Validity and Efficacy of the Elite HRV Smartphone Application during Slow-Paced Breathing.

Slow-paced breathing is a clinical intervention used to increase heart rate variability (HRV). The practice is made more accessible via cost-free smartphone applications like Elite HRV. We investigated whether Elite HRV can accurately measure and augment HRV via its slow-paced breathing feature. Twenty young adults completed one counterbalanced cross-over protocol involving 10 min each of supine spontaneous (SPONT) and paced (PACED; 6 breaths·min-1) breathing while RR intervals were simultaneously recorded via a Polar H10 paired with Elite HRV and reference electrocardiography (ECG). Individual differences in HRV between devices were predominately skewed, reflecting a tendency for Elite HRV to underestimate ECG-derived values. Skewness was typically driven by a limited number of outliers as median bias values were ≤1.3 ms and relative agreement was ≥very large for time-domain parameters. Despite no significant bias and ≥large relative agreement for frequency-domain parameters, limits of agreement (LOAs) were excessively wide and tended to be wider during PACED for all HRV parameters. PACED significantly increased low-frequency power (LF) for Elite HRV and ECG, and between-condition differences showed very large relative agreement. Elite HRV-guided slow-paced breathing effectively increased LF values, but it demonstrated greater precision during SPONT and in computing time-domain HRV.

Limb Dominance Effects on Seated Single-Arm Shot-Put Limb Symmetry Indices Following Shoulder Rehabilitation.

CONTEXT: Typically, most clinical return to activity guidelines recommend that an injured shoulder achieve a 90% to 100% functional performance test limb symmetry index (LSI); however, as previous research demonstrated a 103% to 111% dominant limb bias in seated single-arm shot-put test (SSASPT) performance, the typical criteria might not be appropriate for interpreting SSASPT LSI. Thus, the current objective was to evaluate SSASP LSI differences between dominant and nondominant involved shoulders and to determine how many patients met the suggested 90% to 100% LSI criteria, as well as the 103% for dominant (89% for nondominant) normative SSASPT threshold reported in the literature, at the time of discharge. DESIGN: Cross-sectional. METHODS: Patients with shoulder injury or surgery (n = 78) completed the SSASPT at the time of discharge from rehabilitation and were grouped according to whether the involved shoulder was the dominant (n = 42) or nondominant (n = 32) limb. LSI (involved/uninvolved × 100) was computed from the average of 3 SSASPT trial distances completed with each limb. RESULTS: The LSI for the nondominant involved group (88.9% [12.4%]) was significantly less (confidence intervalDiff, -12.1% to -22.1%) than the dominant involved group (106.0% [9.3%]). While 95.2% of patients in the dominant involved group exhibited LSI > 90%, only 43.8% of patients in the nondominant involved group attained LSI > 90%. Across the entire cohort, the odds of a nondominant involved LSI being below the respective SSASPT normative range were 2.04 (95% confidence interval, 0.80-5.21) times higher than the odds of a dominant involved LSI being below the normative range. CONCLUSIONS: Patients with dominant limb involvement exhibited higher LSI than patients with nondominant limb involvement at discharge from rehabilitation. Particularly when the nondominant shoulder is involved, these results suggest that patients with shoulder injury and surgery may require longer rehabilitation to attain higher levels of upper-extremity function.

Self-recorded heart rate variability profiles are associated with health and lifestyle markers in young adults.

