Limited Return to Preinjury Performance in NCAA Division I American Football Players With Hamstring Injuries.

Background: Hamstring strains are common among elite athletes, but their effect on return to the same level of play in American football has been incompletely characterized. Purpose: Data on National Collegiate Athletics Association Division I college football players with acute hamstring strains were gathered to identify the effects these injuries have on both return to play and athletic performance regarding velocity, workload, and acceleration. Study Design: Case Series; Level of evidence, 4. Methods: Injury data for a single Division I football team were prospectively recorded over a 4-year period. Players wore global navigation satellite system and local positioning system (GNSS/LPS) devices to record movement data in practices and games. The practice and game data were cross-referenced to evaluate players with isolated acute hamstring strains. Comparisons were made regarding players' pre- and postinjury ability to maintain high velocity (>12 mph [19.3 kph]), maximal velocity, triaxial acceleration, and inertial movement analysis (IMA). There were 58 hamstring injuries in 44 players, of which 25 injuries from 20 players had GNSS/LPS data. Results: Players were able to return to play from all 25 injury incidences at a mean of 9.2 days. At the final mean follow-up of 425 days, only 4 players had reached preinjury function in all measurements; 12 players were able to return in 2 of the 4 metrics; and only 8 players reached their preinjury ability to maintain high velocity. For those who did not achieve this metric, there was a significant difference between pre- and postinjury values (722 vs 442 m; P = .016). A total of 14 players were able to regain their IMA. Players who returned to prior velocity or acceleration metrics did so at a mean of 163 days across all metrics. Conclusion: While players may be able to return to play after hamstring strain, many players do not reach preinjury levels of acceleration or velocity, even after 13.5 months. Further studies are needed to confirm these findings, assess clinical relevance on imaging performance, and improve hamstring injury prevention and rehabilitation.

Effect of Age and Body Mass Index on Time to Advanced Imaging and Surgery in Young Athletes With Anterior Cruciate Ligament Injury.

Background: In young athletes with anterior cruciate ligament (ACL) injury, increased times from injury to magnetic resonance imaging (MRI) and injury to surgery can lead to the accrual of new injuries over time. Purpose: To determine the patient characteristics associated with differences in timing between injury, MRI, and surgery in young athletes with ACL tears. Study Design: Case-control study; Level of evidence, 3. Methods: We reviewed the electronic medical records of patients aged 13 to 25 years who underwent isolated primary ACL reconstruction between January 2017 and June 2020 at a single orthopaedic surgery department. The times from injury to MRI, MRI to surgery, and injury to surgery were documented. Patient demographic data (age, sex, body mass index [BMI], race and ethnicity, and insurance type) were recorded. Multivariable analysis was used to determine if any patient characteristic had a significant association with increased time to MRI or surgery. Results: A total of 369 patients (mean age, 18.0 years; 56% female) were included. Both age and BMI were found to be significantly associated with timing of care while holding all other predictors constant. For every 1-year increase in patient age, time from injury to MRI increased by 9.6 days (95% CI, 1.8-17.4 days; P = .02), time from MRI to surgery increased by 7.4 days (95% CI, 4.4-10.5 days; P < .001), and time from injury to surgery increased by 17.0 days (95% CI, 8.4-25.6 days; P < .001). Compared with patients with normal BMI, overweight patients (BMI range, 25-29.9 kg/m2) had an MRI-to-surgery time that was on average 37.2 days (95% CI, 11.7-62.7 days; P < .004) longer and an injury to surgery time that was on average 71.8 days (95% CI, 0.5-143.0 days; P = .048) longer. Obese patients (BMI ≥30 kg/m2) did not demonstrate a significant relationship with the studied time intervals. Conclusion: Increasing age and elevated BMI were found to be associated with increased time to MRI and surgical care in young athletes with ACL injuries.

Effect of Increased Time to Surgery on the Ability of MRI to Rule Out Medial Meniscal Tears in Young Athletes With ACL Injury.

