Risk Of Future Injury Research Articles

Longitudinal Analysis of Inter-Limb Coordination Before and After Anterior Cruciate Ligament Injury: The JUMP-ACL Study

Inter-limb coordination may provide insight into why patients with anterior cruciate ligament reconstructive surgery (ACLR) have an increased risk for future injury and osteoarthritis. The purpose of this study was to compare inter-limb coordination prior-to anterior cruciate ligament (ACL) injury and following ACLR. Unilateral lower extremity biomechanics during a double-leg jump landing were collected prior-to ACL injury (baseline) and after ACLR, rehabilitation, and return to physical activity (follow-up). Sixty-nine participants were included in this analysis: 31 participants suffered an ACL injury since baseline: 12 injured the leg tested at baseline [ACLR-injured leg (ACLR-INJ), n = 12] and 19 injured the leg that was not tested at baseline [ACLR-uninjured leg (ACLR-UNINJ) n = 19]; 38 participants served as matched controls. Inter-limb coordination—calculated as the mean coupling angle—between the hip and knee were measured in the respective leg of each defined group and compared amongst groups at baseline and follow-up. We observed no significant change in sagittal or frontal plane inter-limb coordination amongst groups or across time (P > 0.05). A significant decrease in inter-limb coordination in the transverse plane from baseline and follow-up was observed but limited to the ACLR-INJ group (P = 0.016). The primary finding of this study is that inter-limb coordination between the hip and knee in the sagittal and frontal plane is unchanged by ACL injury and ACLR. This may help explain previous observations of changes in kinematics at both the hip and knee in this population. Our observation of alterations in the transverse plane should be interpreted with caution, but may provide additional evidence for potential mechanisms that lead to the development of osteoarthritis in ACLR patients.

Concussion Recovery Evaluation Using the Inertial Sensor Instrumented Y Balance Test.

The current sports concussion assessment paradigm lacks reliability, has learning effects, and is not sufficiently challenging for athletes. As a result, subtle deficits in sensorimotor function may be unidentified, increasing the risk of future injury. This study examined if the inertial-sensor instrumented Y Balance test could capture concussion-induced alterations in dynamic movement control. A cohort of 226 elite Rugby Union, American football, and ice hockey athletes were evaluated using the inertial-sensor instrumented Y balance test. Dynamic balance performance was quantified using normalized reach distance, jerk magnitude root-mean-squared (Jerk Mag RMS), and gyroscope magnitude sample entropy (Gyro Mag SEn). Concussed athletes who consented to follow-up were evaluated 24 to 48 h post-injury, and at the point of return to full contact training (RTP). Seventeen athletes sustained a concussion and consented to both the 24- to 48-h and RTP follow-up testing. Twenty uninjured control athletes were re-tested 6 months following initial screening. Concussed athletes had reductions in normalized reach distance (Cohens D = 0.66-1.16) and Jerk Mag (Cohens D = 0.57-1.14) 24 to 48 h post-injury, which returned to pre-injury levels by the point of RTP. There was no significant difference in performance between the baseline and 6-month follow-up in the 20 uninjured athletes (Cohens D = 0.06-0.51). There was a statistically significant linear association between Jerk Mag RMS 24 to 48 h post-injury and the natural log of RTP duration (R2 = 0.27 to 0.33). These results indicate that concussed athletes possessed alterations in dynamic movement control 24 to 48 h post-concussion, which typically returns to pre-injury levels by the point of RTP. Further, evaluation of dynamic movement control 24 to 48 h post-injury may aid in the evaluation of recovery prognosis.

