Specificity of weightlifting bench exercises in kayaking sprint performance: A perspective for neuromuscular training

Several studies showed significant differences between bench lift exercises without investigating which is more related, in biomechanical and neuromuscular terms, to improve the sprint flatwater kayak performance. This study aims to compare the power-load and velocity-load neuromuscular parameters performed in prone bench pull (PBP), and bench press (BP) exercises to identify which of them meet the gesture specificity in sprint flatwater kayak performance. Ten elite kayakers participated in this study. Power-load, velocity-load relationships, the maximum dynamic strength, and the kayak sprint performance test were assessed. The power-load and velocity-load relationships showed significant differences between the PBP and BP for each considered load. The kayakers showed a significant correlation between maximum power performed on the PBP and the maximum velocity reached in the kayak sprint (r = 0.80, p < 0.01) and the stroke frequency (r = 0.61, p < 0.05). Conversely, the maximum power performed on the BP did not correlate with the kinematic parameters analyzed. In addition, the maximum dynamic strength in the PBP and BP did not correlate with the maximum velocity and stroke frequency. Furthermore, no significant difference was observed in both the bench exercises for the maximum dynamic strength (p > 0.05). The results of this study suggest that the maximal muscular power expressed in PBP exercise only seems to be more specific in kayak velocity performance compared with maximal dynamic strength and with all dynamic parameters recorded in the BP. This will allow coaches and trainers to use specific bench exercises for specific neuromuscular kayakers’ adaptations during the whole competitive season

Effect of segmental muscle vibration on upper extremity functional ability poststroke: A randomized controlled trial.

Abstract Background: Upper extremity functional impairments are common consequences of stroke. Therefore, continuous investigation of effective interventions for upper extremity functions after stroke is a necessity. Segmental muscle vibration (SMV) is one of the interventions that incorporate sensory stimulation to improve motor cortical excitability. The aim of this study was to investigate the influence of 5-minute SMV application along with supervised physical therapy (SPT) on improving activities of daily living and motor recovery on the hemiparetic upper extremity in patients with stroke. Methods: A sample of 37 patients poststroke (29 males) was randomly allocated to either SPT control group (n=18) or SPT and SMV (SPT-SMV) experimental group (n=19). All patients received 3 sessions per week of SPT for 8 weeks. The SPT-SMV experimental group received SMV at the end of each SPT session. Outcome measures used were Barthel index (BI), modified Ashworth scale, manual muscle testing, and goniometry for range of motion (ROM) assessment. Results: Thirty-four patients completed the study. Patients in both groups improved significantly after treatment in BI, elbow ROM, and elbow muscles strength. However, muscle tone in elbow joint of the hemiplegic upper extremity improved significantly after SMV only in the experimental group (SPT-SMV). Conclusion: The SPT intervention can improve functional outcomes of upper extremity in people after stroke. However, using SMV may have superior effect on improving muscle tone after stroke. Abbreviations: ADL = activities of daily living, BI = Barthel index, MAS = modified Ashworth scale, MMT = manual muscle testing, ROM = range of motion, SMV = segmental muscle vibration, SPT = supervised physical therapy, SPT-SMV = supervised physical therapy and segmental muscle vibration

Right versus left radial artery access for coronary procedures: an international collaborative systematic review and meta-analysis including 5 randomized trials and 3210 patients

BACKGROUND: Radial artery access is a mainstay in the diagnosis and treatment of coronary artery disease. However, there is uncertainty on the comparison of right versus left radial access for coronary procedures. We thus undertook a systematic review and meta-analysis comparing right versus left radial access for coronary diagnostic and interventional procedures. METHODS: Pertinent studies were searched in CENTRAL, Google Scholar, MEDLINE/PubMed, and Scopus, together with international conference proceedings. Randomized trials comparing right versus left radial (or ulnar) access for coronary diagnostic or interventional procedures were included. Risk ratios (RR) and weighted mean differences (WMD) were computed to generate point estimates (95% confidence intervals). RESULTS: A total of 5 trials (3210 patients) were included. No overall significant differences were found comparing right versus left radial access in terms of procedural time (WMD=0.99 [-0.53; 2.51]min, p=0.20), contrast use (WMD=1.71 [-1.32; 4.74]mL, p=0.27), fluoroscopy time (WMD=-35.79 [-3.54; 75.12]s, p=0.07) or any major complication (RR=2.00 [0.75; 5.31], p=0.49). However, right radial access was fraught with a significantly higher risk of failure leading to cross-over to femoral access (RR=1.65 [1.18; 2.30], p=0.003) in comparison to left radial access. CONCLUSIONS: Right and left radial accesses appear largely similar in their overall procedural and clinical performance during transradial diagnostic or interventional procedures. Nonetheless, left radial access can be recommended especially during the learning curve phase to reduce femoral cross-overs

Chirp management in silicon-graphene electro absorption modulators

We study the frequency chirp properties of graphene-on-silicon electro-absorption modulators (EAMs). By experimentally measuring the chirp of a 100 \ub5m long single layer graphene EAM, we show that the optoelectronic properties of graphene induce a large positive linear chirp on the optical signal generated by the modulator, giving rise to a maximum shift of the instantaneous frequency up to 1.8 GHz. We exploit this peculiar feature for chromatic-dispersion compensation in fiber optic transmission thanks to the pulse temporal lensing effect. In particular, we show dispersion compensation in a 10Gb/s transmission experiment on standard single mode fiber with temporal focusing distance (0-dB optical-signal-to-noise ratio penalty) of 60 km, and also demonstrate 100 km transmission with a bit error rate largely lower than the conventional Reed-Solomon forward error correction threshold of 10 123

Adropin and apelin fluctuations throughout a season in professional soccer players : are they related with performance?

Myokines are likely to be involved in the whole-body metabolic adaptive changes that occur in response to regular exercise. We aimed to investigate the association of the two myokines (adropin and apelin) with physical performance in professional soccer players. To this purpose, we analyzed the fluctuations of circulating levels of both adropin and apelin in professional soccer players during a season and evaluated the possible association of these myokines with the performance level. Creatine kinase (CK) and lactate dehydrogenase (LDH) activity as well as iron, transferrin and high-sensitivity C-Reactive protein (hsCRP), ferritin, soluble transferrin receptor (sTfR), free testosterone/cortisol ratio (FTCR), total iron binding capacity (TIBC) were also determined. Fifteen male professional soccer players from an Italian Serie A team were included in this study. Regarding the results of the biochemical analyses, the patterns of changes in the biomarkers of fatigue and inflammation, i.e., HsCRP, CK and LDH reflected the effects of the training throughout the season. No significant changes were observed in adropin, while apelin exhibited variations that seem not to be related with performance. In addition, both adropin and apelin did not represent valuable strategy to assist in the performance assessment of professional soccer players