Background: The prevalence of meniscal tears in patients with anterior cruciate ligament (ACL) injury increases with extended time between injury and ACL reconstruction. Purpose/Hypothesis: The purpose of this study was to determine if there is a relationship between time from magnetic resonance imaging (MRI) to ACL reconstruction and the predictive value of MRI to diagnose meniscal tears in the young active population. It was hypothesized that increased time between MRI and ACL reconstruction would lead to a decrease in the negative predictive value of MRI in diagnosing meniscal tears, as more injuries may accrue over time in the ACL-deficient knee. Study Design: Case series; Level of evidence, 4. Methods: Included were patients aged 13 to 25 years at the authors' institution who underwent primary ACL reconstruction from January 2017 to June 2020. Time from MRI to surgery as well as descriptions of medial and lateral meniscal tears on both MRI and operative reports were documented. Time from MRI to surgery was divided into 4 intervals: 0 to 6 weeks, >6 weeks to 3 months, >3 to 6 months, and beyond 6 months. Multivariable analysis was used to determine the positive and negative predictive values of MRI in diagnosing a meniscal tear as compared with arthroscopic findings. Results: A total of 432 patients were included with a mean age of 17.9 ± 3.4 years. The mean time from MRI to surgery was 70.5 ± 98 days. There was a significant decrease in the negative predictive value of MRI to identify a medial meniscal tear in patients who underwent ACL reconstruction >6 months after imaging (odds ratio, 0.16 [95% CI, 0.05-0.53]; P = .003). This same relationship was not shown for lateral meniscal tears, nor was any other predictor significant. Conclusion: The utility of MRI to rule out a medial meniscal tear significantly diminished in the young athletic population when >6 months passed between MRI and ACL reconstruction. These data suggest these tears occur between the time of the MRI and surgery and that the medial meniscus is more susceptible than the lateral meniscus to new injury once the ACL has torn.

Effect of Delayed Anterior Cruciate Ligament Reconstruction on Repair of Concomitant Medial Meniscus Tears in Young Athletes.

BACKGROUND: Delayed anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with an increased risk of meniscal injury. Limited data are available regarding the relationship between surgical delay and meniscal repairability in the setting of ACLR in young patients. PURPOSE: To determine whether time from ACL injury to primary ACLR was associated with the incidence of medial and/or lateral meniscal repair in young athletes who underwent meniscal treatment at the time of ACLR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Records were retrospectively reviewed for patients aged 13 to 25 years who underwent primary ACLR between January 2017 and June 2020 by surgeons from a single academic orthopaedic surgery department. Demographic data were collected, and operative reports were reviewed to document all concomitant pathologies and procedures. Univariable and multivariable logistic regression analyses were used to determine factors associated with meniscal repair, including time elapsed from ACL injury to surgery. RESULTS: Concomitant meniscal tears were identified and treated in 243 of 427 patients; their mean age was 17.9 ± 3.3 years, and approximately half (47.7%) of patients were female. There were 144 (59.3%) medial tears treated and 164 (67.5%) lateral tears treated; 65 (26.7%) patients had both medial and lateral tears treated. Median time from ACL injury to ACLR was 2.4 months (interquartile range, 1.4-4.7 months). Adjusted univariate analysis showed a statistically significant correlation between medial meniscal repair and time to surgery, with a 7% decreased incidence of medial meniscal repair per month elapsed between injury and surgery (odds ratio, 0.93 per month; 95% CI, 0.89-0.98; P = .006). No similar relationship was found between lateral meniscal repair and time to surgery (odds ratio, 1.02; 95% CI, 0.99-1.06; P = .24). CONCLUSION: In the setting of concomitant ACL and meniscal injuries, surgical delay decreased the incidence of medial meniscal repair in young athletes by 7% per month from time of injury.

Review of human supraspinatus tendon mechanics. Part I: fatigue damage accumulation and failure.