The Association Between Previous Injury And Two Lower Extremity Functional Tests

Previous injury to the lower extremity may increase an athlete’s risk for future injury. Functional screening is one way to determine if an athlete is at a higher risk of future injury. By assessing athletes’ performance on these tests, there is potential for medical providers to implement intervention strategies to decrease risk of future injury. PURPOSE: To determine the association between previous history of injury and two lesser known lower extremity functional tests, the single-leg hip bridge (SLHB) and the single-leg wall-sit (SLWS). METHODS: Sixty-eight recreationally active (participation in exercise or sports for at least 3 days per week for 30 minutes) individuals completed this cross-sectional study. Each participant completed continuous repetitions of a SLHB until failure and repeated on the contralateral leg, as well as a SLWS test, bilaterally, where they were required to hold a single-leg wall sit position until failure. Simple linear regression models were conducted to assess the association between previous injury and the SLHB score and SLWS time. A Poisson regression model was used to assess the association with previous injury for the right and left leg scores on the SLHB. RESULTS: Seventy participants were screened for this study. Of the 70, 2 were excluded, leaving 68 total participants (21 men, 22.4 ± 5.7 years old, 181.96 ± 6.78 cm, and 78.66 ± 10.60 kg and 47 women, 23.3 ± 1.7 years old, 166.30 ± 9.06 cm, and 66.22 ± 9.99 kg). Twenty-five (37%) participants self-reported a previous injury. There was a statistically significant association between a previous injury and the SLHB for the right leg (Relative Risk (RR) = 0.93; 95% Confidence Interval (CI): 0.76-0.93), but not statistically significant association between previous injury and SLHB for the left leg (RR = 0.98; 95% CI: 0.86-1.05). There was no statistically significant association between the SLWS time on either the right (mean difference = 5.57 seconds; 95% CI: -14.17-3.04) or left (mean difference = 5.68 seconds; 95% CI: -13.37-2.02) with previous injury. CONCLUSION: These findings indicate that previous injury to the lower extremity may not affect SLWS time. The SLHB count could be affected depending on the side the injury was on, but additional research is warranted.

Does Baseline Performance On Return-to-Sport Tests Differ Amongst Injured And Uninjured NCAA Division 1 Athletes

One of the most well established risk factors for future injury in athletes is having sustained a previous injury. Currently there is a lack of research regarding baseline performance of athletes on the common return to sport tests. Research evaluating baseline performance can expose the need of implementing an anticipatory rehabilitation program to avoid the risk of future injury. PURPOSE: To investigate the differences in performance on a battery of tests amongst incoming collegiate athletes who have sustained a lower extremity injury in the past 6 months and those who have not. METHODS: 40 (Males: 19 Females: 21) incoming collegiate athletes from an NCAA Division I University completed a battery of baseline tests that assessed their strength, flexibility, dynamic balance, power and speed. Individuals were categorized as injured and uninjured, with injury defined as having a lower extremity injury in the past 6 months (Injured: 16 Uninjured: 24). RESULTS: The left knee flexion strength for injured (.32∓.12/BW) was significantly greater than that of uninjured (.25∓.1/BW; p=.041). The right hip internal rotation strength for injured (.20∓.07/BW) was significantly greater than that of uninjured (.15∓.06/BW; p=.014). The left hip strength was also significantly greater in injured (.20∓.05/BW) compared to uninjured (.15∓.06/BW; p= .004). For balance, the posterolateral reach from the Y-Balance test indicated a significant difference with uninjured (7.58∓6.38 cm) having a greater limb asymmetry compared to injured (3.49 ∓ 3.26 cm; p = .03). The flexibility, power and speed tests did not identify any differences. CONCLUSIONS: The results indicated that athletes who were injured performed better on isometric strength tests and Y- Balance than those with no recent injuries. One potential hypothesis to account for these differences is that the injured athletes could have participated in an individualized rehabilitation program after injury to address their functional deficits, which improved performance. Therefore, this study shows that it could be critical to screen all athletes, whether injured or uninjured, prior to participation in the athletic season.

Injury Incidence In Competitive Wheelchair Tennis Athletes

There is great interest in tennis sports science and in the wheelchair tennis community on the overall injury incidence in competitive wheelchair tennis players. There are biomechanical differences between the wheelchair tennis and the able-bodied tennis serve that have been published. In addition, wheelchair tennis players are required to propel their wheelchair around the court during match play, which exposes the upper extremities and trunk to additional movements during tennis play. Currently, there is a paucity of data published on the injury incidence in competitive wheelchair tennis athletes. PURPOSE: To provide a prospective evaluation of the injury incidence in wheelchair tennis players during their competitive schedule. METHODS: The study is a prospective cohort study of competitive wheelchair tennis players during their seasons. 81 subjects were enrolled at 5 different tennis tournaments over a two year period. Subjects completed an injury history and a training log at the beginning of the study. 39 subjects volunteered for a physical exam at the start of the study. Once enrolled in the study, the subjects were monitored for injuries through weekly email communication. RESULTS: The injury incidence is calculated to be 1.88 injuries per 100 athletic exposures. Of the reported injuries, 2 occurred during match play, 3 occurred during training, and 8 were reported while not playing tennis. There were no statistically significant findings associating physical exam findings and future injury. CONCLUSIONS: An injury incidence in competitive wheelchair tennis athletes obtained while competing and training prospectively contributes to the body of evidence to guide further research to evaluate the mechanism of injuries and develop injury risk reduction strategies in a unique population of high performance athletes. Future injury risk reduction strategies should include a focus on potential causes of non-tennis related injuries in competitive wheelchair tennis players.