PURPOSE: To quantify associations between self-recorded heart rate variability (HRV) profiles and various health and lifestyle markers in young adults. METHODS: Otherwise healthy volunteers (n = 40, 50% male) recorded 60-s, post-waking HRV with a cost-free mobile application in supine and standing positions for 7 days. The 7-day average and coefficient of variation (CV, reflects daily fluctuation) for the mean RR interval and root mean square of successive differences (LnRMSSD) were assessed. 7-day sleep duration and physical activity profiles were characterized via wrist-worn accelerometer. Subsequent laboratory assessments included aerobic fitness ([Formula: see text]O2peak) and markers of cardiovascular, metabolic, and psychoemotional health. Associations were evaluated before and after [Formula: see text]O2peak adjustment. RESULTS: Bivariate correlations (P < 0.05) demonstrated that higher 7-day averages and/or lower CV values were associated with higher activity levels and superior cardiovascular (lower systolic and diastolic blood pressure [BP] and aortic stiffness [cf-PWV]), metabolic (lower body fat percentage, fasting glucose, and low-density lipoprotein cholesterol [LDL-C]), and psychoemotional health (lower perceived stress) markers, with some variation between sexes and recording position. In males, associations between HRV parameters and cf-PWV remained significant following [Formula: see text]O2peak adjustment (P < 0.05). In females, HRV parameters were associated (P < 0.05) with numerous cardiovascular (systolic and diastolic BP, cf-PWV) and metabolic (fasting glucose and LDL-C) parameters following [Formula: see text]O2peak adjustment. CONCLUSIONS: Higher or more stable supine and standing HRV were generally associated with superior health and lifestyle markers in males and females. These findings lay groundwork for future investigation into the usefulness of self-recorded ultra-short HRV as a health-promoting behavior-modification tool in young adults.

Effects of home confinement on mental health and lifestyle behaviours during the COVID-19 outbreak: insights from the ECLB-COVID19 multicentre study.

Although recognised as effective measures to curb the spread of the COVID-19 outbreak, social distancing and self-isolation have been suggested to generate a burden throughout the population. To provide scientific data to help identify risk factors for the psychosocial strain during the COVID-19 outbreak, an international cross-disciplinary online survey was circulated in April 2020. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online survey platform and was promoted by thirty-five research organizations from Europe, North Africa, Western Asia and the Americas. Questions were presented in a differential format with questions related to responses "before" and "during" the confinement period. 1047 replies (54% women) from Western Asia (36%), North Africa (40%), Europe (21%) and other continents (3%) were analysed. The COVID-19 home confinement evoked a negative effect on mental wellbeing and emotional status (P < 0.001; 0.43 ≤ d ≤ 0.65) with a greater proportion of individuals experiencing psychosocial and emotional disorders (+10% to +16.5%). These psychosocial tolls were associated with unhealthy lifestyle behaviours with a greater proportion of individuals experiencing (i) physical (+15.2%) and social (+71.2%) inactivity, (ii) poor sleep quality (+12.8%), (iii) unhealthy diet behaviours (+10%), and (iv) unemployment (6%). Conversely, participants demonstrated a greater use (+15%) of technology during the confinement period. These findings elucidate the risk of psychosocial strain during the COVID-19 home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle AHCL).

Globally altered sleep patterns and physical activity levels by confinement in 5056 individuals: ECLB COVID-19 international online survey.

Symptoms of psychological distress and disorder have been widely reported in people under quarantine during the COVID-19 pandemic; in addition to severe disruption of peoples' daily activity and sleep patterns. This study investigates the association between physical-activity levels and sleep patterns in quarantined individuals. An international Google online survey was launched in April 6th, 2020 for 12-weeks. Forty-one research organizations from Europe, North-Africa, Western-Asia, and the Americas promoted the survey through their networks to the general society, which was made available in 14 languages. The survey was presented in a differential format with questions related to responses "before" and "during" the confinement period. Participants responded to the Pittsburgh Sleep Quality Index (PSQI) questionnaire and the short form of the International Physical Activity Questionnaire. 5056 replies (59.4% female), from Europe (46.4%), Western-Asia (25.4%), America (14.8%) and North-Africa (13.3%) were analysed. The COVID-19 home confinement led to impaired sleep quality, as evidenced by the increase in the global PSQI score (4.37 ± 2.71 before home confinement vs. 5.32 ± 3.23 during home confinement) (p < 0.001). The frequency of individuals experiencing a good sleep decreased from 61% (n = 3063) before home confinement to 48% (n = 2405) during home confinement with highly active individuals experienced better sleep quality (p < 0.001) in both conditions. Time spent engaged in all physical-activity and the metabolic equivalent of task in each physical-activity category (i.e., vigorous, moderate, walking) decreased significantly during COVID-19 home confinement (p < 0.001). The number of hours of daily-sitting increased by ~2 hours/days during home confinement (p < 0.001). COVID-19 home confinement resulted in significantly negative alterations in sleep patterns and physical-activity levels. To maintain health during home confinement, physical-activity promotion and sleep hygiene education and support are strongly warranted.

