Biomechanical and neuromuscular factors receive considerable attention in discussing Return to Sport Following ACL Reconstruction. Psychological considerations, however, despite playing an integral role in returning an injured athlete to their respective sport, often go under-appreciated. The purpose of this piece is therefore to briefly review the literature related to the psychology of ACL injury and surgery, and to discuss how the rehabilitation professional can enhance their understanding of the psychological domain to foster improved outcomes in working with this population of athletes.
Once a patient has successfully met all return to sport criteria, the next step naturally involves returning to sport. While some patients seamlessly return to their pre-injury status, others struggle with simply returning to their sport. One needs to look no further than the case of Derrek Rose, star of the Chicago Bulls and MVP of the NBA in 2011, to appreciate the challenge in returning an athlete to sport. After sustaining an ACL tear and subsequently undergoing surgery, he was sidelined for approximately 16 months. In contrast to this situation, Adrian Peterson, defied all odds by returning to the starting lineup nine months following his surgery. While both of these athletes undoubtedly worked hard throughout the rehabilitation process, other factors may account for the difference in time in returning to their respective sports.
According to a recent systematic review conducted by Te Wierike et al.,fear of re-injury was the leading cause of failure for athletes with an ACL injury and subsequent reconstruction to return to sport. Along these same lines, Ardern et al conducted a systematic review with meta-analysis of return to sport outcomes of nearly 5,000 patients following ACL reconstruction. This study demonstrated that only 63% of patients returned to their pre-injury level of competition. Again, fear of re-injury was the most common reason cited for a reduction in or cessation of sports participation. In agreement with the aforementioned studies, a case-control investigation conducted by Ardern et al, found that significant independent contributions for returning to pre-injury level one year post-operatively were explained by psychological factors. These included subjective readiness to return to sport, fear of re-injury, and sport locus of control. This study also determined that factors influencing athletes’ prospective judgment of their ability to return to sport predicted returning to their pre-injury level.
A cross-sectional study performed by Chmielewski et al found that fear of movement/re-injury levels appear to decrease during ACL reconstruction rehabilitation and are associated with function in the timeframe when patients return to sports. Therefore, being psychologically prepared for return to sport is critical when considering each patient’s readiness. In addition to this study, Ardern et al conducted a systematic review looking into the psychological factors involved in returning athletes to sport following injury. This review of 11 studies and nearly 1,000 patients determined that the three central elements of return to sport were from the self-determination theory, which includes: autonomy (urge to be causal agents of one’s own life and act in harmony with one’s integrated self); competence (seek to control the outcome and experience mastery); and relatedness (universal want to interact). This same study found that positive psychological responses including motivation, confidence, and low fear were associated with an increased likelihood of returning to one’s pre-injury level status in a more timely manner. Naturally, return to sport elicits a certain level of fear and anxiety for all athletes, though individuals who possess these internal motivating factors enjoy improved post-operative outcomes.
Considering this information, the question becomes how can clinicians identify those patients who may be at a psychological disadvantage during the rehabilitation process? According to Chmielewski et al, a patient’s psychosocial profile can be positively altered in the short-term following ACL reconstruction. This means that clinicians must take the time to accurately identify those individuals who may be at risk of poor outcomes due to fear of re-injury or fear avoidance beliefs. This can be accomplished through the use of the Tampa Scale for Kinesiophobia (TSK-11), the Fear Avoidance Beliefs Questionnaire (FABQ), and/or the more specific Injury-Psychological Readiness to Return to Sport (I-PRRS) Scale. Recently, Lentz et al determined that individuals with a lower TSK-11 score were more likely to return to their pre-injury level of competition following ACL reconstruction. While the other two outcome measures have greater scientific backing at this point, the newer I-PRRS has just begun the process of validation. In 2009, Glazer et al published a validation study to support the scale’s utility. The I-PRRS scores were found to be lowest after injury, increased before release to practice, increased again before returning to competition, and had no change after competition. This demonstrates the general progression of psychological preparedness and thus the validity needed to make this a useful measure for clinicians when determining an athlete’s readiness for return to sport.
