Assessment Of Muscle Tone Research Articles

The influence of gestational age and birth weight in the clinical assesment of the muscle tone of healthy term and preterm newborns

To evaluate the influence of gestational age (GA) and birth weight (BW) in the clinical assessment of the muscle tone of healthy term and preterm newborns. Cross sectional study. The muscle tone of healthy 42 preterm and 47 term newborns was quantified and measured with a goniometer (an instrument for measuring angles) respectively between 7th-14th day of life and 24-48 hours of life. Newborns were grouped according to GA and BW and evaluated at fixed time intervals by one examiner. Preterm newborns were matched to term at 40 weeks postconceptional age (PCA). The evolution of muscle tone in the preterm occurred gradually, following PCA, independent of birth weight. Preterm newborns had lower scores in all muscle tone indicators when compared to term at the first assessment. Differences were observed among preterm small for GA and adequate to GA for the indicator heel to ear (p<0.001). When compared at 40 weeks PCA, except for posture, all other indicators were significantly different (p< 0.001) among groups. Prematurity and intrauterine malnutrition are influential factors in some indicators of the newborn muscle tone state. Muscle tone assessment of preterm infants does not seem to be influenced by birth weight, however evolution is clearly related to postconceptional age. When we compared term newborns AGA and SGA it seems to have a clear influence of the birth weight on some indicators of the muscle tone. The use of devices such as the goniometer allows the performance of a more objective assessment of muscle tone and helps to quantify findings.

Early Androgen Deficiency in Infants and Young Boys with 47,XXY Klinefelter Syndrome

Background/Aims: Klinefelter syndrome (KS) is characterized by the karyotype 47,XXY. In this study, we evaluated the physical and testicular failure phenotypes of infants and young boys with KS. Methods: The evaluation included auxologic measurements, biologic indices of testicular function, and clinical assessment of muscle tone in 22 infants and young boys with KS, ages 1–23 months. Results: Mean length, weight, and head circumference in SDS were generally within the normal range at –0.3 ± 1.0, –0.1 ± 1.4, and 0.0 ± 1.5, respectively. Mean penile length and testicular volume SDS were –0.9 ± 0.8 and –1.1 ± 0.8, indicating significantly reduced penile and testicular size. Mean testosterone levels for the boys ≤6 and >6–23 months were 128 ± 131 (4.4 ± 4.5 nmol/l) and 9.5 ± 7.2 ng/dl (0.3 ± 0.2 nmol/l), respectively. High-arched palate was observed in 6/17 boys and clinodactyly (5th finger) was observed in 15/16 boys. Hypotonia was evaluated clinically and was noted to be present in 12/17 boys. Conclusion: The physical phenotype in infants and young boys with KS (1–23 months old) includes normal auxologic measurements and early evidence of testicular failure. Muscle tone was decreased in most of the boys. Testicular volume and penile length were diminished, indicating early androgen deficiency. The neonatal surge in testosterone was attenuated in our KS population. Thus, infants and young boys with KS have evidence of early testicular failure. The etiology of this failure and the clinical role of early androgen replacement require further study.

The Use of a Portable Muscle Tone Measurement Device to Measure the Effects of Botulinum Toxin Type A on Elbow Flexor Spasticity

Chen J-JJ, Wu Y-N, Huang S-C, Lee H-M, Wang Y-L. The use of a portable muscle tone measurement device to measure the effects of botulinum toxin type A on elbow flexor spasticity. Objective To use a portable muscle tone assessment device to measure spasticity after a botulinum toxin type A (BTX-A) injection. Design Before-after trial. Setting Hospital. Participants Ten chronic stroke patients with upper-limb spasticity. Intervention BTX-A was injected in the biceps brachii. Main Outcome Measures The biomechanic parameters, viscous component, and averaged viscosity derived from the acquired reactive resistance and angular displacements, as well as the reflex electromyographic threshold of biceps brachii, were used for spasticity evaluation. Results A statistically significant decrease in averaged viscosity and a significant increase in reflex electromyographic threshold ( P<.05) both indicated reduction in spasticity owing to BTX-A intervention. There was no clear reflex electromyographic activity detected at lower stretch frequencies. Conclusions Our portable design allows for the convenient use of the device for quantifying spasticity in clinics. All quantitative measurements suggest that BTX-A decreases spasticity within 2 weeks of injection. Our portable muscle tone measurement device may be useful for the clinical assessment of elbow flexor spasticity.

Androgen Receptor CAGnRepeat Length Influences Phenotype of 47,XXY (Klinefelter) Syndrome

Klinefelter syndrome (KS; 47,XXY karyotype and variants) is characterized by tall stature and testicular failure, with marked variation in severity of the phenotype. Previous studies have proposed that genetic factors including mosaicism, parental origin of the supernumerary X-chromosome, skewed X inactivation, and androgen receptor (AR) polyglutamine repeat length may contribute to phenotypic variability in KS. The objective of this study was to investigate the roles of these genetic factors in the variability of the KS phenotype. This was a cross-sectional study. The study was performed at a pediatric endocrinology referral clinic. Thirty-five KS boys and men, aged 0.1-39 yr, were studied. There were no interventions. Auxological measurements, biological indices of testicular function, and clinical assessment of muscle tone were the main outcome measures. Genetic studies included karyotyping to detect mosaicism, genotyping of microsatellite markers to determine parental origin of the supernumerary X-chromosome, and genotyping and methylation studies to measure AR polyglutamine (AR CAGn) repeat length and X inactivation ratio. The only genetic factor that significantly influenced the KS phenotype was the AR CAGn repeat length, which was inversely correlated with penile length, a biological indicator of early androgen action. Mosaicism, imprinting, and skewed X inactivation did not account for the variability of the KS phenotype. Normal genetic variation in the AR coding sequence may be clinically significant in the setting of early testicular failure and subnormal circulating testosterone levels, as occur in KS.

Clinical Decision Making and Oral Motor Treatments

Clinical Decision Making and Oral Motor Treatments

Stiffness and postural stability in adults with Down syndrome.

The purpose of this study was to characterize postural sway in quiet standing under eyes-open and eyes-closed conditions, and to obtain a measure of postural stiffness during quiet standing in adults with Down syndrome (DS) versus control subjects. We obtained descriptive measures from centre-of-pressure (COP) data and analysed and compared COP trajectories and postural stiffness estimates from two stochastic models, the "pinned polymer" (PP) and "inverted pendulum" (IP) models. These estimates were correlated with clinical measures of muscle tone. Our results showed that overall, estimated values for postural stiffness from both models were larger for the DS group than for normal controls. In addition, average stiffness measures were greater under the eyes-closed condition than under the eyes-open condition for the DS group. The IP model detected significant trends over trials whereas the PP model did not. Clinical assessment of muscle tone for the DS group ranged from low to high-normal and there was no significant correlation with the postural stiffness measures obtained from either model. These results suggest that individuals with DS have the ability to modulate their underlying "stiffness" under conditions of quiet standing. Furthermore, there appears to be no strong relationship between clinical measures of muscle tone and postural stiffness measures under dynamic conditions.

Pêndulo: um teste simples de medida de espasticidade

Objetivo deste estudo foi investigar a confiabilidade do teste de pêndulo para avaliar o tônus muscular e comparar os dados obtidos entre um grupo de idosos saudáveis e um grupo de pacientes hemiplégicos crônicos da mesma faixa etária. Vinte idosos e 20 hemiplégicos crônicos foram recrutados na comunidade, de forma voluntária. O tônus muscular foi investigado utilizando o índice de relaxamento corrigido (IRC) obtido pelo teste de pêndulo. Para avaliar a confiabilidade do IRC, os dados foram obtidos em dois dias diferentes para ambos os grupos. Testes-t foram empregados para avaliar diferenças entre os grupos e entre os lados afetado e não afetado do grupo hemiplégico. A média do IRC para o lado afetado foi 0,65 (± 0,20) no primeiro dia e 0,66 (± 0,11) no segundo dia. Para o lado não afetado, as médias foram 1,03 (± 0,09) e 1,02 (± 0,11) para os primeiro e segundo dias, respectivamente. Coeficientes de correlação significativos foram observados entre as duas medidas obtidas (r = 0,93 e r = 0,70) para os lados afetado e não afetado, respectivamente. Os resultados do teste-t demonstraram diferenças significativas entre os valores do IRC obtidos no lado afetado comparados com os valores do lado não afetado e os valores de referência. Entretanto, não foram observadas diferenças significativas entre os valores do IRC obtidos no lado não afetado e os valores de referência. Pode-se concluir que o teste de pêndulo apresenta o potencial de ser incluído como um método eficaz de medida de tônus muscular em reabilitação.

Clinical measurement of muscle tone using a velocity-corrected modified Ashworth scale.

To develop a new form of the modified Ashworth scale (MAS) for muscle-tone assessment that combines the MAS score with the passive muscle-stretching velocity during the assessment of muscle tone, resulting in a measure that has higher intertester reliability than the MAS. Twenty-two volunteer subjects with spinal cord injuries at a tertiary care outpatient and inpatient spinal cord injury rehabilitation center affiliated with a university were recruited for this study. A decision tree in which V-MAS scores were obtained was developed. The data obtained from three independent raters, when adjusted by means of the V-MAS, showed an excellent interrater reliability. Results indicated that the V-MAS is a more reliable measure. In addition, the resulting units of the V-MAS, ranging from 0 to 1, are of the same form as pendulum test data. The V-MAS method is quite simple to use because the rater need only measure the angular range and duration of the passive movement to calculate average velocity during the MAS assessment in addition to the normal MAS rating of muscle tone.

Effects of surface spinal cord stimulation on spasticity and quantitative assessment of muscle tone in hemiplegic patients.

Spasticity after a stroke interferes with the normal function of a limb. Electric stimulation has been used in a variety of ways to decrease spasticity. The purposes of this study were (1) to quantify the effectiveness of electric stimulation on decreasing ankle spasticity and (2) to develop a quantitative assessment of muscle tone, which could be replicated in the clinic. Ten patients with hemiparesis resulting from ischemic stroke participated in the study according to the selection criteria. Their mean age was 57 yr, with a mean stroke interval of 12.5 months. Patients received electric stimulation for 45 min through surface electrodes applied to the skin in the 12th thoracic and 1st lumbar areas. All patients received five electric stimulation treatment sessions. The electrical pulses were amplitude modulated frequency beat with a carry frequency of 2500 Hz and a stimulation frequency of 20 Hz. The stimulation intensity was adjusted to each patient to produce a sensory stimulation. The pre- and posttreatment evaluation included surface electromyography activity during passive ankle dorsiflexion, passive ankle dorsiflexion resistance at different angular velocities, as measured by an isokinetic machine and the modified Ashworth scale. Our results indicate that the surface spinal cord stimulation with middle frequency modulated to low frequency for sensory stimulation on the skin of 12th thoracic and first lumbar area is effective in reducing calf muscle spasticity of hemiplegic patients. The isokinetic torque measures for spasticity are a sensitive tool to document the effects of the treatment.

Botulinum Toxin in the Treatment of Spasticity in Children with Cerebral Palsy

The use of botulinum toxin A is a relatively new and innovative therapeutic intervention for children with cerebral palsy. The purpose of this review is to summarize nine articles, all published since 1993, that relate specifically to the use of botulinum toxin A in the management of spasticity in children with cerebral palsy. A range of outcome measures were employed in these studies including assessment of muscle tone, range of motion, appearance, gait analysis, gross or fine motor functional status, and parent or guardian questionnaire. In general, the findings demonstrated significant improvements, especially in muscle tone, range of motion, and functional motor status.

Botulinum Toxin in the Treatment of Spasticity in Children with Cerebral Palsy

The use of botulinum toxin A is a relatively new and innovative therapeutic intervention for children with cerebral palsy. The purpose of this review is to summarize nine articles, all published since 1993, that relate specifically to the use of botulinum toxin A in the management of spasticity in children with cerebral palsy. A range of outcome measures were employed in these studies including assessment of muscle tone, range of motion, appearance, gait analysis, gross or fine motor functional status, and parent or guardian questionnaire. In general, the findings demonstrated significant improvements, especially in muscle tone, range of motion, and functional motor status.

