Dustin R. Grooms

Soccer-specific warm-up and lower extremity injury rates in collegiate male soccer players

CONTEXT A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. OBJECTIVE To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. DESIGN Cohort study. SETTING One American collegiate soccer team followed for 2 seasons. PATIENTS OR OTHER PARTICIPANTS Forty-one male collegiate athletes aged 18-25 years. INTERVENTION(S) The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. MAIN OUTCOME MEASURE(S) Lower extremity injury risk and time lost to lower extremity injury. RESULTS The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). CONCLUSIONS This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer athletes.

Neuroplasticity Following Anterior Cruciate Ligament Injury: A Framework for Visual-Motor Training Approaches in Rehabilitation

SYNOPSIS The neuroplastic effects of anterior cruciate ligament injury have recently become more evident, demonstrating underlying nervous system changes in addition to the expected mechanical alterations associated with injury. Interventions to mitigate these detrimental neuroplastic effects, along with the established biomechanical changes, need to be considered in the rehabilitation process and return-to-play progressions. This commentary establishes a link between dynamic movement mechanics, neurocognition, and visual processing regarding anterior cruciate ligament injury adaptations and injury risk. The proposed framework incorporates evidence from the disciplines of neuroscience, biomechanics, motor control, and psychology to support integrating neurocognitive and visual-motor approaches with traditional neuromuscular interventions during anterior cruciate ligament injury rehabilitation. Physical therapists, athletic trainers, strength coaches, and other health care and performance professionals can capitalize on this integration of sciences to utilize visual-training technologies and techniques to improve on already-established neuromuscular training methods. LEVEL OF EVIDENCE Therapy, level 5.

Brain Activation for Knee Movement Measured Days Before Second Anterior Cruciate Ligament Injury: Neuroimaging in Musculoskeletal Medicine

BACKGROUND Anterior cruciate ligament (ACL) injury has multifactorial causes encompassing mechanical, hormonal, exposure, and anatomical factors. Alterations in the central nervous system also play a role, but their influence after injury, recovery, and recurrent injury remain unknown. Modern neuroimaging techniques can be used to elucidate the underlying functional and structural alterations of the brain that predicate the neuromuscular control adaptations associated with ACL injury. This knowledge will further our understanding of the neural adaptations after ACL injury and rehabilitation and in relation to injury risk. In this paper, we describe the measurement of brain activation during knee extension-flexion after ACL injury and reconstruction and 26 days before a contralateral ACL injury. METHODS Brain functional magnetic resonance imaging data for an ACL-injured participant and a matched control participant were collected and contrasted. RESULTS Relative to the matched control participant, the ACL-injured participant exhibited increased activation of motor-planning, sensory-processing, and visual-motor control areas. A similar activation pattern was present for the contralateral knee that sustained a subsequent injury. CONCLUSIONS Bilateral neuroplasticity after ACL injury may contribute to the risk of second injury, or aspects of neurophysiology may be predisposing factors to primary injury. CLINICAL IMPLICATIONS Sensory-visual-motor function and motor-learning adaptations may provide targets for rehabilitation.

Neuroplasticity Associated With Anterior Cruciate Ligament Reconstruction

STUDY DESIGN: Controlled laboratory study. BACKGROUND: Anterior cruciate ligament (ACL) injury may result in neuroplastic changes due to lost mechanoreceptors of the ACL and compensations in neuromuscular control. These alterations are not completely understood. Assessing brain function after ACL injury and anterior cruciate ligament reconstruction (ACLR) with functional magnetic resonance imaging provides a means to address this gap in knowledge. OBJECTIVE: To compare differences in brain activation during knee flexion/extension in persons who have undergone ACLR and in matched controls. METHODS: Fifteen participants who had undergone left ACLR (38.13 ± 27.16 months postsurgery) and 15 healthy controls matched on age, sex, height, mass, extremity dominance, education level, sport participation, and physical activity level participated. Functional magnetic resonance imaging data were obtained during a unilateral knee motor task consisting of repeated cycles of knee flexion and extension. RESULTS: Participants who had undergone ACLR had increased activation in the contralateral motor cortex, lingual gyrus, and ipsilateral secondary somatosensory area and diminished activation in the ipsilateral motor cortex and cerebellum when compared to healthy matched controls. CONCLUSION: Brain activation for knee flexion/extension motion may be altered following ACLR. The ACLR brain activation profile may indicate a shift toward a visual‐motor strategy as opposed to a sensory‐motor strategy to engage in knee movement. LEVEL OF EVIDENCE: Cohort, level 3.

