PubMed Health⌕ Search

Biomedical subjects

C Tardieu

Publications and source records attributed to C Tardieu.

13 recordsLinked to original sources
PubMed1979

Trophic muscle regulation in children with congenital cerebral lesions.

A decrease in sarcomere number and hypoextensibility of ankle extensors was observed in certain children with congenital cerebral lesions. This phenomenon was reproducible and reversible in normal animals, i.e. trophic regulation adapted the muscle to the imposed length. The form of the torque-ankle angle curve was studied in 30 children. Its modification after treatment was considered as a sign of muscle adaptation. This adaptation was present in one group of 14 children. The steepness of the curve increased or diminished depending on the initial disorder and the treatment administered. In another group, treatment failed to modify the shape of the curve. In certain cases trophic regulation of the muscle appeared to be absent.

Adolescent↗
PubMed1979

Decrease of muscle extensibility and reduction of sarcomere number in soleus muscle following a local injection of tetanus toxin.

Slow soleus muscle in guinea pig developed within 4--6 days after local injection of a sublethal dose of tetanus toxin and 2--4 days after the first signs of local tetanus, a myostatic contracture characterized by a change in the passive tension--lengthening curve associated with a considerable decrease of the sarcomere number. It was demonstrated by clinical and EMG investigations that the soleus did have a tetanic spasm at least within the 2--4 day period of observation. When local tetanus was confined to slow soleus by functional suppression of rapid gastrocnemius and ankle flexor muscles, the decrease of the sarcomere number still persisted. This decrease failed to occur after section of the nerve supplying the soleus when associated with an injection of the tetanus toxin, and was much greater than when the soleus was passively shortened for the same period of time by plaster cast.

Animals↗
PubMed1978

Effects of denervation on the reduction of sarcomere number in cat soleus muscle immobilized in shortened position during seven days.

1) Immobilization of cat soleus muscle in shortened position for only seven days was sufficient to elicit a marked reduction in the sarcomere number of individual muscle fibres and a considerable decrease in extensibility. 2) These effects were similar to those observed in previous experiments (TABARY et al., 1972) during which the muscles were immobilized for four weeks. 3) When a denervation was made just prior to immobilization, then one noted a marked difference in the change: the sarcomere number was only slightly reduced and there was a very small change of extensibility. The contralateral non denervated side showed the expected reduction of sarcomere number and decrease of extensibility. 4) These results contrast with previous observations made on denervated muscles immobilized for a period of four weeks. 5) It is proposed that the differences in sarcomere number adaptation observed in denervated and non denervated immobilized soleus are caused by differences of sarcomere length between the two muscles caused by the absence of presence of muscle contraction.

Animals↗
PubMed1977

Relationship of triceps surae torques to photographed tibia-calcaneum angles in man (II).

A previous paper described an apparatus and method for giving the relationship between triceps surae torque and the tibia-calcaneum angle. As a first approximation we took the angle between the calcaneum and the foot-plate as being invariable in all subjects, when the torque was zero. The aim of the present work is to measure the inter-individual variations of the angle. 1. Guide-marks are selected on the skin; showing the axes of the calcaneum and of the leg. Metal rods indicate the axes thus defined and the true angle between the leg and the calcaneum is measured by photography. The curves drawn from these true angles differ from the preceding curves by 0 degrees to 10 degrees for normal children and +12 degrees to -15 degrees for cerebral palsied children. 2. The photographic method verifies the exactitude of the trigonometrical method of correcting angles that we proposed in the previous paper.

Ankle Joint↗
PubMed1977

To what extent is the tibia-calcaneum angle a reliable measurement of the triceps surae length? Radiological correction of the torque-angle curve (III).

