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Results for “Muscle Hypertonia”

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At least 19 recordsLinked to original sources
PubMed1983

Normal and impaired regulation of muscle stiffness in gait: a new hypothesis about muscle hypertonia.

The activation of leg muscles was analyzed in respect to ankle joint movement and the changes in tension produced by the triceps surae muscle during slow gait in spastic adults and children with cerebral palsy. In normal subjects the increase in tension of the triceps surae in the stance phase of gait is mainly due to an increase in gastrocnemius and soleus EMG. In spastic patients the abnormally high tension development in triceps surae is due more to passive muscle stretch, for the reciprocally organized leg muscle EMG is reduced. It is concluded that the leg extensor muscles in spastic patients exhibit a pseudostretch-reflex behavior due to their mechanical properties, and that this is mainly responsible for muscle hypertonia. The coactivation of the leg muscles seen in children with cerebral palsy, which also is seen in the stepping of the newborn, suggests impaired maturation of the neuronal locomotor pattern.

Adult↗
PubMed1984

Tension development and muscle activation in the leg during gait in spastic hemiparesis: independence of muscle hypertonia and exaggerated stretch reflexes.

In 15 patients with spastic hemiparesis the development of tension of calf muscles in relation to their electrical activation and their stretching period was studied on both sides during locomotion. Only in the spastic leg did isolated small biphasic potentials appear in the gastrocnemius E.M.G. with monosynaptic latency at the beginning of the stance phase, while the remaining gastrocnemius activation was reduced compared to the unaffected side. Perturbations of gait were followed in the spastic leg by a large monosynaptic response, while the polysynaptic reflex response was reduced. In the unaffected leg only a strong polysynaptic response appeared, which suggests a reciprocal modulation of monosynaptic and polysynaptic reflex responses. Tension development paralleled the gastrocnemius E.M.G. in the unaffected leg, while in the spastic leg tension was more closely correlated to muscle stretch. It is concluded that in spasticity the exaggerated monosynaptic reflexes represent only a small part of leg extensor activation during gait and that the tension development does not depend on these reflexes.

Adult↗
PubMed1988

Fusimotor activity: its possible significance in muscle hypertonia.

Apart from the direct influences of muscle spindle sensory endings on skeletomotor neurones a great deal of their reflex drive is provided indirectly via the gamma-loop. Coactivity of skeletomotor and fusimotor neurones provides, on that occasion, for the servoassistance of muscular movement. Fusimotor neurones modulate their discharge rate in parallel with that of the skeletomotor neurons during reflex muscle contraction in decerebrated cats. These modulations take part during the rising phase of the reflex muscle tension as well as during the maintained reflex muscle contraction when small tension oscillations are present in a muscle. Fusimotor firing does not provide the main stimulus for the contractile activity of the muscle in the decerebrated cats but serves to reflect or to reproduce (within the spindle) the extent and the time course of tension changes in a muscle throughout the whole course of its reflex contraction.

Animals↗
PubMed1983

[Functional status of cervical segments of the spinal cord in patients with local muscle hypertonia].

The reflex response of shoulder girdle muscles to stimulation of the ulnar nerve was registered with the use of needle electrodes. The M- and F-responses of the hand muscles were registered simultaneously. The reflex response had a polysynaptic character, and was not constant in the form, amplitude, and latent period. In healthy subjects the polysynaptic response is registered more often in humerus adductors. In the presence of local painful hypertonicity of the muscles the reflex response was registered in all cases. The intensity of the pain syndrome was inversely proportional to the duration of the latent period. The method described can be used for objective assessment of the time course of the pain syndrome and for forecasting the formation of reflex syndromes of cervical osteochondrosis.

Adult↗
PubMed1983

Measurement of torque during passive and active ankle movements in patients with muscle hypertonia. A methodological study.

Torque curves were recorded during passive and active ankle joint movements at three preset angular velocities (30, 60 and 120 degrees/s) with the subject in the supine position and 45 degrees hip and knee angles. Recordings were performed in normal subjects (n = 11), patients with clinical spasticity (n = 10) and patients with Parkinson's disease (n = 7). The torque curves recorded during passive dorsiflexion followed by plantar flexion showed a counterclockwise hysteresis loop with minimal area in the normal subjects and a large area in patients, especially at the highest velocity. The torque increase during dorsiflexion was proportional to the angular velocity in the patients with spasticity but not in the patients with Parkinson's disease. In the patients with spasticity, a good correlation was found between clinical assessment of hypertonia and measurements of torque during passive movements but not torque values during maximal voluntary dorsiflexion. A model for data reduction and estimation of instant slope values on different parts of the torque-angle curve is suggested. The use of ankle torque recordings for evaluation of treatment effects is exemplified.

Adolescent↗
PubMed1985

[Alternating-discrete tonometry in evaluating the efficacy of post-isometric relaxation of local muscle hypertonia].

A technique of tonometry of the local muscular hypertonus has been developed. Its essence lies in the registration of muscle deformation in response to the external exertion varying from 0 to 5 kg. The detected changes in the tonus are expressed in a graphic form. A session of postisometric relaxation is followed by an increase in the muscle tonus for a brief interval, succeeded by its stable decrease over 24-48 hours. The results obtained are discussed in terms of changing proprioceptive afferentation.

Humans↗
PubMedDate not supplied

[Limping and muscle hypertonia concentrated in the calves. Relation to spasmophilia. Clinical and electromyographic study and treatment plan].