Repetitive stress injuries to the rotator cuff, and particularly the supraspinatus tendon (SST), are highly prevalent and debilitating. These injuries typically occur through the application of cyclic load below the threshold necessary to cause acute tears, leading to accumulation of incremental damage that exceeds the body's ability to heal, resulting in decreased mechanical strength and increased risk of frank rupture at lower loads. Consistent progression of fatigue damage across multiple model systems suggests a generalized tendon response to overuse. This finding may allow for interventions before gross injury of the SST occurs. Further research into the human SST response to fatigue loading is necessary to characterize the fatigue life of the tendon, which will help determine the frequency, duration, and magnitude of load spectra the SST may experience before injury. Future studies may allow in vivo SST strain analysis during specific activities, generation of a human SST stress-cycle curve, and characterization of damage and repair related to repetitive tasks.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health.

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response. Factors associated with the degenerative response include increasing age, smoking, hypercholesterolemia, biological sex (variable by tendon), diabetes mellitus, and excessive load post fatigue damage. After injury, the average healing rate of tendon is approximately 1% per day and may be significantly influenced by biologic sex (females have lower collagen synthesis rates) and excessive load after damage. Although magnetic resonance imaging (MRI) is considered the gold standard in assessing acute tears as well as tendinopathic change in the SST, ultrasonography has proven to be a valuable tool to measure tendinopathic change in real time. Ultrasonography can determine multiple mechanical and structural parameters of the SST that are altered in fatigue loading. Thus, ultrasonography may be utilized to understand how these parameters change in response to SST overuse, and may aid in determining the activity level that places the SST at greater risk of rupture.

Anterior Cruciate Ligament Reconstruction with 4-Strand Hamstring Tendon Construct May be Biomechanically Superior to 5-Strand Hamstring Tendon Construct When Using Femoral Suspensory Fixation.

Purpose: To compare stiffness, strain, and load to failure of 4- versus 5-strand hamstring anterior cruciate ligament reconstruction human tendon allografts with femoral suspensory and tibial interference screw fixation. Methods: Allograft hamstring tendons were used to create 10 four-strand (4S) and 10 five-strand (5S) grafts. Grafts were fixed to a uniaxial electromechanical load system via a femoral cortical suspensory button and a bioabsorbable interference screw in bone analogue. Grafts were cycled from 100 Newtons (N) to 250 N for 1,000 repetitions at 0.5 hertz before load to failure testing. Cyclic displacement was defined as the difference in graft length from the first 20 to 30 cycles compared with the last 10 cycles. Trials were recorded on a high-definition camera to allow for digital image correlation analysis. Results: Cyclic displacement more than 1,000 cycles was significantly lower in the 4S compared with the 5S group (0.87 vs 1.11 mm, P = .037). Digital image correlation analysis confirmed that the fifth strand elongated more than the other 4 strands in the 5S constructs (6.1% vs 3.9%, P = .032). Load to failure was greater in the 4S compared with the 5S group but not statistically significant (762 vs 707 N, P = .35). Stiffness was similar between constructs (138.5 vs 138.3 N/mm, P = .96). Conclusions: Compared with cyclically loaded 4S hamstring grafts, the 5S grafts had significantly increased displacement over time in a model of femoral suspensory and tibial interference screw fixation. Clinical Relevance: Anterior cruciate ligament reconstruction with hamstring tendon autograft is a commonly performed surgery with excellent outcomes. It has been shown that graft diameter influences these outcomes. As surgeons use larger grafts, it is important to investigate how these constructs may affect the outcomes of surgery.

Diagnostic performance of MRA in abduction and external rotation position in the detection of glenoid labral lesions: a systematic review and meta-analysis.

