The effect of combining extracorporeal shock waves with continuous static stretching in treating triceps spasticity after a stroke / 中华物理医学与康复杂志

Objective:To observe any effect of supplementing continuous static stretching (CSS) with extracorporeal shock wave therapy (ESWT) in treating triceps surae spasm after a stroke.Methods:Sixty-four stroke survivors with triceps surae spasm were randomly divided into a conventional rehabilitation group, a shock wave group and a combined treatment group. In addition to conventional rehabilitation, the shock wave group received extracorporeal shock wave therapy twice a week and the combined treatment group received the shock waves during continuous static stretching. After 6 weeks of treatment all of the subjects were assessed using the Modified Ashworth Scale (MAS), the Fugl-Meyer Assessment (FMA) and Brunnstrom classification of their functional recovery stage.Results:Before treatment there was no significant difference among the three groups. After the 6 weeks of treatment the average triceps surae tension in all three groups had eased significantly. At that point the average MAS and FMA scores of the shock wave group and the combined treatment group were significantly better than those of the conventional group. The combined treatment group then showed significantly better therapeutic effect than the shock wave group.Conclusions:Applying extracorporeal shock waves during continuous static stretching can significantly improve the stretching′s ability to reduce spasticity and improve motor functioning, at least of the triceps surae. Combining shock waves with modern traction methods is recommended for clinical application.

Application of Ultrasound Shear Wave Elastography in Rehabilitaion Assessment of Triceps Surae and Achilles Tendon after Stroke / 中国康复理论与实践

Objective:To apply the ultrasonic shear wave elastography to evaluate triceps surae and Achilles tendon for patients with lower extremity dyskinesia after stroke. Methods:Thirty-two inpatients during 2018 and 2019 with unilateral lower extremity dyskinesia after stroke were studied with 2-D ultrasound and shear wave elastography on the bilateral triceps surae and Achilles tendons before and after rehabilitation. Shear wave velocity (SWV) of the triceps surae and the Achilles tendons, the length and thickness of Achilles tendon (soleus tendon) were measured. Results:Before rehabilitation, the SWV of the Achilles tendons and the triceps surae increased more in the affected side than in the unaffected side (t > 2.426, P < 0.05), as well as the length of the Achilles tendons (t = 11.801, P < 0.001). After rehabilitation, the SWV of the triceps surae decreased (t > 2.447, P < 0.05), as well as the length of the Achilles tendons (t = 8.577, P < 0.001). Conclusion:Ultrasound shear wave elastography can be used to evaluate the elastic characteristics of the Achilles tendon and the triceps surae, to guide the rehabilitation for stroke patients.

Extracorporeal shock wave therapy alleviates spasticity in the triceps surae after stroke / 中华物理医学与康复杂志

Objective To evaluate the effect of applying extracorporeal shock wave therapy (ESWT) to alleviate triceps surae spasticity after a stroke and to explore the electrophysiological mechanisms involved.Methods Sixty hemiplegic stroke patients with triceps surae spasticity were recruited and randomly assigned to either an ESWT group or a control group,each of 30.Both groups were given routine medication and rehabilitation training.The ESWT group additionally received 3000 shots of ESWT at 0.089 mJ/mm2,1.5 bars and 8 Hz applied once a week for 4 weeks.Before the treatment,immediately afterward,and then 1 and 4 weeks later the subjects were assessed using the composite spasticity scale (CSS),passive range of motion (PROM) measurements,the 10-meter walk test (10MWT),H reflex latency and the Hmax/Mmax ratio.Results The ESWT group showed significant improvement in their average CSS,PROM and 10MWT results at t1,t2 and t3 compared with t0,while the control group had significant improvement in their average CSS and 10MWT scores,but their average PROM score improved significantly only at t1 and t2.The ESWT group showed significantly better progress in terms of their average CSS score at t1 and t2.The groups' average PROM scores were not significantly different,but the ESWT group had faster 10MWT times at t1,t2 and t3.In the ESWT group H reflex latency had lengthened significantly by t1 and the Hmax/Mmax ratio had decreased significantly,but the only significant difference from the controls was in the average H reflex latency at t1.The ESWT was well tolerated and did not cause any severe adverse effects.Conclusions ESWT improves triceps surae spasticity effectively after stroke quite safely.

