A possible anatomical and biomechanical explanation of the 10% rule used in the clinical assessment of prehensile hand movements and handed dominance.

UNLABELLED: A current doctrine in the dynamometric approach to determine lateralization of hand function states that in 10% of cases, the non-dominant hand will be stronger than the dominant hand. In this study, a novel MRI based modelling approach was applied to the first dorsal introsseus muscle (FDI), to determine whether the 10% rule may be applied to the FDI and may be partially explained by the arrangement of the anatomical components of the FDI. METHODS: Initially the force generated by the thumb segment during an isometric pushing task in the horizontal plane was measured from 25 strongly right-handed young males. Nine of these participants then had structural magnetic resonance imaging (sMRI) of the thumb and index osseous compartment. A modelling technique was developed to extract the muscle data and quantify the muscle line of action onto to the first metacarpal bone segment in order to quantify the muscle force at the point of momentary rotation--equilibrium. RESULTS: Eight of 25 subjects exhibited stronger force from the left hand. Six out of nine subjects from the MRI possessed significantly greater angles of attachment of the index osseous compartment on the left (non-dominant) hand. These six subjects also generated greater maximal isometric forces from the FDI of the left side. There was a significantly greater muscle volume for the right FDI muscle as compared to the left as measured from the reconstructed MRI slice data. CONCLUSIONS: The calculated force produced by the muscle is related to the angle of attachment of the muscle to bone in the index osseous compartment. The MRI findings indicate that the 10% rule may be anatomically and biomechanically explained.

[Asymmetry of the viscoelastic properties of the skin and muscle compartments of the left and right hands].

The aim of this research was to discriminate and categorize isolateral stress-strain characteristics contained within the musculocutaneous compartment (MCC) using the model of the first dorsal interosseous muscle (FDI) in vivo. In our approach, the musculocutaneous compartment of the dorsal interosseous muscle was progressively isokinetically compressed by a solid vertical bar with a 0.25 mm incremental step. During each step, the force and deflection were measured and recorded electronically. The subject maintained a constantly relaxed position. Twenty-two strongly right-handed young males returned three data acquisition sequences from each hand. From the sequences, the elastic modulus and the specific energy of deformation were determined for both the total musculocutaneous compartment structure and separately for the discrete cutaneous and muscular compartments. No unilateral pattern of dominance was interpreted from the analysis of the range of indices. There was a highly variable individual pattern of bilateral dominance with no specific indication or predictability represented by the data: only one subject illustrated a data profile confirming the classical approach to right-handed dominance. As the muscle was relaxed and the integument layers were under minimal cortical influence, we suggest that the classical theory of primary cortical influence in motor lateralization does not adequately explain our recorded patterns of mechanical response of the musculocutaneous compartment analyzed in this study.

[Effect of estrogens on the coronary circulation, cardiac contractile function, and development of reperfusion arrhythmia]. / Vliianie éstrogenov na koronarnyi krovotok, sokratitel'nuiu funktsiiu sertdsa i razvitie reperfuzionnykh aritmii.

17-beta-estradiolsulfate (17-ES) was shown to exert a distinct vasoconstrictory effect on coronary vessels resulting in a decrease of the force contraction as well indexes of contractility. The distinct antiarrhythmic effect suggests that 17-ES possesses some properties of calcium antagonist.

[Use of computer-assisted stabilography and the method of computer-assisted biomechanical study of gait in the diagnosis of posture and motor disorders in patients with different forms of infantile cerebral paralysis]. / Primenenie komp'iuternoi stabilografii i metoda komp'iuternogo biomekhanicheskogo issledovaniia pokhodki dlia diagnostiki poznykh i dvigatel'nykh narushenii u bol'nykh s razlichnymi formami detskogo tserebral'nogo paralicha.

The paper presents and analyzes the results of assessment of vertical stability and walk in patients with infantile cerebral paralysis before and after dynamic proprioceptive correction, which is of great importance for differential diagnosis of different forms of this disease, for controlling the course of therapeutical measures, for working out criteria for the efficiency of treatment.

[Regulation of vertical posture in patients with children's cerebral paralysis treated with the method of proprioceptive correction]. / Reguliatsiia vertikal'noi pozy u bol'nykh detskim tserebral'nym paralichom pri lechenii metodom propriotseptivnoi korrektsii.

Maintenance of vertical posture is a complex coordination act dependent on a multi-level system of regulation. Functional state of the visual system may contribute significantly to the implementation of the mechanisms of vertical posture maintenance. Stabilographic examination of healthy teenagers and patients afflicted with the main CCP forms with the method of dynamic proprioceptive correction revealed dependence of posture stability and involvement of the visual analyzer on sex.

[The influence of space loading suits on interhemispheric asymmetry of the brain in infantile spastic cerebral palsy]. / Vliianie kosmicheskogo nagruzochnogo kostiuma na mezhpolusharnuiu asimmetriiu mozga pri spasticheskoi forme detskogo tserebral'nogo paralicha.