Comparison of balance performance between masters Olympic weightlifters and runners.

Balance disorders are a common problem among older adults that greatly increase susceptibility for falls and fractures. Aerobically trained older (masters) athletes tend to exhibit superior balance abilities compared to that of healthy age-matched counterparts. Olympic weightlifting involves tremendous power production and motor skill coordination throughout the body which may prompt unique sensory information acquisition and integration adaptations. The purpose of this investigation was to compare a modified clinical test of sensory interaction and balance performance between middle-aged (~40-60 years) masters Olympic weightlifters (OWL, n = 48) and runners (RUN, n = 42). Average mediolateral center of pressure velocity (MLCPV) was computed during completion of 2 double leg trials (30-s) completed on firm (FI) and foam (FO) surfaces with eyes open (EO) and eyes closed (EC). While there were no significant differences between the groups for either the EO-FI (P = .143, d = 0.34) or EO-FO (P = .209, d = 0.26), the OWL demonstrated significantly better balance (lower MLCPV) than the RUN for both the EC-FI (P = .009, d = 0.59) and EC-FO (P = .001, d = 0.70). The most salient result of this investigation was the identification of better balance performance by the OWL, particularly when visual inputs were unavailable (ie, EC), compared to the RUN. These results suggest that Olympic weightlifting may provide a superior training stimulus for somatosensory and vestibular function compared to running in middle-aged adults, a benefit that may help to offset archetypal age-related balance deficits.

Bone Mineral Density and Muscle Mass in Masters Olympic Weightlifters and Runners.

The authors examined the musculoskeletal implications of delayed exercise adoption in two distinct cohorts of masters athletes with ∼10 years of training experience: Olympic weightlifters (OWLs) and distance runners (RUNs). Total body and regional bone mineral density (BMD), and dual-energy X-ray absorptiometry-derived lean mass were compared in 51 OWLs and 43 RUNs. Multiple linear regression analyses were conducted on BMD and lean mass with the exercise group (i.e., OWLs vs. RUNs), age, sex, and years of experience as independent variables. Age was associated (p < .05) with less femoral (ß = -0.25) and lumbar (ß = -0.27) BMD. Total body (ß = 0.23), lumbar (ß = 0.25), and radial (ß = 0.36) BMD were greater (p < .05) in OWLs versus RUNs. Lean mass was greater in OWLs versus RUNs (ß = 0.29, p < .01), but did not relate to total body BMD (r = .15; p = .08). Greater total and regional BMD and lean mass in OWLs compared with RUNs may reduce risk for developing osteoporosis and/or sarcopenia and associated downstream health outcomes.

Effect of 2- vs. 3-Minute Interrepetition Rest Period on Maximal Clean Technique and Performance.

