Effects of Volitional Preemptive Abdominal Contraction on Shoulder Proprioception Following Shoulder Muscle Fatigue

The abdominal bracing maneuver, a volitional preemptive abdominal contraction (VPAC) strategy, is potentially beneficial to shoulder exercise performance. It is unclear how VPAC use affects shoulder function, including proprioception and shoulder muscle function following shoulder muscle fatigue caused by upper extremity dominant sports movements. Discovering methods that reduce its effects on shoulder proprioception and shoulder muscle function is important for clinical practice in orthopedic rehabilitation. PURPOSE: To identify VPAC effects on shoulder proprioception abilities and to identify VPAC effects on shoulder muscle electromyographic amplitudes, during seated proprioception trials, both with and without muscle fatigue present. METHODS: Thirty-nine participants (26 women, 13 men) participated in this study. Shoulder proprioception was measured by shoulder flexion reproduction angles. Kinematic data were collected during the shoulder flexion trials to determine the accuracy in the subjects’ ability to reproduce a reference angle. All data were collected before and after a shoulder muscle fatigue protocol. Electromyographic data from the anterior deltoid (AD), posterior deltoid (PD), upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and infraspinatus (IF) muscles were used to observe muscle contraction amplitudes during the angle reproduction trials. RESULTS: Shoulder reproduction angles were not significantly affected by VPAC or muscle fatigue. Individually, shoulder muscle fatigue significantly increased UT muscle amplitudes (Mdn = 0.059(0.135), p\u3c.008) and LT muscle amplitudes (Mdn = 0.023(0.059), p\u3c.008). VPAC significantly increased shoulder IF muscle amplitudes (Mdn = 0.019(0.038), p\u3c.008). CONCLUSION: The VPAC did not affect shoulder proprioception in this study, showing that the strategy may not be beneficial to improving proprioception in the shoulder joint. The affects of muscle fatigue on the selected shoulder muscles supported the observations in previous literature concerning muscle fatigue effects on selected shoulder muscle. Clinicians can use this information to assist with the creation of therapeutic exercise for the shoulder joint

Grasping Kinematics from the Perspective of the Individual Digits: A Modelling Study

Grasping is a prototype of human motor coordination. Nevertheless, it is not known what determines the typical movement patterns of grasping. One way to approach this issue is by building models. We developed a model based on the movements of the individual digits. In our model the following objectives were taken into account for each digit: move smoothly to the preselected goal position on the object without hitting other surfaces, arrive at about the same time as the other digit and never move too far from the other digit. These objectives were implemented by regarding the tips of the digits as point masses with a spring between them, each attracted to its goal position and repelled from objects' surfaces. Their movements were damped. Using a single set of parameters, our model can reproduce a wider variety of experimental findings than any previous model of grasping. Apart from reproducing known effects (even the angles under which digits approach trapezoidal objects' surfaces, which no other model can explain), our model predicted that the increase in maximum grip aperture with object size should be greater for blocks than for cylinders. A survey of the literature shows that this is indeed how humans behave. The model can also adequately predict how single digit pointing movements are made. This supports the idea that grasping kinematics follow from the movements of the individual digits

Ezetimibe added to statin therapy after acute coronary syndromes

BACKGROUND: Statin therapy reduces low-density lipoprotein (LDL) cholesterol levels and the risk of cardiovascular events, but whether the addition of ezetimibe, a nonstatin drug that reduces intestinal cholesterol absorption, can reduce the rate of cardiovascular events further is not known. METHODS: We conducted a double-blind, randomized trial involving 18,144 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and had LDL cholesterol levels of 50 to 100 mg per deciliter (1.3 to 2.6 mmol per liter) if they were receiving lipid-lowering therapy or 50 to 125 mg per deciliter (1.3 to 3.2 mmol per liter) if they were not receiving lipid-lowering therapy. The combination of simvastatin (40 mg) and ezetimibe (10 mg) (simvastatin-ezetimibe) was compared with simvastatin (40 mg) and placebo (simvastatin monotherapy). The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, unstable angina requiring rehospitalization, coronary revascularization ( 6530 days after randomization), or nonfatal stroke. The median follow-up was 6 years. RESULTS: The median time-weighted average LDL cholesterol level during the study was 53.7 mg per deciliter (1.4 mmol per liter) in the simvastatin-ezetimibe group, as compared with 69.5 mg per deciliter (1.8 mmol per liter) in the simvastatin-monotherapy group (P<0.001). The Kaplan-Meier event rate for the primary end point at 7 years was 32.7% in the simvastatin-ezetimibe group, as compared with 34.7% in the simvastatin-monotherapy group (absolute risk difference, 2.0 percentage points; hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P = 0.016). Rates of pre-specified muscle, gallbladder, and hepatic adverse effects and cancer were similar in the two groups. CONCLUSIONS: When added to statin therapy, ezetimibe resulted in incremental lowering of LDL cholesterol levels and improved cardiovascular outcomes. Moreover, lowering LDL cholesterol to levels below previous targets provided additional benefit