Anatomical study of the nerve regeneration after selective neurectomy in the rabbit: clinical application for esthetic calf reduction / 대한해부학회지

The purposes of this study were therefore to characterize the degeneration and regeneration of nerves to the calf muscles after selective neurectomy, both macroscopically and microscopically, and to determine the incidence of such regeneration in a rabbit model. Seventy four New Zealand white rabbits were used. Selective neurectomy to the triceps surae muscles was performed, and the muscles were subsequently harvested and weighed 1-4 months postneurectomy. The gastrocnemius muscles were stained with Sihler's solution to enable the macroscopic observation of any nerve regeneration that may have occurred subsequent to neurectomy. The change in triceps surae muscle weight was measured along the time course of the experiment. After neurectomy, nerve degeneration was followed by regeneration in all cases. The weight of the triceps surae muscle decreased dramatically between completion of the neurectomy and 1 month postneurectomy, but increased thereafter. The nerve branches were weakly stained with Sihler's solution until 2 months postneurectomy, and then strongly stained after 3 months. The number of myelinated axons was decreased at 2 month after neurectomy compared to nonneurectomized controls, but then gradually increased thereafter. Although there are currently no reports on the incidence of recovery after calf reduction, it may be a very common occurrence in the clinical field based on our findings. The findings of this study provide fundamental anatomical and surgical information to aid planning and practice in calf-reduction surgery.

Inervación y localización biométrica de los puntos motores del músculo tríceps sural / Innervation and localization of the motor points of triceps surae muscle

La inervación de los músculos es descrita de forma general, faltando datos biométricos sobre el lugar donde penetran los nervios en el vientre muscular. Con el propósito de conocer la inervación y los puntos motores de los componentes del músculo tríceps sural en la población chilena, estudiamos 18 miembros inferiores de individuos, adultos, fijados en formaldehido al 10 por ciento. Se realizó disección por planos, identificando los nervios dirigidos a las cabezas lateral y medial del músculo gastrocnemio y al músculo sóleo, esquematizando y fotografiando los hallazgos. Se identificó el origen de los ramos, respecto a una línea trazada entre las partes más prominentes de los epicóndilos femorales (LBEC), así como también, los puntos de ingreso en el vientre muscular, clasificando estos ramos como principales (R) y secundarios (RS). En todas las muestras la inervación provino del nervio tibial. La cabeza medial del músculo gastrocnemio recibió un ramo (R1) en 15 casos y dos (R1 y R2) en 3 casos. El origen de R1 se localizó en promedio a 23,6 +/- 11,5 mm distal a la LBEC; en 15 casos el R1 se dividió hasta en 4RS. Los puntos donde ingresaron estos últimos respecto a LBEC fueron en promedio 40,4 +/- 11,1 mm el RS1 y 46,9 +/- 9,1 mm el RS2. La cabeza lateral recibió un ramo en 17 casos y dos en 1 caso; el origen de R1 se localizó en promedio a 35,6 +/- 11,8 mm distal a la LBEC; en 12 casos el R1 se dividió hasta en 4RS. Los puntos donde ingresaron estos últimos respecto a LBEC fueron 49,4 +/- 9,3 mm el RS1 y 52,4 +/- 10,6 mm el RS2. El músculo sóleo recibió su ramo de un tronco común con la cabeza lateral del gastrocnemio en 7 casos y un ramo directo R1 en 6 casos y dos ramos (R1 y R2) en 5 casos, de los cuales, en 3 de ellos, recibió un ramo anterior y uno posterior; el origen de R1 se localizó a 40,4 +/- 14,4 mm de LBEC; el origen del tronco común se ubicó a 20,2 mm de esta línea. El R1 se dividió hasta en 7 RS. Estos resultados son un aporte a la anatomía...