Ammar, A, Riemann, BL, Abdelkarim, O, Driss, T, and Hökelmann, A. Effect of 2- vs. 3-minute interrepetition rest period on maximal clean technique and performance. J Strength Cond Res 34(9): 2548-2556, 2020-Currently, it is widely accepted that adopting a long rest period (3-5 minutes) during maximal strength and power exercise is of importance in reducing acute fatigue and maintaining power and technique proficiency. However, despite the fact that weightlifting is an example of maximal strength exercise, only 2 minutes are officially allowed when athletes attempt 2 successive lifts. The purpose of this study was to compare 3- vs. 2-minute intermaximal repetition rest periods (IMRRPs) on performance, rate of perceived exertion (RPE), technical efficiency, and power production during 2 successive maximal repetitions of clean & jerk (C&J). Nine elite weightlifters (age: 24.4 ± 3.6 years, body mass: 77.2 ± 7.1 kg, height 176.0 ± 6.4 cm, and 1 repetition maximum C&J: 170.0 ± 5.0 kg) performed 2 separate testing sessions using 2-minute IMRRP (IMRRP-2) and 3-minute IMRRP (IMRRP-3), in a randomized order, while barbell kinematics and kinetics were recorded. Results showed that the longer IMRRP-3 minutes led to the maintenance of clean technique (from the first to the second repetition) evidenced by a 1.86% lower decline in peak vertical displacement (p = 0.03) and attenuation of increased peak horizontal displacements with a 1.74% (p = 0.03) less backward movement during the first pull, a 3.89% (p = 0.008) less forward movement during the second pull, and a 4.7% (p = 0.005) less backward movement during the catch phase. In addition, attenuation of peak velocity (2.22%; p = 0.02), peak vertical ground reaction force (1.70%; p = 0.03), and peak power (2.14%; p = 0.02) declines were shown using IMRRP-3 compared with IMRRP-2. Increasing IMRRP from 2 to 3 minutes was also shown to decrease RPE values (8.02%; p = 0.008) and to enhance supramaximal C&J performance (1.55%; p = 0.003). The results of this study suggest 3 minutes to be the most advantageous IMRRP in terms of maintaining technical efficiency, power output, reducing fatigue perception, and enhancing performance in elite weightlifters.

Association Between the Seated Single-Arm Shot-Put Test With Isokinetic Pushing Force.

CONTEXT: Previous investigations have examined the reliability, normalization, and underlying projection mechanics of the seated single-arm shot-put (SSASP) test. Although the test is believed to reflect test limb strength, there have been no assessments determining whether test performance is directly associated with upper-extremity strength. OBJECTIVE: To determine the relationship between isokinetic pushing force and SSASP performance and conduct a method comparison analysis of limb symmetry indices between the 2 tests. DESIGN: Controlled laboratory study. SETTING: Biomechanics laboratory. Patients (or Other Participants): Twenty-four healthy and physically active men (n = 12) and women (n = 12). INTERVENTION(S): Participants completed the SSASP and isokinetic pushing tests using their dominant and nondominant arms. MAIN OUTCOME MEASURES: SSASP distance and isokinetic peak force. RESULTS: Significant moderate to strong relationships were revealed between the SSASP distances and isokinetic peak forces for both limbs. The Bland-Altman analysis results demonstrated significantly (P < .002) greater limb symmetry indices for the SSASP (both medicine balls) than the isokinetic ratios, with biases ranging from -0.094 to -0.159. The limits of agreement results yielded intervals ranging from ±0.241 to ±0.340 and ±0.202 to ±0.221 from the biases. CONCLUSIONS: These results support the notion that the SSASP test reflects upper-extremity strength. The incongruency of the limb symmetry indices between the 2 tests is likely reflective of the differences in the movement patterns and coordination requirements of the 2 tests.

Relationship Between Seated Single-Arm Shot Put and Isokinetic Shoulder Flexion and Elbow Extension Strength.

