The Performance of ChatGPT on the American Society for Surgery of the Hand Self-Assessment Examination.

BACKGROUND: This study aims to compare the performance of ChatGPT-3.5 (GPT-3.5) and ChatGPT-4 (GPT-4) on the American Society for Surgery of the Hand (ASSH) Self-Assessment Examination (SAE) to determine their potential as educational tools. METHODS: This study assessed the proportion of correct answers to text-based questions on the 2021 and 2022 ASSH SAE between untrained ChatGPT versions. Secondary analyses assessed the performance of ChatGPT based on question difficulty and question category. The outcomes of ChatGPT were compared with the performance of actual examinees on the ASSH SAE. RESULTS: A total of 238 questions were included in the analysis. Compared with GPT-3.5, GPT-4 provided significantly more correct answers overall (58.0% versus 68.9%, respectively; P = 0.013), on the 2022 SAE (55.9% versus 72.9%; P = 0.007), and more difficult questions (48.8% versus 63.6%; P = 0.02). In a multivariable logistic regression analysis, correct answers were predicted by GPT-4 (odds ratio [OR], 1.66; P = 0.011), increased question difficulty (OR, 0.59; P = 0.009), Bone and Joint questions (OR, 0.18; P < 0.001), and Soft Tissue questions (OR, 0.30; P = 0.013). Actual examinees scored a mean of 21.6% above GPT-3.5 and 10.7% above GPT-4. The mean percentage of correct answers by actual examinees was significantly higher for correct (versus incorrect) ChatGPT answers. CONCLUSIONS: GPT-4 demonstrated improved performance over GPT-3.5 on the ASSH SAE, especially on more difficult questions. Actual examinees scored higher than both versions of ChatGPT, but the margin was cut in half by GPT-4.

Cross-National Generalizability of WISC-V and CHC Broad Ability Constructs across France, Spain, and the US.

The Cattell-Horn-Carroll (CHC) model is based on psychometric cognitive ability research and is the most empirically supported model of cognitive ability constructs. This study is one in a series of cross-national comparisons investigating the equivalence and generalizability of psychological constructs which align with the CHC model. Previous research exploring the cross-cultural generalizability of cognitive ability measures concluded that the factor analytic models of cognitive abilities generalize across cultures and are compatible with well-established CHC constructs. The equivalence of the psychological constructs, as measured by the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V), has been established across English-speaking samples. However, few studies have explored the equivalence of psychological constructs across non-English speaking, nationally representative samples. This study explored the equivalence of the WISC-V five-factor model across standardization samples from France, Spain, and the US. The five-factor scoring model demonstrated excellent fit across the three samples independently. Factorial invariance was investigated and the results demonstrated strict factorial invariance across France, Spain, and the US. The results provide further support for the generalizability of CHC constructs across Western cultural populations that speak different languages and support the continued use and development of the CHC model as a common nomenclature and blueprint for cognitive ability researchers and test developers. Suggestions for future research on the CHC model of intelligence are discussed.

Measurement invariance of the Wechsler Intelligence Scale for children, fifth edition, in Australian and New Zealand and U.S. standardization samples.

Measurement invariance underlies construct validity generalization in psychology and must be demonstrated prior to any cross-population comparison of means and validity correlations. The purpose of this study was to evaluate the measurement invariance of the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) across Australia and New Zealand (A&NZ) versus the U.S. normative samples. The WISC-V is the most widely used assessment of intelligence in children. Participants were census matched, nationally representative samples from A&NZ (n = 528) and the United States (n = 2,200) who completed the WISC-V standardization version. Baseline model estimation was conducted to ensure the same model showed acceptable fit in both samples separately. Measurement invariance was then examined across A&NZ and United States. The five-factor scoring model described in the test manual showed excellent fit in both samples. Results showed that the WISC-V demonstrated strict metric measurement invariance across the A&NZ and U.S. samples. Further, the results were consistent with the Cattell-Horn-Carroll (CHC) framework of cognitive abilities, indicating the generalizability of cognitive abilities across cultures. Small but significant differences in visual spatial latent means were found across females, highlighting the importance of local normative data. These findings suggest that the WISC-V scores can be meaningfully compared across A&NZ and United States and that the constructs, which align with CHC theory, and associated construct validity research, generalize across countries. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

NTRK fusions and Trk proteins: what are they and how to test for them.