The authors report several cases of patients who presented with pain in one or both calves and a limping gait. Clinical examination and the EMG confirmed that these disorders were of musculo-tendinous origin, maximal at the level of the gemellus tendon, frequently forming a tendinitis. The syndrome consists of a hypertonia of the calves which is maximal on waking and which improves on stretching the muscles. Most of the subjects examined suffered from a syndrome of restless legs and presented alterations of the autonomic nervous system and spasmophilia (simultaneous EMG recording of the left and right soleus muscles). Examination of the pathogenesis reveals the possibility of a phenomenon of tonic muscular training synchronous with variations in an elevated and unstable autonomic tone. The authors discuss a possible relationship with spasmophilia and algodystrophy. Finally, they propose a plan of treatment.

Adult↗
PubMed1988

Intrathecal application of drugs for muscle hypertonia.

The literature regarding the intrathecal use of morphine, baclofen, and midazolam to treat spasticity is reviewed. Nine patients with significant spasticity due to different etiologies were treated. Morphine and midazolam decreased spasticity but did not change the patient's functional status. Baclofen improved patient status, but was associated with significant CNS depression in two cases.

Baclofen↗
PubMed1994

Botulinum toxin A in management of cerebral palsy.

The efficacy of local injection of botulinum toxin A in selected skeletal muscles to relieve muscle hypertonia and muscle contracture, and increase range of motion in children with cerebral palsy was studied in an open ABA (baseline-treatment-posttreatment phase) type of study. The first 6 months were the baseline phase, the day of injection the treatment phase, and the next 6 months the posttreatment phase. The patients acted as their own controls. Fifteen children with cerebral palsy (mean age: 6 years, 8 months) were included in the study. All had limb deformities associated with non-fixed joint contractures that had not responded to physical therapy. Clinical assessment of passive and active muscle tone was performed using a modified Ashworth scale. The range of motion to passive movement was measured with a manual goniometer. Botulinum toxin was injected directly into the muscle at several sites. The postinjection scores of muscle hypertonia were significantly lower (P < .01) and the range-of-motion values demonstrated a significant increase (P < .001). Functional improvement was measured by decreased scissoring on standing in all 6 children with adductor muscles injected; all 6 children with knee flexor muscles injected were able to straighten the knees. The 3 children with injected gastrocnemius muscles were able to achieve heel-strike while bare-footed. The study provides evidence that the intramuscular injection of botulinum toxin A in selected skeletal muscles decreases muscle tone and contractures, and increases range of motion and motor function.

Botulinum Toxins↗
PubMed2000

Force during stretches of rat skeletal muscles after hypertonia at short and long lengths.

Following injection of tetanus toxin into rat gastrocnemius muscle to produce hypertonia, plantar flexor muscles were allowed to shorten (S, n=5) without restraint or held lengthened (L, n=3) by splinting. Saline injected rats served as control (n=5). One week after injection, peak forces during 3 stretches with passive muscles and acute isometric force deficits produced by 15 stretches of electrically stimulated muscles were examined under pentobarbital anesthesia. Isometric force and mass of plantar flexors were similar in S rats but 16% lower in L rats compared to control. Peak passive forces were highest in S rats but not different between L rats and control. At the end of the stretch protocol, isometric force deficits were 26% larger in S rats compared to L rats and 17% smaller in L rats compared to control. Acute isometric force deficits produced by stretches of active skeletal muscles were dependent on the muscle length maintained during hypertonia. Our animal model could be used to test rehabilitation interventions during hypertonia of skeletal muscles.

Animals↗
PubMed1994

Voluntary movement at the elbow in spastic hemiparesis.

The relative importance of hyperreflexia and paresis in disturbances of voluntary arm movement was studied in a group of patients (n = 25) with spasticity arising from a unilateral ischemic cerebral lesion. Patient performance was evaluated against data obtained from normal subjects (n = 15). Spastic patients achieved lower maximum movement velocities during flexion or extension than did normal subjects. The more marked the paresis of the elbow flexor and extensor muscles of the patients, relative to the strength of the normal subjects, the greater was this reduction in maximum velocity. For a given velocity, however, the time taken to complete a movement and the time to reach the peak velocity were normal. No relationship was found between the degree of impairment of voluntary movement and the level of passive muscle hypertonia in the antagonist. Although overactivity of the antagonist muscle may play some role in disturbance of movements made at low velocities without an opposing load, antagonist activity during movements made against a load (i.e., under more natural conditions) was at or below normal levels, even in those patients with the most marked passive muscle hypertonia. It is concluded that agonist muscle paresis, rather than antagonist muscle hypertonia, plays the dominant role in the disturbance of voluntary elbow movement following stroke.

Adult↗
PubMedDate not supplied

[Functional evaluation of the perineum in pregnancy. Hypertonia of the levator ani muscles].

In this study, the role of "levator ani muscles hypertonia" among pathogenetic factors of perineal obstetric injuries is analysed. For this purpose, clinical data of 142 pregnant women, who underwent functional evaluation of perineum during pregnancy and 30 days after delivery were examined. Data here reported are not sufficient to confirm the importance of this factor within the pathogenesis of postpartum perineal deficiency. Levator ani hypertonia on one hand seems to be able to obstruct fetal progression, on the other hand it presumably constitutes, as an expression of a good voluntary control of perineal muscles, a favourable prognostic factor.

Adolescent↗