Concussion History and Neuromechanical Responsiveness Asymmetry.

Detection of subtle changes in brain sensorimotor processes may enable clinicians to identify athletes who would derive the greatest benefit from interventions designed to reduce the risk for future injury and progressive neurologic or musculoskeletal dysfunction. To develop a generalizable statistical model for identifying athletes who possess subtle alterations in sensorimotor processes that may be due to previous concussion. Cross-sectional study. Residential Olympic Training Center sports medicine clinic. A primary cohort of 35 elite athletes and a secondary cohort of 40 elite athletes who performed identical tests the preceding year. Two upper extremity tests of visual-motor reaction time and 2 tests of whole-body reactive agility were administered. The whole-body tests required lateral or diagonal responses to virtual-reality targets, which provided measures of reaction time, speed, acceleration, and deceleration. Sport-related concussion history, which was reported by 54% (n = 19) of the athletes in the primary cohort and 45% (n = 18) of the athletes in the secondary cohort. Univariable analyses identified 12 strong predictors of sport-related concussion history, which we combined to create a composite metric with maximum predictive value. Composite lateral asymmetry for whole-body reactive movements and persisting effects of previous musculoskeletal injury yielded a logistic regression model with exceptionally good discrimination (area under the curve = 0.845) and calibration (predicted-observed probabilities within 7 subgroups: r = 0.959, P = .001). Application of the derived model to compatible data acquired from another cohort of elite athletes demonstrated very good discrimination (area under the curve = 0.772) and calibration (within 8 subgroups: r = 0.849, P = .008). Asymmetry in whole-body reactive movement capabilities may be a manifestation of a subtle abnormality in the functional connectivity of brain networks that might be relevant to previously reported associations between sport-related concussion history and musculoskeletal injury occurrence.

Athletes with a concussion history in the last two years have impairments in dynamic balance performance.

The purpose of this study was to determine if National Collegiate Athletics Association Division 1 American Football and Ice Hockey athletes with a history of concussion have impaired dynamic balance control when compared to healthy control athletes. This cross-sectional observational study recruited 146 athletes; 90 control athletes and 56 athletes with a history of concussion. Athletes were tested during a pre-season evaluation using the inertial-sensor instrumented Y Balance Test. Independent variables were normalized reach distance, gyroscope magnitude sample entropy, and jerk magnitude root mean square. Kruskal-Wallis H test and Dunn-Bonferroni analysis demonstrated that individuals with a concussion history within the last 2years have statistically significantly lower jerk magnitude root mean square in the posteromedial (Z=23.22, P=.015) and posterolateral (Z=24.64, P=.010) reach directions, when compared to the control group. There was no significant difference between those who sustained a concussion longer than two years ago and the control group for the posteromedial (Z=-1.25; P=.889) and posterolateral (Z=6.44; P=.469) directions. These findings show that athletes with a concussion history within the last two years possess dynamic balance deficits, when compared to healthy control athletes. Conversely, athletes whose injury occurred greater than 2years ago possessed comparable performance to the healthy controls. This suggests that sensorimotor control deficits may persist beyond clinical recovery, for up to 2years. Therefore, clinicians should integrate balance training interventions into the return-to-play process to accelerate sensorimotor recovery and mitigate the risk of future injury.

Accuracy of the Region of Limb Stability in Predicting Risk for Lower Limb Injury.

This study aimed to determine whether a measure of lower limb segment stability derived from body-worn inertial measurement units can predict risk for lower limb musculoskeletal injury in Division I Collegiate Football Players (D1CFP). The region of limb stability (ROLS) values were collected in a cohort of D1CFP during preseason. ROLS is a measure of knee joint stability, defined by thigh and shank excursion (cm) in the anterior-posterior and medial-lateral direction during single limb stance. The ROLS symmetry index (SI) (%) is the ratio between lower limb ROLS values where 100% suggests absolute symmetry. One-hundred and four D1CFP participated in this study and were divided into two groups: 1) no previous lower limb injury or no in-season injury (n = 70, "noninjured group") and 2) no previous lower limb injury, but in-season injury requiring surgery (n = 34, "injured group" group). The mean ± SD ROLS SI was 82.86% ± 14.75% and 65.58% ± 16.46% for the noninjured and injured group, respectively. Significant differences in ROLS SI were found between groups (P < 0.001). The ROLS SI demonstrated an area under the curve of 0.8 (P < 0.001; 95% confidence interval = 0.71-0.88) with an SE of 0.04, indicating that the ROLS SI has good predictive accuracy in detecting those healthy D1CFP at risk for lower limb injury resulting in surgery. The ROLS SI was found to have good predictive accuracy in detecting individuals at risk for injury that were healthy and asymptomatic during preseason testing. Increase in thigh and shank excursions and/or decrease in SI between lower limbs may be a predictor of risk for future injury.

Differences in Lower Limb Strength and Structure After 12 Weeks of Resistance, Endurance, and Concurrent Training.

To investigate strength and structural adaptations after 12 weeks of resistance, endurance cycling, and concurrent training. Thirty-two healthy males undertook 12 weeks of resistance-only (RT; n = 10), endurance-only (END; n = 10), or concurrent resistance and endurance training (CONC; n = 12). Biceps femoris long head (BFlh) architecture, strength (3-lift 1-repetition maximum), and body composition were assessed. Fascicle length of the BFlh reduced 15% (6%) (P < .001) and 9% (6%) (P < .001) in the END and CONC groups postintervention, with no change in the RT group (-4% [11%], P = .476). All groups increased BFlh pennation angle (CONC: 18% [9%], RT: 14% [8%], and END: 18% [10%]). Thickness of the BFlh increased postintervention by 7% (6%) (P = .002) and 7% (7%) (P = .003) in the CONC and RT groups, respectively, but not in the END group (0% [3%], P = .994). Both the CONC and RT groups significantly increased by 27% (11%) (P < .001) and 33% (12%) (P < .001) in 3-lift totals following the intervention, with no changes in the END cohort (6% [6%], P = .166). No significant differences were found for total body (CONC: 4% [2%], RT: 4% [2%], and END: 3% [2%]) and leg (CONC: 5% [3%], RT: 6% [3%], and END: 5% [3%]) fat-free mass. Twelve weeks of RT, END, or CONC significantly modified BFlh architecture. This study suggests that conventional resistance training may dampen BFlh fascicle shortening from cycling training while increasing strength simultaneously in concurrent training. Furthermore, the inclusion of a cycle endurance training stimulus may result in alterations to hamstring architecture that increase the risk of future injury. Therefore, the incorporation of endurance cycling training within concurrent training paradigms should be reevaluated when trying to modulate injury risk.

Identification of Risk Factors Prospectively Associated With Musculoskeletal Injury in a Warrior Athlete Population.

Musculoskeletal injuries are a primary source of disability. Understanding how risk factors predict injury is necessary to individualize and enhance injury reduction programs. Because of the multifactorial nature of musculoskeletal injuries, multiple risk factors will provide a useful method of categorizing warrior athletes based on injury risk. Prospective observational cohort study. Level 2. Baseline data were collected on 922 US Army soldiers/warrior athletes (mean age, 24.7 ± 5.2 years; mean body mass index, 26.8 ± 3.4 kg/m2) using surveys and physical measures. Injury occurrence and health care utilization were collected for 1 year. Variables were compared in healthy versus injured participants using independent t tests or chi-square analysis. Significantly different factors between each group were entered into a logistic regression equation. Receiver operating characteristic curve and accuracy statistics were calculated for regression variables. Of the 922 warrior athletes, 38.8% suffered a time-loss injury (TLI). Overall, 35 variables had a significant relationship with TLIs. The logistic regression equation, consisting of 11 variables of interest, was significant (adjusted R2 = 0.21; odds ratio, 5.7 [95% CI, 4.1-7.9]; relative risk, 2.5 [95% CI, 2.1-2.9]; area under the curve, 0.73). Individuals with 2 variables had a sensitivity of 0.89, those with 7 or more variables had a specificity of 0.94. The sum of individual risk factors (prior injury, prior work restrictions, lower perceived recovery from injury, asymmetrical ankle dorsiflexion, decreased or asymmetrical performance on the Lower and Upper Quarter Y-Balance test, pain with movement, slower 2-mile run times, age, and sex) produced a highly sensitive and specific multivariate model for TLI in military servicemembers. A better understanding of characteristics associated with future injury risk can provide a foundation for prevention programs designed to reduce medical costs and time lost.

