Correlation of throwing velocity to the results of lower body field tests in male college baseball players

Baseball-specific athleticism, potential, and performance have been difficult to predict. Increased muscle strength and power can increase throwing velocity but the majority of research has focused on the upper body. The present study sought to determine if bilateral or unilateral lower-body field testing correlates with throwing velocity. Baseball throwing velocity scores were correlated to the following tests: medicine ball (MB) scoop toss and squat throw, bilateral and unilateral vertical jumps, single and triple broad jumps, hop and stop in both directions, lateral to medial jumps, 10- and 60-yd sprints, and both left and right single-leg 10-yd hop for speed in 42 college baseball players. A multiple regression analysis (forward method), assessing the relationship between shuffle and stretch throwing velocities and lower-body field test results determined that right-handed throwing velocity from the stretch position was most strongly predicted by lateral to medial jump right (LMJR) and body weight (BW; R2 = 0.322), whereas lateral to medial jump left (LMJL; R2 = 0.688) predicted left stretch throw. Right-handed shuffle throw was most strongly predicted by LMJR and MB scoop (R2 = 0.338), whereas LMJL, BW, and LMJR all contributed to left-handed shuffle throw (R2 = 0.982). Overall, this study found that lateral to medial jumps were consistently correlated with high throwing velocity in each of the throwing techniques, in both left-handed and right-handed throwers. This is the first study to correlate throwing velocity with a unilateral jump in the frontal plane, mimicking the action of the throwing stride

A lower limb assessment tool for athletes at risk of developing patellar tendinopathy

Achilles tendinopathy is a common injury in running sports however the exact etiology of Achilles injury is still unclear. In recent years, altered neuromotor recruitment patterns of the triceps surae have been hypothesized to create differential intra-tendinous loads leading to pathology; however, this hypothesis has not been investigated. Further, the effect foot orthoses may have on neuromotor recruitment of the triceps surae in Achilles tendinopathy has not been investigated. Methods: The electromyographic activity of the triceps surae was recorded during an over-ground running task. Fifteen Achilles injured participants and 19 asymptomatic controls were assessed in a footwear only condition. The Achilles injured participants were also assessed running in a pre-fabricated foot orthoses. Results: In Achilles injured participants, there was a significant difference between soleus and lateral gastrocnemius offset times during running compared to the asymptomatic controls (p \u3c 0.05). There were no significant differences in triceps surae muscle activity between the footwear only and footwear and orthoses condition in the Achilles injured participants. Conclusions: The finding that triceps surae activity is altered in participants with Achilles tendinopathy may have clinical importance as it suggests that intra-tendinous loads are altered which may contribute to pathological changes. Further, foot orthoses have no immediate effect on the neuromotor control of the triceps surae

HOOK-GRIP IMPROVES POWER CLEAN KINETICS AND KINEMATICS

The purpose of this study was to compare one repetition maximum (1RM), as well as biomechanical outputs across a range of loads (75-100%) in the power clean (PC) utilizing the hook grip (HG) or closed-grip (CG). Eleven well-trained males (PC 1RM=1.34xBW) with at least six months of HG experience volunteered. Following a familiarization session, PC 1RM testing with the HG and CG were completed in random order, 5-7 days apart on a force platform with linear position transducers and 2D motion capture. The HG condition resulted in greater PC 1RM (6.6%, ES=0.43), peak barbell velocity (2.9-5.2%, ES=0.41-0.70) and relative peak barbell power (5.7-15.1%, ES=0.32-0.71) at all submaximal loads compared to CG. No substantial differences were found in horizontal bar-path (ES=-0.27-0.32). The results of this study suggest that athletes who implement weightlifting movements in their physical preparation should adopt the HG

Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain

Background: Individuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre. Methods. This study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and internal obliques (IO) of 11 individuals with CLBP and evident PR to 9 healthy controls during the hollowing manoeuvre in seven positions of the upper quarter. Results: Using magnitude based inferences it was likely (\u3e75%) that controls had a higher ratio of left IO:RA activation with supine (cervical neutral), asymmetrical tonic neck reflex (ATNR) left and right, right cervical rotation and cervical extension positions. A higher ratio of right IO:RA was detected in the cervical neutral and ATNR left position for the control group. The CLBP group were more likely to show higher activation of the left RA in the cervical neutral, ATNR left and right, right cervical rotation and cervical flexion positions as well as in the cervical neutral and cervical flexion position for the right RA. Conclusions: Individuals with CLBP and PR manifested altered activation patterns during the hollowing maneuver compared to healthy controls and that altering cervical and upper extremity position can diminish the group differences. Altered cervical and limb positions can change the activation levels of the IO and EO in both groups. © 2014 Parfrey et al.; licensee BioMed Central Ltd

The acute neuromuscular responses to cluster set resistance training: A systematic review and meta-analysis

