Homozygous CNP Mutation and Neurodegeneration in Weimaraners: Myelin Abnormalities and Accumulation of Lipofuscin-like Inclusions.

A progressive neurological disorder was observed in a male neutered Weimaraner. Clinical signs included fecal incontinence, lethargy, moderate paraparesis, proprioceptive pelvic limb ataxia, falling, cognitive decline, incoordination, decreased interest in food, changes in posture, and episodes of trance-like behavior. Neurologic signs were first observed at approximately 4 years, 10 months of age and progressed slowly. Magnetic resonance imaging showed generalized brain atrophy with areas of white matter pathology. Humane euthanasia was elected at 6 years, 7 months of age due to increasing severity of the neurological signs. Autofluorescent intracellular granules were observed in the cerebral and cerebellar cortexes, optic nerve, and cardiac muscle of the affected dog. These abnormal inclusions in the cerebral cortex and cardiac muscle immunolabeled with antibodies to mitochondrial ATP synthase subunit c protein, like that observed in the neuronal ceroid lipofuscinosis group of lysosomal storage diseases. Immunolabeling also demonstrated pronounced neuroinflammation in brain tissues. The ultrastructural appearances of the disease-related inclusion bodies in the brain and optic nerve were quite variable. The ultrastructure and locations of many of the inclusions in the nervous tissues suggested that they were derived, at least in part, from the myelin surrounding axons. The storage bodies in the cardiac muscle were located in mitochondria-rich regions and consisted of parallel arrays of membrane-like components interspersed with electron-dense flocculent material. The disease was characterized by pronounced abnormalities in the myelin of the brain and optic nerve consisting of distinctive areas of ballooning between the layers of myelin. The whole genome sequence generated from the affected dog contained a homozygous G-to-A missense mutation in CNP, which encodes proteins with CNPase enzyme activity and a structural role in myelin. The mutation predicts a Thr42Met amino acid sequence substitution. Genotyping of archived Weimaraner DNA samples identified an additional G > A variant homozygote with a clinical history and brain lesions similar to those of the proband. Of 304 Weimaraners and over 4000 other dogs of various breeds, the proband and the other Weimaraner that exhibited similar signs were the only two that were homozygous for the CNP missense variant. CNPase immunolabeling was widespread in brain tissues from normal dogs but was undetectable in the same tissues from the proband. Based on the clinical history, fluorescence and electron-microscopy, immunohistochemistry, and molecular genetic findings, the late-onset Weimaraner disorder likely results from the missense mutation that results in CNPase deficiency, leading to myelin abnormalities, accumulation of lysosomal storage bodies, and brain atrophy. Similar disorders have been associated with different CNP variants in Dalmatians and in human subjects.

Impact of Prolonged Sport Stoppage on Knee Injuries in High School Athletes: An Ecological Study.

CONTEXT: In March 2020, public health concerns resulted in school closure throughout the United States. The prolonged sport cessation may affect knee injury risk in high school athletes. The purpose of this study was to describe and compare risk of knee injuries in high school athletes during 2019-2020 and 2020-2021 academic years, and stratify by gender, severity, mechanism of injury, injury type, and knee anatomic region. DESIGN: Historical-prospective cohort study. METHODS: This historical-prospective cohort study included 176 schools in 6 states matched by sport participation in control and COVID years from July 1, 2019 to June 30, 2021. Injury rates per 1000 athletes per year were calculated with 95% confidence intervals. A negative binomial regression was performed to assess potential differences in knee injuries between academic years. RESULTS: 94,847 and 72,521 high school athletes participated in the 2019-2020 (19-20) and 2020-2021 (20-21) seasons. Knee injury risk was higher in the 20-21 season (19-20: 28.89% [27.82-29.96]; 20-21: 33.82% [32.50-35.14]). Risk increased for male athletes from 2019-2020 to 2020-2021 (19-20: 29.42% [28.01-30.83]; 20-21: 40.32% [38.89-41.75]). Female knee injury risk was similar between years (19-20: 25.78% [24.29-27.27]; 20-21: 26.03% [24.31-27.75]). Knee injuries increased by a ratio of 1.2 ([95% CI, 1.1-1.3], P < .001) during 2020-2021. CONCLUSIONS: Knee injury risk and relative risk increased among males in 2020-2021. Results indicate changes in knee injury risk following return from COVID shelter in place among high school athletes and implicate potential negative downstream effects of interrupted sports training and participation on high school injury risk.