The knowledge of innervation of muscles is generally described, but we can complement the point where the nerves penetrate the muscle belly, from the biometric standpoint. In order to know the innervation and motor points in the components of the triceps surae muscle, 18 formolized lower limbs of adult Chilean individuals were studied. Planes dissection was performed by identifying the point nerve of the lateral and medial head of gastrocnemius muscle and soleus muscle. All specimens were schematized and photographed. We identified the source of the branches, about a line drawn between the most prominent parts of the femoral epicondyles (BECL), as well as the points of entry into the muscle belly, classifying these branches as principal (BR) and secondary ( SBR). In all samples the innervations came from the tibial nerve. The medial head of the gastrocnemius muscle received one branch (BR1) in 15 cases and two (BR1 and BR2) in 3 cases. The BR1 origin is located on average 23.6 +/- 11.5 mm distal to the BECL, in 15 cases the BR1 split up into four SBR. The points where these latter entered in muscular belly regarding BECL were on average: 40.4 + 11.1 mm (SBR1) distal to this line and 46.9 +/- 9.1 mm (SBR2). The lateral head received one branch in 17 cases and two in 1 case; the origin of BR1 was found on average to 35.6 +/- 11,8 mm distal to the BECL; in 12 cases the BR1 was divided up in four SBR. Regarding to BECL the SBR entered in muscle belly distal to this line, 49.4 +/- 9.3 mm (SBR1) and 52.4 +/- 10.6 mm (SBR2). The soleus muscle received his branch from a common trunk with the lateral head of the gastrocnemius in 7 cases and one direct branch BR1 in 6 cases and two branches (BR1 and BR2) in 5 cases, of which 3 of them received one anterior branch and posterior branch; the origin of BR1 was located 40.4 ± 14.4 mm distal to the BECL; the common trunk origin was located at 20.2 mm distal from this line...

Feathered fibres of human soleus muscle / Fibras penniformes del músculo sóleo humano

The large size of superficial group of muscles of back of leg is a characteristic feature of the musculature of man being related directly to its erect posture and mode of progression. Triceps surae is one of the powerful muscles of the body after Gluteus maximus and Quadriceps femoris. To make the muscle more powerful nature has devised a unique method of packing the fibers in a small space by pennation. There exists a bipenniform mass as a peculiarly human feature. Its feathered fasciculi arise from the deep (anterior) surface of the soleus muscle. Most of the textbooks of Anatomy and the available literature on the triceps surae or the tendoachillis do not appreciate and describe this fascinating aspect of the muscle. It was Schafer et al. (1923) who gave a detailed account of this muscle. Standring et al. (2005) have also described this muscle in great detail. We have studied the unique features of this part of soleus muscle. Bipennate arrangement was seen in 86 percent (right-83 percent; left-89 percent); and its maximum width was found to be 3.63 cm (Rt-3.71cm; Lt-3.55cm). Median tendinous septum was directed backwards and medially. Thus this muscle will further increase the power of contraction of soleus, which is so very important for a bipedal gait.

El gran tamaño de los grupos musculares superficiales de la parte posterior de la pierna es un rasgo característico de la musculatura del hombre siendo relacionado directamente con su postura erguida y el modo de progresión. El músculo tríceps sural es uno de los músculos más potentes del cuerpo después de los músculos glúteo magno y cuadríceps femoral. Para hacer al músculo más potente, la naturaleza ha ideado un método único de empaquetamiento de las fibras en un pequeño espacio por pennación. Existe una masa bipenniforme como una característica peculiarmente humana. Los fascículos pennados surgen desde la superficie profunda (anterior) del músculo sóleo. La mayoría de los textos de Anatomía y la literatura disponible sobre el músculo tríceps sural o el tendón de Aquiles no se aprecia ni se describe este aspecto fascinante que tienen los músculos. Fue Schafer (1923) quien dió una detallada descripción del músculo sóleo y posteriormente, Standring et al. (2005) también describieron detalladamente al músculo. Estudiamos las características únicas de esta parte del músculo sóleo, observando una disposición bipenniforme en el 86 por ciento de los casos (derecha 83 por ciento; izquierda 89 por ciento). El ancho máximo del músculo fue de 3,63 cm (derecha 3,71cm; izquierda 3,55cm). El septo tendinoso mediano se dirigió hacia posterior y medial, aumentando así aún más el poder de contracción del músculo sóleo, el cual es muy importante para la bipedestación.

