tendermindedness (D.W. Jackson et al., 1978; Valliant, 1981), toughmindedness (Wittig & Schurr, 1994), and trait irritability (Ivarsson & Johnson). In addition, in a study of elite youth ice-hockey players, low athletic identity was associated with increased risk for a first injury, but high athletic identity was associated with increased risk for subsequent injuries (McKay, Campbell, Meeuwisse, & Emery, 2013). Potentially more important than these associations are the contributions of personality factors to the prediction of sport injury occurrence in the interactive relationships described in the following paragraphs. Personality may also contribute to behaviors that increase an athlete’s risk of injury. For example, Webbe and Ochs (2007) found that elite male soccer players who scored high on extroversion (i.e., tendency toward assertive, enthusiastic, outgoing behavior) reported heading the ball more frequently than did those who scored low on extroversion. More recently, Akehurst and Oliver (2014) found that in their sample of 100 professional dancers, obsessive passion was positively associated with the tendency to report engaging in behavior that placed the dancer at increased risk for injury and that this relationship was mediated by dependence on dance. History of Stressors Seminal research by Holmes (1970) documented a positive association between injury and life-event stress in a sample of collegiate football players. Since then, history of stressors has been the most studied and most consistently supported psychosocial predictor of sport injury. In a review of more than 40 studies that examined the relationship between life stress and sport injury, J.M. Williams and Andersen (2007) “found that approximately 85 percent of the studies found some correlation between life event stress and injury risk” (p. 383). Indeed, the association between life stress and sport injury is remarkably robust, having been demonstrated across a wide variety of sports and levels of competition (e.g., youth, elite) in studies that varied in their definitions of injury and in their measures of life stress. Support for a relationship between life stress and sport injury is strongest for negative life-event stress and total life-event stress (i.e., stress from life events perceived as negative plus those perceived as positive). Associations have also been reported between positive lifeevent stress and sport injury occurrence but with less consistency than for total and negative life-event stress (J.M. Williams & Andersen, 2007). Since the review by J.M. Williams and Andersen (2007), ongoing research has provided additional documentation for the association between sport injury occurrence—as well as time lost due to injury—and both negativelife event stress (Dunn, Smith, & Smoll, 2001; Gunnoe, Horodyski, Tennant, & Murphey, 2001; Johnson & Ivarsson, 2011; Sibold, 2005) and total life-event stress (Dvorak et al., 2000; Galambos, Terry, Moyle, & Locke, 2005; Gunnoe et al.; Olmedilla, Prieto, & Blas, 2011; Steffen et al., 2009). For example, Dunn et al. reported that stress attributable to sport-specific negative life events predicted time lost due to injury over and above general negative lifeevent stress for male athletes but not for female athletes. On the other hand, a history of one specific type of stressor—physical abuse— has been associated with an elevated risk for injury among female athletes but not among male athletes (Timpka, Janson, et al., 2014). In contrast to the volumes of research addressing the relationship between sport injury occurrence and major life-event stress, relatively little attention has been paid to the role of daily hassles (i.e., minor negative life events). The literature review performed by J.M. Williams and Andersen (2007) noted that because of the ever-changing nature of daily hassles, they must be assessed frequently over the course of a sport season. These researchers further observed that in studies where daily hassles were measured on only one occasion, no significant relationship was found between daily hassles and sport injury occurrence. B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. 30 Psychology of Sport Injury However, a different pattern has been found in studies that assessed daily hassles on multiple occasions. For example, in studies where measures of daily hassles were administered on a weekly basis, athletes who became injured had experienced either a significant increase in daily hassles during the week just before injury (Fawkner, McMurray, & Summers, 1999) or a near-significantly higher (p = .085) level of daily hassles before injury (Ivarsson & Johnson, 2010) as compared with athletes who did not become injured. Thus, it is possible that stress from minor life events affects sport injury risk but that this risk is short lived. A consistent positive association has been documented between the third type of stressor identified in the stress–injury model—previous injury—and the occurrence of sport injury. In general terms, previous injury has been positively correlated with subsequent