Development of an exercise therapy referral clinical support tool for patients with osteoporosis at risk for falls.

BACKGROUND: The purpose of this study was to develop a clinical support tool for osteoporosis clinic providers to support risk assessment and referrals for evidence-based exercise therapy programs. METHODS: A sequential Delphi method was used with a multidisciplinary group of national falls experts, to provide consensus on referral to exercise therapy for patients at risk for falls. The Delphi study included a primary research team, expert panel, and clinical partners to answer the questions: (1) "What patient characteristics are needed to develop a clinical support tool?"; (2) "What are the recommended exercise referrals for patients with osteoporosis at risk for falls?" The consensus process consisted of two rounds with 8 weeks between meetings. Two qualitative researchers analyzed the data using a modified version of a matrix analysis approach. RESULTS: The following were the most important variables to include when determining exercise therapy referrals for patients with osteoporosis: Patient history and demographics, falls history over the last year, current physical function and balance, caregiver and transportation status, socioeconomic and insurance status, and patient preference. Potential exercise therapy referrals included one-on-one physical therapy, group physical therapy, home health, community-based exercise programs, and not acceptable for exercise therapy. CONCLUSIONS: Patient characteristics including patient history, physical function and balance performance, socioeconomic and insurance status, and patient preference for exercise therapy are important to inform both the medical provider and patient with osteoporosis to choose the most appropriate exercise therapy referral. Adoption of the algorithmic suggestions may have a significant impact on uptake and adherence to exercise therapy, ultimately improving patient physical function and reducing falls risk.

Initial versus Subsequent Injury and Illness and Temporal Trends Among Professional Hockey Players.

Background: Research is limited investigating injuries/illness incidence among National Hockey League (NHL) players. This study sought to establish injury/illness incidence, initial versus subsequent injury risk among NHL players, and determine temporal trends of injury and illness incidence. Hypothesis: Variations in injury incidence by body region, and initial versus subsequent injury would be observed among positions. Study Design: Retrospective cohort study. Methods: Publicly available data were utilized. NHL players 18 years or older between 2007-2008 to 2018-2019 were included. Injury and illness was stratified by position and body segment. Incidence rate (IR), and initial versus subsequent injury and illness risk ratios were calculated. Temporal trends were reported. Results: Nine thousand, seven-hundred and thirty four injuries and illnesses were recorded. Centers had the highest overall IR at 15.14 per 1000 athlete game exposures (AGEs) (95%CI:15.12-15.15) and were 1.4 times more likely to sustain a subsequent injury compared to other positions. The groin/hip/thigh was the most commonly injured body region with an IR of 1.14 per 1000 AGEs (95%CI:1.06-1.21), followed by the head/neck (0.72 per 1000 AGEs, 95%CI:0.66-0.78). Combined injury and illness IR peaked in 2009-2010 season at 12.01 (95%CI: 11.22-12.79). The groin/hip/thigh demonstrated peak incidence during the 2007-2008 season (2.53, 95%CI:2.17-2.90); head/neck demonstrated a peak incidence in 2010-2011 season (Overall: 1.03, 95%CI:0.81-1.26). Injuries reported as 'lower body' increased over time. Conclusions: Positional differences were observed; centers demonstrated the highest overall IR, and subsequent injury risk. Injury by body region was similar to previous literature. Head/neck and concussion decreased over time supporting rule changes in body checking and visor wear. Clinicians should be aware that 'lower body' injuries increased over time; therefore, injuries to the groin/hip/thigh or knee are likely underreported. Level of Evidence: Level 3.

Comparing Self-Reported Running Distance and Pace With a Commercial Fitness Watch Data: Reliability Study.

