Eccentric exercise can influence tendon mechanical properties and matrix protein synthesis. mRNA for collagen and regulatory factors thereof are upregulated in animal tendons, independent of muscular contraction type, supporting the view that tendon, compared with skeletal muscle, is less sensitive to differences in type and/or amount of mechanical stimulus with regard to expression of collagen...

OBJECTIVES To conduct a feasibility study to compare concentric and eccentric rotator cuff strengthening exercises for rotator cuff tendinopathy. METHODS A total of 11 patients with rotator cuff tendinopathy who were on the waiting list for arthroscopic subacromial decompression surgery were randomised to perform eccentric rotator cuff strengthening exercises, concentric strengthening exercis...

Background Pre-workout supplements purportedly enhance feelings of energy, reduce fatigue and improve exercise performance. The purpose of this study was to examine the performance effects of caffeinated and non-caffeinated multi-ingredient pre-workout supplements. Methods In a counterbalanced, double-blind, placebo-controlled design, eccentric and concentric force production during lower bod...

The objective of this study was to assess the influence of left ventricular (LV) geometric pattern on coronary vasomotion in patients with essential hypertension. We studied 34 hypertensive patients, who had never been treated, with angiographically normal coronary arteries. Patients were classified into four LV geometric patterns by echocardiography: normal, concentric remodeling, eccentric hy...

Rapid eccentric contractions of the quadriceps have been shown to produce a more variable motor outcome than isometric and concentric contractions (Christou & Carlton, 1999, 2000). These findings provide additional support to the hypothesis that the central nervous system may control gradation of muscle force differently for eccentric contractions (Enoka, 1996). Several studies suggest that whe...

Differences in structural remodeling are believed to be influenced by hormonal systems in hypertension. The objective of the present study was to investigate the change in the circulating catecholamine beta-adrenergic system in the left ventricle remodeling process in hypertensives. One hundred and thirty-four men (mean age, 53 years) had essential hypertension and underwent echocardiography be...

LOCOMOTION IS ARGUABLY one of the most ubiquitous and important manifestations of life, equally important to feeding as to escape predators. Evolution came up with three molecular motors to power motion: the actomyosin system Levitsky (11); the microtubule, dynein-based flagellar motors of eukaryotes (13); and the flagellar rotary motors of bacteria (15). All three systems serve propulsion, i.e...

[Purpose] This study investigated the changes in the slope of EMG-time curves (relationship) at the maximal and different levels of dynamic (eccentric and concentric) and static (isometric) contractions. [Subjects and Methods] The subject was a 17 year-old male adolescent. The surface EMG signal of the dominant arm's biceps brachii (BB) was recorded through electrodes placed on the muscle belly...

Isokinetic moment ratios of the hamstrings (H) and quadriceps (Q) muscle groups, and their implication in muscle imbalance, have been investigated for more than three decades. The conventional concentric H/Q ratio with its normative value of 0.6 has been at the forefront of the discussion. This does not account for the joint angle at which moment occurs and the type of muscle action involved. A...

LOCOMOTION IS ARGUABLY one of the most ubiquitous and important manifestations of life, equally important to feeding as to escape predators. Evolution came up with three molecular motors to power motion: the actomyosin system Levitsky (11); the microtubule, dynein-based flagellar motors of eukaryotes (13); and the flagellar rotary motors of bacteria (15). All three systems serve propulsion, i.e...