OBJECTIVE: To compare the diagnostic performance of direct magnetic resonance arthrography (MRA) for labral lesions during conventional, abduction and external rotation (ABER), conventional plus abduction, and external rotation (ABER) positioning by using a systematic review and meta-analysis. MATERIALS AND METHODS: A comprehensive literature search was performed on the two main concepts of magnetic resonance arthrography: extremity position and labral lesions. Inclusion criteria consisted of original studies that assessed the diagnostic accuracy of MR arthrography in ABER and conventional position alone or combined for the diagnosis of labral lesions by using surgical findings as the reference standard. Meta-analyses were performed that compared MR arthrography during conventional positioning, ABER, and conventional plus ABER positioning. RESULTS: Nine studies met the inclusion and exclusion criteria. A total of 733, 504, and 313 lesions assessed by conventional MRA, ABER MRA, and conventional plus ABER MRA, respectively, were included in our analysis. Pooled sensitivities of MRA in conventional, ABER, and conventional plus ABER position for labral tear diagnosis were 81.5%, 81.6%, and 95.7%, respectively. Pooled specificities of MRA in conventional, ABER, and conventional plus ABER position for labral tear diagnosis were 88.8%, 85.6%, and 94.5%, respectively. Summary receiver operator characteristic (ROC) curve demonstrated improved accuracy of conventional plus ABER MRA compared with conventional MRA or ABER MRA with the area under the curve (AUC) of 0.99, 0.90, and 0.88, respectively. CONCLUSION: Conventional plus ABER MRA showed increased diagnostic accuracy compared to both ABER MRA and conventional MRA alone in the diagnosis of labral lesions.

Radiological Society of North America/Quantitative Imaging Biomarker Alliance Shear Wave Speed Bias Quantification in Elastic and Viscoelastic Phantoms.

OBJECTIVES: To quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms. METHODS: Two elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz. RESULTS: The SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) across the viscoelastic phantoms. The focal depth and appraiser were less significant sources of SWS variability than the system and site. Magnetic resonance elastography best matched the ultrasonic SWS in the viscoelastic phantoms using a 140 Hz source but had a - 0.27 ± 0.027-m/s (-12.2% ± 1.2%) bias when using the clinically implemented 60-Hz vibration source. CONCLUSIONS: Shear wave speed reconstruction across different manufacturer systems is more consistent in elastic than viscoelastic phantoms, with a mean difference bias of < ±10% in all cases. Magnetic resonance elastographic measurements in the elastic and viscoelastic phantoms best match the ultrasound systems with a 140-Hz excitation but have a significant negative bias operating at 60 Hz. This study establishes a foundation for meaningful comparison of SWS measurements made with different platforms.

Biomechanical Effects of Blood Flow Restriction Training after ACL Reconstruction.

INTRODUCTION: After anterior cruciate ligament reconstruction surgery, returning the knee to previous levels of strength and function is challenging, with the failure to do so associated with an increased risk of reinjury and long-term degenerative problems. Blood flow restriction (BFR) is gaining popularity as a rehabilitation technique; however, its effects on the mechanics of these exercises have not been fully explored. In this study, we aimed to determine the acute effects of BFR on the performance of a step-up exercise protocol and to assess the acceptability of the technique. METHODS: Twenty individuals (12 female/8 male; mean age, 30.6 yr) who had recently undergone anterior cruciate ligament reconstruction and 20 controls (11 female/9 male, mean age 28.0 yr) performed a step-up exercise protocol with and without BFR. Lower limb kinematics and kinetics were measured and compared between groups and conditions. Testing was completed in June 2019. RESULTS: Participants in both groups had increased external rotation of the tibia of 2° (P < 0.001) and reductions in knee flexion and rotation torques around the joint of around 50% (P < 0.001) when using BFR compared with nonrestricted step-up exercise. The intervention was found to increase the difficulty of the exercise and induce moderate levels of discomfort (P < 0.001). CONCLUSION: The present study provides cautious support for the use of BFR, showing that there are minimal changes in knee joint mechanics when performing the same exercise without BFR, and that the changes do not increase joint torques at the knee. From an acute biomechanical perspective, the intervention appears safe to use under qualified supervision; however, effects of repetitive use and long-term outcomes should be monitored.

Management of Glenohumeral Joint Osteoarthritis.