BACKGROUND: There is substantial evidence exploring the reliability of running distance self-reporting and GPS wearable technology, but there are currently no studies investigating the reliability of participant self-reporting in comparison to GPS wearable technology. There is also a critical sports science and medical research gap due to a paucity of reliability studies assessing self-reported running pace. OBJECTIVE: The purpose of this study was to assess the reliability of weekly self-reported running distance and pace compared to a commercial GPS fitness watch, stratified by sex and age. These data will give clinicians and sports researchers insights into the reliability of runners' self-reported pace, which may improve training designs and rehabilitation prescriptions. METHODS: A prospective study of recreational runners was performed. Weekly running distance and average running pace were captured through self-report and a fitness watch. Baseline characteristics collected included age and sex. Intraclass correlational coefficients were calculated for weekly running distance and running pace for self-report and watch data. Bland-Altman plots assessed any systemic measurement error. Analyses were then stratified by sex and age. RESULTS: Younger runners reported improved weekly distance reliability (median 0.93, IQR 0.92-0.94). All ages demonstrated similar running pace reliability. Results exhibited no discernable systematic bias. CONCLUSIONS: Weekly self-report demonstrated good reliability for running distance and moderate reliability for running pace in comparison to the watch data. Similar reliability was observed for male and female participants. Younger runners demonstrated improved running distance reliability, but all age groups exhibited similar pace reliability. Running pace potentially should be monitored through technological means to increase precision.

An Expedited Sling Immobilization Protocol After Isolated Biceps Tenodesis Results in Clinical and Patient-Reported Postoperative Outcomes Equivalent to a Standard Rehabilitation Protocol.

Purpose: To characterize clinical and patient-reported outcomes for patients after isolated biceps tenodesis (BT) who underwent either standard or expedited sling immobilization protocols following surgery. Methods: This retrospective cohort study compared patients who were assigned to use a sling for either 4 to 6 weeks (standard) or 0 to 2 weeks (expedited) following an isolated BT. Primary endpoint included rate of re-rupture, surgical revision, loss of fixation, and Popeye deformity. Secondary endpoints included shoulder range of motion (ROM) as well as pre- and postoperative patient-reported outcomes (PROs) of pain and function. Missing data were managed via multiple imputation with chained equations. Complication prevalence 95% confidence intervals were calculated using the Clopper Pearson method and a series of hierarchical mixed effects linear regressions were performed to assess differences between sling interventions in PROs and ROM. Results: The average age of the standard cohort (n = 66) was 49 years (±14 years), and the average age of the expedited cohort (n = 69) was 47 years (±14 years). The expedited and standardized cohorts demonstrated 0.4 and 0.3 complications per 10,000 exposure days, respectively, with no significant difference between groups (1.4 [95% confidence interval 0.2-10.0], P = .727). There was no demonstrated difference in forward flexion, abduction, or external ROM. The expedited group had less improvement in visual analog scale for pain scores that was not clinically significant and there were no differences in PROs of function. Conclusions: No statistically significant difference in the rate of re-rupture, surgical revision, loss of fixation, or Popeye deformity was noted between protocols after isolated BT. Furthermore, there were no clinically significant differences in ROM or PROs identified between protocols after isolated BT. This study suggests that patients who have undergone isolated BT may safely discontinue sling use within 2 weeks after surgery. Level of Evidence: Level III, retrospective comparative study.

Effects of Ball Size and Weight on Throwing Kinematics and Kinetics in Youth Baseball Athletes.

BACKGROUND: In baseball, youth athletes play on smaller fields with shorter distances between bases, shorter pitching distances, and smaller mounds. Despite this, youth athletes use baseballs weighing the same amount as those used at the professional level, possibly predisposing youth baseball players to injuries. PURPOSE: (1) To determine the effects of throwing a smaller, lighter, and both smaller and lighter baseball on throwing arm stress in youth athletes and (2) to also investigate how changing the ball size and weight would affect elbow varus torque, shoulder distraction force, and throwing arm internal rotation velocity during the throwing motion. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: This cross-sectional cohort study analyzed the kinematics and kinetics of 38 youth baseball players (mean age, 8.3 ± 0.8 years) throwing a baseball modified in size and weight. Three-dimensional motion data were collected using a retroreflective marker set and a 12-camera motion analysis system. Full-body kinematics and kinetics were calculated using commercial software. Participants threw 5 different types of baseballs 3 times each, in random order, with full effort from a pitching mound to a target 14 m away. The balls used were a 5-oz regular baseball, 5-oz (0.142-kg) baseball with a 5% reduced circumference, 4-oz (0.113-kg) baseball, 4-oz baseball with a 5% reduced circumference, and 3-oz (0.085-kg) baseball. Analysis of variance was used to determine statistical differences in elbow varus torque, shoulder distraction force, and throwing arm internal rotation velocity among baseball types. The Tukey post hoc test was used to further investigate differences between the ball groups, considering P < .05 to be significant. RESULTS: Analysis of variance detected a significant difference in elbow varus torque among ball groups (P = .024). The Tukey post hoc test revealed a moderate difference in elbow varus torque between the 5-oz baseball (4.73 ± 1.06 percentage body weight × height [%BW × H]) and 3-oz baseball (4.06 ± 0.83 %BW × H) (P = .017; d = 0.677 [95% CI, 0.08-1.27]). No significant differences were found in shoulder distraction force or throwing arm internal rotation velocity among ball groups. CONCLUSION: Compared with a 5-oz baseball, throwing a 3-oz baseball resulted in decreased elbow varus torque with a moderate effect size.