EFFECT OF TWO PASSIVE STRETCHING METHODS FOR TRICEPS SURAE ON DORSIFLEXION OF ANKLE JOINT / 体力科学

Stretching for the triceps surae muscle in the knee flexed position (medical stretching: MS) and knee extended position (static stretching: SS) were performed and the effect on the dorsiflexion angle of the ankle joint was examined. Five elderly females were selected as subjects. We measured the maximal dorsiflexion angle of the ankle joint in the following leg positions: (1) the maximal dorsiflexion angle in the extended knee position (EDF angle) and (2) the maximal dorsiflexion angle in the 90°flexed-knee position (FDF angle). There was a significant increase in the maximal dorsiflexion angle after MS and SS were carried out (p<0.01), but there was no significant difference between MS and SS. It was concluded that MS for triceps surae is equally effective as SS in increasing the maximal dorsiflexion angle of the ankle joint.

ELECTROMYOGRAM PATTERNS DURING SUSTAINED LOW-LEVEL PLANTAR FLEXIONS AND CHANGES IN BLOOD FLOW FOR "ALTERNATE ACTIVITY" AMONG THE TRICEPS SURAE MUSCLES / 体力科学

Several studies have described "Alternate activity", in which individual muscles of the synergistic muscle group alternate between high activity and silent periods, and rotate in a complementary pattern to maintain constant torque, during sustained low-level contractions. The purpose of this study was to investigate the physiological property of alternate activity among the synergists. Eight human subjects performed static contractions at an ankle joint angle of 110° plantar flexion at 10% maximal voluntary contraction (MVC) for 120 min. Simultaneously, a surface electromyogram (EMG) was recorded of the triceps surae muscles. Doppler ultrasound techniques were used to measure blood velocity and the arterial diameter of the popliteal artery during exercise. Maximal torque at MVC and mean EMG (mEMG) level decreased significantly after sustained isometric low-level contractions, but there was no significant difference in the mEMG/maximal force ratio of triceps surae muscles, which is thought to indicate peripheral fatigue between pre- and post-exercise. Throughout the "Alternate activity", arterial diameter and pulse rate did not change, but blood flow significantly increased (p<0.001) depending on an increase in blood velocity. These results suggest that "Alternate activity" among the triceps surae muscles may be one mechanism that functions either to decrease or to postpone peripheral fatigue during sustained low-level contraction.

Anatomical Locations of the Motor Points of the Triceps Surae Muscles

OBJECTIVE: To identify the range of the precise locations of the motor points of triceps surae muscles in relation to bony landmarks. METHOD: Eight limbs of four male cadavers were dissected. The number and location of the motor points from the tibial nerve to each head of the triceps surae muscle were identified related to the bony landmarks. Bony landmarks were medial and lateral epicondyles of the femur, and medial and lateral malleolli of the tibia. The length of the lower leg was defined as the distance from the intercondylar line of the femur to the intermalleolar line of the tibia. The locations of the motor points were expressed as the vertical distance from the intercondylar line, which was normalized to the length of the lower leg. RESULTS: The most proximal motor points of the medial gastrocnemius, lateral gastrocnemius, and soleus were located in 9.6+/-3.5%, 12.0+/-3.4% and 20.5+/-3.9% of the lower leg below the intercondylar line of the femur. The most distal points were in 37.5+/-5.5%, 37.9+/-2.3% and 46.7+/-3.6%. CONCLUSION: The identification of the locations of motor points related to the bony landmarks would increase the ease and accuracy of the motor point blocks to the triceps surae muscles.