Clinimetric Analysis of Pressure Biofeedback and Transversus Abdominis Function in Individuals With Stabilization Classification Low Back Pain

STUDY DESIGN Descriptive laboratory study. OBJECTIVE To determine if a proposed clinical test (pressure biofeedback) could detect changes in transversus abdominis (TrA) muscle thickness during an abdominal drawing-in maneuver. BACKGROUND Pressure biofeedback may be used to assess abdominal muscle function and TrA activation during an abdominal drawing-in maneuver but has not been validated. METHODS Forty-nine individuals (18 men, 31 women) with low back pain who met stabilization classification criteria underwent ultrasound imaging to quantify changes in TrA muscle thickness while a pressure transducer was used to measure pelvic and spine position during an abdominal drawing-in maneuver. A paired t test was used to compare differences in TrA activation ratios between groups (able or unable to maintain pressure of 40 ± 5 mmHg). The groups were further dichotomized based on TrA activation ratio (high, greater than 1.5; low, less than 1.5). Sensitivity, specificity, and likelihood ratios were calculated. RESULTS There was not a significant difference (P = .57) in TrA activation ratios (able to maintain pressure, 1.59 ± 0.28; unable to maintain pressure, 1.54 ± 0.24) between groups. The pressure biofeedback test had low sensitivity of 0.22 (95% confidence interval [CI]: 0.10, 0.42) but moderate specificity of 0.77 (95% CI: 0.58, 0.89), a positive likelihood ratio of 0.94 (95% CI: 0.33, 2.68), and a negative likelihood ratio of 1.02 (95% CI: 0.75, 1.38). CONCLUSION Successful completion on pressure biofeedback does not indicate high TrA activation. Unsuccessful completion on pressure biofeedback may be more indicative of low TrA activation, but the correlation and likelihood coefficients indicate that the pressure test is likely of minimal value to detect TrA activation. This study was registered with ClinicalTrials.gov (NCT01015846).J Orthop Sports Phys Ther 2013;43(3):184-193. Epub 16 November 2012. doi:10.2519/jospt.2013.4397.

Epidemiology of Football Injuries in the National Collegiate Athletic Association, 2004-2005 to 2008-2009

Background: Research has found that injury rates in football are higher in competition than during practice. However, there is little research on the association between injury rates and type of football practices and how these specific rates compare with those in competitions. Purpose: This study utilized data from the National Collegiate Athletic Association Injury Surveillance System (NCAA ISS) to describe men’s collegiate football practice injuries (academic years 2004-2005 to 2008-2009) in 4 event types: competitions, scrimmages, regular practices, and walkthroughs. Study Design: Descriptive epidemiological study. Methods: Football data during the 2004-2005 to 2008-2009 academic years were analyzed. Annually, an average of 60 men’s football programs provided data (9.7% of all universities sponsoring football). Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (RRs), 95% CIs, and injury proportions were reported. Results: The NCAA ISS captured 18,075 football injuries. Most injuries were reported in regular practices (55.9%), followed by competitions (38.8%), scrimmages (4.4%), and walkthroughs (0.8%). Most AEs were reported in regular practices (77.6%), followed by walkthroughs (11.5%), competitions (8.6%), and scrimmages (2.3%). The highest injury rate was found in competitions (36.94/1000 AEs), followed by scrimmages (15.7/1000 AEs), regular practices (5.9/1000 AEs), and walkthroughs (0.6/1000 AEs). These rates were all significantly different from one another. Distributions of injury location and diagnoses were similar across all 4 event types, with most injuries occurring at the lower extremity (56.0%) and consisting of sprains and strains (50.6%). However, injury mechanisms varied. The proportion of injuries due to player contact was greatest in scrimmages (66.8%), followed by regular practices (48.5%) and walkthroughs (34.9%); in contrast, the proportion of injuries due to noncontact/overuse was greatest in walkthroughs (41.7%), followed by regular practices (35.6%) and scrimmages (21.9%). Conclusion: Injury rates were the highest in competitions but then varied by the type of practice event, with higher practice injury rates reported in scrimmage. In addition, greater proportions of injuries were reported in regular practices, and greater proportions of exposures were reported in regular practices and walkthroughs. Efforts to minimize injury in all types of practice events are essential to mitigating injury incidence related to both contact and noncontact.

Central Nervous System Adaptation After Ligamentous Injury: a Summary of Theories, Evidence, and Clinical Interpretation

The array of dysfunction occurring after ligamentous injury is tied to long-term clinical impairments in functional performance, joint stability, and health-related quality of life. To appropriately treat individuals, and in an attempt to avoid sequelae such as post-traumatic osteoarthritis, investigators have sought to better establish the etiology of the persistent dysfunction present in patients who have sustained joint ligament injuries to the lower extremities. Recent evidence has suggested that changes within the brain and central nervous system may underlie these functional deficits, with support arising from direct neurophysiologic measures of somatosensory dysfunction, motor system excitability, and plasticity of neural networks. As research begins to utilize these findings to develop targeted interventions to enhance patient outcomes, it is crucial for sports medicine professionals to understand the current body of evidence related to neuroplasticity after ligamentous injury. Therefore, this review provides (1) a comprehensive and succinct overview of the neurophysiologic techniques utilized in assessing central nervous system function after ligamentous injury, (2) a summary of the findings of previous investigations utilizing these techniques, and (3) direction for further application of these techniques in the prevention and rehabilitation of joint injury.