O15 ESOPHAGEAL MOTILITY OF LUNG TRANSPLANT RECIPIENTS DIAGNOSED WITH SYSTEMIC CONNECTIVE TISSUE DISORDER: A SINGLE-CENTER EXPERIENCE

Abstract Aim To examine the esophageal motility of lung transplant recipients diagnosed with systemic connective tissue disorder, and to evaluate the changes Backgrounds The decision to offer lung transplantation to patients diagnosed with a systemic connective tissue disorder (CTD) is frequently complicated by associated esophageal dysmotility. Absent or ineffective esophageal motility and associated gastroesophageal reflux disease are serious risk factors of posttransplant bronchiolitis obliterans syndrome and subsequent allograft dysfunction. The aim of our study was to evaluate esophageal motility of lung transplant recipients with systemic CTDs, focusing on 1-year survival. Methods After IRB approval of this retrospective cohort study, we reviewed patients who underwent lung transplant at our institution between January 2012 and December 2017. Patients with systemic CTDs such as scleroderma, rheumatoid arthritis, systemic lupus erythematosus, polymyositis, dermatomyositis, mixed connective tissue disorder, and Sjögren syndrome were included. Endoscopy studies, high-resolution manometry (HRM), and ambulatory pH studies were re-evaluated. Results A total of 545 patients underwent lung transplant during study period; of these, 34 met study criteria. Detailed demographic characteristics of the study cohort are shown in Table 1. The overall 1-year survival was 85.3%. Of the 34 patients diagnosed with a systemic CTD (mean age: 59.24 ± 10.44 years; 24/34 women [70.6%]), 27 had both pre- and posttransplant esophageal function testing data available. 7 patients were diagnosed with complete aperistalsis, 5 patients had ineffective esophageal motility, and the remaining 15 patients had normal or hypercontractile esophageal motility (Figure 1). Pathologic distal acid exposure in each of these groups was 57.1%, 40.0%, and 26.7%, respectively. Seven patients with aperistalsis (5 with scleroderma, 1 with polymyositis, and 1 with dermatomyositis) showed no improvement in esophageal body motility, regardless of underlying CTD. 1-year survival in these patients was 55.5%. Five patients with ineffective esophageal motility (3 with rheumatoid arthritis, 1 with scleroderma, 1 with mixed connective tissue disorder) showed significant peristaltic improvement (mean positive change in distal contractile integral: 1288 ± 391.3 mmHg*cm*s and in the number of normal swallows 6.4 ± 1.4 out of 10). All 5 patients with ineffective esophageal motility were alive 1 year posttransplant. Conclusion In our experience, preexisting absent esophageal body motility (i.e., peristalsis) is unlikely to improve after transplantation in patients with systemic CTDs. This cohort of patients appeared to have a significantly decreased 1-year survival. In contrast, ineffective esophageal body motility improved significantly after transplant and was associated with excellent 1-year survival. Detailed esophageal evaluation is necessary in patients with a systemic connective tissue disorder to minimize the risk of future allograft injury.

Cartilage damage at the time of anterior cruciate ligament reconstruction is associated with weaker quadriceps function and lower risk of future ACL injury.

To determine whether articular cartilage damage noted at the time of primary anterior cruciate ligament reconstruction (ACLR) affects the likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6months after surgery or risk of recurrent ACL injury. Five hundred and eight patients underwent primary ACLR and diagnostic arthroscopy. All identified cartilage lesions were graded using the Outerbridge system. All patients underwent isokinetic strength testing. The association between cartilage Outerbridge grade and a ≥ 90% Limb Symmetry Index (LSI) and recurrent ACL injury risk at mean 38.7month follow-up (SD 31.8) was evaluated via multivariate regression analysis. Grade 2 or higher damage was present in 394 (77.5%) of patients, grade 3 or higher in 143 (28.1%) and grade 4 in 83 (16.4%) at time of ACLR. Ipsilateral ACLR graft rupture occurred in 31 (6.1%) of patients. Contralateral ACL injury occurred in 19 (3.7%). Patients with grade 2 or higher damage were significantly less likely to meet an LSI goal of ≥ 90% for fast (300°/s) isokinetic extension. There was no association with slow isokinetic extension. Cartilage lesion severity at or beyond grade 2 had a similar effect on isokinetic testing results regardless of compartment involvement or performance of microfracture. Patients with grade 2-4 cartilage damage were less likely to sustain a second ipsilateral ACL injury or a contralateral native ACL injury. Cartilage damage seen at time of ACL reconstruction is common and associated with lower likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6months after surgery. However, lower recurrent ACL injury rates are seen in patients with concurrent cartilage damage. These data may inform future clinical decisions regarding operative managment of recurrent ACL injuries. III.