Relationships between the gastrocnemius or soleus muscle thickness and the calcaneal bone stiffness in postmenopausal women / 体力科学

The gastrocnemius muscles are composed predominantly of type II B and II A fibers while the soleus muscle is composed of type I fibers. However, the relationships between the calcaneal bone stiffness and the triceps surae muscles consisting of the different types of skeletal muscle fibers are unknown. The purpose of this study was to investigate the relationships between the calcaneal bone stiffness and the gastrocnemius or soleus muscle thickness in 73 postmenopausal women. We measured the speed of sound (SOS) and the broad band ultrasound attenuation (BUA), using a ultrasonic measurement of the calcaneal and the gastrocnemius or soleus muscle thickness used to measure the B-mode ultrasound anatomy. There was a significant differences in age between the high-and low-SOS groups. In the high-BUA group, the body mass index, the lower leg girth and the triceps surae muscle thickness were significantly higher than those in the low-BUA group. This data indicated that SOS is related to ageing and BUA is related to the body mass or the muscle thickness. The other side, stiffness and SOS were significantly correlated with the gastrocnemius muscle thickness, but not with the soleus muscle mass. Therefore, this study suggests that the calcaneal bone stiffness is closely related to the muscle thickness, which may be related especialy to the fast twitch muscle.

Effects of local cooling and heating in the triceps surae muscles during sustained isometric contraction / 体力科学

A study was conducted to examine activity patterns of surface electromyograms (EMGs) in the triceps surae muscles (medial gastrocnemius, MG ; lateral gastrocnemius, LG ; soleus, SOL) during isometric contraction in plantar flexion (60% MVC, 20% MVC) after immersion in water at three different temperatures. Seven healthy male subjects were immersed in water at 2-3°C (ICE), 19-21°C (MID), and 40-42°C (HOT) . The results of the study are summarized as follows :<BR>1) In the MG and LG, there was a slight increase in the rate of integrated electromyograms (IEMGs) in the MG (the main agonist muscle) . However, the rate of increase in the LG, which is the synergistic muscle, was much greater than that in the MG when contraction was sustained at 60% MVC. Therefore, the activity pattern suggests that muscle activity in the LG compensates for that in the MG.<BR>2) The IEMGs of the SQL with sustained contraction, increased significantly after immersion in HOT and MID, but the IEMGs decreased after immersion in ICE. These results suggest that the recruitment threshold in slow-type motor units should increase during sustained isometric contrac-tion in ICE.<BR>As illustrated above, the activity of the LG increased to compensate for that of MG. In the SQL, muscle activity with sustained contraction decreased in ICE. These results suggest that control mechanisms of the central nervous system might play an important role in the associated movement of the triceps surae muscles.

Localization of the Motor Nerve Branches and Motor Points of the Hamstring Muscles and Triceps Surae Muscle

OBJECTIVE: To identify the precise locations of the motor branches and motor points of hamstring and triceps surae muscles to the bony landmarks. METHOD: Twenty-eight limbs of 14 adult cadavers were anatomically dissected. The adult cadavers were selected randomly without regard to gender and age. The cadravers which were unable to obtain a neutral position or which received a trauma to the posterior thighs or the lower legs were excluded from the study. The number and location of the motor branches and motor points from sciatic nerve to each hamstirng muscles and from tibial nerve to each triceps surae muscles were identified related to the bony landmarks. Bony landmarks were ischial tuberosity, medial and lateral epicondyles of femur, and medial and lateral malleolli of tibia. The length of femur was defined as the distance from the ischial tuberosity to the intercondylar line of femur and the length of lower leg was defined as the distance from the intercondylar line of femur to the intermalleolar line of tibia. The locations of the muscular branches and the motor points were expressed as the percentage of the length of femur and lower leg. RESULTS: One muscular branch from the sciatic nerve to the semimembranosus muscle and from the posterior tibial nerve to the soleus muscle, and one or two muscular branches to the biceps femoris, semitendinosus, and semimembranosus, medial gastrocnemius, lateral gastrocnemius and soleus muscle were located at 23.0+/-5.7%, 21.0+/-10.5%, 25.0+/-10.3% of the femur from the ischial tuberosity and 2.0+/-6.2%, 4.0+/-3.3% and 10.0+/-3.3% of the lower leg from the intercondylar line of femur. There were one to four motor points in the hamstring and triceps surae muscles. The motor points of biceps femoris, semitendinosus and semimembranosus were located at 33.0+/-7.8%, 28.0+/-14.5% and 48.0+/-19.0% of the femur. The motor points of the medial gastrocnemius, lateral gastrocnemius and soleus were located in 5.0+/-0.6%, 10.0+/-3.0% and 18.0+/-4.3% of the lower leg below the intercondylar line of femur. CONCLUSION: The identification of the locations of muscular branches and motor points related to the bony landmarks from this study would increase the accuracy of the motor branch blocks or motor point blocks to the hamstrings and triceps surae muscles.