The Management of Glenohumeral Joint Osteoarthritis Evidence-Based Clinical Practice Guideline is based on a systematic review of published studies for the treatment of glenohumeral joint osteoarthritis. The purpose of this clinical practice guideline is to address the management of patients with glenohumeral joint osteoarthritis. It is not intended to address the management of glenohumeral joint arthritis from etiologies other than osteoarthritis (ie, rheumatoid arthritis, inflammatory arthritis, posttraumatic arthritis, osteonecrosis, rotator cuff tear arthroplasty, capsulorrhaphy arthroplasty, and postinfections arthroplasty) This guideline contains 13 recommendations to assist all qualified and appropriately trained healthcare professionals involved in the management of glenohumeral joint osteoarthritis. In addition, the work group highlighted the need for better research for implant survivorship of total shoulder arthroplasty, the efficacy of physical therapy and other nonsurgical treatment modalities, the use of advanced imaging modalities and software and their impact on clinical and functional outcomes, complication rates or implant survivorship, and the need for high-quality studies demonstrating improved clinical outcomes and/or implant survivorship for the use of reverse shoulder arthroplasty as opposed to anatomic shoulder arthroplasty in challenging situations.

What Is the Survivorship After Hip Arthroscopy for Femoroacetabular Impingement? A Large-database Study.

BACKGROUND: Patients with femoroacetabular impingement (FAI) may experience lasting clinical improvement after hip arthroscopy; however, some patients will still eventually undergo early conversion to THA due to unresolved symptoms and progression of arthritis. However, the risk of this has been only incompletely characterized in prior studies. QUESTIONS/PURPOSES: Using a large healthcare claims database over a 5-year period (2011-2016), we asked: (1) What is the survivorship free from THA after arthroscopic osteoplasty performed for FAI? (2) What identifiable demographic factors and patient characteristics are associated with early conversion to THA after hip arthroscopy performed for FAI? METHODS: We included all patients who underwent hip arthroscopy for FAI, between the ages of 12 years and 63 years, with 3 months of claims data before hip arthroscopy and minimum 2-year follow-up. A total of 4730 hip arthroscopy patients from 2011 to 2014 were retrieved from a US commercial claims database. Hip arthroscopy incidence doubled over time from 1.2 to 2.1 persons per 100,000. Temporal trends, patient demographics, diagnoses at time of arthroscopy, and patient comorbidities were retrieved and logistic regression performed. Survivorship analysis on 11,323 patients (lifting the 2-year follow-up requirement) was also performed to identify independent variables associated with early risk of conversion to THA. RESULTS: In patients undergoing hip arthroscopy for FAI, the overall proportion of conversion to THA within 2 years after hip arthroscopy was 7% (338 of 4730). After controlling for confounding variables such as sex, obesity, and depression, we found the following were independently associated with increased odds of conversion to THA: older age (odds ratio 1.08 [95% CI 1.01 to 1.10]; p < 0.001), osteoarthritis (OR 2.91 [95% CI 2.27 to 3.77]; p < 0.001), joint inflammation (OR 1.89 [95% CI 1.16 to 3.09]; p = 0.01), and a history of opioid use (OR 2.17 [95% CI 1.69 to 2.79]; p < 0.001). Survivorship analysis similarly revealed that older age (hazard ratio 1.08 [95% CI 1.07 to 1.09]; p < 0.001), osteoarthritis (HR 2.53 [95% CI 2.13 to 3.01]; p < 0.001), joint inflammation (HR 1.53 [95% CI 1.10 to 2.11]; p = 0.01), a history of opioid use (HR 2.02 [95% CI 1.71 to 2.38]; p < 0.001), and smoking (HR 1.55 [95% CI 1.14 to 2.11]; p = 0.005), were independently associated with increased odds of conversion to THA within 2 years after hip arthroscopy for FAI. CONCLUSIONS: Although the findings of this study are limited and should not be taken in isolation, patients with FAI who are older, carry diagnoses of inflammatory or degenerative articular disease, or who use opioids or smoke should be counseled about a potentially increased risk of undergoing early conversion to THA after hip arthroscopy. Future studies to further examine the effect of these diagnoses in prospectively collected cohorts, incorporating radiographic and patient-reported outcome measures, are needed. LEVEL OF EVIDENCE: Level III, prognostic study.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know.