The NTRK genes include a family of three genes, NTRK1, NTRK2, and NTRK3, which are associated with fusions with a variety of partner genes, leading to upregulation of three proteins, TrkA, TrkB, and TrkC. NTRK fusions occur in a variety of solid tumors: at high incidence in secretory carcinoma of the breast and salivary glands, congenital mesoblastic nephroma, and infantile fibrosarcoma; at intermediate incidence in thyroid carcinoma, particularly postradiation carcinomas and a subset of aggressive papillary carcinomas, Spitzoid melanocytic neoplasms, pediatric midline gliomas (particularly pontine glioma), and KIT/PDGFRA/RAS negative gastrointestinal stromal sarcomas; and at a low incidence in many other solid tumors. With new FDA-approved treatments available and effective in treating patients whose tumors harbor NTRK fusions, testing for these fusions has become important. A variety of technologies can be used for testing, including FISH, PCR, DNA, and RNA-based next-generation sequencing, and immunohistochemistry. RNA-based next-generation sequencing represents the gold standard for the identification of NTRK fusions, but FISH using break-apart probes and DNA-based next-generation sequencing also represent adequate approaches. Immunohistochemistry to detect increased levels of Trk protein may be very useful as a screening technology to reduce costs, although it alone does not represent a definitive diagnostic methodology.

Potential Predictors of Vertical Jump Performance: Lower Extremity Dimensions and Alignment, Relative Body Fat, and Kinetic Variables.

ABSTRACT: Daugherty, HJ, Weiss, LW, Paquette, MR, Powell, DW, and Allison, LE. Potential predictors of vertical jump performance: Lower extremity dimensions and alignment, relative body fat, and kinetic variables. J Strength Cond Res 35(3): 616-625, 2021-The association of structural and kinetic variables with restricted vertical jump (RVJ) displacement without and with added mass was examined in 60 men and women. Added mass (weighted vest) simulated a 5% increase in body fat (BF%). Independent variables included BF%, thigh length, and static Q-angle (Q-angles), and while performing RVJ, different expressions of frontal-plane knee angle (FPKA), dynamic Q-angle (Q-angled), vertical ground reaction force (vGRF), concentric vertical impulse (Iz), concentric rate of force development (CRFD), and vertical power (Pz). Variables having significant (p ≤ 0.05) negative correlations with RVJ displacement included BF% (r = -0.76) and Q-angles (r = -0.55). Those having significant (p ≤ 0.05) positive correlations with RVJ displacement included peak and average concentric Pz (r range = 0.74-0.81), peak and average concentric vGRF (r range = 0.46-0.67), Iz (r range = 0.32-0.54), thigh length (r = 0.31), minimum Q-angled (r = 0.31), and maximum FPKA (r = 0.28). Variables not associated (p > 0.05) with RVJ displacement included minimum and excursion FPKA (r = 0.11 and 0.23), maximum, excursion, and average Q-angled (r = 0.24, 0.11, and 0.22), and CRFD (r range = 0.19-0.24). A simple regression model predicted RVJ displacement (p = 1.00) for the simulated 5% increase in body fat. To maximize jumping performance, (a) high levels of body fat should be avoided, (b) peak and average Pz, vGRF, and Iz should be maximized through training, and (c) having a lower Q-angles is associated with better jumping ability.

Isolated Scaphoid Dislocation From Low-Energy Wrist Trauma.

Isolated scaphoid dislocation is an extremely rare injury typically caused by high-energy trauma. We present the first observed case of isolated scaphoid dislocation resulting from a non-traumatic injury of the wrist in power-grip tension in a patient with a questionable history of Marfan Syndrome. A 20-year-old right-hand dominant man presented to the emergency department with right wrist pain and deformation after carrying a table. The patient reported a possible history of Marfan Syndrome, but it had never been definitively diagnosed. Imaging revealed radial dislocation of the scaphoid. Bedside closed reduction was performed followed by outpatient ligament reconstruction with return to normal activities at 6 months. Early diagnosis and management lead to an improved prognosis for isolated scaphoid dislocation. Regardless of patient history or mechanism of injury, treatment options include closed reduction, percutaneous fixation, and/or open reduction with internal fixation and ligamentous reconstruction.

Ankle kinetics and plantarflexor morphology in older runners with different lifetime running exposures.