Open science practices need substantial improvement in prognostic model studies in oncology using machine learning.

OBJECTIVE: To describe the frequency of open science practices in a contemporary sample of studies developing prognostic models using machine learning methods in the field of oncology. STUDY DESIGN AND SETTING: We conducted a systematic review, searching the MEDLINE database between December 1, 2022, and December 31, 2022, for studies developing a multivariable prognostic model using machine learning methods (as defined by the authors) in oncology. Two authors independently screened records and extracted open science practices. RESULTS: We identified 46 publications describing the development of a multivariable prognostic model. The adoption of open science principles was poor. Only one study reported availability of a study protocol, and only one study was registered. Funding statements and conflicts of interest statements were common. Thirty-five studies (76%) provided data sharing statements, with 21 (46%) indicating data were available on request to the authors and seven declaring data sharing was not applicable. Two studies (4%) shared data. Only 12 studies (26%) provided code sharing statements, including 2 (4%) that indicated the code was available on request to the authors. Only 11 studies (24%) provided sufficient information to allow their model to be used in practice. The use of reporting guidelines was rare: eight studies (18%) mentioning using a reporting guideline, with 4 (10%) using the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis Or Diagnosis statement, 1 (2%) using Minimum Information About Clinical Artificial Intelligence Modeling and Consolidated Standards Of Reporting Trials-Artificial Intelligence, 1 (2%) using Strengthening The Reporting Of Observational Studies In Epidemiology, 1 (2%) using Standards for Reporting Diagnostic Accuracy Studies, and 1 (2%) using Transparent Reporting of Evaluations with Nonrandomized Designs. CONCLUSION: The adoption of open science principles in oncology studies developing prognostic models using machine learning methods is poor. Guidance and an increased awareness of benefits and best practices of open science are needed for prediction research in oncology.

Can a Psychologic Profile Predict Successful Return to Full Duty After a Musculoskeletal Injury?

BACKGROUND: Psychologic variables have been shown to have a strong relationship with recovery from injury and return to work or sports. The extent to which psychologic variables predict successful return to work in military settings is unknown. QUESTIONS/PURPOSES: In a population of active duty soldiers, (1) can a psychologic profile determine the risk of injury after return to full duty? (2) Do psychologic profiles differ between soldiers sustaining injuries in the spine (thoracic or lumbar) and those with injuries to the lower extremities? METHODS: Psychologic variables were assessed in soldiers returning to full, unrestricted duty after a recent musculoskeletal injury. Most of these were noncombat injuries from work-related physical activity. Between February 2016 and September 2017, 480 service members who were cleared to return to duty after musculoskeletal injuries (excluding those with high-velocity collisions, pregnancy, or amputation) were enrolled in a study that tracked subsequent injuries over the following year. Of those, we considered individuals with complete 12-month follow-up data as potentially eligible for analysis. Based on that, approximately 2% (8 of 480) were excluded because they did not complete baseline surveys, approximately 2% (11 of 480) were separated from the military during the follow-up period and had incomplete injury data, 1% (3 of 480) were excluded for not serving in the Army branch of the military, and approximately 2% (8 of 480) were excluded because they were not cleared to return to full duty. This resulted in 450 soldiers analyzed. Individuals were 86% (385 of 450) men; 74% (331 of 450) had lower extremity injuries and 26% (119 of 450) had spinal injuries, including soft tissue aches and pains (for example, strains and sprains), fractures, and disc herniations. Time-loss injury within 1 year was the primary outcome. While creating and validating a new prediction model using only psychological variables, 19 variables were assessed for nonlinearity, further factor selection was performed through elastic net, and models were internally validated through 2000 bootstrap iterations. Performance was deciphered through calibration, discrimination (area under the curve [AUC]), R 2 , and calibration in the large. Calibration assesses predicted versus actual risk by plotting the x and y intersection of these values; the more similar predicted risk values are to actual ones, the closer the slope of the line formed by the intersection points of all subjects is to equaling "1" (optimal calibration). Likewise, perfect discrimination (predicted injured versus actual injured) presents as an AUC of 1. Perfect calibration in the large would equal 0 because it represents the average predicted risk versus the actual outcome rate. Sensitivity analyses stratified groups by prior injury region (thoracic or lumbar spine and lower extremity) as well as the severity of injury by days of limited duty (moderate [7-27 days] and severe [28 + days]). RESULTS: A model comprising primarily psychologic variables including depression, anxiety, kinesiophobia, fear avoidance beliefs, and mood did not adequately determine the risk of subsequent injury. The derived logistic prediction model had 18 variables: R 2 = 0.03, calibration = 0.63 (95% confidence interval [CI] 0.30 to 0.97), AUC = 0.62 (95% CI 0.52 to 0.72), and calibration in the large = -0.17. Baseline psychologic profiles between body regions differed only for depression severity (mean difference 1 [95% CI 0 to 1]; p = 0.04), with greater mean scores for spine injuries than for lower extremity injuries. Performance was poor for those with prior spine injuries compared with those with lower extremity injuries (AUC 0.50 [95% CI 0.42 to 0.58] and 0.63 [95% CI 0.57 to 0.69], respectively) and moderate versus severe injury during the 1-year follow-up (AUC 0.61 [95% CI 0.51 to 0.71] versus 0.64 [95% CI 0.64 to 0.74], respectively). CONCLUSION: The psychologically based model poorly predicted subsequent injury. This study does not minimize the value of assessing the psychologic profiles of injured athletes, but rather suggests that models looking to identify injury risk should consider a multifactorial approach that also includes other nonpsychologic factors such as injury history. Future studies should refine the most important psychologic constructs that can add the most value and precision to multifactorial models aimed at identifying the risk of injury. LEVEL OF EVIDENCE: Level III, prognostic study.