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.

Monitoring changes in knee surface morphology after anterior cruciate ligament reconstruction surgery using 3Dsurface scanning.

STUDY DESIGN: Prospective case series. BACKGROUND: After surgical reconstruction of the anterior cruciate ligament, recovery to pre-injury levels of knee function is challenging. Postoperative edema and muscle atrophy are common roadblocks to full function and are evident in changes to the surface morphology of the knee. There are currently few accessible objective tools to accurately track these morphological changes. OBJECTIVES: We aimed to determine if 3D surface scanning can be used to monitor changes in the external shape of the knee after surgery and throughout the rehabilitation process. METHODS: Thirty participants had 3D surface scans taken of their knee, along with questionnaire-based functional outcomes prior to surgery (baseline), and at two-week, six-week, 12-week, and 26-week timepoints post-surgery. Volumetric changes relative to pre-op were assessed using generalized linear growth models for key anatomical regions and correlated with functional outcomes. RESULTS: Significant swelling of the patella region compared to baseline was evident immediately after surgery (14%, p < 0.001), before returning to pre-operative levels. Changes in volume at this region were significantly associated with patient-reported functional outcomes. Reductions in volume of the regions corresponding to the vastus medialis and lateralis muscles were significant at 12 weeks post-surgery (p = 0.018 and 0.01 respectively) but returned to baseline levels at six months. CONCLUSION: We demonstrate the use of 3D surface scanning as a method for capturing detailed measurements of knee surface morphology after surgery. Significant changes in external morphology are evident during the rehabilitation process.

THE USE OF MICROSOFT KINECT ™ FOR ASSESSING READINESS OF RETURN TO SPORT AND INJURY RISK EXERCISES: A VALIDATION STUDY.

INTRODUCTION: Assessing readiness of return to sport after procedures such as anterior cruciate ligament (ACL) reconstruction is a complex process, complicated by the pressures that athletes face in returning to sport as quickly as possible. Advances in motion analysis have been able to demonstrate movements that are risk factors for initial ACL injury and subsequent reinjury after reconstruction. An inexpensive, objective measure is needed to determine when athletes are ready to return to sport after ACL reconstruction. PURPOSE: The aim of this study was to compare the use of a single camera, markerless motion capture technology to 3D motion capture during lower extremity movements that pose as risk factors for ACL injury. STUDY DESIGN: Cross Sectional Study. METHODS: This study assessed the validity of the Microsoft Kinect™ against an established 3-dimensional motion analysis system in 20 healthy subjects. Knee kinematics were assessed during impact activity in the coronal and sagittal plane specifically evaluating peak knee valgus and peak knee flexion during single leg hop and jump from box exercises. Intraclass correlation coefficients and 95% limits of agreement (LoA) were determined for each kinematic variable. RESULTS: For the single leg hop, the mean absolute difference in the sagittal plane was 10.4 ° (95% LoA [-11.7 °, 26.8 °]), and in the frontal plane was 5.31 ° (95% LoA [-8 °, 13.9 °]). Similarly, for the jump from box landing on one leg, there was a difference of 7.96 ° (95% LoA [-17.7 °, 21.3 °]) and 4.69 ° (95% LoA [-6.3 °, 12.6 °]) respectively. For the jump from box, two-foot land, turn and pivot, the mean absolute difference between the systems was 7.39 ° (95% LoA [-17.8 °, 19.7 °]) in the sagittal and 4.22 ° (95% LoA [-5.9 °, 11.6 °]) in the frontal plane respectively. Intraclass correlation coefficients for each activity ranged from 0.553 to 0.759. CONCLUSION: The results from the Microsoft Kinect™ were found to be in poor agreement with those from a standard motion capture system. Measuring complex lower extremity movements with the Microsoft Kinect™ does not provide adequate enough information to use as an assessment tool for injury risk and return to sport timing. LEVEL OF EVIDENCE: Level III.