American Football Players in Preseason Training at Risk of Acute Kidney Injury Without Signs of Rhabdomyolysis.

OBJECTIVE: This study was designed to identify changes in blood biomarkers that would indicate excessive muscle breakdown during the initial 10 days of preseason training in collegiate American football players and subsequently increase their risk of acute kidney injury (AKI). DESIGN: Prospective cohort study. SETTING: Preseason, heat acclimatization period. PARTICIPANTS: Twenty-five Division I American football players. INTERVENTION: Clinical biomarkers for muscle damage were measured during a preseason training camp. Samples were obtained before camp and approximately 5 and 10 days into camp after completion of heat acclimatization training. MAIN OUTCOMES: Creatine kinase, myoglobin, lactate dehydrogenase, and creatinine were measured. Glomerular filtration rate (GFR) was calculated. Urine was collected at each blood draw to qualitatively identify hematuria and red blood cells. RESULTS: A high percentage of athletes had an asymptomatic reduction in kidney function over the 10-day period. Ten of 23 athletes did have a significant, 31.6%, mean reduction in GFR, placing each at risk of AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification. The plasma myoglobin for the at risk of AKI group had a mean value 8× above their baseline mean on day 5 and statistically significant mean 13× higher on day 10 than baseline. The not at risk of AKI group did not have significant differences between days 0, 5, and 10. CONCLUSIONS: A relatively high percentage of athletes had an asymptomatic reduction in kidney function during the intense preseason training period. 43.4% of athletes in this study had a significant 31.6% mean reduction in GFR over the 10 days. According to RIFLE classification, this placed each athlete "at risk" of AKI.

Neurocognitive and Reactive Return to Play Testing Protocol in Overhead Athletes Following Upper Extremity Injury.

The incidence of upper extremity (UE) injuries in sport, particularly with the shoulder and elbow in baseball/softball players, appears to be increasing yearly, especially in younger age athletes. Improving the objective criteria and testing methods used to determine return to play (RTP) readiness following non-operative or post-operative management of UE injuries is one aspect of the rehabilitation process that may significantly help in reducing reinjury rates. Currently, the majority of clinicians are still using post operative time frame and/or strength/range of motion as their main criteria for clearance to RTP following UE injury. This demonstrates an inadequate reflection of the actual unpredictable, dynamic environment athletes are returning to participate in. In our clinical experiences, objective testing to allow for clearance to sport participation should incorporate neurocognitive and reactive testing to promote improvements in the athlete's ability to dual task and focus/concentrate on the multi-dimensional tasks at hand. We know that neuroplastic changes occur following UE injury resulting in decreased proprioception and increased motor activation with simple UE tasks. Currently the research on UE return to play testing is limited. The purpose of this clinical commentary was to describe the utilization and provide reference values for a series of reactive neurocognitive UE tests, to assist with RTP, in high school and collegiate overhead athletes (baseball and softball) utilizing the Blaze Pod light system. The use of a more dynamic reactive testing battery may decrease the reinjury rates when an athlete is cleared for participation by measuring readiness in chaotic circumstances that are more reflective of the sporting environment the athlete is working to return to resulting in a greater sense of confidence, performance and prevention of reinjuries.

The Effects on Knee Swelling, Range of Motion and Pain using a Commercially Available Hot/Cold Contrast Device in a Rehabilitation and Sports Medicine Setting.

Background and Purpose: Contrast therapy consists of alternating thermotherapy and cryotherapy repeatedly to assist in the management of acute, subacute, and chronic musculoskeletal conditions. This has been utilized for several decades with good to excellent subjective and objective results reported for patients with swelling (acute to chronic), pain, and loss of motion. Typically, the intervention is performed by either the use of a hot and cold whirlpool or by applying hot and cold packs which can be very time consuming and labor intensive. The purpose of this study was to determine the efficacy of a single treatment of the Hyperice X system in reducing knee joint pain, swelling and stiffness in active patients and young injured athletes. A secondary purpose was to measure patient satisfaction with the use of the device. Subjects: Fifty subjects (34 males and 16 females) with a mean age of 22.2 +/- 4.9 yrs (ranging from 17 to 45 yrs of age) were recruited. Subjects presented with various types of knee pain, both non-operative and operative, secondary to ligamentous, tendinous, cartilage, muscle, and/or meniscus pathology. The subjects were in various stages of rehabilitation with six in the acute stage, 24 in subacute stage, and 20 in the chronic stage. The subjects participated in a variety of different sports at various levels of competition ranging from recreational to professional. Methods: Subjects were recruited from one of two centers: an athletic training room or an outpatient sports medicine rehabilitation center. They were evaluated for baseline pain using the visual analog scale (VAS),verbal patient satisfaction on a scale of 1-10, verbal assessment of knee tightness, knee circumference, and knee flexion range of motion. The Hyperice X was applied to the knee utilizing the contrast setting for a total of 18 minutes with three six-minute cycles, each consisting of three minutes of heat therapy and three minutes of cold therapy. The contrast therapy was applied at the initiation of the physical therapy session and all subjective and objective measures were repeated immediately post contrast treatment. Results: The VAS scores significantly improved following the treatment session with the mean score pretreatment of 2.59 and following the treatment of 1.68. Knee circumference improved for mid patella and 5 cm below mid patella, but no significant improvement was noted at the 5 cm above the patella region. Knee flexion improved from 130 degrees pre-treatment to 134 degrees post treatment. Knee extension improved from 2.72 degrees of hyperextension to 3.44 degrees, both of which were statistically significant(p<.001). Conclusion: Contrast therapy utilizing the Hyperice X device demonstrated effectiveness in affecting pain reduction, swelling, and knee ROM. A commercially available device providing contrast therapy, may enhance outcomes in athletes after even a single treatment. In addition, the device was found to be easy to use, clinically practical, and demonstrated very high subjective patient satisfaction. Level of Evidence: Level 3.