Running promotes better cardiovascular health and has positive effects on the musculoskeletal system in older adults. However, older adults have lower ankle plantarflexor torques and positive powers during running, and exhibit changes in plantarflexor morphology than young adults. Since older runners who run as much as younger runners exhibit youthful ankle mechanical outputs, running exposure may preserve the locomotor factors that mediate running speed. The purpose of this study was to compare ankle mechanical output during running and plantarflexor morphological characteristics between older runners who have low or high lifetime running exposure. Ten older runners with low lifetime running exposure and nine older runners with high lifetime running exposure performed over-ground running trials at 3.0 m/s (±5%) while kinematic and ground reaction force (GRF) data were collected and used to compute joint angular kinetics. Right medial gastrocnemius morphological characteristics were assessed using ultrasonography at rest and during isometric contractions. Ankle torques, powers, and plantarflexor morphology were compared between groups. Older runners with different lifetime running exposures ran with similar ankle mechanical output (i.e. no effect of running exposure) (p > .05) and exhibited similar medial gastrocnemius morphology during isometric testing. The findings from this study demonstrate that lifetime running exposure does not appear to influence ankle mechanical output or plantarflexor morphology in middle-aged runners.

Footwear and Sex Differences in Performance and Joint Kinetics During Maximal Vertical Jumping.

Smith, RE, Paquette, MR, Harry, JR, Powell, DW, and Weiss, LW. Footwear and sex differences in performance and joint kinetics during maximal vertical jumping. J Strength Cond Res 34(6): 1634-1642, 2020-This investigation examined the effects of footwear and sex on vertical jump displacement and joint power contributions. Twenty-three young adults with basketball experience performed 3 maximal countermovement vertical jumps in minimal and standard footwear. Ground reaction force and 3D kinematic data were collected during jumping. Footwear by sex analysis of variance for all dependent variables and effect sizes (d) was computed. An interaction effect showed that men produced greater lower-limb-positive work than women in standard footwear. Men jumped higher than women (d = 2.53) and produced greater peak ankle, knee and hip joint moments (d > 0.99), positive joint powers (d > 1.07) and, positive knee and hip joint work (d > 1.04) with no sex differences for negative joint powers and work (p > 0.05). Minimal footwear produced less peak-positive knee power (d = 0.27) and less positive ankle (d = 0.34) and knee (d = 0.21) joint work than standard footwear. Because negative joint power and work were similar between sexes, men may be better able to use the stretch-shortening cycle compared with women. Higher joint mechanical demands may provide a better vertical jumping training stimulus in standard compared with minimal footwear. Future studies should investigate footwear training effects on performance and joint mechanics during jumping.

EBV-Associated Lymphoproliferative Disorders: Update in Classification.

Although about 90% of the world's population is infected by EBV only a small subset of the related infections result in neoplastic transformation. EBV is a versatile oncogenic agent involved in a multitude of hematopoietic, epithelial, and mesenchymal neoplasms, but the precise role of EBV in the pathogenesis of many of the associated lymphoid/histiocytic proliferations remains hypothetical or not completely understood. Additional studies and use of evolving technologies such as high-throughput next-generation sequencing may help address this knowledge gap and may lead to enhanced diagnostic assessment and the development of potential therapeutic interventions.

Epstein-Barr virus incidental expression in bone marrow cells: a study of 230 consecutive bone marrow biopsy samples.

Epstein-Barr virus (EBV) is associated with many neoplastic hematologic conditions, but scattered EBV-positive cells can be detected in lymph nodes of healthy individuals and they usually represent latently infected lymphocytes. The incidence of EBV detection in normal bone marrow samples has not been studied and is largely unknown. The lack of knowledge regarding the true incidence of encountering bystander latent EBV-positive cells in the bone marrow may potentially lead to a diagnostic dilemma when assessing a staging bone marrow for a patient with an EBV-positive B or T/NK-cell lymphoma. The aim of our study was to investigate the rate of detection of EBV expression in bone marrow samples and correlate any positive findings with various clinical parameters including patient's age, sex, clinical history, immune status, and any neoplastic transformation if follow-up data are available. We retrospectively studied 230 consecutive bone marrow biopsies performed in 2013 and found 5 cases (2.17%) with scattered EBV-positive cells by in situ hybridization. The observed scattered EBV-positive cells are largely small in size and likely represent bystander, latently infected cells. The rate of detection of EBV-positive cells in the bone marrow appears to be slightly higher in immunodeficient individuals (3%) than in immunocompetent patients (1%).

Immunohistochemical detection of PD-L1 among diverse human neoplasms in a reference laboratory: observations based upon 62,896 cases.