injury in numerous studies (e.g., Emery, Meeuwisse, & Hartmann, 2005; Kucera, Marshall, Kirkendall, Marchak, & Garrett, 2005; Lysens et al., 1984; Marshall, Covassin, Dick, Nassar, & Agel, 2007; Timpka, Jacobsson, et al., 2014; W. van Mechelen et al., 1996; J.M. Williams, Hogan, & Andersen, 1993). Previous injury has also been positively correlated with subsequent injury among athletes with specific injuries. Among youth soccer players, for example, injury to a given region of the body has been positively correlated with subsequent injury to that same region (Steffen, Myklebust, Andersen, Holme, & Bahr, 2008). Similarly, hip and groin injuries incurred by youth and junior soccer players have been correlated with the same types of injury in the players’ adult and senior soccer years (Gabbe, Bailey, et al., 2010). In other sports, concussions experienced during the competitive years have been correlated with concussions experienced in retirement by American football players (Guskiewicz et al., 2007), previous hamstring injuries have been correlated with subsequent hamstring injuries in Australian football players (Gabbe, Bennell, Finch, Wajswelner, & Orchard, 2006), and previous ankle sprains have been correlated with subsequent ankle sprains in elite badminton players (Yung, Chan, Wong, Cheuk, & Fong, 2007). Moreover, not sustaining an injury in the previous year has been found to be protective against injury among nonelite netball players (McManus, Stevenson, & Finch, 2006). Among events in an athlete’s history of stressors, previous injury is unique in at least one important way. Namely, it is unclear whether the elevated risk associated with previous injury results from a fear of reinjury that induces a magnified stress response or from an actual reinjury attributable either to incomplete healing or to somatic weakness in the injured area (M.B. Andersen & Williams, 1988). In cases where the current injury occurs in a location different from that of the previous injury, the fear-of-reinjury pathway is a tenable explanation. In cases where the current injury occurs in the same location as the previous injury, the actual-reinjury pathways seem more likely to be involved insofar as the current injury may simply be either a continuation of an unhealed previous injury or a new injury to a site that is especially vulnerable for anatomical, biomechanical, or other reasons. The matter is complicated by the finding that previous injury is associated with elevated perceptions of injury risk (Reuter & Short, 2005; Short, Reuter, Brandt, Short, & Kontos, 2004)—a variable that is, in itself, inversely related to the occurrence of sport injury (Kontos, 2004). Thus, it appears that a previous injury may elicit a cognitive response of wariness that helps protect against subsequent injury but is insufficient to offset the vulnerability to injury that an injury history confers on the athlete. Unfortunately, the research designs of the studies examining previous injury as a predictor of sport injury occurrence do not allow for any conclusions about how previous injury is related to current injury. Coping Resources Of the three major categories of stress-response predictors in the stress–injury model, coping resources have received the least attention from researchers and, not surprisingly, shown the fewest associations with the occurrence of sport injury. Coping-resource variables for B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. Among the psychosocial factors that may contribute to the occurrence of sport injury, one stands out from the pack: life stress. This factor has been studied the most in relation to sport injury and has been most consistently associated with sport injury occurrence. Given the importance of life stress as a predictor of sport injury, professionals who are charged with maintaining athletes’ health are well advised to know their athletes’ life-stress levels. Assessment of athletes’ life stress can be traced back to groundbreaking studies of the relationship between life stress and health conducted at the University of Washington by Thomas Holmes and his colleagues. Holmes and Rahe (1967) interviewed more than 5,000 people about life events they had experienced that seemed to be related to health problems they had incurred. Based on the interview data, the investigators developed the Social Readjustment Rating Scale (SRRS) to measure people’s experience of stressful life events. Using the scale, respondents were asked to indicate which of a list of 43 major life events they had experienced during the previous year. On the assumption that life changes are stressful, each event in the SRRS was assigned a weighted value of “life-change units” (LCUs); higher values were assigned to events deemed more stressful. For instance, the two most heavily weighted events—death of a spouse and divorce—were assigned LCU values of 100 and 73, respectively, whereas being fired from a job was assigned 47 LCUs. Life-change values were also assigned to events generally considered positive, such as marriage (50 LCUs), outstanding personal