Feasibility of Implementing Patient-Reported and Physical Performance Measures to Identify and Manage Fall Risk in Older Adults Within a Secondary Fracture Clinic.

The purpose of this study was to assess the feasibility of implementing both electronic and in-person assessments to assess falls risk in an older adult secondary fracture clinic. Electronic data capture feasibility was defined as the proportion of patients that completed the electronic questionnaires prior to their clinic visit. In-clinic feasibility was defined in two ways: (1) the proportion of patients that consented to participate at their clinic visit; (2) time to complete testing. Patients were contacted electronically through their health system portal for electronic consent. Patients were invited to complete consent, the STopping Elderly Accidents, Deaths, and Injuries (STEADI) falls risk assessment tool, and the visual analog scale (VAS) for pain. The Short Physical Performance Battery (SPPB) was performed at the clinic visit. A total of 310 patients were contacted electronically. No patients (0%) provided consent through their health portal. Of the 310 patients, 200 (65%) consented in person (Ineligible: 67 [21%]; Declined: 43 [14%]), resulting in an 82% response rate. In-person data collection took a median of 38.48 (Range: 12.34-54.30) minutes to complete. It was not feasible to contact and collect older adult patient data electronically prior to clinic; but, was feasible to obtain these patient-reported outcomes and physical performance data in person.

Up Front and Open? Shrouded in Secrecy? Or Somewhere in Between? A Meta-Research Systematic Review of Open Science Practices in Sport Medicine Research.

