[Stretching the triceps surae muscle after 40 degrees C warming in patients with cerebral palsy]. / Etirement du triceps sural après réchauffement à 40 degrees chez l'IMC.

PURPOSE OF THE STUDY: Equinus in patients with cerebral palsy results from at least two factors: excessive contracture of the triceps surae and muscle retraction. Tendon surgery and progressive lengthening techniques using plaster walking boots can provide variable improvement in retraction. We compared the effect of this technique when applied with or without prior 40 degrees C warming in the same patients. We also assessed the efficacy of this treatment method in terms or degree of retraction, patient age, puberty maturity, and sex. MATERIALS AND METHODS: This series included 70 muscles in 52 patients with cerebral palsy aged 2 years 11 months to 21 years (mean 8 years 3 months). Common features in these patients were: - equinus mainly explained by triceps retraction, - no history of prior surgery on the triceps tendon, - knee flexion less than 15 degrees in the upright position, - easily reduced lateral deformation of the foot, - absence of mediotarsal dislocation, - triceps stretching could be achieved without triggering unacceptably intense contracture. The retraction of the triceps surae was measured from the maximal passive dorsal flexion angle of the foot, before and after applying each stretching boot. The difference between these measurements gave the gain obtained with the plaster boot. Protocol R- (stretching with plaster boot) consisted in a series of slow stretchings for 10 minutes before making the boot which was worn 7 days. Recurrent retraction in these same patients warranted another treatment within a delay of 3 to 17 months (mean delay 8.7 months). The same treatment then followed protocol R+ where the stretching was preceded by immersion of the segment in a 40 degrees C water bath for 10 minutes. RESULTS: Mean gain obtained with protocol R+ (warming) was 6.8 degrees knee extended and 7.1 degrees knee flexed. These differences were highly significant in both cases (p <0.0001). We had no failures with protocol R+ while with protocol R- (stretching without warming) the gain was nil or less than 5 degrees for 29 muscles knee extended and for 32 muscles, knee flexed. The gain was not related to age, sex or puberty maturity. It was not related to the angle of dorsal flexion of the foot prior to stretching. DISCUSSION: Our findings demonstrate that when the conditions allowing prolonged stretching of the triceps surae are present, prior warming at 40 degrees C for 10 minutes leads to an improvement in muscle lengthening in all patients, even in those for whom prior treatment had been unsuccessful without warming. This observation would indicate that the mechanisms allowing greater lengthening are present in all patients with cerebral palsy but that they cannot be triggered due to abnormal muscle viscosity related to distal vasomotor disorders frequently observed in this condition. Further research is needed to detail this point.

Extensibility of hip adductors in children with cerebral palsy.

The passive extension of relaxed hip adductor muscles was measured in 20 normal children and 10 children (aged nine to 13 years) with cerebral palsy (CP) by a method that could distinguish between shortening of the muscle body and tendon. No muscle-body contracture occurred in the children with CP during treatment (physiotherapy plus moderate stretching on an apparatus for six hours a day); only the tendons were short. However, four children showed signs of muscle-body contracture after interrupting treatment for six to eight weeks. It is possible that muscle-body contracture can be prevented by non-surgical methods, although tendon shortening can, at present, only be treated surgically.

[Is surgery of the hip adductor muscles justified in children with cerebral palsy?]. / La chirurgie des adducteurs de la hanche est-elle justifiée chez l'enfant infirme moteur cérébral?