CONTEXT: A recent report demonstrated moderate to strong relationships between seated single-arm shot-put (SSASP) test performance and isokinetic pushing forces at varying velocities, directly supporting the SSASP test as a reflection of multijoint upper-extremity strength. Yet, no previous work appears to have assessed whether the SSASP test is more reflective of shoulder flexion or elbow extension strength. OBJECTIVE: To examine the relationship between isokinetic shoulder flexion and elbow extension strength and SSASP test performance and to compare limb symmetry indices (LSI) between the 2 tests. DESIGN: Correlational design. SETTING: Biomechanics laboratory. Patients (or Other Participants): A total of 30 healthy and physically active young adults. INTERVENTION(S): Participants completed the SSASP test and concentric isokinetic (60°/s and 180°/s) shoulder flexion and elbow extension using their dominant and nondominant arms. MAIN OUTCOME MEASURES: SSASP test performance and isokinetic shoulder flexion and elbow extension peak torques as well as LSI between the 2 tests. RESULTS: Strong relationships were observed between SSASP ranges and isokinetic peak torques at each velocity for both shoulder and elbow (r ≥ .804, P < .001). While the Bland-Altman results on the LSI only demonstrated a significant bias for the shoulder (60°/s, P = .009), limits of agreement results demonstrated extremely wide intervals (32.5%-52.1%). CONCLUSIONS: The SSASP test is a multijoint upper-extremity functional performance test that is reflective of equal shoulder flexion and elbow extension contributions; however, there was large variability regarding the agreement between the SSASP LSI and isokinetic shoulder and elbow strength LSI.

A Biomechanical Analysis of the Effects of Bouncing the Barbell in the Conventional Deadlift.

Krajewski, K, LeFavi, R, and Riemann, B. A biomechanical analysis of the effects of bouncing the barbell in the conventional deadlift. J Strength Cond Res 33(7S): S70-S77, 2019-The purpose of this study is to analyze biomechanical differences between the bounce and pause styles of deadlifting. Twenty physically active males performed deadlifts at their 75% one-repetition maximum testing using both pause and bounce techniques in a within-subjects randomized study design. The average peak height the barbell attained from the 3 bounce style repetitions was used to compute a compatible phase for analysis of the pause style repetitions. Net joint moment impulse (NJMI), work, average vertical ground reaction force (vGRF), vGRF impulse, and phase time were computed for 2 phases, liftoff to peak barbell height and the entire ascent. Additionally, the ankle, knee, hip, and trunk angles at the location of peak barbell bounce height were computed. During the liftoff to peak barbell height phase, although each of the joints demonstrated significantly less NJMI and work during the bounce style, the hip joint was impacted the most. The average vGRF was greater for the bounce; however, the vGRF impulse was greater for the pause. The NJMI results for the ascent phase were similar to the liftoff to peak barbell height phase, whereas work was significantly less for the bounce condition compared with the pause condition across all 3 joints. Strength and conditioning specialists using the deadlift should be aware that the bounce technique does not allow the athlete to develop maximal force production in the early portion of the lift. Further analyses should focus on joint angles and potential vulnerability to injury when the barbell momentum generated from the bounce is lost.

Kinetic and kinematic patterns during high intensity clean movement: searching for optimal load.

The aim of the present study was to investigate loading effects on kinematic and kinetic variables among elite-weightlifters in order to identify an optimal training load to maximize power production for clean-movement. Nine elite-weightlifter (age: 24 ± 4years, body-mass: 77 ± 6.5kg, height: 176 ± 6.1cm and 1RM clean: 170 ± 5kg) performed 2 separate repetitions of the clean using 85, 90, 95% and 100%, in a randomized order, while standing on a force platform and being recorded using 3D-capture-system. Differences in kinematics (barbell displacement, velocity and acceleration) and kinetics (power, vertical ground reaction force (vGRF), rate of force development (RFD), and work) across the loads were statistically assessed. Results revealed significant load effects for the majority of the studied parameters (p < 0.01) and showed that typical bar-displacement, greatest bar-velocity and peak-power were achieved at 85 and 90% 1RM (p < 0.001). Additionally greater average power was shown for 90 and 95% (p < 0.01) and greater work and vGRF were shown for 90, 95 and 100% than 85% 1RM (p < 0.05). Load had no significant effect on peak-vGRF and peak-RFD (p > 0.05). The results of this study, suggest 90% 1RM to be the most advantageous load to train explosive-force and to enhance power-outputs while maintaining technical efficiency in elite-weightlifters.

Intersession reliability of self-selected and narrow stance balance testing in older adults.

