Neural control of the soleus H-reflex correlates tothe laterality pattern in limbs

BACKGROUND： Previous studies have demonstrated the relationship of lower limb dominance with left- and right-handedness, supporting findings suggest that there is a role for peripheral factors in the neural control of movement. OBJECTIVE： To investigate the effect of laterality pattern on the neural mechanisms of motor control at the peripheral level. DESIGN, TIME AND SETTING： A controlled observation experiment was performed at the Motor Diagnostics Laboratory of the Academy of Physical Education in Katowice, Poland, in June 2009. PARTICIPANTS： Twenty young male adults aged 21-23 years and presenting two laterality patterns in hand-foot combination （right handed-right footed and left handed-left footed groups） took part in the experiment. All participants were carefully screened to eliminate any neurological or muscle disease or trauma. METHODS： The experiment included a laterality evaluation and the motor evoked potentials of dominant and non-dominant limbs. Measures were done through the use of the Hoffmann-reflex （H-reflex） circuitry. The soleus H-reflex parameters elicited at rest in lower extremities were compared. The soleus H-reflex and the direct motor response were elicited in lower extremities of each participant in the same laboratory session. MAIN OUTCOME MEASURES： Onset latencies and min-max amplitudes of the direct motor response and the H-reflex; the motor and sensory conduction velocities; and symmetry coefficients of response parameters. RESULTS： The analysis of symmetry coefficients of direct and late motor responses confirmed differences between two laterality patterns in amplitude and latency of the H-reflex as well as in a sensory conduction velocity （P 〈 0.05）, but not in direct motor response parameters. The amplitude of the H-reflex and the calculated sensory la afferent conduction velocity in the dominant lower extremity were significantly depressed in the right-sided group in comparison to the left-sided group （P = 0.001）. The right-sided group presented significantly higher motor fiber conduction velocity in the dominant leg than in the non-dominant leg （P = 0.006）, with no similar effect in the left-sided group. CONCLUSION： The neural control of the H-reflex elicited at rest is related to the laterality pattern in hand-foot combination in healthy adults. This result strongly suggests the possible existence of intrinsic control mechanisms of afferent feedback related to functional dominance in human limbs.

Effects of hyperbaric oxygen therapy on human psychomotor performance:A review

Psychomotor performance is the coordination of a sensory or ideational(cognitive)process and a motor activity.All sensorimotor processes involved in planning and execution of voluntary movements need oxygen supply and seem to be significantly disrupted in states of hypoxia.Hyperbaric oxygen therapy has become a widely used treatment in routine medicine and sport medicine due to its beneficial effects on different aspects of human physiology and performance.This paper presents state-of-the-art data on the effects of hyperbaric oxygen therapy on different aspects of human psychomotor function.The therapy’s influence on musculoskeletal properties and motor abilities as well as the effects of hyperbaric oxygenation on cognitive,myocardial and pulmonary functions are presented.In this review the molecular and physiological processes related to human psychomotor performance in response to hyperbaric oxygen are discussed to contribute to this fast-growing field of research in integrative medicine.