INTRODUCTION: Restricted passive hip abduction in children with cerebral palsy (CP) may be caused by uninhibited resting contractions and/or retractions, i.e., shortened muscle body or tendons. Pathological short tendons require surgical intervention, but lack of muscle body elasticity responds to physiotherapy or a postural splinting. Clinical examination can distinguish between short tendons and short muscle body. The thigh is slowly and passively extended while palpating the tendon. Tension is detected in the tendon when the leg is at angle Ao. The elastic tension of the muscle body then increases until no further movement is possible, at angle Amax. The difference Amax-Ao is an index of the structural length of the muscle body. If this difference is reduced during passive straightening there is shortening of the muscle body; if it is displaced it indicates shortening of the tendon. The value Ao indicates the muscular or tendon origin of the retraction for a given passive limitation (Amax). This study defines the physiological values of Ao and the relative precisions of chemical and instrumental measurements. MATERIALS AND METHODS: A total of 30 children aged 9-11 years, 10 CP patients (7 girls and 3 boys, mean age 10.3 years) and 20 controls (11 girls and 9 boys, mean age 10.5 years) were studied. All the CP children had lower limb spasticity and adopted an adduction posture. None had undergone hip muscle surgery. Ao and Amax were measured clinically with a goniometer and EMG to monitor muscle silence, and experimentally using a deformable parallelogram and force transducers. RESULTS: The minimum physiological value of Ao was 8 degrees with the knee flexed and 0 degree with the knee extended. Smaller values of this angle indicated tendon retraction. The difference between Ao and Amax in the controls and CP children was < or = 10 degrees; the reproducibilities of the clinical measurement of Ao and Amax were very similar. DISCUSSION: Clinical examination provides an acceptably accurate method of distinguishing between tendon and muscle body retraction of adductor muscles in CP children. The conditions required for successful measurement are: careful examination with strict positional reference and sufficiently relaxed pelvic muscles. A hip extension angle Ao of less than 8 degrees with the knee flexed or 0 degree with the knee straight indicates tendon retraction requiring tendon surgery, otherwise, the retraction involves only the muscle body. This reduced elasticity can be overcome by prolonged extension (at least 6 hours/24). Effective muscle extension may be hindered by non-suppressed adductor contractions. This must be overcome prior to physiotherapy by surgery of the ramus ant. n. obturatorii. CONCLUSION: Clinical measurement of Ao of adductor muscles is a reliable way of distinguishing between tendon retractions requiring surgery and muscle body retractions resulting from staying too long in a position with the muscle shortened. This muscle body shortening can be due to lack of physiotherapy or a stretching apparatus treatment, pathological contractions, or compensation for disorders of the controlateral limb.

Swallowing disturbances associated with drooling in cerebral-palsied children.

The oral stage of swallowing was studied in two groups of 10 cerebral-palsied (CP) children (one drooled and the other did not), and 10 normal children, aged six to 14 years. Small amounts of liquid (0.5 to 1mL) were placed under the tongue or behind the lower lip and intra-oral pressure was measured during the suction and propulsion stages. The CP children who drooled showed no abnormality in the propulsion of liquid towards the pharynx, but all showed abnormal suction of liquid onto the tongue. The difficulty seems to be associated with three types of disturbance: incomplete lip-closure during swallowing, low suction-pressure and prolonged delay between the suction and propelling stages.

Toe-walking in children with cerebral palsy: contributions of contracture and excessive contraction of triceps surae muscle.

The study was designed to provide a quantitative analysis of toe-walking in children with cerebral palsy (CP). The total internal moment developed about the ankle joint during locomotion and the passive component of this internal moment were measured. The contributions of the active and passive components were expressed as the ratio (R) between the passive moment and the total internal moment. Measurements were compared for 13 children with CP and 5 healthy children. For the data analysis, the children with CP, exhibiting apparently similar toe-walking, were divided into two groups: 1) Group CPI and 2) Group CPII. Group CPI was characterized by a small ratio R value, which indicated the presence of excessive contractions of the triceps surae muscle during locomotion. In Group CPII, the ratio R value was abnormally high, which indicated that a contracture (ie, structural change of the muscle or the tendon) was entirely or at least partly responsible for toe-walking. Each group requires a different therapeutic strategy.

[Is surgery of the tendons of the knee flexor muscles justified in cerebral palsy?]. / La chirurgie tendineuse des fléchisseurs du genou est-elle justifiée chez l'infirme moteur cérébral?

The lengths of the tendons and muscle belly connective tissue envelopes of the knee flexor muscles of 6 healthy and 11 children with cerebral palsy were measured. The restricted passive knee extension was found to be associated with abnormally short tendons in all cases of contracture. This correlation provided an experimental support for the surgical lengthening of the tendon.

For how long must the soleus muscle be stretched each day to prevent contracture?

The extent to which treatment of passive muscle contracture could be minimised without loss of efficiency was studied. Soleus muscle contracture was measured by the difference between the ankle angles at which minimal and maximal resistance occurred during slow dorsiflexion of the ankle. This examination was done twice, at the beginning and end of a seven-month observation period. During the observation period, also, the ankle angles were measured throughout a 24-hour period in the ordinary life of the child. The number of hours per 24-hour period during which the soleus muscle was stretched above a minimal threshold length was calculated. The major finding was that there was no progressive contracture when the soleus was stretched for at least six hours a day (the same time as in non-handicapped children). On the other hand, there was progressive contracture when the stretching time was as short as two hours. Two of the cases examined illustrated the possible causes of success or failure of night splints. These results provide new guidelines for the continuous treatment of children with cerebral palsy.

Flexibility of scoliosis. What does it mean? Is this terminology appropriate?

This work is a critical analysis of the term "flexibility of scoliosis." The authors demonstrate that this measure includes two very different and noncorrelated phenomena: the collapse and the reducibility of the structural curve. In 228 paralytic curves, these two phenomena were quantified and correlated with different parameters of scoliosis: sex, stage of maturation, curve pattern, number of vertebrae in the curve, spinal and abdominal test values, and the scoliotic evolution rate. Reducibility can be predicted since it is an elasticity process. Collapse is more complex, but it is a prognostic factor for evolution and effectiveness of treatment. The preliminary results of a similar study of idiopathic scoliosis are the same.