BACKGROUND: Despite the common practice of using force platforms to assess balance of older adults, few investigations have examined the reliability of postural screening tests in this population. AIM: We sought to determine the test-retest reliability of self-selected and narrow stance balance testing with eyes open and eyes closed in healthy older adults. METHODS: Thirty older adults (>65 years) completed 45 s trials of eyes open and eyes closed stability tests using self-selected and narrow stances on two separate days (1.9 ± .7 days). Average medial-lateral center of pressure velocity was computed. RESULTS: The ICC results ranged from .74 to .86, and no significant systematic changes (P < .05) occurred between the testing sessions for any of the tests. The standard error of measurement ranged from 15.9 to 23.6%. DISCUSSION: Reliability estimates were similar between the two stances and visual conditions assessed. Slightly higher coefficients were identified for the self-selected stances compared to the narrow stances under both visual conditions; however, there were negligible differences between the sessions. The within subject session-to-session variability provides a basis for further research to consider differences between fallers and non-fallers. CONCLUSION: Reliability for eyes open and closed balance testing using self-selected and narrow stances in older adults was established which should provide a foundation for the development of fall risk screening tests.

Residual Effects of Same Day Lower Extremity Strength Training on Countermovement Jump Performance in Collegiate Women Athletes.

Balancing of strength programming intensity with sport demands is necessary to avoid excessive workloads that could inhibit performance. To expand previous jump height focused literature, this study evaluated whether countermovement jump (CMJ) movement strategies, including eccentric characteristics, might reveal CMJ execution strategy shifts to achieve similar afternoon CMJ height following a morning resistance training session (RTS). Fifteen collegiate women's soccer and volleyball athletes (18-24 years, 73.6 ± 8.4 kg, 1.74 ± 0.19 m) participating in an offseason RTS completed five CMJs during two afternoon sessions (48 h apart), one 4-6 h post morning RTS, and one on a rest day. The RTS consisted of 2 sets of 10 repetitions at 70-80% 1RM for the back squat, the front squat, and the forward lunge. Vertical ground reaction forces were recorded from which 13 outcome measures describing elements of the eccentric and concentric CMJ phases were computed. No significant differences in jump height (p = 0.427, d = 0.17) or outcome measures (p = 0.091-0.777, d = -0.07-0.21) between sessions with exception of a significant concentric phase time decrease (p = 0.026, d = 0.23) following the RTS were identified. Given the magnitude of the mean concentric phase time change (0.01 s), the result likely has limited practical meaning. As these results confirm previous CMJ height literature, practitioners have further evidence that a morning RTS does not interfere or enhance afternoon CMJ performance in athletic women.

Reliability of Upper Extremity Functional Performance Tests for the Non-overhead Athlete.

Background: While there have been reliability studies conducted on several upper extremity functional performance tests (UEFPT), there are several complicating factors that inhibit the ability to draw definitive consensus about the reliability of the tests in both females and males. Having reliability estimates for UEFPT in the same cohort facilitates direct comparison of their relative and absolute reliability. Purpose: To establish the test-retest reliability of the closed kinetic chain upper extremity stability test (CKCUEST), seated medicine ball chest pass test (SMBCPT) and hands-release push-up test (HRPUT) in a cohort of males and females with a history of non-overhead sport participation. A secondary purpose was to examine the associations between the three UEFPT. Study Design: Test-retest reliability, single cohort study. Methods: Forty adults (20 females, 20 males) with a history of non-overhead sport participation completed three UEFPT during two data collection sessions three to seven days apart. Measures of systematic bias, absolute reliability and relative reliability were computed between the sessions. Additionally, correlational analyses were conducted between the three UEFPT. Results: Only the UECKCST (both sexes) demonstrated significant (p≤ 0.003) second session performance improvements. All three tests exhibited excellent relative reliability (intraclass correlational coefficients ≥ 0.823) and except for the HRPUT in males, coefficients of variation were all below 8.8%. Except for a significant relationship (r=.691, p=0.001) between the UECKCST and SMBCPT for the females there were no other associations between the three UEFPT. Conclusion: All three UEFPT demonstrated sufficient reliability. Thus, all three assessments can be used for serial assessments to progress a patient through rehabilitation as well as contribute to the criteria used in making return to sport decisions. Level of Evidence: 3.

