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The purpose of the article was to analyze the histological changes in the gastrocnemius muscle under conditions of experimental ischemia of different duration and simultaneously administration of C60 fullerenes as an antioxidant.The experiment was conducted on inbred Wistar line rats weighing 140-160 g. The animals were divided in groups: control; animals with ischemia (1, 2 and 3 hours); control, animals with ischemia (1, 2 and 3 h), animals with ischemia (1, 2 and 3 h) and C60 fullerenes administration. Unilateral vascular ischemia was induced by tourniquet ligating the main arteries. Histologic processing of the tissue was carried out according to standard histological methods, stained with Van Gison method. Morphometric indices (thickness of muscle fibers and the size of interfibrillary space) were measured using the VideoTest Morphology 5.0 program. The therapeutic effect of an aqueous colloidal solution of C60 fullerenes on the level of pathomorphological changes in the test muscle was also analyzed. The musculus gastrocnemius is resistant to light ischemic damages under condition of intraperitoneal administration of C60 fullerenes, which are potent antioxidants and are able to absorb free radicals effectively. However, studies have shown that with increasing the duration of ischemic damage, the protective effect of fullerenes decreases in proportion to the duration of ischemia. In particular, the initial tendency to the destruction of muscle fibers, the disturbance of the membrane integrity, the replacement of the muscle tissue by the connective tissue , the severance of sarcomeres, the loss of the transverse striated , the absence of nuclei, the hyperemia of the capillary duct are noted. Necrotic-destructive changes that occur due to the excess of no inactivated superoxide and hydroxide radicals also observed. Thus, the laboratory study can serve as a basis for the development of drugs for muscle pathologies, and will help to develop a comprehensive methodology for the treatment of early stages of ischemic damage to human skeletal muscle.

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 comparative histological and morphometric study based on selected skeletal muscles musculus pectoralis superficialis and musculus gastrocnemius in two lines of meat-type chickens, Anak Titan and Isa 215, was performed to detect potential differences regarding the effect of three production systems (chickens raised indoors in a conventional facility, indoors with limited outdoor access and outdoors with an umbrella roof) on muscle structure. The muscle fiber size was found to be affected by the production system, while the impact of the breeding line was less apparent. Disseminated fiber degeneration occurred more frequently in both examined muscles of Isa chickens raised outdoors. Necrotic fibers were very often infiltrated by mononuclear cells and underwent phagocytosis. The intensity of abnormal changes in muscle structure, including tiny fibers, fibers with hyaline cytoplasm and fibers with central nuclei, was substantially higher in chickens having outdoor access. This trend was particularly noticeable in musculus pectoralis superficialis and within the Isa 215 line. This indicates that it is more difficult for chickens of this line to adapt to changing environmental conditions. Significant changes observed in both muscles of birds raised outdoors can be considered highly undesirable with respect to the breeding objectives and breeding strategies for meat-type chickens. Environmental factors were found to play a more important role in chickens of the highly selected Isa 215 line, thus pointing to their worse adaptability to the less stable outdoor conditions. Furthermore, the present results suggest that the indoor housing system with access to an outdoor area can be an alternative to the traditional production system with regard to Anak Titan chickens.

Three genotypes of ostrich (South African Black, Zimbabwean Blue Necks and crosses between Zimbabwean Blue Neck males x South African Black females) were used to investigate the influence of genotype on the fatty acid composition of the musculus gastrocnemius and musculus iliofibularis, and abdominal and breast fat depots. Total saturated fatty acids in both the m. gastrocnemius and m. iliofibularis were higher in crosses (36.4% and 35.9%) than in South African Black ostriches (32.9% and 30.4%), whereas mono-unsaturated fatty acids were highest in South African Black ostriches. Total polyunsaturated fatty acids in the m. gastrocnemius were lowest in South African Black ostriches (26.5%) compared with the Zimbabwean Blue Necks (33.2%). Neither the ratio of polyunsaturated to saturated (0.73 to 0.99) nor n-6 to n-3 (1.6 to 2.2) fatty acids were influenced by genotype, although the ratio of polyunsaturated to saturated fatty acids in Zimbabwean Blue Necks was higher in the m. gastrocnemius (0.99) than in the m. iliofibularis (0.73). Differences in individual fatty acids were prominent in the breast fat, and total saturated and mono-unsaturated fatty acids differed between genotypes in both breast and abdominal fat. Only the ratio of polyunsaturated to saturated fatty acids in the fat depots differed between South African Black (0.48) and Zimbabwean Blue Neck ostriches (0.42). The latter ratio was higher in the breast (0.50) than abdominal (0.42) fat in Zimbabwean Blue Necks. These results indicate that crossbreeding of different genotypes of ostriches reared under similar conditions does influence the overall fatty acid profiles of meat and fat.Keywords: Struthio camelus, SFA, MUFA, PUFA, crossbreeding

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.