accomplishment (29 LCUs), vacation (13 LCUs), and Christmas (12 LCUs). Although Holmes (1970) used the SRRS to document a positive association between life stress and injury in collegiate football players, the applicability of the SRRS for athletes was limited because it excluded many events that can produce substantial stress in an athlete’s life. Consequently, Bramwell, Masuda, Wagner, and Holmes (1975) developed a sport-specific version of the SRRS called the Social and Athletic Readjustment Rating Scale (SARRS), which eliminated a few irrelevant life events and added 20 new ones relevant to athletes, such as being dropped from a team (52 LCUs), having trouble with a head coach (35 LCUs), and making a major error in a competition (27 LCUs). Thus the SARRS was better equipped than the SRRS to capture the sorts of stressors typically encountered by athletes. In a prospective study, Bramwell et al. found that collegiate football players who sustained an injury during the competitive season had significantly higher scores on the SARRS than did players who did not sustain an injury. The approach to measuring life stress used in the SRRS and the SARRS fell out of favor due to criticisms about combining positive and negative life events into a single index of life stress and about preassigning point values for each event. For instance, Sarason, Johnson, and Siegel (1978) argued that the processes of adapting to positive and negative events may not be the same and that individuals may differ in their perceptions of the degree of stress associated with a given event. Therefore, in their own Life Experience Survey (LES), Sarason et al. separated positive and negative life events and allowed respondents to provide their own ratings of the level of stress involved in life events experienced in the recent past. In turn, using a version of the LES modified for the sport setting, Passer and Seese (1983) investigated positive and negative life stress as independent predictors of injury among Focus on Application Assessing Life Stress (continued) which significant correlations have been obtained include coping resources (Hanson, McCullagh, & Tonymon, 1992; J.M. Williams et al., 1986), coping skills (Noh, Morris, & Andersen, 2005; T.J. Rogers & Landers, 2005), coping strategies (Ivarsson & Johnson, 2010), and social support (Hardy, Richman, & Rosenfeld, 1991). As one would expect, higher lev- els of coping resources and coping skills were negatively associated with injury frequency (i.e., were associated with the occurrence of fewer injuries). In contrast, coping strategies and social support were positively associated with injury frequency. In other words, greater reported use of self-blame (Ivarsson & Johnson, 2010; Timpka, B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. 31 Focus on Application Assessing Life Stress (continued) 32 collegiate male football players. However, in a study comparing the ability of the SARRS and the LES to predict the occurrence of injury in gymnasts, neither instrument gained a distinct advantage over the other; in fact, scores on neither instrument were associated with the occurrence of injury (J.M. Williams, Tonymon, & Wadsworth, 1986). In a later attempt, Petrie (1992) developed a measure of life stress that borrowed the LES approach of separating positive and negative life events and asking respondents to rate their own level of stress associated with each of a lengthy list of events. Some of the events were drawn from the LES and other existing inventories, but the remainder were derived from lists generated by collegiate athletes—for example, suspension from the team for nonacademic reasons, receipt of an athletic scholarship, continual poor team performance. The resulting instrument, the Life Events Scale for College Athletes (LESCA), contained 21 sport-specific events (as compared with 16 on the SARRS). It outperformed the SARRS in predicting injury among female collegiate gymnasts and has become the standard means of assessing history of stressors among collegiate athletes in research investigations. The LESCA can be used to screen for elevated levels of life stress in both team and individual-athlete settings. Although norms are not available for the instrument, athletes with high scores (e.g., one or two standard deviations above the mean for the team) can be identified for follow-up and possible intervention. When working with individual athletes, LESCA responses can be used to generate face-to-face discussion with athletes about recent sources of stress (e.g., “What kinds of difficulty have you been having with your roommate?”), biopsychosocial responses to stress (e.g., “How have these challenges affected your sleep? Your schoolwork? Your relationships with your teammates?”), coping attempts (e.g., “What have you done to try make things less stressful?”), and, if deemed appropriate, approaches to stress management. Conversations of this sort should, of course, be carried out in private. Although it is possible to use an inventory such as the LESCA and an interview to assess athletes’ stress levels