Previous papers gave some methods for the reliable measurement of the tibia-calcaneum angle. It is of common use to evaluate the physical properties of triceps surae on the basis of torque-angle curves. However this method is reliable only if each tibia-calcaneum angle corresponds to a defined distance between the insertions of the muscle in subjects of the same height. Evidence is given by radiological measurements that this correspondance is correct in normal children. However, this is no longer true in certain cerebral palsied children because of abnormal translation of the calcaneum and/or abnormal ratio of bone sizes. In this case the torque-angle curves do not define properly the torque-length curves. A method of correction is given. This correction may be as high as 15 degrees.

Ankle Joint↗
PubMed1977

The relationship between sarcomere length in the soleus and tibialis anterior and the articular angle of the tibia-calcaneum in cats during growth.

Sarcomere number and sarcomere length were studied in six groups of kittens ranging in age from 10 minutes to 5 months and compared with those of adult cats. Although the soleus muscle is a slow contracting muscle and the tibialis anterior a fast contracting muscle, both have previously been shown to have the same range relative to ankle movement. For a given angle of articulation the sarcomere length was found to be the same at all ages except perhaps for the newly born. In contrast, the sarcomere number differed considerably, being much higher in the older animals. The relationship between active tension and muscle length was also measured, and again no difference was found between the muscles at any age, although the shape of the curves for the soleus and tibialis anterior was different.

Aging↗
PubMed1976

An apparatus and a method for measuring the relationship of triceps surae torques to tibio-tarsal angles in man.

1. The apparatus and method described give the relationship of triceps surae torque to the absolute tibio-tarsal angle. Data of the anatomy of the foot and the axis of the ankle are taken into consideration. They make complementary measurements necessary, which in certain cases enable the angle recorded by the apparatus to be corrected so as to obtain the true angle. 2. The reliability of the apparatus and the technique of linkage of subject to apparatus are judged by examination of the torque-angle plots obtained by passive stretching of the triceps in 7 subjects for whom correction is monor. Good reliability was observed during the session and from one session to another. The plot is exponential. The merits of the method of correcting angles are illustrated in three subjects with the same protocol: when plots are not corrected, they are more dispersed during the session and no longer exponential. These results justify the considerable correction of the angle that we propose in the study of isometric contractions.

Adult↗
PubMed1976

Functional adaptation of sarcomere number of normal cat muscle.

1. Physiological and histological data were obtained from soleus and tibialis anterior muscles of normal adult cats to study to what extent fibre length and sarcomere number varied between animals and how this was related to the physiological characteristics of the muscles. 2. For a given muscle, the variation in the sarcomere number of individual muscle fibres between animals was found to be about 25%. These difference could partly be explained by comparing the number of sarcomeres and the length of the fibula, which was chosen as an index of the size of the animal. The average sarcomere number in the tibialis anterior muscle was about 60% greater than in the soleus. The variations between animals and between the anterior tibialis and soleus muscles were significantly greater than the variations observed within the same muscle. 3. The sarcomere length is dependent upon the articular angle, that is to say, the length change imposed on the muscle. These length changes are more extensive in the soleus muscle (100%) than in the tibialis anterior muscle (60%). A very significant correlation was found between articular angle and sarcomere length (for soleus r = 0.98, for tibialis anterior r = 0.94). 4. Although fibre length did vary considerably within a given muscle, the sarcomere length showed only minor variations at any given angle. This suggests that sarcomere number is determined in each individual muscle fibre. Such an adaptation implies a concomitant adaptation of the tendinous part of the fibre. This adaptation, resulting in definite sarcomere length at a definite angle, has obvious physiological implications. 5. Conventional length vs. active tension curves were established for the soleus and the tibialis anterior muscles. It is suggested that the difference between the sarcomere number of the two muscles may result in the difference between the shape of curves of these two muscles. 6. Active torque-angle curves were established for the two muscles in situ. The shapes of the curves for soleus and tibialis anterior are similar in spite of the different mechanical conditions of the two muscles. This fact helps to explain why the two muscles, despite their similar articular range, had very different sarcomere number.

Adaptation, Physiological↗