Strength and Power Training in Rehabilitation: Underpinning Principles and Practical Strategies to Return Athletes to High Performance.

Injuries have a detrimental impact on team and individual athletic performance. Deficits in maximal strength, rate of force development (RFD), and reactive strength are commonly reported following several musculoskeletal injuries. This article first examines the available literature to identify common deficits in fundamental physical qualities following injury, specifically strength, rate of force development and reactive strength. Secondly, evidence-based strategies to target a resolution of these residual deficits will be discussed to reduce the risk of future injury. Examples to enhance practical application and training programmes have also been provided to show how these can be addressed.

Does Juvenile Play Programme the Equine Musculoskeletal System?

Simple SummaryLocomotor play is a common behaviour expressed across a diverse range of species. As a cursorial animal, the horse is capable of locomotor activity within a relatively short time after birth. In the foal, spontaneous locomotor play occurs early in life and has an obvious role in the development of locomotor skills. The intensity and vigour of locomotor play increases with age and this, in turn, provides cumulative increases in the loads the musculoskeletal system experiences. These progressive cumulative loading cycles (bouts of locomotor play), in both the timing and magnitude, reflect the microstrain required to stimulate bone development based on the mechanostat theorem. Data from the published literature were presented to provide empirical support for this hypothesis. Thus, spontaneous locomotor play may be vital to ensure optimal bone development in the horse. Modern production systems need to provide appropriate opportunities for foals to perform spontaneous locomotor play to optimise bone development and reduce the risk of future musculoskeletal injury later in life.In mammals, play behaviour appears innate and, because of this, may provide insight into the frequency and intensity of load that is required to stimulate positive musculoskeletal development. The objective of this review was to explore the interaction between play and tissue (bone) development at a molecular through to whole-animal level, with specific focus on the horse as a model. The basis of our understanding of the response of bone to loading is the mechanostat theorem. This assumes that at a tissue level, bone attempts to keep localised strain within the physiological range of 1500–2500 microstrain. Loads above this range result in a modelling response to reduce strain, and strain below this threshold results in remodelling to maintain the localised physiological range. In foals, locomotor play is dramatic and vigorous, with cumulative increases in both intensity and complexity. Based on published literature describing locomotor play in foals and the microstrain at different gaits in the horse, it was proposed that locomotor play in foal aligns with the mechanostat theorem in both the magnitude and frequency of load cycles applied. The cumulative increases in the complexity and intensity of locomotor play as the foal develops, in turn, ensure the strain rates associated with play remain above the local physiological range and promote material and architectural changes in the distal limb bones. Thus, spontaneous locomotor play may be vital to ensure optimal bone development in the horse. Modern management systems need to provide appropriate opportunities for foals to perform spontaneous locomotor play to optimise bone development and reduce the risk of future musculoskeletal injury later in life.

Hamstring Graft Harvest Side Does Not Affect Performance or RTS Rates and Does Not Increase Risk for Future Hamstring Injuries Following UCL Reconstruction in Professional Baseball Players

