16 research outputs found

    Increasing Ball Velocity in the Overhead Athlete: A Meta-Analysis of Randomized Controlled Trials

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    Overhead athletes routinely search for ways to improve sport performance, and one component of performance is ball velocity. The purpose of this meta-analysis was to investigate the effect of different strengthening interventions on ball and serve velocity. A comprehensive literature search with pre-set inclusion and exclusion criteria from 1970 to 2014 was conducted. Eligible studies were randomized control trials including the mean and SDs of both pretest and posttest ball velocities in both the experimental and the control groups. The outcome of interest was ball/serve velocity in baseball, tennis, or softball athletes. Level 2 evidence or higher was investigated to determine the effect different training interventions had on velocity. Pretest and posttest data were extracted to calculate Hedges\u27s g effect sizes with 95% confidence intervals (CIs). Methodological qualities of the final 13 articles within the analysis were assessed using the Physiotherapy Evidence Database scale. The majority of the articles included in this analysis had an effect on velocity with the strongest effect sizes found in periodized training (Hedges\u27s g = 3.445; 95% CI = 1.976-4.914). Six studies had CI that crossed zero, indicating that those specific interventions should be interpreted with caution. Consistent and high-quality evidence exists that specific resistance training interventions have an effect on velocity. These findings suggest that interventions consisting of isokinetic training, multimodal training, and periodization training are clinically beneficial at increasing velocity in the overhead athlete over different windows of time

    More Elevated Fastballs Associated with Placement on the Injured List Due to Shoulder Injury

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    Purpose To evaluate whether impending shoulder injury was associated with changes in pitch location or velocity immediately preceding injury. Methods Pitchers placed on the injured list (IL) due to a shoulder injury between 2015 and 2020 were identified in the Major League Baseball transactions database. Four-seam fastball velocity and frequency of pitch location for each pitch type was collected for each player in the season before placement on the IL and within 1 month of placement on the IL with a minimum of 55 pitches thrown of 1 type. Pitch locations were collected as identified by Baseball Savant’s Game-Day Zones. Game-Day Zones were consolidated into high (above the strike zone midpoint) versus low, arm side (closer to the pitcher’s arm side of the plate) versus opposite side, and within the strike zone versus out of zone. Repeated measures analysis of variance determined differences in four-seam velocity and the location distribution of 4-seam fastballs, change-ups, and breaking balls among each group. Results In total, 267 pitchers were placed on the IL for a shoulder injury with the majority diagnosed with inflammation (89/267) followed by strain or sprain (69/267). Four-seam fastball locations significantly increased above the mid-point of the zone (45.9% vs 42.4%, P = .008) and out of the strike zone (48.5% vs 46.5%, P = .011) within a month before IL placement. There was no significant change in 4-seam fastball velocity immediately before IL placement. Conclusions Pitchers threw more elevated 4-seam fastballs and out-of-zone 4-seam fastballs in the month before IL placement for shoulder injury. These findings suggest that a loss of 4-seam fastball command decreases with impending shoulder injury. Level of Evidence IV, prognostic case series

    Using Photoelectron Spectroscopy and Quantum Mechanics to Determine d-Band Energies of Metals for Catalytic Applications

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    Muscle activation in coupled scapulohumeral motions in the high performance tennis serve

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    Objective: To evaluate muscle activation patterns in selected scapulohumeral muscles in the tennis serve. These patterns of muscle activation have not been evaluated in other studies of the tennis serve. Fine wire and surface EMG was used to calculate onset and offset timing of muscle activation. Design: Controlled laboratory study. Setting: Biomechanical laboratory. Subjects: 16 tennis players (age 18–40) with rated skills (National Tennis Rating Program (NTRP) rating 4.5– 6.5; club tournament level or higher) were subjects. Main outcomes measure: Dependent variables of muscle activation onset and offset as well as sequencing of the stabilising muscles of the scapula (upper trapezius, lower trapezius, serratus anterior; the muscles that position the arm) anterior deltoid and posterior deltoid; and the muscles of the rotator cuff muscles (supraspinatus, infraspinatus, teres minor) during the tennis serve motion. Results: Patterns of muscle activation were observed during the tennis serve motion. The serratus anterior (2287 ms before ball impact) and upper trapezius (2234 ms) were active in the early cocking phase, while the lower trapezius (2120 ms) was activated in the late cocking phase just before the acceleration phase. The anterior deltoid (2250 ms) was activated in early cocking, while the posterior deltoid (2157 ms) was activated later. The teres minor (2214 ms) was activated early in the cocking phase. The supraspinatus (2103 ms) was activated in late cocking. The infraspinatus (+47 ms after ball impact) was activated in followthrough. All muscles except infraspinatus were activated in duration of more than 50% of the service motion. Conclusions: This study demonstrates that there are patterns of activation of muscles around the scapulohumeral articulation in the normal accomplished tennis serve. Rehabilitation and conditioning programs for tennis players should be structured to restore and optimise the activation sequences (scapular stabilisers before rotator cuff), task specific functions (serratus anterior as a retractor of the scapula, lower trapezius as a scapular stabiliser in the elevated rotating arm) and duration of activation of these muscles