The paper presents the study concerning influence of somatosensory stimulation (single wearing of either space loading costume "PENGUIN" or its modification--"ADELY" costume) on the individual profile of interhemispheral cerebral assymmetry (IPIHCA) in patients with spastic form of infantile cerebral paralysis (ICP). The computer stabilograph analyzed motor arms' asymmetry, sensory asymmetry of visual hemiareas, asymmetry of the position of centre of gravity. It is shown that peculiarities of the realization of the standing position either with visual control or without it both in healthy individuals and in patients depended on initial IPIHCA. Initial stability was higher in healthy individuals than in patients, besides in healthy persons it was higher in right-handers while in patients--in left-handers. There was possibility of changes of both IPIHCA and stability during keeping up vertical position even during single somatosensory stimulation. For elaboration of new criteria of the estimation of the efficiency of treatment in patients with CNS damages, including ICP, it is necessary to take into consideration different influence of somatosensory stimulation on IPIHC in right-handers and left-handers.

[The individual profile characteristics of cerebral interhemispheric asymmetry during visual stimulation in healthy subjects and in patients with the spastic form of infantile cerebral palsy]. / Osobennosti individual'nogo profilia mezhpolusharnoi asimmetrii mozga pri zritel'noi stimuliatsii u zdorovykh i bol'nykh spasticheskoi formoi detskogo tserebral'nogo paralicha.

Individual profiles of brain interhemispheric asymmetry (IPA) and stability in maintenance of the vertical posture have been studied in healthy children and adults and patients with the spastic form of the infantile cerebral palsy before and after visual stimulation. The IPA were built on the basis of motor asymmetry of hands, asymmetry of visual half-fields, and asymmetry of muscle extension tone in vertical position in Romberg test at computer stabilograph. The visual stimulation was realized by unilateral tachistoscopic administration of a verbal stimulus in the visual half-field on the side of worst detection of the master stimulus during the procedure of initial IPA construction. The IPA were different in children, adults, and patients. Even single visual stimulation changed the initial IPA (not only its visual but motor and stability-related components). A correlation was shown between the individual features of realization of the vertical position, initial IPA, age of the subjects, and presence/absence of the cerebral palsy. The visual stimulation led to a decrease in initially low stability and, on the contrary, an increase in initially high stability both in healthy subjects and patients with cerebral palsy, regardless of their handedness. Increase in stability of the vertical posture was accompanied by a decrease in the role of the visual analyzer, and, on the contrary, decrease in stability was associated with an increase in the role of the visual analyzer in stability control. It is necessary to take into account the dissimilar action of sensory stimulation on the IPA and stability of the vertical posture in assessment of the effects of sensory stimulation on healthy persons and patients with CNS lesions, in particular, with cerebral palsy, in the course of development of new ways of treatment.

[Effect of ionospheric parameters on the respiratory and cardiac system, function of the brain and higher nervous system activity in healthy people]. / Vozdeistvie ionosfernykh parametrov na dykhatel'nuiu i serdechnuiu sistemy, funktsii golovnogo mozga i vysshuiu nervnuiu deiatel'nost' zdorovykh liudei.

Effects of complex ionospheric parameters on the parameters of 4 systems of healthy people: respiration and cardiological systems, functions of brain and central neural activity, were studied. Results indicating the presence of highly significant multiple correlations of these biosystems with the complex of ionospheric parameters were received.

[Changes in individual profiles of cerebral hemispheric asymmetry during somatosensory stimulation due to wearing of G-suits by healthy adults and children]. / Izmenenie individual'nogo profilia mezhpolusharnoi asimmetrii mozga pri somatosensornoi stimuliatsii nosheniem kosmicheskogo nagruzochnogo kostiuma u zdorovykh vzroslykh i detei.

Presented are results of the investigations of individual profiles of the brain interhemispheric asymmetry (IPIHA) in healthy grown-ups and children prior to, during, and immediately after somatosensory stimulation. The somatosensory stimulation was performed by one-time wearing of space g-loading suit PENGUIN and its modification ADELIE. IPIHA was studied by the main functional asymmetries including motor hand asymmetry, sensory asymmetry of the visual hemispheres, body mass center asymmetry (BMA) using a computerized stabilimeter indirectly measuring the muscle tone of contralateral extensor. Results demonstrate differences in IPIHA of grown-ups and children, persons with right- and left-hand motor asymmetry. It was shown that peculiar features of standing posture acquisition with and without visual control are original IPIHA and age dependent. Initial stability was higher in grown-ups than children and right-handed grown-ups and left-handed children. IPIHA and stability of the vertical posture can be modified even during single somatosensory stimulation. Unequal effects of the somatosensory stimulation on IPIHA in right- and left-handed subjects of varying age dictate the necessity to allow for these differences when assessing effects of the somatosensory stimulation in grown-ups and developing criteria of effective therapy of patients with CNS pathology, specifically, infantile cerebral paralysis.