For static and dynamic conditions muscle geometry of the musculus gastrocnemius medialis of the rat was compared at different muscle lengths. The dynamic conditions differed with respect to isokinetic shortening velocity (25 50 and 75 mm/s) of the muscle-tendon complex and in constancy of force (isotonic) and velocity (isokinetic) during shortening. Muscle geometry was characterized by fibre length and angle as well as aponeurosis length and angle. At high isokinetic shortening velocities (50 and 75 mm/s) small differences in geometry were found with respect to isometric conditions: aponeurosis lengths differed maximally by -2%, fibre length only showed a significant increase (+3.2%) at the highest shortening velocity. The isotonic condition only yielded significant differences of fibre angle (–4.5%) in comparison with isometric conditions. No significant differences of muscle geometry were found when comparing isotonic with isokinetic conditions of similar shortening velocity. The small differences of geometry between isometric and dynamic conditions are presumably due to the lower muscle force in the dynamic condition and the elastic behaviour of the aponeurosis. It is concluded that, unless very high velocities of shortening are used, the relationship between muscle geometry and muscle length in the isometric condition may be used to describe muscle geometry in the dynamic condition.

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.

The metabolic fate of 57Co-labeled methylcobalamin (57Co-CH3-B12) at various doses (5, 50 and 500 μg/kg/day) after consecutive, intraperitoneal administration within 7 days to rats, of which the right sciatic nerve was degenerated by crushing, was studied. The uptake of radioactivity by sciatic nerve in both sides was increased with time and doses but the radioactivities in sciatic nerve and muscles innervated by this nerve such as musculus gastrocnemius were significantly higher in crushed side than in intact one at all doses investigated. The distribution of radioactivity in tissues other than nerve and muscles was also increased with time and doses. The highest uptake was observed in kidney, followed by adrenal gland, pancreas and liver and the lowest in brain and testis. The urinary excretion of radioactivity in each dosage within 24 hr after every administration of 57Co-CH3-B12 was found to be nearly constant at each dose during 7 days, namely, about 25, 70 and 75%/day at 5, 50 and 500 μg/kg/day, respectively.

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.

Rat gastrocnemius medialis (GM) and semimembranosus (SM) muscles have a very different morphology. GM is a very pennate muscle, combining relatively short muscle fibre length with sizable fibre angles and long muscle and aponeurosis lengths. SM is a more parallel-fibred muscle, combining a relatively long fibre length with a small fibre angle and short aponeurosis length. The mechanisms of fibre shortening as well as angle increase are operational in GM as well as SM. However, as a consequence of isometric contraction, changes of fibre length and angle are greater for GM than for SM at any relative muscle length. These differences are particularly notable at short muscle lengths: at 80% of optimum muscle length, fibre length changes of approximately 30% are coupled to fibre angle changes of 15° in GM, while for SM these changes are 4% and 0.6°, respectively. A considerable difference was found for normalized active slack muscle length (GM approximately 80 and SM approximately 45%).This is explained by differences of degree of pennation as well as factors related to differences found for estimated fibre length-force characteristics. Estimated normalized active fibre slack length was considerably smaller for SM than for GM (approximately 40 and 60% respectively). The most likely explanation of these findings are differences of distribution of optimum fibre lengths, possibly in combination with differences of myofilament lengths and/or fibre length distributions.

1. In a previous paper we have shown (Schafer and Schafer, 1973), that a pronounced change in the sensitivities of the primary spindle afference is observed during cold shivering and during an artificial fusimotor stimulation. Now we will give a theoretical interpretation of these experimental results. We are of the opinion that the tremor of the musculus gastrocnemius is due to an instability of the stretch reflex feedback system. We show that the instability is caused by property changes of the spinal cord and sensitivity changes of the primary spindle afference. The sensitivity of the primary spindle afference is determined by the intensity of the γ-innervation. 2. The transfer functions of the servo elements muscle, muscle spindle, and spinal cord are established. We deduce from these transfer functions an expression which describes the discharge pattern of a primary afference during a ramp stretch of the muscle and, moreover, we can apply Hurwitz's instability criterion. From this criterion, it is to be seen that the observed sensitivity changes of the primary afference influence the servo loop in the direction of an instability. 3. The importance of the secondary endings and the Golgi tendon organs to the generation of a tremor are discussed. 4. We comment upon the idea that the spinal cord should have a pacemaker function during cold shivering.