Can vibration-induced illusions be used as a muscle perception test for normal and cerebral-palsied children?

Since poor control of muscle contractions in cerebral palsy may be due partly to defective processing of data originating from muscle, the need arose for a test as uncontaminated as possible by other afferent effects. For 18 normal children, vibration of the brachial biceps tendon always gave the illusion of elbow extension; when the triceps was vibrated the opposite illusion occurred. For 22 cerebral-palsied children the vibration test was successful for 26 elbows and failed for 18. These failures might provide a future explanation for certain therapeutic failures.

Scoliosis and trunk muscles.

This study examines the role of muscular deficiencies in the origin and development of paralytic scoliosis. We studied spine films of 108 scoliotic curves of poliomyelitic children and results of muscle tests made during the growth phase. We investigated the relationship between spinal and abdominal muscle test values, determined 2 years after the child had experienced the acute phase of anterior polioimyelitis, and the convexity, evolution rate, effects of gravity, and reducibility of the scoliotic deformity. Although paralysis certainly is responsible for triggering scoliosis, it plays no role in determining convexity for thoracic and lumbar patterns, and has little bearing on thoracolumbar curves. It is not at all correlated with the evolution rate, reducibility, or degree of collapse with gravity. The general laws governing the evolution of scoliosis, whatever its origin, are outlined, and several possible pathogenic factors are suggested.

Muscle hypoextensibility in children with cerebral palsy: II. Therapeutic implications.

Twenty-nine children with cerebral palsy and triceps surae hypoextensibility were divided into 2 groups. In group I trophic regulation of the muscle was defective and in group II it was normal. Torque values were plotted against tibiocalcanean angles before and after treatment, which consisted of muscle lengthening by successive plaster casting or of surgical elongation of the tendon or the aponeurosis. In group I, casting had no effect, but surgery increased passive dorsiflexion and gave definite clinical improvement without modifying the range of passive muscle stretch. In group II, with normal muscle adaptation, plaster casts were successful when tolerated. Children in this group required braces after surgery to prevent rapid recurrence of hypoextensibility. Both casting and surgery increased the passive muscle stretch. There was a displacement of the starting point of the passive and active curves in both groups. This is an unavoidable side-effect which makes walking on tiptoes impossible after casting or surgery.

Effects on torque angle curve of differences between the recorded tibia-calcaneal angle and the true anatomical angle.

The present study gives the results of a comparison of the recorded and true tibia-calcaneal angles in 17 normal subjects and in 14 patients with abnormally hypoextensible non contracting triceps. 1. For a minimal passive torque, the difference between true and recorded angles varied considerably from one individual to another. The mean and ranges for the two groups were respectively: -8 degrees (+7 degrees, -21 degrees) and -7 degrees (+5 degrees, -20 degrees). 2. When the passive torque increased as a result of slow passive lengthening of the muscle, the true curve was steeper than the recorded one, owing to differences between the two angle measurements. For each of the two groups the differences in means and ranges were respectively: 6 degrees (0 degrees, +13.5 degrees) and 8 degrees (3 degrees, 12 degrees). 3. Subjects made isometric voluntary contractions of the triceps surae at fixed angles which corresponded to step by step muscle lengthening. The resulting true curve was much steeper than the recorded curve. The differences in means and ranges were: 7 degrees (1.5 degrees, +15 degrees) in children of the two groups and respectively 3 degrees (0 degrees, +9 degrees) and 12 degrees (10 degrees, 14 degrees) in adults of the two groups. The present results show that this methodology was the only reliable way of correctly obtaining passive and active torque-angle curves, measuring differences between subjects, appreciating the effects of treatments and these by ascertaining whether or not trophic muscle regulation was defective.

Variation in the long-term results of elongation of the tendo Achillis in children with cerebral palsy.

Clinical assessment of equinus in children before and after operation was made over a twenty-year period (1958-1978), and three groups were defined. Forty-three muscles (Group I) had abnormal shortening without spasticity and the deformity progressed steadily despite immediate improvement after operation; this was considered to be the result of a lack of muscle growth during bone growth. Forty-one muscles (Group II) had both shortening and spasticity with an imbalance which might be unchanged after operation, or reversed or improved. Fourteen muscles (Group III) had spasticity only and progression was unpredictable and could not be defined. Improvement in gait was regularly observed in Group I in the early years after operation. In Groups II and III the results were variable. These results did not depend on surgical technique but on differences in pathophysiology.

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.

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.

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.