Reliability of Upper Extremity Functional Performance Tests for Overhead Sports Activities.

Background: There is lack of consensus on which tests, particularly upper extremity functional performance tests (FPT) that should be used for clinical decision making to progress a patient through a rehabilitation program or criteria for return to sport (RTS). Consequently, there is a need for tests with good psychometric properties that can be administered with minimal equipment and time. Purpose: (1) To establish the intersession reliability of several open kinetic chain FPT in healthy young adults with a history of overhead sport participation. (2) To examine the intersession reliability of the limb symmetry indices (LSI) from each test. Study Design: Test-retest reliability, single cohort study. Methods: Forty adults (20 males, 20 females) completed four upper extremity FPT during two data collection sessions three to seven days apart: 1) prone medicine ball drop test 90°shoulder abduction (PMBDT 90°), 2) prone medicine ball drop test 90°shoulder abduction/90° elbow flexion (PMBDT 90°-90°), 3) half-kneeling medicine ball rebound test (HKMBRT), 4) seated single arm shot put test (SSASPT). Measures of systematic bias, absolute reliability and relative reliability were computed between the sessions for both the original test scores and LSI. Results: Except for the SSASPT, all tests demonstrated significant (p ≤ 0.030) improvements in performance during the second session. Generally, for the medicine ball drop/rebound tests, the absolute reliability was the highest (less random error) for the HKMBRT, next the PMBDT 90°followed by PMBDT 90°-90°. Excellent relative reliability existed for the PMBDT 90°, HKMBRT, and SSASPT, whereas fair to excellent relative reliability for the PMBDT 90°-90°. The SSASPT LSI revealed the highest relative and absolute reliability. Conclusion: Two tests, HKMBRT and SSASPT demonstrated sufficient reliability; therefore, the authors' recommend those tests can be used for serial assessments to advance a patient through a rehabilitation program as well as criteria for progression to RTS. Level of Evidence: 3.

Blood alcohol concentration as a measure of risk among pedestrian fatalities in the U.S., 2016-2020.

OBJECTIVE: In the United States, deaths among pedestrians have increased dramatically since 2009 relative to other vulnerable road users, with substance use described as an important risk factor. This study aimed to explore blood alcohol concentrations (BAC g/dL) among pedestrian fatalities in the United States between 2016 and 2020. Exploring the presence of alcohol among pedestrian cases will support targeted interventions designed to reduce risk. METHODS: This study utilized pedestrian fatality and alcohol screening data provided by the Fatality Analysis Reporting System (FARS). Logistic models were examined to identify statistical associations (ORs, 95% CI) by age, race, and sex relative to positive BAC exposure (BAC > 0.0 g/dL), mild exposure (BAC > 0.0 < .079 g/dL), moderate to severe alcohol exposure (BAC 0.08-.299 g/dL), and severe exposure (BAC ≥ 0.30 g/dL). RESULTS: Between 2016 and 2020, 33,375 pedestrian fatalities were reported to FARS with 75.1% of cases retained for analysis (n = 25,077). Fatalities were more likely to be White (69.3%), male (69.9%), and between 25-64 years of age (67.3%). 74.0% of fatalities were tested for alcohol, with 40.9% screening positive. Females, cases ≥ 75 years of age, and those identified as Asians reported the lowest odds of being positive for alcohol exposure. CONCLUSIONS: Results suggest an ongoing threat to pedestrians due to alcohol consumption and that exposure odds vary by demographic characteristics. Unfortunately, analytical approaches to understanding the roles played by drugs and alcohol among vulnerable road users tend to be marginalized in the literature. Analytical, evidence-based investigations are needed to curtail the risk of pedestrian fatalities in the U.S.