The Reliability of Measurement of Postural Alignment to Assess Muscle Tone Change

Summary Summary This pilot study using normal volunteers looks at inter-rater and intra-rater reliability when testing a clinical measure of postural alignment in normal subjects, using the coefficient of variation as a means of analysis. Results show the difference to be less than 5% in all tests. It is therefore, statistically significant. This indicates that the method of measuring is reliable and would be worth further investigation as a clinical measuring tool for physiotherapists working with hemiplegic patients whose muscle tone shows changes. This evaluation was conducted between August 1992 and February 1993.

Correlations between dose, plasma concentrations, and antispastic action of tizanidine (Sirdalud).

In a double blind, placebo controlled, cross over study the correlations between single doses (2, 4, and 8 mg), plasma concentrations, and antispastic action of tizanidine were investigated in 16 patients with extensor spasticity of the legs due to multiple sclerosis. An electrogoniometer was used to assess muscle tone at knee extensors, applying Wartenberg's pendulum test. Blood samples, a clinical assessment of muscle tone by the Ashworth scale, and muscle strength by the British Medical Research Council scale were obtained concomitantly. Confirmatory analysis using the change in the relaxation index (R2 value) 1.5 hours after each treatment, showed a statistically significant (p = 0.0123) linear dose-response relation between single doses and antispastic action of tizanidine. Further statistical analysis showed a strong within patient linear correlation between plasma concentrations and antispastic action at 4 and 8 mg doses (p = 0.014 and 0.004 respectively), but only weak between patient correlations. The analysis of the dose-plasma concentration relation showed results consistent with linear pharmacokinetics. The comparison of changes in the R2 ratio with concomitant Ashworth scores showed a significant correlation between the two. It is concluded that there are linear correlations between single doses, plasma concentrations, and antispastic action of tizanidine. Because of the strong within patient but weak between patient correlation between plasma concentrations and antispastic action of tizanidine the effective doses should be determined individually.

Stretch-induced electromyographic activity and torque in spastic elbow muscles. Differential modulation of reflex activity in passive and active motor tasks.

Stretch-evoked electromyographic (EMG) activity and torque signals have been studied in elbow joint muscles of both sides of patients with spastic hemiparesis and healthy subjects. In order to reveal differences in the generation of muscle tone between clinical assessment and functional movement, stretches of different velocities and amplitudes were applied during passive and quasi-functional active motor tasks. In spastic patients the strength and duration of the EMG responses following stretching of flexor and extensor muscles during both passive and active tasks were dependent on the stretch velocity and duration, respectively. This effect was seen on both the spastic and unaffected side. Under passive conditions EMG activity after stretching was negligible in the limb muscles of healthy subjects, of small amplitude in unaffected limbs of the patients, but was strong in affected muscles. Under active conditions, the amplitude of the early (M1) component of the EMG signal was larger, while the later components (M2 and M3) were smaller. These differences were due more to a change in reflex gain than to a change in reflex threshold when the stretch velocity signal was the basis for calculation. It is suggested that in spastic paresis, modulation of stretch-induced EMG activity in the spastic limb becomes restricted to a smaller range with a poor ability to switch off under passive conditions. Furthermore, the reflex EMG activity suffers a reduced facilitation under active conditions. In comparison with unaffected limbs the stretch-evoked torque on the affected side was increased under passive conditions (due to the extra EMG activity) and decreased under active conditions (due to a reduced EMG activity). An increased torque to EMG ratio was found in spastic flexor and extensor muscles during active tasks. This is thought to be due to changes in mechanical muscle fibre properties suffered as a consequence of defective muscle activation following cerebral lesions. The consequences for clinical assessment of muscle tone and therapy of spastic movement disorder are discussed.