Neuroscience Application to Noncontact Anterior Cruciate Ligament Injury Prevention

Context: Many factors, including anatomy, neuromuscular control, hormonal regulation, and genetics, are known to contribute to the noncontact anterior cruciate ligament (ACL) injury risk profile. The neurocognitive and neurophysiological influences on the noncontact ACL injury mechanism have received less attention despite their implications to maintain neuromuscular control. Sex-specific differences in neurocognition may also play a critical role in the elevated female ACL injury risk. This report serves to frame existing literature in a new light to consider neurocognition and its implications for movement control, visual-motor function, and injury susceptibility. Evidence Acquisition: Sources were obtained from PubMed, MEDLINE, Web of Science, and LISTA (EBSCO) databases from 1990 onward and ranged from diverse fields including psychological and neuroscience reviews to injury epidemiology and biomechanical reports. Study Design: Clinical review. Level of Evidence: Level 5. Results: Neurological factors may contribute to the multifactorial ACL injury risk paradigm and the increased female injury susceptibility. Conclusion: When developing ACL injury prevention programs, considering neurocognition and its role in movement, neuromuscular control, and injury risk may help improve intervention effectiveness.

Eccentric Exercise to Enhance Neuromuscular Control

Context: Neuromuscular alterations are a major causal factor of primary and secondary injuries. Though injury prevention programs have experienced some success, rates of injuries have not declined, and after injury, individuals often return to activity with functionality below clinical recommendations. Considering alternative therapies to the conventional concentric exercise approach, such as one that can target neuromuscular injury risk and postinjury alterations, may provide for more effective injury prevention and rehabilitation protocols. Evidence Acquisition: Peer-reviewed sources available on the Web of Science and MEDLINE databases from 2000 through 2016 were gathered using searches associated with the keywords eccentric exercise, injury prevention, and neuromuscular control. Hypothesis: Eccentric exercise will reduce injury risk by targeting specific neural and morphologic alterations that precipitate neuromuscular dysfunction. Study Design: Clinical review. Level of Evidence: Level 4. Results: Neuromuscular control is influenced by alterations in muscle morphology and neural activity. Eccentric exercise beneficially modifies several underlying factors of muscle morphology (fiber typing, cross-sectional area, working range, and pennation angle), and emerging evidence indicates that eccentric exercise is also beneficial to peripheral and central neural activity (alpha motorneuron recruitment/firing, sarcolemma activity, corticospinal excitability, and brain activation). Conclusion: There is mounting evidence that eccentric exercise is not only a therapeutic intervention influencing muscle morphology but also targets unique alterations in neuromuscular control, influencing injury risk.

Ball-Contact Injuries in 11 National Collegiate Athletic Association Sports: The Injury Surveillance Program, 2009–2010 Through 2014–2015

CONTEXT   Surveillance data regarding injuries caused by ball contact in collegiate athletes have not been well examined and are mostly limited to discussions of concussions and catastrophic injuries. OBJECTIVE   To describe the epidemiology of ball-contact injuries in 11 National Collegiate Athletic Association (NCAA) sports during the 2009-2010 through 2014-2015 academic years. DESIGN   Descriptive epidemiology study. SETTING   Convenience sample of NCAA programs in 11 sports (mens football, womens field hockey, womens volleyball, mens baseball, womens softball, mens and womens basketball, mens and womens lacrosse, and mens and womens soccer) during the 2009-2010 through 2014-2015 academic years. PATIENTS OR OTHER PARTICIPANTS   Collegiate student-athletes participating in 11 sports. MAIN OUTCOME MEASURE(S)   Ball-contact-injury rates, proportions, rate ratios, and proportion ratios with 95% confidence intervals were based on data from the NCAA Injury Surveillance Program during the 2009-2010 through 2014-2015 academic years. RESULTS   During the 2009-2010 through 2014-2015 academic years, 1123 ball-contact injuries were reported, for an overall rate of 3.54/10 000 AEs. The sports with the highest rates were womens softball (8.82/10 000 AEs), womens field hockey (7.71/10 000 AEs), and mens baseball (7.20/10 000 AEs). Most ball-contact injuries were to the hand/wrist (32.7%) and head/face (27.0%) and were diagnosed as contusions (30.5%), sprains (23.1%), and concussions (16.1%). Among sex-comparable sports (ie, baseball/softball, basketball, and soccer), women had a larger proportion of ball-contact injuries diagnosed as concussions than men (injury proportion ratio = 2.33; 95% confidence interval = 1.63, 3.33). More than half (51.0%) of ball-contact injuries were non-time loss (ie, participation-restriction time <24 hours), and 6.6% were severe (ie, participation-restriction time ≥21 days). The most common severe ball-contact injuries were concussions (n = 18) and finger fractures (n = 10). CONCLUSION   Ball-contact-injury rates were the highest in womens softball, womens field hockey, and mens baseball. Although more than half were non-time-loss injuries, severe injuries such as concussions and fractures were reported.