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In this article was investigated the development progressive fatigue dynamic of isolated natively musculus gastrocnemius medialis during tetanic contraction in alcoholic rats (n = 15). Registration of tetanic contraction of the isolated muscular preparation was registered in the isometric mode, during it’s direct electric stimulation. The results of research shows the absence of significant changes in isolated natively musculus gastrocnemius medialis development progressive fatigue in alcoholic rats, in comparison to intact animals.В роботі проаналізовано динаміку розвитку прогресивної втоми ізольованого нативного musculus gastrocnemius medialis в алкоголізованих щурів під час тетанічного скорочення. Дослідження проведено на 30 5-місячних шурах самцях лінії Wistar: алкоголізовані щурі (n = 15), інтактні щурі (n = 15). Реєстрація тетанічного ско- рочення ізольованого м’язового препарату здійснена в ізометричному режимі, під час його безпосередньої електричної стимуляції. Результати дослідження показали, що динаміка розвитку прогресивної втоми ізольо- ваного нативного musculus gastrocnemius medialis в алкоголізованих щурів, порівняно з інтактними щурами, достовірно не змінюється, і як і в контролі, має асиметричний характер.

Kendo is a high load-type sport, especially for the lower leg muscles. The purpose of this study was to evaluate changes in the hardness of the gastrocnemius medialis (GM) using real-time tissue elastography (RTE) during training at a Kendo training camp. Eleven college male Kendo athletes participated in a 5-day Kendo training camp, and the hardness of the GM, the circumference of the lower legs, and the ankle range of motion (ROM) were examined during the course of training. The strain ratio of the GM to a reference material was used to estimate changes in muscle hardness during the training period. The results showed that the strain ratio of the GM significantly increased at days 3, 4, and 5, in comparison to the baseline values obtained prior to training (p < 0.05), indicating that the hardness of the GM increased after high-intensity exercise. Meanwhile, the circumference of the lower leg did not change over the course of training; while the ROM values significantly decreased at days 4 and 5 relative to the baseline, suggesting the increased muscle hardness resulted from increased muscle stiffness. These results suggest the muscle hardness of athletes who engage in repetitious high load-type sports are tense on the next day of hard training, and the hardness continues, as in this case, until the last day of camp. In addition, RTE measurements of muscle hardness may allow a more sensitive detection of changes in muscle properties than what is possible with ROM measurements.

Hintergrund Die Einschrankung der Dorsalextension im oberen Sprunggelenk (DE) ist haufig mit unterschiedlichen Beschwerden am Fus und Sprunggelenk assoziiert. Die haufigste Ursache ist die M. Gastrocnemiusverkurzung (MGV). Die Diagnose basiert auf der klinischen Untersuchung der DE bei gestrecktem und flektiertem Kniegelenk. Aktuell ist nicht bekannt, ab welchem Knieflexionsgrad der Einfluss des M. gastrocnemius auf die DE aufgehoben ist. Ziel der Studie war es, dies zu untersuchen.

Common foot and ankle pathologies have been linked to isolated Musculus gastrocnemius tightness (MGT). Various examination techniques have been described to assess MGT. Still, a standardized examination procedure is missing. Literature argues for weightbearing examination but the degree of knee flexion needed to eliminate the restraining effect of the M. gastrocnemius on ankle dorsiflexion (ADF) is unknown. This manuscript investigates the effect of knee flexion on ankle dorsiflexion and provides a detailed description of a standardized examination protocol. Examination on 20 healthy individuals revealed, that 20° of knee flexion is sufficient to fully eliminate the influence of the M. gastrocnemius on ADF. This builds the prerequisite for a standardized examination for MGT. Non-weightbearing and weightbearing examination of ADF has to be conducted with the knee fully extended and at least 20° flexed. Two investigators should conduct non-weightbearing testing with the subject in supine position. In order to obtain reliable results, the axis of the fibula should be marked. One examiner can conduct weightbearing examination with the subject in lunge stance. Isolated MGT is present if ADF is impaired with the knee fully extended and knee flexion results in a significant ADF increase. The herein presented standardized examination is the prerequisite for future studies aiming at establishing norm values.