OBJECTIVE: To investigate open science practices in research published in the top 5 sports medicine journals from May 1, 2022, and October 1, 2022. DESIGN: A meta-research systematic review. LITERATURE SEARCH: Open science practices were searched in MEDLINE. STUDY SELECTION CRITERIA: We included original scientific research published in one of the identified top 5 sports medicine journals in 2022 as ranked by Clarivate: (1) British Journal of Sports Medicine, (2) Journal of Sport and Health Science, (3) American Journal of Sports Medicine, (4) Medicine and Science in Sports and Exercise, and (5) Sports Medicine-Open. Studies were excluded if they were systematic reviews, qualitative research, gray literature, or animal or cadaver models. DATA SYNTHESIS: Open science practices were extracted in accordance with the Transparency and Openness Promotion guidelines and patient and public involvement. RESULTS: Two hundred forty-three studies were included. The median number of open science practices in each study was 2, out of a maximum of 12 (range: 0-8; interquartile range: 2). Two hundred thirty-four studies (96%, 95% confidence interval [CI]: 94%-99%) provided an author conflict-of-interest statement and 163 (67%, 95% CI: 62%-73%) reported funding. Twenty-one studies (9%, 95% CI: 5%-12%) provided open-access data. Fifty-four studies (22%, 95% CI: 17%-27%) included a data availability statement and 3 (1%, 95% CI: 0%-3%) made code available. Seventy-six studies (32%, 95% CI: 25%-37%) had transparent materials and 30 (12%, 95% CI: 8%-16%) used a reporting guideline. Twenty-eight studies (12%, 95% CI: 8%-16%) were preregistered. Six studies (3%, 95% CI: 1%-4%) published a protocol. Four studies (2%, 95% CI: 0%-3%) reported an analysis plan a priori. Seven studies (3%, 95% CI: 1%-5%) reported patient and public involvement. CONCLUSION: Open science practices in the sports medicine field are extremely limited. The least followed practices were sharing code, data, and analysis plans. J Orthop Sports Phys Ther 2023;53(12):1-13. Epub 20 October 2023. doi:10.2519/jospt.2023.12016.

Baseball Pitchers who Suffer Latissimus Dorsi and Teres Major Tendon Injuries Have a High Return to Play Rate After Either Operative or Nonoperative Treatment.

Purpose: To provide a concise overview of the prevalence, diagnostic workup, management options, surgical techniques, and reported outcomes in the treatment of latissimus dorsi (LD) and teres major (TM) injuries in professional baseball pitchers. Methods: A systematic review of studies reporting on professional baseball players who sustained LD or TM injuries was performed. Data were collected including patient presentation, injury management strategies, return-to-play (RTP) rates, time to RTP, patient-reported outcome measures, player performance after RTP, preinjury factors associated with injury, and complications. Results: Nine studies with 159 professional baseball players with a LD or TM injury were identified. All studies (2 retrospective cohort studies with high risk of bias and 7 case series) reported shoulder pain after pitching, and magnetic resonance imaging was performed in all cases to confirm diagnosis. Twenty-three patients underwent surgical treatment, whereas 136 patients underwent nonsurgical treatment. Overall RTP rates and performance between surgical and nonsurgical groups were similar (75% to 100% vs 75% to 93%), although the largest study reported improved performance with surgery. Two studies described a surgical technique with a posterior axillary approach and endosteal button fixation of the LD tendon. All studies reported a progressive strengthening and throwing program prior to returning to sport. Conclusion: Professional baseball players who suffer a LD or TM injury have predictable clinical presentations and imaging findings. There is a high RTP rate and performance with both surgical and nonsurgical management. The heterogeneity and low level of evidence of available literature precludes comparative conclusions between treatment approaches. Level of Evidence: IV systematic review of Level III and IV studies.

Assessing the association between on-field heading technique and head impact kinematics in a cohort of female youth soccer players.

There is concern that exposure to soccer headers may be associated with neurological sequelae. Training proper heading technique represents a coachable intervention that may reduce head acceleration exposure. The objective was to assess relationships between heading technique and head kinematics in female youth soccer players. Fourteen players (mean age = 14.4 years) wore instrumented mouthpieces during practices and games. Headers were reviewed by three raters to assign a technique score. Mixed models and LASSO regression evaluated associations of technique with peak linear acceleration (PLA), rotational acceleration (PRA), rotational velocity (PRV), and head impact power ratio (HIP Ratio) while adjusting for session type and ball delivery. Two hundred eighty-nine headers (n = 212 standing, n = 77 jumping) were analyzed. Technique score (p = 0.043) and the technique score - session type interaction (p = 0.004) were associated with PRA of standing headers, whereby each 10-unit increase in technique score was associated with an 8.6% decrease in PRA during games but a 5.1% increase in PRA during practices. Technique was not significantly associated with any other kinematic metrics; however, peak kinematics tended to decrease as technique score increased. LASSO regression identified back extension and shoulder/hip alignment as important predictors of peak kinematics. Additional research on heading technique and head acceleration is recommended.

A Homozygous MAN2B1 Missense Mutation in a Doberman Pinscher Dog with Neurodegeneration, Cytoplasmic Vacuoles, Autofluorescent Storage Granules, and an α-Mannosidase Deficiency.

