Diagnosed concussion is associated with increased risk for upper extremity injury in community rugby players in males only.

Objectives: To cross-sectionally determine 1) the association between lifetime diagnosed concussion and upper extremity musculoskeletal injury (UE-MSI) amongst a novel cohort of community rugby union players and 2) the sex specific risk of UE-MSI given concussion history among these rugby players.

Methods: 1,037 (31.0% female, 31.

Cognitive Training Improves Joint Stiffness Regulation and Function in ACLR Patients Compared to Healthy Controls.

As cognitive function is critical for muscle coordination, cognitive training may also improve neuromuscular control strategy and knee function following an anterior cruciate ligament reconstruction (ACLR). The purpose of this case-control study was to examine the effects of cognitive training on joint stiffness regulation in response to negative visual stimuli and knee function following ACLR. A total of 20 ACLR patients and 20 healthy controls received four weeks of online cognitive training.

Contact or Collision Sport History, Repetitive Neurotrauma, and Patient-Reported Outcomes in Early to Midadulthood.

Context: Data on the early to midlife effects of repetitive neurotrauma on patient-reported outcomes have been delimited to homogeneous samples of male athletes without comparison groups or accounting for modifying factors such as physical activity.

Objective: To determine the effect of contact or collision sport participation and repetitive neurotrauma on patient-reported outcomes among early to middle-aged adults.

Design: Cross-sectional study.

Effects of contact/collision sport history on gait in early- to mid-adulthood.

Background: To determine the effect of contact/collision sport participation on measures of single-task (ST) and dual-task (DT) gait among early- to middle-aged adults.

Methods: The study recruited 113 adults (34.88 ± 11.

Concussion is not associated with elevated rates of lower-extremity musculoskeletal injuries in National Football League Players.

Objective: Emerging evidence has identified an ~2x elevated risk of musculoskeletal (MSK) injury in the year following a concussion. Most of these studies have examined a single college/university athletic department and may lack generalizability to professional sports. Therefore, the purpose of this study was to assess the odds of post-concussion MSK injury utilizing publicly available National Football League (NFL) injury reports.

Concussion Knowledge and Attitudes in Reserve Officers' Training Corps Cadets.

Introduction: Military members' knowledge of concussion signs and symptoms may be critical to appropriate concussion identification and health-seeking behavior, particularly for those in leadership roles. The current study aimed to characterize concussion knowledge and attitudes among future military officers undergoing U.S.

Identifying Range-of-Motion Deficits and Talocrural Joint Laxity After an Acute Lateral Ankle Sprain.

Context: Approximately 72% of patients with an ankle sprain report residual symptoms 6 to 18 months later. Although 44% of patients return to activity in less than 24 hours after experiencing a sprain, residual symptoms should be evaluated in the long term to determine if deficits exist. These residual symptoms may be due to the quality of ligament tissue and motion after injury.

Age of First Exposure to Collision Sports Does Not Affect Patient Reported Outcomes in Women and Men Community Rugby Players.

Purpose: This study aimed to determine the relationship between age of first exposure (AFE) to repetitive head impacts through contact/collision sports and patient-reported outcomes in community rugby players.

Methods: We recruited community rugby players older than 18 yr with at least 1 yr of contact rugby participation to complete an online survey. Participants completed the Brief Symptom Inventory-18 (BSI-18), Short-Form Health Survey 12 (SF-12), and Satisfaction with Life Scale (SWLS) via Qualtrics.

Diagnosed concussion is associated with increased risk for lower extremity injury in community rugby players.

Objectives: To determine (1) the association between lifetime diagnosed concussion and lower extremity musculoskeletal injury (LE-MSI) among community rugby union players and (2) the sex specific risk of LE-MSI given concussion history among males and females.

Design: Retrospective survey.

Methods: 1037 (59.

Concussion history is associated with increased lower-extremity injury incidence in Reserve Officers' Training Corps cadets.

Introduction: Concussions have been associated with an increased risk of lower-extremity musculoskeletal injury (LE-MSI) in athletes and US Army soldiers, creating an added economic, physical and social burden. Yet, there is a paucity of evidence on this relationship among Reserve Officers' Training Corps (ROTC) cadets, a group which engages in activities with high-injury risk and will subsequently commission as active duty officers. This study aimed to examine the association between concussions and LE-MSI in ROTC cadets.

No Clinical Predictors of Postconcussion Musculoskeletal Injury in College Athletes.

Purpose: This study aimed to identify clinical predictors of postconcussion subsequent musculoskeletal (MSK) injuries.

Methods: We recruited 66 National Collegiate Athletic Association intercollegiate student-athletes with a diagnosed concussion as well as 36 National Collegiate Athletic Association student-athletes without a concussion. All participants completed a multifaceted concussion baseline consisting of 1) 22-item 0-6 self-reported symptom checklist with outcomes including both the number of symptoms endorsed (0-22) and 2) total symptom score (0-132), 3) Standard Assessment of Concussion, 4) Balance Error Scoring System, 5) Immediate Post-Concussion Assessment and Cognitive Testing, 6) clinical reaction time, and 7) the King-Devick as well as demographic and injury characteristics.

Negative Emotion and Joint-Stiffness Regulation Strategies After Anterior Cruciate Ligament Injury.

Context: Fear of reinjury after an anterior cruciate ligament (ACL) reconstruction (ACLR) may be associated with persistent deficits in knee function and subsequent injury. However, the effects of negative emotion on neuromuscular-control strategies after an ACL injury have remained unclear.

Objective: To identify how negative emotional stimuli affect neural processing in the brain and muscle coordination in patients after anterior cruciate ligament reconstruction compared with healthy control participants.

Reactive knee stiffening strategies between various conditioning histories.