Reliability of scapular classification in examination of professional baseball players.

BACKGROUND: Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable. QUESTIONS/PURPOSES: We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players. METHODS: Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal). RESULTS: We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084. CONCLUSION: We found low reliability of visual observation and classification of scapular movement. CLINICAL RELEVANCE: Current evaluation strategies for evaluating subtle scapular abnormalities are limited. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Ground reaction force patterns in plyometric push-ups.

Compared with lower extremity plyometrics, data concerning the loads and intensity associated with upper extremity plyometrics are limited. The purpose of this study was to compare vertical ground reaction force (vGRF) characteristics between the clap push-up and box drop push-ups from 3.8 cm (BD1), 7.6 cm (BD2), and 11.4 cm (BD3) heights and limbs (dominant, nondominant). Twenty-two healthy active male subjects (age 25.9 ± 1.3 years, height 1.8 ± 0.08 m, mass 87.6 ± 12 kg) performed 4 repetitions of each push-up variation in a random order. Four dependent variables, peak vGRF, time-to-peak vGRF, loading rate (LR), and propulsion rate (PR) were calculated for each extremity. Statistical analysis consisted of separate limb by variation repeated measures analysis of variance. In addition, ground contact time (GCT) was statistically compared between variations. The GCT for the clap push-up (p = 0.033) was significantly less than that for BD1 and BD2. No significant differences were revealed for time-to-peak vGRF (p = 0.717). Peak vGRF was significant between dominant and nondominant limbs (p = 0.045). Post hoc analysis of a significant limb by variation interaction in LR (p < 0.001) revealed the dominant limb to be significantly greater than the nondominant one in all 4 push-up variations. Furthermore, for both limbs, the clap LR was significantly greater than BD1, BD2, and BD3. The clap PR was significantly greater than BD1, BD2, and BD3. These data add rationale for determining upper extremity plyometric progression. The peak vGRFs are similar, and altering the box height did not affect peak vGRF. In contrast, the clap demonstrated the highest LR and PR suggesting that it may be a more powerful exercise than BD1, BD2, and BD3. The higher LR (Clap and BD3) for the dominant extremity illustrates bilateral disparity in the rate of eccentric loading.

Relationships between the seated single arm shot put test and Quick-DASH in patients being discharged from physical therapy.

BACKGROUND: Research examining the relationship between patient reported outcomes (PRO) and upper extremity functional performance tests (UEFPT) in patients with shoulder pathology are limited. OBJECTIVE: To assess the relationship between the seated single arm shot put test (SSASPT) and the PRO Quick-Disabilities of Arm, Shoulder, and Hand (DASH) in patients being discharged from physical therapy after shoulder injury or surgery. METHODS: Six physical therapists who regularly use the SSASPT and DASH from six different clinical sites provided SSASPT scores and completed Quick-DASH forms on 75 patients being discharged from rehabilitation following shoulder injury or surgery. Patients were grouped according to whether the involved shoulder was the dominant (n = 43) or nondominant (n = 32) limb. Three separate simple linear regression models, whole cohort and two patient groups, were created to determine the magnitude of the relationships (standardized betas) and change (betas) between DASH scores and the SSASPT limb symmetry index (LSI). RESULTS: Neither whole cohort nor two groups exhibited statistically significant (P > .05) relationships between LSI and Quick-DASH scores based upon the standardized betas (-0.197-0.038). Additionally, neither the standardized betas (z = 1.49, P = .135) nor betas (z = 1.28, P = .200) were statistically different between the two groups. CONCLUSIONS: The current study revealed no association between SSASPT and the Quick-DASH at discharge from physical therapy following shoulder injury or surgery. Consequently, it may be important to perform a battery of tests that include both subjective PRO and objective UEFPT tests to obtain a comprehensive perspective of the patient's functional and perceived status.