These outcome measures may give us the ability to more accurately identify those individuals at risk for suboptimal outcomes. Regardless of baseline mentality, however, recovery from injury demands a psychologically driven process. This Biopsychosocial Model is composed of 4 distinct processes (Wiese-Bjornstal et al). The first of which is Cognition, which includes the thoughts an athlete experiences following injury. Within this category lies the athlete’s internal Health Locus of Control (HLOC), which is the capacity that the athlete believes they control the events in their life. Nyland et al found that athletes with a high internal HLOC were more satisfied with their knee function in addition to their ability to perform ADLs, and participate in sport following ACL reconstruction. The second category is the patient’s Affect. This concerns the way an athlete feels following injury. As most clinicians appreciate, injuries can lead to substantial psychological changes, sometimes verging on depression. Studies have shown, however, that there are positive psychological changes as rehabilitation progresses, with fewer negative emotions and more positive feelings about returning to sport. In light of this information, the fear of re-injury has significant impact on the rehabilitation process and can lead to sub-optimal outcomes, potentially preventing return to athletics. The Behavior of the patient throughout the rehabilitation process can also be an influential factor. The two most important behaviors for patients following ACL reconstruction are avoidance coping and rehabilitation adherence. Avoidance coping can be broken into behavioral avoidance coping (the conscience decision to remove oneself from a threatening environment) and cognitive avoidance coping (the responses aimed at denying or minimizing the seriousness of a crisis). While these avoidance techniques may be beneficial in the recovery process, poor adherence to physical therapy has been shown to be detrimental to recovery. Brewer et al found that patients who had a higher score for adherence experienced fewer knee symptoms compared to those who demonstrated poor adherence to their physical therapy program. The final cornerstone to the Biopsychosocial Model is the Outcome. A deficiency or inadequacy in any combination of the three previous categories can negatively impact a patient’s post-rehabilitation outcome. As was shown by Lentz et al, return to pre-injury level of sports participation is multi-factorial and those who did return had less knee joint effusion, fewer episodes of knee instability, lower knee pain intensity, higher quadriceps peak torque-body weight ratio, higher IKDC scores, and lower TSK-11 scores.
Finally, considering this model and the personality traits associated with successful outcomes, what can clinicians do to foster improved outcomes following ACL injury and/or surgery? Regardless of whether or not reconstruction is performed following ACL injury, several psychological interventions have been proven beneficial for athletes during their rehabilitation (relaxation, imagery, training of self-efficacy, and modeling). Cupal and Brewer conducted a randomized controlled trial comparing the outcomes of patients who received relaxation and guided imagery training in conjunction with a typical post-operative protocol to those who only completed the protocol. In the end, the experimental group had greater knee strength, less re-injury anxiety, and less pain compared with the placebo and control group. In order to improve patients’ self-efficacy through modeling, Maddison et al gave their intervention group two separate videos to aid the ability of their athletes’ to cope throughout the rehab process. This study showed that patients, who watched the videos, perceived less pain and had more self-efficacy than those who did not receive this intervention. It should also be noted that athletes often benefit from discussing their injury (i.e. how it happened and how it has affected their life). Additionally, Mankad et al found that athletes who wrote about their injury in the form of written disclosure statements had a reduction of stress and total mood disturbances.
Returning an athlete to sport requires the use of a specific criterion-based protocol, functional sport-specific testing, and proper psychological management of stressors and emotions associated with the injury. Successful rehabilitation of an athlete back to their sport involves careful consideration of all of these aspects. Considerable attention has been paid to the pathoanatomical, biomechanical, and neuromuscular aspects though sports medicine professionals often neglect the psychological impact. As the recognition and implementation of psychologically-driven interventions increases, positive outcomes with regards to return to sport should follow.