Changes in activity in triceps surae muscles during prolonged isometric contractions / 体力科学

In order to examine muscle activities, surface electromyo-grams (EMGs) were recorded from the triceps surae muscles (lateral gastrocnemius: LG, medial gastrocnemius: MG, soleus: SOL) during prolonged isometric contractions at 20°of ankle joint angle under constant load (10% MVC) . The results were summarized as follows;<BR>1) EMG recordings were obtained which showed complementary activity in each muscle in the time course. Changes in activity was found between whole muscles in the synergist of triceps surae muscles.<BR>2) Muscle activity most frequently took the form of MG+SOL, followed by MG acting alone and SOL acting alone. Ta/Ts value (the ratio of total activity period and total silent period on EMG activity) showed 4.0 in MG and SOL. In contrast, it showed 0.3 in the LG.<BR>3) In the latter half of all exercise times, frequent changes in activity were shown, and Ta/Ts value increased in the gastrocnemius muscle and decreased in the soleus muscle. These results indicate that frequent changes in activity in the latter half were caused by the reduc tion in Ts in the gastrocnemius muscle, and the reduction in Ta in the soleus muscle.<BR>4) Mean integrated EMGs increased significantly in the middle and latter phases in each burst activity, but those in the latter phase did not increase compared to those in the middle phase. These results suggest that the rotation of activity between muscles may have occured before the remarkable increase of EMG activity with fatigue.

Electromyogram patterns during ankle joint movements at various angular velocities in the triceps surae muscles / 体力科学

Surface electromyograms (EMGs) were recorded from the triceps surae muscles in order to examine muscle activities during concentric and eccentric ankle joint movements at various angular velocities under constant load (5 and 10%MVC) . The results were summarized as follows ;<BR>1) At slow angular velocity (6 deg/s) of ankle joint movement, EMG amplitude tended to increase at a larger ankle joint angle in the gastrocnemius muscle, and at a smaller angle in the soleus muscle.<BR>2) Following an increase in angular velocities (6→30→60 deg/s), peak values of integrated EMGs were significantly increased (7-15%) in the medial gastrocnemius muscle. However, these peak values were significantly decreased in the soleus muscle (22-49%) . These results suggest selective recruitment of motor units depending on angular velocity.<BR>3) Ankle joint angle at the peak integrated EMGs was significantly increased following an increase in angular velocity (6→30→60 deg/s) in the soleus muscle. This suggests that the angle at the recruitment of motor units may be dependent on angular velocity in the soleus muscle.

Human body composition determined by cadaver dissection / 体力科学

Sixty-two embalmed cadavers of elderly Japanese individuals, ranged in age from 44-98 years (48 males, 14 females), were completely dissected, and the weights of skin plus subcutaneous adipose tissue (SSATW) and Triceps Surae Muscle (TSMW) determined. Then subcutaneous adipose tissue free weight (SSATFW) was determined by subtracting SSATW from body weight (BW) .<BR>SSATW and percentage of SSATW relative to BW in females (8.9 kg, 19.8%) were larger than those in males (6.1 kg, 12.7%) . On the other hand, TSMW and percentage of TSMW relative to BW in males (313.6 g, 0.65%) were larger than those in females (210.6g, 0.49%) . BW, SSATFW, TSMW were highly correlated (p<0.01) with each other in males. However, in females, TSMW was not significantly correlated (p>0.05) with those variables. The slopes of regression lines for SSATW against BW and SSATFW for females were about twice as steep as those for males.<BR>From these results, it was suggested that females carried a higher proportion of their adipose tissue externally than males and relationship between muscle weight and inner adipose tissue weight in females was more variable than in males.

