An emerging area of research has identified that an increased risk of musculoskeletal injury may exist upon returning to sports after a sport-related concussion. The mechanisms underlying this recently discovered phenomenon, however, remain unknown. One theorized reason for this increased injury risk includes residual neuromuscular control deficits that remain impaired despite clinical recovery. Thus, the objectives of this review were: (1) to summarize the literature examining the relationship between concussion and risk of subsequent injury and (2) to summarize the literature for one mechanism with a theorized association with this increased injury risk, i.e., neuromuscular control deficits observed during gait after concussion under dual-task conditions. Two separate reviews were conducted consistent with both specified objectives. Studies published before 9 December, 2016 were identified using PubMed, Web of Science, and Academic Search Premier (EBSCOhost). Inclusion for the objective 1 search included dependent variables of quantitative measurements of musculoskeletal injury after concussion. Inclusion criteria for the objective 2 search included dependent variables pertaining to gait, dynamic balance control, and dual-task function. A total of 32 studies were included in the two reviews (objective 1 n = 10, objective 2 n = 22). According to a variety of study designs, athletes appear to have an increased risk of sustaining a musculoskeletal injury following a concussion. Furthermore, dual-task neuromuscular control deficits may continue to exist after patients report resolution of concussion symptoms, or perform normally on other clinical concussion tests. Therefore, musculoskeletal injury risk appears to increase following a concussion and persistent motor system and attentional deficits also seem to exist after a concussion. While not yet experimentally tested, these motor system and attentional deficits may contribute to the risk of sustaining a musculoskeletal injury upon returning to full athletic participation.

Previous literature has identified dynamic postural control deficits along with increased motor evoked potential latency and decreased amplitude after concussion, suggesting that the brain may be unable to effectively coordinate movement. Our findings underscore the need to explore functional movement and dynamic postural control assessments in postconcussion injury assessment protocols.

Context: Understanding concussion-assessmment and -management practices that athletic trainers (ATs) currently use will allow clinicians to identify potential strategies for enhancing the quality of care provided to patients. Objective: To assess current clinical concussion diagnostic and return-to-participation practices among ATs. Design: Cross-sectional study. Setting: Web-based survey. Patients or Other Participants: A link to the survey was sent randomly to a convenience sample of 3222 members of the National Athletic Trainers' Association. A total of 1053 (32.7%) certified ATs (experience as an AT = 11.2 ± 9.1 years) responded to the survey. Intervention(s): Prospective participants received electronic correspondence informing them of the purpose of the study and providing a link to the Web-based survey instrument. A reminder e-mail was sent approximately 6 weeks later, and the survey remained online for a total of 8 weeks. Main Outcome Measure(s): We collected information on the annual number of concussions assessed and tools employed to diagnose, manage, and safely return an athlete to participation. Descriptive statistics were computed for each variable. Results: Participants reported observing 10.7 ± 11.0 concussions per year. Clinical examination (n = 743, 70.6%) was the most commonly reported means for evaluating and diagnosing concussion. Less than half of our respondents employed the Standardized Assessment of Concussion (n = 467, 44.3%), any variation of the Romberg test (n = 461, 43.8%), and computerized neuropsychological testing (n = 459, 43.6%). Clinical examination (n = 773, 73.4%), return-to-participation guidelines (n = 713, 67.7%), physician recommendation (n = 660, 62.7%), or player self-report (n = 447, 42.5%) contributed to the return-to-participation decisions of ATs. Only 20.8% (n = 219) of ATs reported using all 3 recommended domains of the concussion battery. Conclusions: Our study demonstrated a growth in the number of ATs incorporating objective clinical measures of concussion as a part of their concussion management. Conversely, fewer ATs reported using a standard clinical examination in their concussion assessment. These findings suggest ATs must continue to increase their use of both objective concussion assessment tools and the standard clinical examination.

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Among high school athletes, concussion increased the odds of sustaining subsequent time-loss lower extremity injuries but not non-time-loss injuries. By definition, time-loss injuries may be considered more severe than non-time-loss injuries. The exact mechanism underlying the increased risk of lower extremity injury after concussion remains elusive and should be further explored in future research.

Head impact biomechanics studies have provided valuable insights into understanding collision sports and for informing evidence-based rule and policy changes. These have included changing the football kickoff, ice hockey body checking ages, and head-to-head hits in both sports. Given soccer's global popularity, and the growing public concern for the potential long-term neurological implications of collision and contact sports, studying soccer has the potential to impact many athletes and the sports medicine professionals caring for them.

Injury rates in NCAA men's and women's tennis were similar overall. Practice injury rates in men's and women's tennis have declined, although competition rates have not changed. These findings may help inform injury prevention programmes in the future.

Prior studies suggest that concussion may lead to an increased risk of a subsequent time-loss sport-related injury, but the mechanisms responsible are unknown. We measured the symptom and dual-task gait outcomes for athletes initially post-concussion and after clinical recovery. Participants then self-reported any additional injuries incurred in the year after their concussion. Forty-two athletes (52% female, mean age = 16.8 ± 3.2 years) completed the study. They underwent a dual-task gait evaluation and symptom inventory within 21 days post-concussion, and again after they were deemed clinically recovered. Approximately one year later, participants documented if they had sustained any subsequent sport-related injuries. The repeated measures analysis of variance (ANOVA) was used to evaluate changes in dual-task gait and symptoms across time and between groups. A significant group*time interaction (p = 0.02) indicated that the group that went on to sustain a subsequent time-loss injury after returning to sports (n = 15) demonstrated significant average walking speed dual-task cost worsening across time (-17.9 ± 9.1% vs. -25.1 ± 12.5%; p = 0.007). In contrast, the group that did not sustain an additional injury walked with consistent dual-task cost values across time (-25.2 ± 9.2% vs. -24.6 ± 8.4%; p = 0.76). Symptoms improved for all participants (main effect of time, p < 0.001; Post-Concussion Symptom Scale [PCSS] = 25.0 ± 16.9 vs. 2.8 ± 7.5; p < 0.001), but did not differ between groups (p = 0.77). Significant dual-task gait cost worsening throughout concussion recovery was associated with time-loss injuries during sports in the year after a concussion. These findings indicate that worsening ability to execute a concurrent gait and cognitive task may relate to the risk of incurring an injury during sports after clinical concussion recovery.