at any time, the logical point for conducting a stress screening is during the preseason so that areas of vulnerability can be addressed preventively before athletes have been exposed to substantive risks on the field of play. Jacobsson, et al., 2014), behavioral disengagement, and acceptance coping strategies (Ivarsson & Johnson)—as well as greater reported number of social support providers (Hardy et al., 1991)—were related to greater frequency of sport injury. Although unexpected, the result for coping strategies could result not from athletes’ use of coping strategies per se but from athletes who were under a great deal of stress tending to adopt more coping strategies in order to deal with that stress but still experiencing more injuries as a result of the stress (and its consequences). The result for social support is more difficult to explain. Regardless, the counterintuitive findings for both coping strategies and social support are more the exception than the rule for coping resources as a whole. This reality is indicated, for example, in the upcom- ing section on interactive relationships between variables, wherein coping resources are shown to moderate relationships between other psychosocial risk factors and sport injury occurrence in ways that make more intuitive sense. Mood States Although not explicitly part of the stress–injury model, mood states have been examined as potential predictors of sport injury occurrence. Studies have consistently found a positive association between indexes of sport injury occurrence and negative emotions, such as anger (Galambos et al., 2005; Lavallee & Flint, 1996; Plante & Booth, 1997; N.J. Thompson & Morris, 1994; Yang et al., 2014), cognitive anxiety (Kolt & Kirkby, 1994), confusion (Galambos et B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. Antecedents of Sport Injury   33 al.), depression (Galambos et al.; Lavallee & Flint), fatigue (Galambos et al.; Kleinert, 2007; Kolt & Kirkby, 1994), and tension (Galambos et al.; Lavallee & Flint). In addition, inverse relationships have been documented between sport injury occurrence and the positive emotion of vigor (Galambos et al.; Lavallee & Flint). The exact nature of the observed relationships between mood states and sport injury occurrence has not been determined, because both positive and negative moods can influence the stress response and can be influenced by personality, history of stressors, and coping resources. Miscellaneous Factors Several additional psychosocial variables have been identified as predictors of the occurrence of sport injury. These variables, which do not fit neatly into the categories of the stress–injury model, include attention-deficit/hyperactivity disorder (ADHD; Tan et al., 2014), hyperactivity (Timpka, Jacobsson et al., 2014), neurocognitive functioning (Swanik, Covassin, Stearne, & Schatz, 2007), perceived motivational climate (Steffen et al., 2009), physical self-perceptions (Janelle, Kaminski, & Murray, 1999), positive states of mind (J.M. Williams et al., 1993), sociability (Kleinert, 2007), and sport-specific tactical skills (Soligard, Grindem, Bahr, & Anderson, 2010). Elevated risk of injury is associated with high levels of perceived mastery climate, perceived sport competence, sociability, and sport-specific tactical skills. Elevated risk is also associated with slow reaction time, slow processing speed, and low levels of perceived physical strength, positive states of mind (i.e., ability to stay focused and relaxed), visual memory, and verbal memory. The importance of these findings will be determined as they are replicated (or not) and interpreted within the stress–injury and multifactorial models. Interactive Relationships As depicted in figures 2.2 and 2.3, the multifactorial and stress–injury models show that the process by which athletes become injured includes a complex series of events involving multiple risk factors. Given this complexity, it is not surprising that many key findings about using psychological and social variables to predict sport injury occurrence involve interactive relationships. In the simplest type of interaction in this particular context, the relationship between a given risk factor (e.g., life stress) and the occurrence of sport injury differs depending on the level of a second risk factor (e.g., social support). For example, Petrie (1992) found a significant positive relationship between negative life stress and sport injury occurrence for athletes with low social support but a nonsignificant relationship for athletes with high social support. In this case, then, social support moderated the relationship between life stress and the occurrence of sport injury. Similarly, coping strategies were found to moderate the relationship between self-efficacy and sport injury; specifically, self-efficacy was positively associated with both emotional calming and risky behavior, the former of which was negatively associated with injury occurrence and the latter of which was positively associated with injury occurrence (Rubio, Pujals, de la Vega, Aguado, & Hernández, 