Effects of ramp and ballistic contractions on post-exercise hyperemia in human triceps surae / 体力科学

This study was designed to compare post-exercise hyperemia between ramp and ballistic contractions in human triceps surae. Subject was asked to extend ankle joint in range of 20 degrees for 1 sec and with maximum effort against loads of 10, 20, 30 or 40% of maximum voluntary contraction (MVC) in ankle extensors. Amount of post-exercise hyperemia was calculated from changes in calf girth recorded by using two strands mercury-in-rubber gauge.<BR>1) Calf girth after contractions transiently decreased below precontraction level and increased gradually until its peak value, over precontraction level, in about 8 sec. Calf girth recovered to resting level for about 30 sec.<BR>2) After ramp contractions, amount of decrease of calf volume increased in order to loads of 10, 20, 30 and 40% MVC, but was not so after ballistic contractions. Amount of its increase, excess precontraction level, depended on loads in both conditions. These values were below 1.0m<I>l</I>/100 m<I>l</I> tissue.<BR>3) Amount of decrease of calf volume after ramp contraction was larger than that of ballistic contraction, but amount of its increase was inverse.<BR>4) There was significant coefficient between calf volume increase after contraction and maximum inflow rate (m<I>l</I>/min/100 m<I>l</I> tissue) calculated from the maximum gradient in rising phase of calf girth (r=0.5508, p<0.001) .<BR>From these results, it is suggested that“milking action”in muscle generate with ramp contraction, and that disturbance of pulsatile inflow to muscle and chemical and neuronal regulations to generate post-exercise hyperemia pronouncely act by ballistic contraction.

Effect of physical activity in daily life on muscle weight and relative weight of the m. triceps surae / 体力科学

In this paper, effects of physical activity in daily life on m. triceps surae were considered comparing the cadavers with decubitus with those without decubitus on muscle weight and relative muscle weight. The muscles were dissected from 18 cadavers (13 males and 5 females) aged 36 to 90 which were preserved in a 10% formalin solution for about one year. Immediately after the removal, weights of gastrocnemius and soleus were measured.<BR>Mean values of the muscle weights of soleus, gastrocnemius and combined total were heavier in male than in female. Those of the relative weights of soleus were larger than those of gastrocnemius in both sexes. The muscle weights showed remarkable inter-individ-ual variations and sexual differences. The decubitus group (non-active group) showed lighter muscle weight than the normal group did in both sexes. However, there were no differences in the relative muscle weight between both groups in both sexes.<BR>The rate of lack of m. plantaris was 11.1%.<BR>From these results, it was suggested that the relative muscle weight might not be influenced by physical activity in daily life but the muscle weight might change consid-erably related to it.

Effect of phasic muscle contraction for acceleration of voluntary muscle relaxation / 体力科学

I found that transient development in sustained tension occur before voluntarily, rapid muscle relaxation in elbow flexors and likely contribute to accelerate velocity of muscle relaxation. In this study, I attempted to clarify whether the transient development depended on contraction of phasic muscle.<BR>Electromyograms and evoked potentials in gastrocnemius and soleus muscles were recorded respectively during the muscle relaxation of ankle extensors without flexor muscle contraction. The sustained tensions before muscle relaxation were 10, 20, and 30% of the maximum plantar flexion strength. The following results were obtained:<BR>1) Frequency of appearance of the transient tension development was about 42% at 10% of the maximum plantar flexion strength, but decreased with the increase of the sustained tension.<BR>2) On comparing between the velocity of muscle relaxation with and without the transient tension develoment, the former was significantly faster than the latter only at 10% of sustained tension. (p<0.001)<BR>3) At the transient tension development H-reflex in gastrocnemius was potentiated, but inhibited in soleus muscle.<BR>These results suggest that the transient tension development is due to contraction of the gastrocnemius muscle and inhibition of the activity of soleus muscle via a mechanism that excitation of PT cell evoke IPSPs in spinal slow α-motoneurons.