A 7-month-old Doberman Pinscher dog presented with progressive neurological signs and brain atrophy suggestive of a hereditary neurodegenerative disorder. The dog was euthanized due to the progression of disease signs. Microscopic examination of tissues collected at the time of euthanasia revealed massive accumulations of vacuolar inclusions in cells throughout the central nervous system, suggestive of a lysosomal storage disorder. A whole genome sequence generated with DNA from the affected dog contained a likely causal, homozygous missense variant in MAN2B1 that predicted an Asp104Gly amino acid substitution that was unique among whole genome sequences from over 4000 dogs. A lack of detectable α-mannosidase enzyme activity confirmed a diagnosis of a-mannosidosis. In addition to the vacuolar inclusions characteristic of α-mannosidosis, the dog exhibited accumulations of autofluorescent intracellular inclusions in some of the same tissues. The autofluorescence was similar to that which occurs in a group of lysosomal storage disorders called neuronal ceroid lipofuscinoses (NCLs). As in many of the NCLs, some of the storage bodies immunostained strongly for mitochondrial ATP synthase subunit c protein. This protein is not a substrate for α-mannosidase, so its accumulation and the development of storage body autofluorescence were likely due to a generalized impairment of lysosomal function secondary to the accumulation of α-mannosidase substrates. Thus, it appears that storage body autofluorescence and subunit c accumulation are not unique to the NCLs. Consistent with generalized lysosomal impairment, the affected dog exhibited accumulations of intracellular inclusions with varied and complex ultrastructural features characteristic of autophagolysosomes. Impaired autophagic flux may be a general feature of this class of disorders that contributes to disease pathology and could be a target for therapeutic intervention. In addition to storage body accumulation, glial activation indicative of neuroinflammation was observed in the brain and spinal cord of the proband.

Organizational risk profiling and education associated with reduction in professional pitching arm injuries: a natural experiment.

Background: Risk profiling and education are strategies implemented to help reduce injury risk; however, currently. there is little evidence on the effect of these interventions on injury incidence. The purpose of this study was to evaluate the influence of risk profiling and education on upper extremity injury incidence in minor league (MiLB) pitchers and to stratify by injury severity. Methods: A prospective natural experiment study was conducted from 2013 to 2019 on MiLB pitchers. Beginning in the 2015 season, pitchers were examined and risk profiled for upper extremity injury. Shoulder external, internal, total range of motion, horizontal adduction, and humeral torsion were measured. Organizational risk profiling and education was implemented starting in 2015, based on preseason assessments. Chi-squared test was performed to investigate potential differences between shoulder range of motion risk categories between 2013-2014 (pre) and 2015-2019 (post) seasons. Interrupted time series analyses were performed to assess the association between organizational risk profiling and education on arm injury in MiLB pitchers and were repeated for 7-27 and 28+ day injury severity. Results: 297 pitchers were included (pre: 119, post: 178). Upper extremity injury incidence was 1.5 injuries per 1000 athletic exposures. Pitchers in the 2015-2019 seasons demonstrated increased preseason shoulder injury risk for internal (P = .003) and external (P = .007), while the 2013-2014 seasons demonstrated greater horizontal adduction risk (P = .04). There were no differences between seasons for total range of motion risk (P =.76). Risk profiling and education resulted in an adjusted time loss upper extremity injury reduction for the 2015-2019 seasons (0.68 (95% CI: 0.47, 0.99)), which impacted 7-27 days (0.62 (95% CI: 0.42, 0.93)) but not for 28+ days (0.71 (95% CI: 0.47, 1.06)) time loss. There was no reduction in combined trunk and lower extremity injuries for the 2015-2019 seasons (1.55 (95% CI: 0.79, 3.01)). Conclusions: Organizational risk profiling and education appear to reduce professional pitching overall and 7-27-day upper extremity injury risk by 33%-38%. There was no difference in trunk and lower extremity injuries over the period, strengthening the reduction in upper extremity injury risk results. This suggests that while injury risk increased over time, organizational risk profiling mitigated the expected increase in upper extremity injury rates. Risk profiling and education can be used as a clinical screening and intervention tool to help decrease upper extremity injuries in professional baseball populations.

Sample size requirements are not being considered in studies developing prediction models for binary outcomes: a systematic review.