Background: Cluster sets (CSs) are a popular resistance training (RT) strategy categorised by short rest periods implemented between single or groups of repetitions. However, evidence supporting the effectiveness of CSs on acute intra-session neuromuscular performance is still equivocal. Objective: The objective of this investigation was to determine the efficacy of a single session of CSs to attenuate losses in force, velocity and power compared to traditional set (TS) training. Methods: Screening consisted of a systematic search of EMBASE, Google Scholar, PubMed, Scopus and SPORTDiscus. Inclusion criteria were (1) measured one or more of mean/peak force, velocity or power; (2) implemented CSs in comparison to TSs; (3) an acute design, or part thereof; and (4) published in an English-language, peer-reviewed journal. Raw data (mean ± standard deviation) were extracted from included studies and converted into standardised mean differences (SMDs) and ± 95% confidence intervals (CIs). Results: Twenty-five studies were used to calculate SMD ± 95% CI. Peak (SMD = 0.815, 95% CI 0.105–1.524, p = 0.024) and mean (SMD = 0.863, 95% CI 0.319–1.406, p = 0.002) velocity, peak (SMD = 0.356, 95% CI 0.057–0.655, p = 0.019) and mean (SMD = 0.692, 95% CI 0.395–0.990, p \u3c 0.001) power, and peak force (SMD = 0.306, 95% CI − 0.028 to 0.584, p = 0.031) favoured CS. Subgroup analyses demonstrated an overall effect for CS across loads (SMD = 0.702, 95% CI 0.548–0.856, p \u3c 0.001), included exercises (SMD = 0.664, 95% CI 0.413–0.916, p \u3c 0.001), experience levels (SMD = 0.790, 95% CI 0.500–1.080, p \u3c 0.001) and CS structures (SMD = 0.731, 95% CI 0.567–0.894, p \u3c 0.001) with no difference within subgroups. Conclusion: CSs are a useful strategy to attenuate the loss in velocity, power and peak force during RT and should be used to maintain neuromuscular performance, especially when kinetic outcomes are emphasised. However, it remains unclear if the benefits translate to improved performance across all RT exercises, between sexes and across the lifespan

The acute neuromuscular responses to cluster set resistance training: A systematic review and meta-analysis

Background: Cluster sets (CSs) are a popular resistance training (RT) strategy categorised by short rest periods implemented between single or groups of repetitions. However, evidence supporting the effectiveness of CSs on acute intra-session neuromuscular performance is still equivocal. Objective: The objective of this investigation was to determine the efficacy of a single session of CSs to attenuate losses in force, velocity and power compared to traditional set (TS) training. Methods: Screening consisted of a systematic search of EMBASE, Google Scholar, PubMed, Scopus and SPORTDiscus. Inclusion criteria were (1) measured one or more of mean/peak force, velocity or power; (2) implemented CSs in comparison to TSs; (3) an acute design, or part thereof; and (4) published in an English-language, peer-reviewed journal. Raw data (mean ± standard deviation) were extracted from included studies and converted into standardised mean differences (SMDs) and ± 95% confidence intervals (CIs). Results: Twenty-five studies were used to calculate SMD ± 95% CI. Peak (SMD = 0.815, 95% CI 0.105–1.524, p = 0.024) and mean (SMD = 0.863, 95% CI 0.319–1.406, p = 0.002) velocity, peak (SMD = 0.356, 95% CI 0.057–0.655, p = 0.019) and mean (SMD = 0.692, 95% CI 0.395–0.990, p \u3c 0.001) power, and peak force (SMD = 0.306, 95% CI − 0.028 to 0.584, p = 0.031) favoured CS. Subgroup analyses demonstrated an overall effect for CS across loads (SMD = 0.702, 95% CI 0.548–0.856, p \u3c 0.001), included exercises (SMD = 0.664, 95% CI 0.413–0.916, p \u3c 0.001), experience levels (SMD = 0.790, 95% CI 0.500–1.080, p \u3c 0.001) and CS structures (SMD = 0.731, 95% CI 0.567–0.894, p \u3c 0.001) with no difference within subgroups. Conclusion: CSs are a useful strategy to attenuate the loss in velocity, power and peak force during RT and should be used to maintain neuromuscular performance, especially when kinetic outcomes are emphasised. However, it remains unclear if the benefits translate to improved performance across all RT exercises, between sexes and across the lifespan

Structure and dynamics of the Shapley Supercluster

We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various telescopes and from the literature. Our data reveal that the main plane of the SSC (v~ 14500 km/s) extends further than previous estimates, filling the whole extent of our survey region of 12~degrees by 30~degrees on the sky (30 x 75~h-1 Mpc). There is also a connecting structure associated with the slightly nearer Abell~3571 cluster complex (v~ 12000km/s. These galaxies seem to link two previously identified sheets of galaxies and establish a connection with a third one at V= 15000 km/s near R.A.= 13h. They also tend to fill the gap of galaxies between the foreground Hydra-Centaurus region and the more distant SSC. In the velocity range of the Shapley Supercluster (9000 km/s < cz < 18000 km/s), we found redshift-space overdensities with b\_j < 17.5 of ~5.4 over the 225 square degree central region and ~3.8 in a 192 square degree region excluding rich clusters. Over the large region of our survey, we find that the intercluster galaxies make up 48 per cent of the observed galaxies in the SSC region and, accounting for the different completeness, may contribute nearly twice as much mass as the cluster galaxies. In this paper, we discuss the completeness of the velocity catalogue, the morphology of the supercluster, the global overdensity, and some properties of the individual galaxy clusters in the Supercluster.Comment: Accepted for publication in Astronomy and Astrophysic

Cerebral Responses To Innocuous Somatic Pressure Stimulation Following Aerobic Exercise Rehabilitation In Chronic Pain Patients: A Functional Magnetic Resonance Imaging Study

The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain