Importance of muscle selection for EMG signal analysis during upper limb rehabilitation of stroke patients.

Current work highlights the importance of muscle selection to evaluate paralysis and recovery level of stroke patients when comparing synergies of affected and non-affected side of the body. The proposed method allows the selection of important muscles that highly contribute to the specific movements according to the power and frequency distribution of the electromyographic signals.. Users participating performed steering-wheel-based therapy focused on upper limb rehabilitation. Final results show that with the appropriate muscles selection, it is possible to compute a Similarity Index between right and left arms (during symmetric motion) associated to the level of paralysis and potential recovery of a given subject.

Clarification of muscle synergy structure during standing-up motion of healthy young, elderly and post-stroke patients.

Standing-up motion is an important daily activity. It has been known that elderly and post-stroke patients have difficulty in performing standing-up motion. The standing-up motion is retrained by therapists to maximize independence of the elderly and post-stroke patients, but it is not clear how the elderly and post-stroke patients control their redundant muscles to achieve standing-up motion. This study employed the concept of muscle synergy to analyze how healthy young adults, healthy elderly people and post-stroke patients control their muscles. Experimental result verified that four muscle synergies can represent human standing-up motion. In addition, it indicated that the post-stroke patients shift the weights of muscle synergies to finish standing-up motion comparing to healthy subjects. Moreover, different muscle synergy structures were associated with the CoM and joint kinematics.

Effects of the histamine H(1) receptor blocker, pyrilamine, on spontaneous locomotor activity of rats with long-term portacaval anastomosis.

To find out whether the changes in the brain histaminergic system are involved in the pathophysiology of portal-systemic encephalopathy, we examined the effects of histamine H(1) receptor blockade on spontaneous locomotor activity, feeding, and circadian rhythmicity in rats with portacaval anastomosis (PCA). Pyrilamine, an H(1) receptor blocker (15 mg/kg/day), was delivered with osmotic minipumps. Spontaneous locomotor activity was recorded for 72 hours in the open-field with an electromagnetic detector. Food intake was monitored twice daily at the end of the light (7 PM) and the dark (7 AM) phases for 3 days. Histamine H(1) receptor density in the suprachiasmatic nucleus (SCN) was examined with receptor autoradiography, employing [(3)H]pyrilamine. PCA surgery led to decreased movement time and velocity and flattened amplitude of the circadian rhythms of locomotion and feeding. In sham-operated rats, pyrilamine significantly decreased the movement time and velocity, as well as the total food consumption and completely abolished the circadian rhythmicity of locomotion. In contrast, pyrilamine increased the movement time and velocity in PCA-operated rats, particularly in the dark phase, and improved the precision of the circadian rhythms of locomotion and feeding. Histamine H(1) receptor density was not altered by PCA surgery, whereas pyrilamine treatment led to the complete blockade of H(1) receptors in both sham- and PCA-operated rats. We suggest that histaminergic imbalance has contributed to the generation and maintenance of the decreased spontaneous locomotor activity and altered circadian rhythmicity following PCA surgery in the rat, probably via an H(1) receptor-mediated mechanism.