    Hormones, Menstrual Distress, and Migraine Across the Phases of the Menstrual Cycle

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    Objective—The primary objectives of the present study were to (1) contrast reproductive hormone levels and ratings of menstrual distress of female migraineurs with those of a control group in each menstrual cycle phase, (2) examine correlations between hormone levels and migraine frequency, severity, and migraine-related disability, and (3) examine correlations between menstrual distress and migraine frequency, severity, and migraine-related disability. A secondary objective was to evaluate the validity of a migraine disability measure modified to reflect 7-day recall. Background—Further controlled, prospective study is needed regarding the temporal relationships between reproductive hormones at each stage of the menstrual cycle and fluctuations in migraine activity across the cycle. Methods—Twenty-three women (17 with migraine, 6 control participants) completed laboratory hormone assays and measures of menstrual distress and disability at each phase of one menstrual cycle, and monitored their headache activity daily during the same cycle. Results—The migraine group evidenced lower premenstrual luteinizing hormone and more menstrual distress symptoms at each phase of the menstrual cycle. Hormones were associated with migraine activity and disability within cycle phases, and across phases in a time-lagged manner. Menstrual distress was associated with ovulatory phase migraine activity and with migraine-related disability across the menstrual cycle. A retrospective 7-day migraine disability measure appeared to be a consistently valid index. Conclusions—Both reproductive hormones and menstrually related distress appear to predict migraine activity and disability. These associations were evident not only for perimenstrual migraine, but also for migraine at each phase of the menstrual cycle

    More Elevated Fastballs Associated with Placement on the Injured List due to Shoulder Injury

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    Purpose: To evaluate whether impending shoulder injury was associated with changes in pitch location or velocity immediately preceding injury. Methods: Pitchers placed on the injured list (IL) due to a shoulder injury between 2015 and 2020 were identified in the Major League Baseball transactions database. Four-seam fastball velocity and frequency of pitch location for each pitch type was collected for each player in the season before placement on the IL and within 1 month of placement on the IL with a minimum of 55 pitches thrown of 1 type. Pitch locations were collected as identified by Baseball Savant’s Game-Day Zones. Game-Day Zones were consolidated into high (above the strike zone midpoint) versus low, arm side (closer to the pitcher’s arm side of the plate) versus opposite side, and within the strike zone versus out of zone. Repeated measures analysis of variance determined differences in four-seam velocity and the location distribution of 4-seam fastballs, change-ups, and breaking balls among each group. Results: In total, 267 pitchers were placed on the IL for a shoulder injury with the majority diagnosed with inflammation (89/267) followed by strain or sprain (69/267). Four-seam fastball locations significantly increased above the mid-point of the zone (45.9% vs 42.4%, P ÂŒ .008) and out of the strike zone (48.5% vs 46.5%, P ÂŒ .011) within a month before IL placement. There was no significant change in 4-seam fastball velocity immediately before IL placement. Conclusions: Pitchers threw more elevated 4-seam fastballs and out-of-zone 4-seam fastballs in the month before IL placement for shoulder injury. These findings suggest that a loss of 4-seam fastball command decreases with impending shoulder injury. Level of Evidence: IV, prognostic case series

    Improved NYVAC-based vaccine vectors.

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    While as yet there is no vaccine against HIV/AIDS, the results of the phase III Thai trial (RV144) have been encouraging and suggest that further improvements of the prime/boost vaccine combination of a poxvirus and protein are needed. With this aim, in this investigation we have generated derivatives of the candidate vaccinia virus vaccine vector NYVAC with potentially improved functions. This has been achieved by the re-incorporation into the virus genome of two host range genes, K1L and C7L, in conjunction with the removal of the immunomodulatory viral molecule B19, an antagonist of type I interferon action. These novel virus vectors, referred to as NYVAC-C-KC and NYVAC-C-KC-ΔB19R, have acquired relevant biological characteristics, giving higher levels of antigen expression in infected cells, replication-competency in human keratinocytes and dermal fibroblasts, activation of selective host cell signal transduction pathways, and limited virus spread in tissues. Importantly, these replication-competent viruses have been demonstrated to maintain a highly attenuated phenotype
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