The effect of whole body vibration-induced post-activation potentiation upon indices of isometric and dynamic force/power production during, and following a six-week periodised Smith machine back squat protocol.

Purpose. The purpose of this study was to examine the chronic and acute effects of a 6 wk, periodized Squat training program, with (G2) or without (G3) low frequency vibration upon select force characteristics, as well as to changes in body composition. Methods. Participants (G1 n = 6; G2 n = 13; G3 n = 11; ranged in age from 18 to 30 years) were randomized into either a 6 wk periodized Squat training regimen, with or without whole body low frequency vibration or a control group. Measures of dynamic and isometric strength (1RM Squats and Isometric Quarter Squats), dynamic power (Depth Jumps and Squat jumps with a 20 Kg load) and body composition (DXA) were assessed. Results. Both training groups increased significantly for the Squat 1RM from baseline to week 7 compared to the controls. There were significant group differences for Rate of Force Development at 250 ms, initial peak in force, and Peak RFD. There were also significant group differences for Force at 250ms, Force at initial peak, and MVC. There were significant differences in Peak jump power between G2 and G3 from weeks 1 to 3 under both jumping conditions. Both training groups had significant increases in total lean tissue, lean trunk tissue, and lean leg tissue (g), and significant decreases in percent leg fat. Conclusions. Whole body vibration did not improve maximal force generating capability beyond resistance training alone and actually lead to a decreased performance

The Efficacy of Partial Squats on Measures of Strength and Explosiveness: An Exploratory Study

Abstract available in the 8th Annual Coaches and Sport Science College

The acute effects of whole body vibration on isometric mid-thigh pull performance

The purpose of the present investigation was to examine the acute effects of whole body vibration (WBV) on isometric mid-thigh pull force–time curve (FTC) characteristics. Eleven recreationally trained subjects were randomly assigned to three treatment conditions: sham no vibration protocol (T1), vibration protocol 30 Hz 2–4 mm amplitude (T2), and vibration protocol 30 Hz 2–4 mm (T3). After completing a standardized warm-up, the subject stood on a vibration platform with the knee at a 120° angle and performed one of the three interventions. Each treatment condition required the subject to stand on the platform for thirty-second treatments, each separated by thirty seconds of recovery. Five minutes after the completion of the treatment conditions, the subjects performed the isometric mid-thigh pull. All FTCs were analyzed with standardized procedures for peak force (PF) and peak rate of force development (PRFD). A 1 × 3 repeated measures analysis of variance (ANOVA) was used to compare the three treatments. Additionally, coefficients of variance (CV), as well as intraclass and interclass correlations, were performed. There were no significant differences (p \u3e 0.05) for any of the FTC analyses performed in this investigation. The CV and the 95% confidence interval (CI) indicate that the WBV protocol resulted in trivial changes in PF and beneficial changes in PRFD. A 30 Hz 2–4 mm amplitude WBV does not result in a significant increase in isometric mid-thigh pull performance

Inter-Segmental Coordination during a Unilateral 180° Jump in Elite Rugby Players: Implications for Prospective Identification of Injuries

Musculoskeletal injuries often occur during the execution of dynamic sporting tasks that involve rotation. The prescription of appropriate prevention strategies of musculoskeletal injury relies on assessments to identify risk, but current assessment tools focus on uniplanar movements. The purpose of this paper is to demonstrate the utility of the unilateral 180 • jump as a potential assessment tool for injury risk in the lower body by (1) providing descriptive kinematics of the knee, thigh, and pelvis (2) conducting inter-segmental coordination analysis, and (3) comparing the knee kinematics between the dominant and non-dominant limb (NDL) during the loading (LOP) and landing phase (LAP). Elite rugby players completed one session, performing five 180 • unilateral jumps on each limb while collecting kinematic data. Independent t-tests were used to compare peak angles of DL and NDL. Continuous Relative Phase (CRP) plots were constructed for thorax and pelvis in the transverse plane. At the loading phase, the non-dominant limb had greater peak knee abduction (ABD) (p = 0.01). At the landing phase, the dominant limb had greater peak knee adduction (ADD) (p = 0.05). At the landing phase, the non-dominant limb had greater peak knee ABD (p = 0.01). CRP plots indicate participants can utilize a thorax-led, pelvis-led, or synchronized rotational method. Bilateral asymmetries were observed, indicated by significant differences in the bilateral landing phase peak ADD/ABD, which is of particular interest considering all participants were healthy. Therefore, additional research is needed to determine thresholds for injury risk during rotational tasks

The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations.

Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http://umd.be/TREAT_DMD/). We analyzed genetic data for 7,149 DMD mutations held within the database. A total of 5,682 large mutations were observed (80% of total mutations), of which 4,894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1,445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0.3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations)

Gluons and the quark sea at high energies: distributions, polarization, tomography

This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that will be able to collide electrons and positrons with polarized protons and with light to heavy nuclei at high energies, offering unprecedented possibilities for in-depth studies of quantum chromodynamics. This report is organized around four major themes: i) the spin and flavor structure of the proton, ii) three-dimensional structure of nucleons and nuclei in momentum and configuration space, iii) QCD matter in nuclei, and iv) Electroweak physics and the search for physics beyond the Standard Model. Beginning with an executive summary, the report contains tables of key measurements, chapter overviews for each of the major scientific themes, and detailed individual contributions on various aspects of the scientific opportunities presented by an EIC.Comment: 547 pages, A report on the joint BNL/INT/Jlab program on the science case for an Electron-Ion Collider, September 13 to November 19, 2010, Institute for Nuclear Theory, Seattle; v2 with minor changes, matches printed versio

A Comparison of the Effects of 6 Weeks of Traditional Resistance Training, Plyometric Training, and Complex Training on Measures of Strength and Anthropometrics

Complex training (CT; alternating between heavy and lighter load resistance exercises with similar movement patterns within an exercise session) is a form of training that may potentially bring about a state of postactivation potentiation, resulting in increased dynamic power (P max) and rate of force development during the lighter load exercise. Such a method may be more effective than either modality, independently for developing strength. The purpose of this research was to compare the effects of resistance training (RT), plyometric training (PT), and CT on lower body strength and anthropometrics. Thirty recreationally trained college-aged men were trained using 1 of 3 methods: resistance, plyometric, or complex twice weekly for 6 weeks. The participants were tested pre, mid, and post to assess back squat strength, Romanian dead lift (RDL) strength, standing calf raise (SCR) strength, quadriceps girth, triceps surae girth, body mass, and body fat percentage. Diet was not controlled during this study. Statistical measures revealed a significant increase for squat strength (p = 0.000), RDL strength (p = 0.000), and SCR strength (p = 0.000) for all groups pre to post, with no differences between groups. There was also a main effect for time for girth measures of the quadricepsmuscle group (p = 0.001), the triceps surae muscle group (p = 0.001), and body mass (p = 0.001; post hoc revealed no significant difference). There were main effects for time and group × time interactions for fat-free mass % (RT: p = 0.031; PT: p = 0.000). The results suggest that CT mirrors benefits seen with traditional RT or PT. Moreover, CT revealed no decrement in strength and anthropometric values and appears to be a viable training modality

Development of Strength and Power

An effective strength and conditioning program is an essential component of the preparation of any athlete or sportsperson. Strength and Conditioning for Sports Performance is a comprehensive and authoritative introduction to the theory and practice of strength and conditioning, providing students, coaches and athletes with everything they need to design and implement effective training programs