Targeting of the PD1/PD-L1 immune checkpoint pathway has rapidly gained acceptance as a therapeutic strategy for a growing number of malignancies. Testing for expression of PD-L1 in tumor cells and immune cells has been used as a companion or complementary test for drugs targeting the PD1/PD-L1 pathway. We evaluated the results of PD-L1 testing in a large reference lab cohort. Using Food and Drug Administration-approved methods and interpretive instructions for each individual test, 62,896 cases were evaluated for PD-L1 using antibody clone 22C3, 28-8, SP142, or SP263. Case data analyzed included test results and information on tumor location and clinical history. No clinical outcome information was available and no attempt was made to correlate PD-L1 results with any other tests performed. The following numbers of cases were evaluated: 22C3 with tumor proportion score [n = 52585], 22C3 with combined positive score [n = 2631], 28-8 [n = 4191], SP142 [n = 850], and SP263 [n = 70]. In 22C3/tumor proportion score cases, the general results were as follows: negative 33.1% (n = 17,405), (low) expression 33.9% (n = 17,822), and high expression 29.5% (n = 15,486). In cases identified as metastatic, the results were as follows: negative 35.9% (n = 1411), (low) expression 30.8% (n = 1211), and high expression 30.7% (n = 1208). We found broad ranges of expression in tumor types with increasing positivity, as adenocarcinomas were reported as poorly differentiated, whereas squamous cell carcinomas showed more positivity as tumors were described as well-differentiated. The results of many individual tumor types were evaluated and showed, in general, high levels of positive expression. Practical challenges and observations of PD-L1 stain results and interpretation are also discussed.

Epstein-Barr virus (EBV)-associated lymphoid proliferations, a 2018 update.

Epstein-Barr virus (EBV) has been linked to many human neoplasms including hematopoietic, epithelial, and mesenchymal tumors. Since our original review of EBV-associated lymphoproliferative disorders in 2007, many advances and developments have been reported. In this review, we will examine the recent advances in EBV-associated lymphoid/histiocytic proliferations, dividing them into reactive, B cell, T/NK cell, immunodeficiency-related, and histiocytic/dendritic cell proliferations.

Immunohistochemistry and alternative FISH testing in breast cancer with HER2 equivocal amplification.

PURPOSE: While HER2 testing is well established in directing appropriate treatment for breast cancer, a small percentage of cases show equivocal results by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Alternative probes may be used in equivocal cases. We present a single community-based institution's experience in further evaluating these cases. PATIENTS AND METHODS: Between 2014 and 2016, 4255 samples were submitted for HER2 amplification testing by alternative probes, TP53, RAI1, and RARA. Of the patients tested by FISH, 505/3908 (12.9%) also had IHC data. RESULTS: Most (73.9%) FISH equivocal cases remained equivocal after IHC testing. However, 50.5% of equivocal cases were classified as HER2 amplified by alternative probes. Most cases were positive by more than one probe: 78% of positive cases by RAI1 and 73.9% by TP53. There was a significant difference between IHC and FISH alternative testing (p < 0.0001) among the equivocal cases by conventional FISH testing, 44% of IHC negative cases became positive while 36% of the positive IHC cases became negative by alternative FISH testing. Available data showed that 41% of patients were treated with palbociclib and were positive by alternative FISH. CONCLUSION: The prevalence of double HER2 equivocal cases and the discrepancy between IHC and alternative FISH testing suggest that FISH alternative testing using both RAI1 and TP53 probes is necessary for conclusive classification. Because almost half of FISH equivocal cases converted to HER2 amplified upon alternative testing, clinical studies to determine the benefit of anti-HER2 therapy in these patients are urgently needed.

Potential Utility of a Loaded Treadmill Protocol for Tactical Athletes.

Swearingen, JT, Weiss, LW, Smith, WA, Stephenson, MD, and Schilling, BK. Potential utility of a loaded treadmill protocol for tactical athletes. J Strength Cond Res 32(3): 610-616, 2018-Aerobic capacity is an important variable for tactical athletes, with V[Combining Dot Above]O2max being the most direct way of estimating it in a laboratory setting. A mode-specific protocol involving fixed-weight, torso-borne loads was assessed in the current study. On 4 separate days, 15 men (age 22.1 ± 2.7 years, mass 85.1 ± 10.6 kg, height 179.0 ± 7.7 cm) performed a weighted treadmill walking protocol (2 trials) and a nonweighted treadmill running protocol (2 trials). Both the weighted and nonweighted protocols were reliable, with intraclass correlation coefficient values of 0.79 and 0.87, respectively. V[Combining Dot Above]O2peak values from both protocols were highly correlated (r = 0.90, p < 0.01). However, V[Combining Dot Above]O2peak was higher during the nonweighted protocol (t = 7.547, d = 2.47, p < 0.01). Work rate was calculated for both the last completed stage and stage during which participants reached fatigue. Work rates for both protocols on the last completed stage were similar (t = 1.44, d = 0.83, p = 0.17), although the work rate for the final attempted stage was greater for the weighted-walking protocol (t = 5.85, d = 3.60, p < 0.01). These data suggest a weighted-walking V[Combining Dot Above]O2peak that is highly associated with a running V[Combining Dot Above]O2peak. This test may be applied to those who routinely perform torso-borne load carriage, such as tactical athletes. Future weighted-walking protocols should seek achieve higher resolution, especially near the end stage of the test where subjects reach volitional fatigue. Large increases in work rate may not be feasible at the end stages of the test.