Objectives: Ulnar collateral ligament reconstruction (UCLR) is a successful procedure in professional baseball players. It is unclear if hamstring tendon harvest side for UCLR alters a player’s risk of subsequent hamstring injuries. The purpose of this study was to compare, performance, return to sport (RTS) rate, and injury rates between professional baseball players with a history of UCLR using an ipsilateral (drive leg) hamstring autograft to those with UCLR using contralateral (landing leg) hamstring autograft. The authors’ hypothesized that players with prior UCLR using ipsilateral (drive leg) hamstring autograft will have the same RTS rate and performance upon RTS, but higher number of subsequent lower extremity injuries than those using contralateral (landing leg) hamstring autograft. Methods: All players between 2010-2015 who underwent UCLR using hamstring autograft were included. Surgical details of their procedure were recorded using operative reports. Players with a hamstring UCLR were compared within group to compare grafts taken from the drive leg vs. landing leg. Results: Overall, 191 players underwent UCLR using hamstring autograft (58 [30%] landing/contralateral and 133 [70%] ipsilateral/drive leg). The docking technique was more common in the contralateral/landing leg group while the figure-of-8 technique was more common in the ipsilateral/drive leg group (p&gt;0.001). More patients in the ipsilateral/drive leg group underwent concomitant treatment of the ulnar nerve than the contralateral/landing leg group (p&lt;0.001). No difference existed in return to sport (RTS) rates, or timing of RTS between groups. No differences in subsequent ipsilateral or contralateral hamstring injuries between players who underwent UCLR using hamstring from the ipsilateral/drive leg or contralateral/landing leg was seen (p=1.000; p=0.460 respectively). No difference in overall upper or lower extremity injury rates existed between groups. Conclusion: No difference in RTS rate, performance upon RTS, or subsequent hamstring, lower extremity, or upper extremity injury rates existed between players who underwent UCLR using hamstring autograft from the ipsilateral/drive or contralateral/landing leg.

Quadricep Femoris Strength at Return to Sport Identifies Limb at Increased Risk of Future ACL Injury after ACL Reconstruction in Young Athletes

Objectives: The ability of current return to sport (RTS) criteria to identify young, active patients after ACL reconstruction (ACLR) independently, at high risk for future ipsilateral or contralateral ACL injury is limited. The purpose of this study was to determine if meeting current, standard RTS criteria collectively, or in part, would identify young athletes at risk for an ipsilateral or contralateral ACL injury after primary ACLR and RTS. The tested hypothesis was the likelihood of an ipsilateral or contralateral 2nd ACL injury in the first 2 years after RTS would be the same in groups that successfully met or failed to meet all RTS criteria prior to RTS. The second hypothesis was that quadriceps femoris strength at the time of RTS would identify which limb was at greatest risk for future ACL injury. Methods: One hundred eighty-one patients (116 female) with a mean age of 16.7±2.9 years old underwent ACLR and were released to return to pivoting/cutting sports. These patients were enrolled in a prospective, observational cohort study, completed a RTS assessment and were tracked for occurrence of an ipsilateral graft tear or contralateral ACL injury after ACLR for 24 months. The RTS assessment included 6 tests: isometric quadriceps strength, 4 functional hop tests and the International Knee Documentation Committee (IKDC) patient reported outcome survey. Limb symmetry index (LSI) was calculated for strength and hop test assessments [(inv/uninv)*100]. Subjects were classified into groups that successfully passed all 6 RTS tests at a level of 90 compared to those that failed to meet all 6 criteria. Chi Square tests and Fisher Exact Tests were used to determine if successfully passing all 6 RTS measures resulted in a reduced risk of 2nd ACL injury in the first 24 months after RTS as well as to assess if ability to successfully pass individual RTS criteria resulted in reduced risk of 2nd ACL injury. Results: Thirty-nine (21.5%) patients suffered a 2nd ACL injury with 18 ipsilateral graft failures and 21 contralateral ACL tears in the first 24 months after RTS following ACLR. At the time of RTS, 57 patients (31.5%) achieved LSI values of 90% or greater on all testing as well as an IDKC value of 90 or greater. At this level, there was no difference in ipsilateral graft failures between patients who passed all RTS criteria (15.8%) and those who failed at least 1 criterion (7.3%; p=0.08). There was also no difference in contralateral ACL injuries between patients who passed all RTS criteria (7.0%) and those who failed at least 1 criterion (13.7%; p=0.22). When individual RTS criterion were evaluated, patients who failed to achieve 90% quadriceps strength LSI were 84% less likely to suffer an ipsilateral graft failure (OR=0.16; 95%CI: 0.04, 0.74;p=0.009), but 3 times more likely to suffer a contralateral ACL injury (OR=2.5; 95%CI:1.0, 6.5;p=0.05). Conclusion: Current criteria to evaluate readiness to return young athletes to pivoting and cutting sports, may not identify young, active patients independently at high risk for a future ipsilateral graft tear or contralateral ACL injury. Inability to achieve 90% LSI on an isometric quadriceps strength assessment resulted in a reduced risk of ipsilateral graft failure, but an increased risk in contralateral ACL injury after ACLR and RTS. Further investigation is needed on the relationship between quad strength and side of future ACL injury and whether other factors may help contribute to a predictive model of future ACL injury specific to limb.