A comparison of the assessment of spasticity by the Wartenberg pendulum test and the Ashworth grading scale in patients with multiple sclerosis

The Wartenberg pendulum test is an objective quantitative method for the assessment of muscle tone. We have compared the results of measurements of muscle tone using this method with traditional clinical assessments graded on the Ashworth scale. Two indices ( R1 and R2) were measured from the Wartenberg test. Both were related to readings from the Ashworth scale. The ratio R2 (the ratio of the amplitude of the first swing to the difference in angle between the start and finish positions), however, showed a linear relationship throughout the range of spasticity tested in contrast to the curvilinear relationship shown by R1 (the ratio of the amplitude of the first swing to the difference between the rebound angle and the start angle). Significant changes in the ratio R2 without any corresponding change in the Ashworth grading were observed. It is concluded that the Wartenberg ratio R2 and the Ashworth scale assess similar features of the muscle and/or its motor control, but that the pendulum test provides a more finely graded observer- independent measurement.

Interrater Reliability in the Assessment of Muscle Tone of Infants and Children

The assessment of muscle tone is an integral part of the neurological examination of infants and children. Detection of an alteration in muscle tone aids in establishing a diagnosis, is used as justification for therapeutic services, and is viewed as an indicator of neurological change. The purpose of this study was to establish the degree of interrater reliability among pediatric physical therapists in the assessment of muscle tone in children age birth to three years. Six physical therapists were raters. Each rater was randomly assigned to nine evaluations. Eighteen children were evaluated by a group of three raters. The testing protocol included observation of the child's spontaneous movement for 10 minutes, followed by a 10 minute assessment period in which the raters individually assesssed the child using the rater's preferred method of evaluation. Following the evaluation, each rater completed a tone summary form, scoring: (1) clinical impression of abnormality, (2) tone sumary statement, and (3) tone type and severity for the four extremities and the neck and trunk. Total percent agreement on clinical impression of abnormality was 61.1%; agreement on tone summary was 55.6%; agreement for severity of body part ranged from 40.7% to 51.9% (78.9% of the time agreement on severity varied by zero or one point). As this represents low reliability in the clinical setting, therapists should be very cautious regarding clinical decisions based on an assessment of muscle tone. Interrater reliability was affected by: (1) the lack of a standard technique of method for assessing tone; (2) the lack of consistant terminology to describe tonal state and severity; (3) specific problems with the scoring method for tone summary; and (4) lack of a category for abnormal fluctating tone.

Interrater Reliability in the Assessment of Muscle Tone of Infants and Children

The assessment of muscle tone is an integral part of the neurological examination of infants and children. Detection of an alteration in muscle tone aids in establishing a diagnosis, is used as justification for therapeutic services, and is viewed as an indicator of neurological change. The purpose of this study was to establish the degree of interrater reliability among pediatric physical therapists in the assessment of muscle tone in children age birth to three years. Six physical therapists were raters. Each rater was randomly assigned to nine evaluations. Eighteen children were evaluated by a group of three raters. The testing protocol included observation of the child's spontaneous movement for 10 minutes, followed by a 10 minute assessment period in which the raters individually assesssed the child using the rater's preferred method of evaluation. Following the evaluation, each rater completed a tone summary form, scoring: (1) clinical impression of abnormality, (2) tone sumary statement, and (3) to...

Objective Assessment of Muscle Tone in Stroke Patients

Objective Assessment of Muscle Tone in Stroke Patients

Electromyographic assessment of spasticity.

We define the concept of muscle tone and describe the signs and symptoms of its alteration in spasticity. In assessing muscle tone it is important to consider all the inputs and outputs affecting it, using biomechanical-EMG techniques for measuring active tone. We list the various features of the myotatic and defence reflexes that are altered in spastics and analyze the altered parameters in relation to the tonic reflexes. The degree of displacement, the position from which it is initiated and the velocity of displacement constitute a specific, sensitive and reliable criterion. We report the results of a personal study of these reflexes and of the shortening reflexes.

Does the Wartenberg pendulum test differentiate quantitatively between spasticity and rigidity? A study in elderly stroke and Parkinsonian patients.

The results of applying the Wartenberg pendulum test to the assessment of muscle tone in populations of stroke and Parkinsonian patients are described. The test was able to distinguish between increased muscle tone of the spastic or rigid type. The Parkinsonian patients showed a marked reduction of the maximum velocity of the leg swing, with the relaxation index tending to a value of about one. In contrast the affected limb of stroke patients showed a lesser reduction of the velocity of the swing, the relaxation index tending to a value of less than one.