Genomic analysis of follicular dendritic cell sarcoma by molecular inversion probe array reveals tumor suppressor-driven biology.

Follicular dendritic cell sarcoma is a rare malignant neoplasm of dendritic cell origin that is currently poorly characterized by genetic studies. To investigate whether recurrent genomic alterations may underlie the biology of follicular dendritic cell sarcoma and to identify potential contributory regions and genes, molecular inversion probe array analysis was performed on 14 independent formalin-fixed, paraffin-embedded samples. Abnormal genomic profiles were observed in 11 out of 14 (79%) cases. The majority showed extensive genomic complexity that was predominantly represented by hemizygous losses affecting multiple chromosomes. Alterations of chromosomal regions 1p (55%), 2p (55%), 3p (82%), 3q (45%), 6q (55%), 7q (73%), 8p (45%), 9p (64%), 11q (64%), 13q (91%), 14q (82%), 15q (64%), 17p (55%), 18q (64%), and 22q (55%) were recurrent across the 11 samples showing abnormal genomic profiles. Many recurrent genomic alterations in follicular dendritic cell sarcoma overlap deletions that are frequently observed across human cancers, suggesting selection, or an active role for these alterations in follicular dendritic cell sarcoma pathogenesis. In support of a tumor suppressor-driven biology, homozygous deletions involving tumor suppressor genes CDKN2A, RB1, BIRC3, and CYLD were also observed. Neither recurrent gains nor amplifications were observed. This genomic characterization provides new information regarding follicular dendritic cell sarcoma biology that may improve understanding about the underlying pathophysiology, provide better prognostication, and identify potential therapeutic markers for this rare disease.

Fibrin-associated EBV-positive Large B-Cell Lymphoma: An Indolent Neoplasm With Features Distinct From Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation.

Incidental cases of localized fibrin-associated Epstein-Barr virus (EBV)+ large B-cell proliferations have been described at unusual anatomic sites and have been included in the category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI) in the WHO Classification. We describe 12 cases and review the literature to define their clinicopathologic spectrum and compare features with typical cases of DLBCL-CI. Median age was 55.5 years with a M:F ratio of 3. In all 12 cases, the lymphoma was an incidental microscopic finding involving atrial myxomas (n=3), thrombi associated with endovascular grafts (n=3), chronic hematomas (n=2), and pseudocysts (n=4). All cases tested were nongerminal center B-cell origin, type III EBV latency, and were negative for MYC rearrangements and alternative lengthening of telomeres by FISH. Most showed high CD30, Ki67, and PD-L1, and low to moderate MYC and p53 expression. Among 11 patients with detailed follow-up, 6 were treated surgically, 3 with cardiac or vascular lesions had persistent/recurrent disease at intravascular sites, and 4 died of causes not directly attributable to lymphoma. Reports of previously published fibrin-associated cases showed similar features, whereas traditional DLBCL-CI cases with a mass lesion had significantly higher lymphoma-associated mortality. Fibrin-associated EBV+ large B-cell lymphoma is clinicopathologically distinct from DLBCL-CI, warranting separate classification. Most cases, particularly those associated with pseudocysts, behave indolently with the potential for cure by surgery alone and may represent a form of EBV+ lymphoproliferative disease rather than lymphoma. However, primary cardiac or vascular disease may have a higher risk of recurrence despite systemic chemotherapy.

How Much Does WAIS-IV Perceptual Reasoning Decline Across the 20 to 90-Year Lifespan When Processing Speed is Controlled?