Landing adaptations following isolated lateral meniscectomy in athletes.

PURPOSE: Objective functional outcomes following isolated radial lateral meniscus tears in the athlete between the ages of 14-25 are not clearly defined. The objective of this study was to determine whether patients following lateral meniscectomy demonstrate lower extremity asymmetries relative to control athletes 3 months after surgery. We hypothesized that following lateral meniscectomy, athletes aged 14-25 years old would demonstrate altered landing biomechanics compared to sex, age, height, weight, and sport-matched controls. METHODS: A total of 18 subjects were included in this study. Nine patients (7 men and 2 women, 20.1 ± 2.8 years) who had undergone first-time isolated radial lateral meniscus tears were tested 3 months following partial lateral meniscectomies and compared to nine sex, age, height, weight, and sport-matched controls (7 men and 2 women, 19.7 ± 3.1 years). A ten-camera motion analysis system and two force platforms were used to collect three trials of bilateral drop landings. A 2X2 ANOVA was used to test the interaction between side (involved vs. uninvolved) and group (patient vs. control). RESULTS: The patient group landed with a decreased internal knee extensor moment compared to the uninvolved side and controls (interaction P < 0.05). The involved limb quadriceps isokinetic torque was not decreased compared to the contralateral or control (n.s.). Decreased knee extensor moments were significantly associated with reduced measures of function (IKDC scores: r = 0.69; P < 0.05). CONCLUSIONS: Athletes who return to sport at approximately 3 months following a partial lateral meniscectomy may employ compensation strategies during landing as evidenced by reduced quadriceps recruitment and functional outcome scores. Clinicians should focus on improving quadriceps function during landing on the involved leg in an attempt to decrease residual limb asymmetries. LEVEL OF EVIDENCE: Case-control study, Level III.

Blood Flow Restriction Training.

Muscle weakness and atrophy are common impairments after musculoskeletal injury. Blood flow restriction (BFR) training offers the ability to mitigate weakness and atrophy without overloading healing tissues. It appears to be a safe and effective approach to therapeutic exercise in sports medicine environments. This approach requires consideration of a wide range of factors, and the purpose of our article is to provide insights into proposed mechanisms of effectiveness, safety considerations, application guidelines, and clinical recommendations for BFR training after musculoskeletal injury. Whereas training with higher loads produces the most substantial increases in strength and hypertrophy, BFR training appears to be a reasonable option for bridging earlier phases of rehabilitation when higher loads may not be tolerated by the patient and later stages that are consistent with return to sport.

Physiological Monitoring Detected Changes During Women's Soccer Anterior Cruciate Ligament Injury.

A growing number of studies utilizing wearable technologies are examining the influence of the autonomic nervous system (ANS) on intense training, recovery, and injury risk. Exercise biometric (EB) data were collected on collegiate, female soccer players during a preseason camp. One player sustained an anterior cruciate ligament (ACL) injury. Baseline anthropometric and EB data were compared to non-injured, position-matched teammates. All players had similar baseline testing. The injured athlete had a higher body mass index (BMI) and slower vision reaction time (RT). On the day of her injury (DOI), relative percentage heart rate recovery (tHRR) between intense training sets was calculated. Relative percentage tHRR was much lower for the injured athlete, indicating reduced recovery between training sets immediately prior to the injury. Also on DOI, the injured athlete had a lower glomerular filtration rate (GFR). In addition to BMI and RT differences, the lower relative percentage tHRR and GFR on the DOI observed for the injured athlete may reflect an imbalanced ANS recovery, and potentially to risk factors leading to her ACL injury.

Lack of eye discipline during headers in high school girls soccer: A possible mechanism for increased concussion rates.