Previous injury is associated with heightened countermovement jump force‐time asymmetries in professional soccer players

Previous injury is associated with increased risk of future injury. Residual inter‐limb deficits are a potential contributing factor leading to compensatory movement patterns on return to sport. The purpose of this study was to examine the effects of previous severe injury on bilateral ground reaction force asymmetries measured during a countermovement jump using a dual force platform. A total of 34 male professional soccer players (age 19 ± 2 years) were subdivided into two groups; previous severe injury (N = 17) or no severe injury (N = 17). Previously injured players showed significantly greater asymmetry in concentric phase variables (P 0.05; d = 0.33). There were no significant between‐group differences in bilateral jump performance parameters (P > 0.05). These data indicate that despite being cleared to return to sport, participating in elite‐level training, full competition and exhibiting no decrements in jump performance, significant inter‐limb asymmetries persist in the concentric and eccentric phases of the CMJ.

Land leg vs. Drive Leg Hamstring Graft Harvest Side Does Not Affect Performance or RTS Rates and Does Not Increase Risk for Future Hamstring Injuries Following UCLR in Professional Baseball Pitchers

Land leg vs. Drive Leg Hamstring Graft Harvest Side Does Not Affect Performance or RTS Rates and Does Not Increase Risk for Future Hamstring Injuries Following UCLR in Professional Baseball Pitchers

Functional Movement Assessments Are Not Associated with Risk of Injury During Military Basic Training.

Musculoskeletal injuries (MSK-I) in the U.S. military accounted for more than four million medical encounters in 2017. The Military Entrance Processing Screen to Assess Risk of Training (MEPSTART) was created to identify MSK-I risk during the first 180 days of military service. Active duty applicants to the United States Army, Navy, Air Force, and Marine Corps between February 2013 and December 2014 who consented completed a behavioral and injury history questionnaire and the MEPSTART screen [Functional Movement Screen (FMS), Y-Balance Test (YBT), Landing Error Scoring System (LESS), and Overhead Squat assessment (OHS)] the day they shipped to basic training. Male (n = 1,433) and Female (n = 281) applicants were enrolled and MSK-I were tracked for 180 days. Binomial logistic regression and multivariate Cox proportional hazards modeling were used to assess relationships among MEPSTART screens and MSK-I independent of age, BMI, sex, Service, injury history, and smoking status. Analyses were finalized and performed in 2017. The only functional screen related to injury was the LESS score. Compared to those with good LESS scores, applicants with poor LESS scores had lower odds of MSK-I (OR = 0.54, 95% CI = 0.30-0.97, p = 0.04), and a lower instantaneous risk of MSK-I during the first 180 d (HR = 0.58, 95%CI = 0.34-0.96, p = 0.04). However, secondary receiver operator characteristic (ROC) analyses revealed poor discriminative value (AUC = 0.49, 95%CI = 0.43-0.54). Functional performance did not predict future injury risk during the first 180 days of service. Poor LESS scores were associated with lower injury risk, but ROC analyses revealed little predictive value and limited clinical usefulness. Comprehensive risk reduction strategies may be preferable for mitigating MSK-I in military training populations.

Athlete Monitoring in Rugby Union: Is Heterogeneity in Data Capture Holding Us Back?

In an effort to combat growing demands on players, athlete monitoring has become a central component of professional sport. Despite the introduction of new technologies for athlete monitoring, little is understood about the practices employed in professional rugby clubs. A questionnaire was circulated amongst conditioning staff across the 12 Premiership rugby clubs to capture the methods used, relative importance, perceived effectiveness and barriers to the use of multiple different athlete monitoring measurements. Previous injury, Global Positioning System (GPS) metrics, collision counts and age were deemed the most important risk factors for managing future injury risk. A wide range of GPS metrics are collected across clubs with high-speed running (12/12 clubs), distance in speed zones (12/12 clubs) and total distance (11/12 clubs) the most commonly used. Of the metrics collected, high-speed running was deemed the most important for managing future injury risk (5/12 clubs); however, there was considerable variation between clubs as to the exact definition of high-speed running, with both absolute and relative measures utilised. While the use of such monitoring tools is undertaken to improve athlete welfare by minimising injury risk, this study demonstrates the significant heterogeneity of systems and methods used by clubs for GPS capture. This study therefore questions whether more needs to be done to align practices within the sport to improve athlete welfare.