[The significance of visual analyzer in controlling the standing posture in individuals with the spastic form of child cerebral paralysis while wearing "Adel" suit]. / Znachenie zritel'nogo analizatora v kontrole pozy stoianiia u lits so spasticheskoi formoi detskogo tserebral'nogo paralicha pri noshenii kostiuma "Adeli".

The paper discussed the results of stabilographic examination of the children suffered from the spastic form of child cerebral paralysis (CCP) treated by means of graded wearing of "Adel" suit which is a modification of the "Penguin" spacesuit. There has been studied the state of 30 children before treatment with the use of "Adel" suit and after the treatment as well as following the several courses of wearing the suit. Besides the patients, eleven healthy volunteer subjects (control group) were examined. There have been obtained the results pointing to the fact that in the healthy persons when they try to achieve the standing posture the leading role pertains to visual analyzer, at the same time, in the patients with spastic form of CCP the realization of standing posture depends upon the severity of the motor function disorders. When in the process of control stabilographic examination the patients suffered from spastic form of CCP demonstrate the significant role of the visual analyzer in achieving the standing posture, the use of the "Adel" suit is most desirable. The use of the "Adel" suit in the CCP patients with a decreased role of visual analyzer in achieving the standing pose as it was found under control examination enhances its significance in controlling the position of the center of gravity of the body.

[Role of vestibular and visual analyzers in changes of postural activity of patients with childhood cerebral palsy in the process of treatment with space technology]. / Rol' vestibuliarnogo i zritel'nogo analizatorov v izmenenii poznoi aktivnosti u bol'nykh detskim tserebral'nym paralichom v protsesse lecheniia s ispol'zovaniem kosmicheskoi tekhnologii.

The paper presents the findings of stabiligraphic investigations of children afflicted with the hyperkinetic child's cerebral paralysis treated with the method of graduated wearing suit ADELI. This suit is a modification of space-designated PINGUIN used to counteract the adverse effect of long-term microgravity on the skeletal muscles and the skeleton. 30 children were investigated prior to, immediately after, and in a delayed period after this treatment. A group of 11 healthy volunteers were also investigated as their control. The program of investigation included routine stabilimetry, the station test, and head rolling tests. The results demonstrate that in healthy subjects the standing pose is primarily acquired and sustained by means of the visual analyzer, whereas the CCP patients pose could attain this pose with a significantly weakened control by the visual analyzer. Application of ADELI increases the role of visual analyzer in the control of standing pose. Following the treatment, the stabilimetric indices of patients changed for the better and approached those in healthy subjects.

[Myocardial heterogeneity and cardiac arrhythmias]. / Geterogennost' miokarda i aritmii serdtsa.

Analysis of publications according to which myocardium consists of heterogeneous elements functioning as the whole. Evolution of ideas about structural-functional organization of heart tissue is shown. The conception and model of cluster structural-functional organization of myocardium are formulated. On this model processes of circulation of stimulation under fibrillation of heart ventricles are analysed.

[Sympathetic control of spontaneous cardiac defibrillation]. / Simpaticheskii kontrol' spontannoi defibrilliatsii serdtsa.

The parameters of transmembrane potentials of cardiomyocytes and dynamics of fibrillation process have been investigated when altering the level of sympathetic action on the heart by injection of rausedile, katecholamines and by stimulation of the nucleus of hypothalamus. It was shown that the injection of rausedile decreases rest potential and potential activity, meanwhile electrical irritation significantly increases the period of spontaneously reversible fibrillation.

[Effects of bonnecor on transmembrane potentials of cardiomyocytes of the ventricular contractile myocardium of the intact heart and ventricular fibrillation]. / Vliianie bonnekora na transmembrannye potentsialy kardiomiotsitov sokratitel'nogo miokarda zheludochkov intaktnogo serdtsa i fibrilliatsiiu zheludochkov.

The microelectrode technique has shown that bonnecor given in a dose of as many as 2 mg/kg increases the action potential amplitude, but when its dose is increased up to 3 mg/kg, the agent decreases the action potential amplitude of ventricular cardiomyocytes in the guinea-pig, the resting potential remaining steady. Administration of bonnecor prevents ventricular fibrillation after aconitine application and provokes ventricular fibrillation and flutter when the focus of ectopic automatism is formed.

[Role of heart mass in the spontaneous defibrillation process]. / Rol' massy serdtsa v protsesse spontannoi defibrilliatsii.

The duration of periods of the spontaneous reversible fibrillation of heart ventricles of different masses of guinea pigs, rabbits, pigeons and chickens was investigated. It was demonstrated, that a heart mass doesn't play an important role in the process of spontaneous heart ventricles defibrillation. Only the number of strong contacts and the level of the parasympathetic control are determined.