The sport of soccer is the fastest growing and most popular sport worldwide. With this growth and popularity, attention needs to be given to this athletic population. Sports related concussions is a topic that has gained attention both in the media and by governmental organizations, with growing initiatives in diagnosis, prevention and treatment. The act of soccer heading is thought to contribute to increased concussion incidence. Current evidence reveals that within the high school soccer athletic population, female athletes incur a higher concussion rate than males. This is often attributed to many things including differing cervical spinal musculature, skull thickness, etc., but a definitive reason has not yet been found. Other behaviors, such as field awareness and eye discipline™ on the field of play, may also be contributing factors that result in females incurring a greater concussion rate than males. For the purposes of this paper we define eye discipline™ as the ability to keep the eyes engaged in sporting activity with high risk potential. We present our hypothesis that high school female soccer players are more likely to have their eyes closed when in position for heading the ball as compared to high school male soccer players and this lack of visual awareness may increase the risk of concussion. Should these differences be substantiated between males and females, it may initiate and promote discussion of the need for vision training in the high school athletic setting. As a tool for injury prevention, vision training may improve specific visual parameters improving athletes' abilities to process the field of play and prepare for or avoid injury causing situations. Through ocular motor and visual conditioning, an athlete may become more eye disciplined™, and more likely to have their eyes open during heading of the ball, and more likely to avoid concussions.

Effects of postural control manipulation on visuomotor training performance: comparative data in healthy athletes.

PURPOSE/BACKGROUND: Visuomotor ability is an important parameter for neurologic function and effective sport performance. Adding a balance challenge during a structured eye-hand coordination task, such as hitting lights on a light board (Dynavision™), has not been previously reported. Using Division I football players, the aim of this study was to determine normative data on a dual-task performance regimen combining a visuomotor light board task with a balance task. The intent is to use such normative data and baseline data as part of a concussion management program. METHODS: Division I college football team members, n=105, were consented. Subjects first performed Dynavision™ D2™ Visuomotor Training Device (D2™) eye-hand coordination tasks, the A* and the RT; they then performed the same tasks with an added balance challenge, standing on a BOSU® ball. RESULTS: Ninety-four athletes completed the full testing procedure on the D2™ system. The mean score of the A* test was 93 ± 11.0 hits per minute; and the mean on the A* test with the added BOSU® balance challenge was 83.7 ± 9.2 hits per minute. The mean RT time was 0.33 ± 0.036 seconds. Mean reaction time increased to 0.38 ± 0.063 while the subject stood on the BOSU® ball. Performance on the D2™ A* and RT were both statistically significantly different in the dual task condition (p<0.05). CONCLUSIONS: Results show an approximate 10% decline in D2™ performance when healthy individuals stand on a BOSU® ball. From the data presented here, the authors determined that there is a 10% decrement in performance when one's balance is challenged on the BOSU® ball. A fall in performance of substantially greater than 10% may indicate abnormal vestibulocerebellar regulatory processing of balance and motion. Further research, using these normative data is needed to determine more specific parameters for definitions of impairment and return-to-play and if there is utility for such studies as part of a concussion management program. LEVEL OF EVIDENCE: III.

MEDIAL FOOT LOADING ON ANKLE AND KNEE BIOMECHANICS.

BACKGROUND: The incidence of anterior cruciate ligament (ACL) injuries among females continues at disproportionate rates compared to males, with research indicating inconclusive multifactorial causality. Data from previous retrospective studies suggest an effect of abnormal foot and ankle biomechanics on pathology at the knee, including the ACL. OBJECTIVE: To determine if a relationship exists between plantar foot loading patterns during normal gait and high risk biomechanics purported to increase risk of ACL injury. METHODS: Dynamic barefoot plantar pressure distribution was measured on 33 female collegiate soccer players. Groups were divided according to their predominant gait loading pattern (medial or lateral). Three dimensional (3-D) motion analysis was conducted during drop vertical jumps to assess vertical ground reaction force and discrete angle and joint moment variables of the lower extremities. RESULTS: No significant differences occured in sagittal or coronal plane knee joint kinematics and kinetics between the medial and lateral loading groups. DISCUSSION: Dynamic foot and ankle biomechanics during gait do not appear to be related to lower extremity kinematics or kinetics during landing in collegiate female soccer players. CONCLUSION: The exact cause of the abnormal differences in female landing biomechanics has not been irrefutably defined. This study suggests no effect of foot and ankle biomechanics exists on the landing mechanics of female soccer players.

Management of the Patient with an ACL/MCL Injured Knee.

The knee is a mobile functional anatomical unit which plays a key role in recreational function. In the last three decades, the knee has received a great deal of attention in the sports medicine literature, particularly in respect to isolated ligament pathology and management. In reference to combined multiple ligament pathology, a more limited number of articles exist, and indeed lead to confusing management. Although hundreds of publications address the topic of surgical correction of the anterior cruciate ligament (ACL), debate continues regarding clinical intervention for the patient with combined ACL and medial collateral ligament (MCL) management. Issues exist which the clinician must consider, including which structures require repair, timing of surgical intervention, and rehabilitation approaches. This article will attempt to define a treatment algorithm for the clinician to consider with simultaneous injury to the ACL and MCL.