2014). A more complex type of interaction effect—conjunctive moderation—has also been identified as relevant to the prediction of sport injury in a study by R.E. Smith, Smoll, and Ptacek (1990). In the context of sport injury, conjunctive moderation involves two or more moderating variables that, when occurring simultaneously in a particular combination or pattern, maximize the relationship between a given risk factor and the injury outcome of interest. The study by Smith and colleagues demonstrated conjunctive moderation in which the association between negative life stress and time lost due to injury was greatest for athletes who were low in both social support and psychological coping skills. In fact, the literature abounds with examples of interactive relationships in the prediction of sport injury occurrence with B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics. 34 Psychology of Sport Injury psychosocial factors. Studies in which a personal attribute acted as a moderating variable include those of R.E. Smith, Ptacek, and Smoll (1992) and Petrie (1993). Smith and colleagues reported that sensation seeking—a personality variable involving the extent to which a person seeks out and tolerates emotionally arousing situations—moderated the relationship between negative life-event stress and time lost due to injury in a sample of high school athletes. Specifically, the association was significant and positive for athletes who were low in sensation seeking but nonsignificant for athletes who were high in sensation seeking. In Petrie’s study of American football players, two moderating effects were identified: 1. Trait anxiety was positively associated with injury occurrence for starters but unrelated to injury occurrence for nonstarters. 2. Positive life-event stress was directly related to time lost due to injury for players with high trait anxiety but unrelated for players with low trait anxiety. In a study by N.J. Thompson and Morris (1994), the moderating variable was life-event stress, and a personal attribute (attentional vigilance) was the factor whose relation with injury was moderated. Specifically, attentional vigilance was negatively related to injury occurrence in American football players if a major stressor had been experienced in the previous 12 months; the association was positive, however, if a major stressor had not been experienced in the past 12 months. Thus, although personal attributes generally serve as moderators of the relationships between other variables and sport injury, their relationships with injury outcomes can also be moderated by other factors. Coping resources have also been found to moderate relations between life-event stress and sport injury outcomes. In particular, social support has emerged as a frequent moderator. For example, in findings similar to those of Petrie (1992), as just described, Patterson, Smith, Everett, and Ptacek (1998) reported that social support moderated the relationship between life stress and injury. Specifically, high levels of negative life stress were associated with elevated risk for injury among ballet dancers with low social support but were unrelated to injury among ballet dancers with high social support. Complementary results were reported by Hardy et al. (1991), who found that when male athletes had high levels of negative life stress, they experienced fewer injuries when they had high levels of social support than when they had low levels of social support. The findings of Hardy et al. did not apply, however, to female athletes or to other types of life stress (e.g., total life change, positive life stress). In addition, the conjunctive moderating effect involving social support reported by R.E. Smith et al. (1990), discussed earlier, was bolstered by Maddison and Prapavessis (2005). They found that the positive relationship between negative life stress and time lost due to injury in male rugby players was maximized when social support was low and when both avoidance coping and previous injury were high. This finding suggests that negative life stress exerts its greatest adverse effect on athletes’ well-being when a host of other risk factors are present. It is likely that the interactive relationships identified to date among psychosocial predictors of sport injury merely scratch the surface of potential moderating effects. Indeed, given the full spectrum of biopsychosocial variables included in the multifactorial model, numerous possible combinations of factors may confer injury risk on athletes. To uncover such combinations, we need large-scale research studies that measure extensive arrays of prospective contributors to injury repeatedly over time. Mechanisms of Psychosocial Influence on Sport Injury Occurrence Given the general nature of the multifactorial model and the multitude of ways in which athletes can become injured, it is no surprise that the model is silent with respect to the mecha- B.W. Brewer and C.J. Redmond, Psychology of Sport Injury, Champaign, IL: Human Kinetics, 2017). For use only in Psychology of Sport Injury Course 1–Sport Medics.