Postural control is critical for effective performance of all goal-directed activities. For maintenance of postural equilibrium against gravity and environmental disturbances, central nervous system produces centrally organized patterns of muscle activity based on initial conditions, perturbation characteristics, learning and intention. These organized strategies are called "postural strategies...

OBJECTIVE To examine whether self-pacing reduces the physiological challenge of performing 5000 m rowing ergometry exercise in comparison with a matched-intensity exercise condition in which a constant effort pacing strategy is enforced. METHODS Nine healthy well-trained male participants volunteered to participate in three 5000 m rowing conditions (two submaximal and one maximal conditions) ...

The purpose of this study was to examine the role of active muscle mass on cardiovascular drift (CVdrift) during prolonged exercise. Twelve subjects with peak oxygen uptake (VO2peak) of 3.52 ± 0.52 L·min(-1) (mean ± SD) cycled for 55 min with 80 revolutions per minute with either two legs (2-legged) or one leg (1-legged). Oxygen uptake was at 60% of VO2peak throughout the 2-legged trial and at ...

During maximal contractions, the sum of forces exerted by homonymous muscles unilaterally is typically larger than the sum of forces exerted by the same muscles bilaterally. This phenomenon is known as the bilateral deficit (BLD), and it is suggested that this deficit is due to neural inhibition. It remains unclear, however, whether such inhibition is mediated by supraspinal mechanisms or by re...

[Purpose] The aim of the present study was to investigate the possibility of an interaction between stretching induced deficit (SFD) and bilateral deficits (BLD) during maximal voluntary isometric hand flexion under PNF stretch and no-stretch conditions through measurement of EMG and force production. [Subjects and Methods] Ten physically active male Caucasian students (age, 24.1±2.38 years; bo...

The aim of this study was to investigate the acute effects of unilateral ankle plantar flexors static- stretching on surface electromyography (sEMG) and the center of pressure (COP) during a single-leg balance task in both lower limbs. Fourteen young healthy, non-athletic individuals performed unipodal quiet standing for 30s before and after (stretched limb: immediately post-stretch, 10 and 20 ...

PURPOSE Studies have both supported and refuted the concept that it is the intent to perform ballistic contractions that determines velocity-specific gains in resistance training. The purpose of this investigation was to determine whether ballistic intent is as effective as ballistic movement in improving muscle activation, force, movement time, and reaction time. METHODS Subjects completed 8...

Muscle fiber conduction velocity (MFCV) is studied in 51 healthy volunteers using an invasive (IMFCV) and a surface (S-MFCV) EMG technique in the biceps brachii, in order to acquire normal values and to study reproducibility and effects of gender and age. In the invasive technique, muscle fibers are directly stimulated with needle electrodes, and the latencies of the evoked potentials are measu...

Surface electromyogram (EMG), blood pressure (BP), blink rate (BR) and heart rate (HR) were recorded before and during 4 types of mental task. The mental task involved 3 tasks that encompassed the memory (M), visual search (VS) and color-word (CW) tasks besides the control task (CT) of maintaining a similar posture while focusing on a single spot on the computer screen. Except for CW, any volun...

OBJECTIVE To study the influence of 10 min of cyclic twisting motion on abdominal and back muscle activities. BACKGROUND Repetitive (cyclic) occupational activity was identified by many epidemiological reports to be a risk factor for the development of work-related musculoskeletal disorders. Biomechanical and physiological confirmation, however, is lacking. METHODS Trunk muscle electromyogr...