A total of 47 racing greyhounds were enrolled in this study on two race days (in July and September, resp.) at a racetrack. Twelve of the dogs participated in the study on both days. Thermographic images were taken before and after each race. From the images, superficial temperature points of selected sites (tendo calcaneus, musculus gastrocnemius, musculus gracilis,andmusculus biceps femoris portio caudalis) were taken and used to investigate the differences in superficial temperatures before and after the race. The thermographic images were compared between the right and left legs of a dog, between the raced distances, and between the two race days. The theoretical heat capacity of a racing greyhound was calculated. With regard to all distances raced, the superficial temperatures measured from themusculus gastrocnemiuswere significantly higher after the race than at baseline. No significant differences were found between the left and right legs of a dog after completing any of the distances. Significant difference was found between the two race days. The heat loss mechanisms of racing greyhounds during the race through forced conduction, radiation, evaporation, and panting can be considered adequate when observing the calculated heat capacity of the dogs.

Surgical Principles The gastrocnemius is elongated by multiple incisions of its strong anterior aponeurotic tendinous sheet, a structure which is usually ignored in standard textbooks of anatomy. Lengthening of the muscle is achieved by postoperative stretching exercises and by reflex inhibitive casting. The technique was first used by Baumann in 1980 and was presented with its results in 1988 at the annual meeting of the Swiss Orthopaedic Society.

The disorder level in standing posture of the aged was evaluated by the disappearance period of electric discharge in musculus gastrocnemius(Silent Period). Subjects were nine aged people and ten healthy young people . They were ordered to stand in the upright position on both flat floor and forwardly sloped plate by 20 degrees with a vibrators fastened on both tendon achilles. Vibration at the frequency of 70 Herz was appliedfor one minutes, and tibial nerve was stimulated with the supramaximal electrical stimulation at 0.2 Herz of frequency.1) Under the resting condition, silent period of the aged was 24.0ms on flat floor and 10.8ms on sloped plate longer than those of young people.2) Both aged and young people showed longer silent period during receiving vibration than under the resting condition. Prolongation of silent period which implies lowered excitability of α motorneurons at the cornua anterius of spinal cord at the upright position suggested that the upper central nervous systems might control greatly outside stimulation on proprioceptors.

SUMMARY The differences between the action of succinyldicholine and succinyl-monocholine on striated muscle has been studied, using an electromyographic technique. Doses of succinylmonocholine (5-10 mg per kg body weight) caused electrical changes very similar to those observed in previous studies on the dicholine. Split potentials and larger split complexes, typical of fasciculations, were recorded from the diaphragm. Activity of the fasciculation type could not be recorded in the gastrocnemius muscle. Apnoeic doses of succinylmonocholine caused a very rapid onset of neuromuscular block in die tonic and phasic muscles, always first seen in the gastrocnemius (phasic) muscle. ZUSAMMENFASSUNG Mittels Elektromyographie wurden die Wirkungsunterschiede zwischen Succinyldicholin und Succinylmonocholin auf die Skelettmuskulatur unter-sucht. Succinylmonocholindosen von 5-10 mg pro kg Korpergewicht verursachten elektrische Veranderungen, die den bei fruheren Untersuchungen mit dem Dicholin beobachteten sehr ahnlich waren. Spaltpotentiale und grossere Spalt-komplexe, typisch fur Faszikulationen wurden vom Zwerchfell registriert. Vom Musculus gastrocnemius konnte keine Faszikulationsaktivitat registriert werden. Atemlahmende Dosen von Succinylmonocholin verursachten einen sehr raschen Eintritt des neuromuskularen Blocks in tonische und phasische Muskeln, der immer zuerst im Gastrocnemius, einem phasischen Muskel, gesehen wurde.

Several months after cross-union of the tibial and peroneal nerves and full muscle reinnervation motor behavior was monitored and was tested by electromyographic recordings from both musculus tibialis anterior (TA) and musculus gastrocnemius medialis (MG). In addition spinal motoneuron pools were labelled by injecting wheat-germ agglutinin-horseradish peroxidase (WGA-HRP) into experimental and control TA muscles. Though the location of TA motoneurons was similar in all 9 mice tested and suggested successful cross-reinnervation, running behavior and EMG patterns varied remarkably. In some animals the alternating activities of TA and MG muscles remained more or less clearly separated from each other but were out of phase with the running cycle. A somewhat better motor behavior was accompanied by simultaneous activity in both muscles. Voluntary running in wheels for several kilometers per day did not visibly improve motor coordination indicating the absence of activity-related synaptic readjustments.