Optimizing joint stiffness through appropriate muscular activation is crucial for maintaining stability and preventing injury. Conditioning techniques may affect joint stability by increasing joint stiffness and altering neuromuscular control; however no studies have assessed this in a controlled setting. Fifteen endurance athletes, 12 power athletes, and 15 control subjects sat on a stiffness device that generated a rapid knee flexion perturbation and were instructed to react to the perturbation.

Neuroplastic changes in anterior cruciate ligament reconstruction patients from neuromechanical decoupling.

The purpose of this study was to identify how the brain simultaneously perceives proprioceptive input during joint loading in anterior cruciate ligament reconstruction (ACLR) patients, when compared to healthy controls. Seventeen ACLR patients (ACLR) and seventeen controls (CONT) were tested for the somatosensory cortical activation using electroencephalography (EEG) while measuring knee laxity using a knee arthrometer. The relationship between cortical activation and joint laxity within group was also examined.

Ankle Strength Deficits in a Cohort of College Athletes With Chronic Ankle Instability.

Context: Lateral ankle sprains commonly occur in an athletic population and can lead to chronic ankle instability.

Objective: To compare ankle strength measurements in athletes who have mechanical laxity and report functional instability after a history of unilateral ankle sprains.

Design: Retrospective cohort.

The relationship between the sensory responses to ankle-joint loading and corticomotor excitability.

Purpose: Maintaining joint stability is dependent on the ability of the nervous system to sense and react to potentially injurious loads. In attempts to understand the neurophysiologic mechanisms underlying joint stability, this afferent and efferent activity has been quantified separately at the cortical, segmental and peripheral levels using various electrophysiologic techniques in vivo. However, no studies have attempted to quantify sensory and motor activation at multiple levels of the nervous system in a single subset, to understand potential adaptations for optimizing joint stability.

Evaluating Postural Control and Ankle Laxity Between Taping and High-Top Cleats in High School Football Players.

Context: Lateral ankle sprains are the most common injuries in high school sports. While ankle taping is a preferred method of external prophylactic support, its restrictive properties decline during exercise. The Under Armour Highlight cleat is marketed on the premise that it provides added support without the need for additional ankle taping.

The Relationship Between Joint Stiffness and Muscle Activity in Unstable Ankles and Copers.

Context: Rolling sensations at the ankle are common after injury and represent failure in neural regulation of joint stiffness. However, deficits after ankle injury are variable and strategies for optimizing stiffness may differ across patients.

Objective: To determine if ankle stiffness and muscle activation differ between patients with varying history of ankle injury.

The Effect of Shoulder Plyometric Training on Amortization Time and Upper-Extremity Kinematics.

Context: Plyometric training is credited with providing benefits in performance and dynamic restraint. However, limited prospective data exist quantifying kinematic adaptations such as amortization time, glenohumeral rotation, and scapulothoracic position, which may underlie the efficacy of plyometric training for upper-extremity rehabilitation or performance enhancement.

Objective: To measure upper-extremity kinematics and plyometric phase times before and after an 8-wk upper-extremity strength- and plyometric-training program.

A sex comparison of reactive knee stiffness regulation strategies under cognitive loads.

Background: Sex differences may exist in cognitive faculties and neuromuscular strategies for maintaining joint stability. The purpose of this study was to assess whether preparatory and reactive knee stiffening strategies are affected differently in males and females exposed to sex-biased cognitive loads.

Methods: 20 male and 20 female volunteers were tested for knee joint stiffness and quadriceps and hamstring muscle activation patterns throughout a rapid eccentric knee extension perturbation.

Assessing performance, stability, and cleat comfort/support in collegiate club soccer players using prophylactic ankle taping and bracing.

Soccer athletes at all levels of play are keenly aware of their equipment needs including cleat wear, and want to be protected from injury but without impeding on-field performance. Ankle injury is a common disorder that is prevalent in the sport of soccer and recent improvements in ankle prophylaxis interventions have proven effective. The aim of this study was to determine if the use of elastic taping or a neoprene sleeve alters performance, stability, and cleat comfort/support in soccer players compared to wearing a soccer cleat without any external support.

Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding.

Context: Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding.

Objectives: To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding.

Design: Cross-sectional study.

Brains and Sprains: The Brain's Role in Noncontact Anterior Cruciate Ligament Injuries.

Small mental errors in judgment or coordination at illtimed phases of movement planning could lead to the rapid, premature onset of large joint forces during sports. If these loads are not fully anticipated, then preprogrammed muscle contractions may be insufficient for stiffness levels to provide dynamic restraint, regardless of sex. This sequence of events would limit the capacity of muscles to act in a load-compensating manner, thereby exposing capsuloligamentous structures to failure.

Adaptations of the Shoulder to Overhead Throwing in Youth Athletes.

Context: The high number of repetitions and high forces associated with overhead throwing lead to anatomical adaptations, such as humeral retrotorsion and posterior-capsule thickness, in elite and professional baseball athletes. However, little is known about the origin and progression of these changes that may account for the increasing trend of chronic shoulder injuries in youth baseball and precipitate subsequent pathologic conditions throughout a young athlete's lifetime.

Objective: To investigate the relationship of age and upper extremity dominance on humeral retrotorsion, posterior-capsule thickness, and glenohumeral range of motion.

The use of shear thickening nanocomposites in impact resistant materials.

The work presented here demonstrates using a novel, field-responsive nanocomposite based on shear thickening fluids (STFs) as responsive protective materials with superior damping and energy adsorption properties. Peak forces and accelerations measured using an instrumented Instron drop tower demonstrate that STF nanocomposite prototypes and impact foam taken from a commercial football helmet have similar performance for low kinetic energy impacts. However, tests with STF nanocomposite samples exhibit significantly reduced peak acceleration and peak force for impacts above 15 J.