The most prominent pattern of cognitive change over the lifespan centers on the difference between patterns of maintained abilities on tests of crystallized knowledge and patterns of steady decline on tests of problem solving and processing speed. Whereas the maintained-vulnerable dichotomy is well established in the literature, questions remain about cognitive decline in problem solving when processing speed is controlled. This relationship has been examined in cross-sectional studies that typically used non-clinical tests with non-representative samples of adults. This study extended these findings to the most popular clinical test, the Wechsler Adult Intelligence Scale -4th ed. (WAIS-IV), using its carefully stratified sample as the source of data (ages 20-90 for Indexes, ages 16-90 for Perceptual Reasoning subtests). Multivariate Analysis of Covariance (MANCOVA) revealed that 70-80% of the variance in declining reasoning ability was shared with the speed factor. This was true (a) on the index and subtest level and (b) regardless of the type of problem-solving task employed. Such robust findings have important clinical and research implications for neuropsychologists, who most frequently use the Wechsler scales as part of their assessment battery.

Changes in resting mitogen-activated protein kinases following resistance exercise overreaching and overtraining.

PURPOSE: Many physiological maladaptations persist after overreaching and overtraining resistance exercise (RE). However, no studies have investigated changes in mitogen-activated protein kinases (MAPK) after overtraining in humans, despite their critical role regulating exercise-induced muscular adaptations. The purpose of this study was to describe the changes in total and resting phosphorylation status of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38-MAPK following a period of RE overreaching or overtraining. METHODS: Following 2-4 weeks of normal training (low volume/low intensity), two groups of males performed either a high-power overreaching protocol (HPOR n = 6, mean ± SD, age 23 ± 3.4 years, mass 86.5 ± 17.7 kg, height 1.77 ± 0.06 m) or high-intensity overtraining protocol (HIOT n = 8, age 19.8 ± 1.8 years, mass 76.8 ± 6.7 kg, height 1.8 ± 0.06 m). Resting muscle biopsies were obtained at baseline (BL; end of normal training period) and 24 h after the final session of stressful training (i.e., HPOR or HIOT programs). Total MAPK and ratio of phosphorylated/total (p-MAPK)- ERK1/2, JNK, and p38-MAPK were analyzed via western blotting. 2 × 2 (group × time) ANOVA determined differences in MAPK between BL and post-training protocols. RESULTS: Compared to BL, total-ERK increased after HPOR, but decreased after HIOT (p ≤ 0.05). p-ERK1/2/total-ERK increased after HIOT (p ≤ 0.05). The ratio of p-JNK/total-JNK and p-ERK1/2/total-ERK decreased after HPOR (p ≤ 0.05); however, this result was primarily due to increased total MAPK content. p-p38-MAPK decreased after HPOR (p ≤ 0.05). CONCLUSION: Total and p-MAPK are differentially expressed after HPOR and HIOT RE. These changes are likely involved in the maladaptation reported in overreaching and overtraining exercise. This is the first study describing altered MAPK in RE overtrained and overreached humans.

Do Lower-Body Dimensions and Body Composition Explain Vertical Jump Ability?

Caia, J, Weiss, LW, Chiu, LZF, Schilling, BK, Paquette, MR, and Relyea, GE. Do lower-body dimensions and body composition explain vertical jump ability? J Strength Cond Res 30(11): 3073-3083, 2016-Vertical jump (VJ) capability is integral to the level of success attained by individuals participating in numerous sport and physical activities. Knowledge of factors related to jump performance may help with talent identification and/or optimizing training prescription. Although myriad variables are likely related to VJ, this study focused on determining if various lower-body dimensions and/or body composition would explain some of the variability in performance. Selected anthropometric dimensions were obtained from 50 university students (25 men and 25 women) on 2 occasions separated by 48 or 72 hours. Estimated body fat percentage (BF%), height, body weight, hip width, pelvic width, bilateral quadriceps angle (Q-angle), and bilateral longitudinal dimensions of the feet, leg, thigh, and lower limb were obtained. Additionally, participants completed countermovement VJs. Analysis showed BF% to have the highest correlation with countermovement VJ displacement (r = -0.76, p < 0.001). When examining lower-body dimensions, right-side Q-angle displayed the strongest association with countermovement VJ displacement (r = -0.58, p < 0.001). Regression analysis revealed that 2 different pairs of variables accounted for the greatest variation (66%) in VJ: (a) BF% and sex and (b) BF% and body weight. Regression models involving BF% and lower-body dimensions explained up to 61% of the variance observed in VJ. Although the variance explained by BF% may be increased by using several lower-body dimensions, either sex identification or body weight explains comparatively more. Therefore, these data suggest that the lower-body dimensions measured herein have limited utility in explaining VJ performance.