BACKGROUND: Having an appropriate sample size is important when developing a clinical prediction model. We aimed to review how sample size is considered in studies developing a prediction model for a binary outcome. METHODS: We searched PubMed for studies published between 01/07/2020 and 30/07/2020 and reviewed the sample size calculations used to develop the prediction models. Using the available information, we calculated the minimum sample size that would be needed to estimate overall risk and minimise overfitting in each study and summarised the difference between the calculated and used sample size. RESULTS: A total of 119 studies were included, of which nine studies provided sample size justification (8%). The recommended minimum sample size could be calculated for 94 studies: 73% (95% CI: 63-82%) used sample sizes lower than required to estimate overall risk and minimise overfitting including 26% studies that used sample sizes lower than required to estimate overall risk only. A similar number of studies did not meet the ≥ 10EPV criteria (75%, 95% CI: 66-84%). The median deficit of the number of events used to develop a model was 75 [IQR: 234 lower to 7 higher]) which reduced to 63 if the total available data (before any data splitting) was used [IQR:225 lower to 7 higher]. Studies that met the minimum required sample size had a median c-statistic of 0.84 (IQR:0.80 to 0.9) and studies where the minimum sample size was not met had a median c-statistic of 0.83 (IQR: 0.75 to 0.9). Studies that met the ≥ 10 EPP criteria had a median c-statistic of 0.80 (IQR: 0.73 to 0.84). CONCLUSIONS: Prediction models are often developed with no sample size calculation, as a consequence many are too small to precisely estimate the overall risk. We encourage researchers to justify, perform and report sample size calculations when developing a prediction model.

Barriers and facilitators to implementation of musculoskeletal injury mitigation programmes for military service members around the world: a scoping review.

INTRODUCTION: Musculoskeletal injury (MSK-I) mitigation and prevention programmes (MSK-IMPPs) have been developed and implemented across militaries worldwide. Although programme efficacy is often reported, development and implementation details are often overlooked, limiting their scalability, sustainability and effectiveness. This scoping review aimed to identify the following in military populations: (1) barriers and facilitators to implementing and scaling MSK-IMPPs; (2) gaps in MSK-IMPP research and (3) future research priorities. METHODS: A scoping review assessed literature from inception to April 2022 that included studies on MSK-IMPP implementation and/or effectiveness in military populations. Barriers and facilitators to implementing these programmes were identified. RESULTS: From 132 articles, most were primary research studies (90; 68.2%); the remainder were review papers (42; 31.8%). Among primary studies, 3 (3.3%) investigated only women, 62 (69%) only men and 25 (27.8%) both. Barriers included limited resources, lack of stakeholder engagement, competing military priorities and equipment-related factors. Facilitators included strong stakeholder engagement, targeted programme design, involvement/proximity of MSK-I experts, providing MSK-I mitigation education, low burden on resources and emphasising end-user acceptability. Research gaps included variability in reported MSK-I outcomes and no consensus on relevant surveillance metrics and definitions. CONCLUSION: Despite a robust body of literature, there is a dearth of information about programme implementation; specifically, barriers or facilitators to success. Additionally, variability in outcomes and lack of consensus on MSK-I definitions may affect the development, implementation evaluation and comparison of MSK-IMPPs. There is a need for international consensus on definitions and optimal data reporting elements when conducting injury risk mitigation research in the military.

Poor handling of continuous predictors in clinical prediction models using logistic regression: a systematic review.

BACKGROUND AND OBJECTIVES: When developing a clinical prediction model, assuming a linear relationship between the continuous predictors and outcome is not recommended. Incorrect specification of the functional form of continuous predictors could reduce predictive accuracy. We examine how continuous predictors are handled in studies developing a clinical prediction model. METHODS: We searched PubMed for clinical prediction model studies developing a logistic regression model for a binary outcome, published between July 01, 2020, and July 30, 2020. RESULTS: In total, 118 studies were included in the review (18 studies (15%) assessed the linearity assumption or used methods to handle nonlinearity, and 100 studies (85%) did not). Transformation and splines were commonly used to handle nonlinearity, used in 7 (n = 7/18, 39%) and 6 (n = 6/18, 33%) studies, respectively. Categorization was most often used method to handle continuous predictors (n = 67/118, 56.8%) where most studies used dichotomization (n = 40/67, 60%). Only ten models included nonlinear terms in the final model (n = 10/18, 56%). CONCLUSION: Though widely recommended not to categorize continuous predictors or assume a linear relationship between outcome and continuous predictors, most studies categorize continuous predictors, few studies assess the linearity assumption, and even fewer use methodology to account for nonlinearity. Methodological guidance is provided to guide researchers on how to handle continuous predictors when developing a clinical prediction model.