The relation between Ashworth scores and neuromechanical measurements of spasticity following stroke (original) (raw)
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Biomechanical measurement of post-stroke spasticity
Age and Ageing, 2006
Background: spasticity following stroke is common, but clinical measurement is difficult and inaccurate. The most common measure is the modified Ashworth scale (MAS) which grades resistance to passive movement (RPM), but its validity is unclear. Aim: to assess the validity of the MAS. Methods: spasticity was clinically graded using MAS and RPM measured biomechanically in the impaired arm of 111 patients following stroke. The biomechanical device measured RPM, applied force, angular displacement, mean velocity, passive range of movement (PROM) and time required.
Quantitative measures of spasticity in post-stroke patients
Clinical Neurophysiology, 2000
Objective: Quantitative evaluation of muscle tone in post-stroke patients; correlation of biomechanical indices with conventional clinical scales and neurophysiological measures; characterization of passive and neural components of muscle tone.Methods: Mechanical stretches of the wrist flexor muscles of 53 post-stroke patients were imposed by means of a torque motor at constant speed. Patients were clinically studied using the Ashworth scale for
Biomechanical examination of a commonly used measure of spasticity
Clinical Biomechanics, 2001
Background. An increase in the prevalence of neurological disability puts pressure on service providers to restrict costs associated with rehabilitation. Spasticity is an important neurological impairment for which many novel and expensive treatment options now exist. The antispastic eects of these techniques remain unexplored due to a paucity of valid outcome measures. Aim. To develop a biomechanical measure of resistance to passive movement, which could be used in routine clinical practice, and to examine the validity of the modi®ed Ashworth scale. Study design. Repeated measure cross-section study on 16 subjects who had a unilateral stroke one-week previously and had no elbow contractures. Outcome measures. Simultaneous measurement of resistance to passive movement using a custom built measuring device and the modi®ed Ashworth scale. Passive range of movement and velocity were also measured. The``catch'', a phenomenon associated with the modi®ed Ashworth scale, was identi®ed by the assessor using a horizontal visual analogue scale and biomechanically quanti®ed using the residual calculated from a linear regression technique. Results. Half the study population had a modi®ed Ashworth score greater than zero. The association between the two measures was poor (j 0:366). The speed and range of passive movement were greater in subjects with modi®ed Ashworth score``0'' (P < 0:05). Resistance to passive movement was higher in the impaired arm (P < 0:05) and tended to decrease with repeated measures and increasing speeds. Conclusions. A device to measure resistance to passive movement at the elbow was developed. The modi®ed Ashworth scale may not provide a valid measure of spasticity but a measure of resistance to passive movement in an acute stroke population. Relevance Spasticity is an important neurological impairment for which many novel and expensive treatment options are being made available. There is a paucity of clinically usable outcomes to measure spasticity. A device to measure resistance to passive movement at the elbow, which was more reliable than the modi®ed Ashworth scale was developed. This device may provide a much needed objective clinical measure to evaluate the ecacy of antispasticity treatment.
Correlation of Resting Elbow Angle with Spasticity in Chronic Stroke Survivors
Frontiers in Neurology, 2015
Objective: To evaluate whether resting joint angle is indicative of severity of spasticity of the elbow flexors in chronic stroke survivors. Methods: Seventeen hemiparetic stroke subjects (male: n = 13; female: n = 4; age: 37-89 years; 11 right and 6 left hemiplegia; averaged 54.8 months after stroke, ranging 12-107 months) participated in the study. The number of subjects with modified Ashworth scale score (MAS) = 0, 1, 1+, 2, and 3 was 3, 3, 5, 3, and 3, respectively. In a single experimental session, resting elbow joint angle, MAS, and Tardieu scale score (Tardieu R1) were measured. A customized motorized stretching device was used to stretch elbow flexors at 5, 50, and 100°/s, respectively. Biomechanical responses (peak reflex torque and reflex stiffness) of elbow flexors were quantified. Correlation analyses between clinical and biomechanical assessments were performed. Results: Resting elbow joint angle showed a strong positive correlation with Tardieu R1 (r = 0.77, p < 0.01) and a very strong negative correlation with MAS (r = −0.89, p < 0.01). The resting angle also had strong correlations with biomechanical measures (r = −0.63 to −0.76, p < 0.01). Conclusion: Our study provides experimental evidence for anecdotal observation that the resting elbow joint angle correlates with severity of spasticity in chronic stroke. Resting angle observation for spasticity assessment can and will be an easy, yet a valid way of spasticity estimation in clinical settings, particularly for small muscles or muscles which are not easily measurable by common clinical methods.
Measurement of Elbow Spasticity in Stroke Patients Using a Manual Spasticity Evaluator
2006
Spasticity is often seen in patients with central nervous system lesion, such as stroke. It hinders functional movement and may induce pain. Current measures for assessing spasticity are either quantitative but not convenient to use or convenient to use in clinics but lack of objective quantification. We developed a manual spasticity evaluator (MSE) to evaluate the spasticity quantitatively and potentially suitable for a clinical setting. Joint position and torque from 10 subjects with right hemiplegia and 9 healthy subjects were measured conveniently and used to evaluate spasticity and determine the catch angle. EMG signal was obtained from the biceps brachii and triceps brachii to corroborate the mechanical measurement of the MSE. Results showed that the MSE provided a convenient and quantitative measurement of spasticity, including presence of catch angle, increase in joint stiffness, and decrease in joint range of motion in the stroke patients, as compared with healthy subjects. EMG signals corroborated MSE assessment of the catch angle.
Prevalence, onset, evolution, and prediction of spasticity poststroke
Revista Ciencias de la Salud
Introduction: Because of the the complex physiopathology of spasticity, it is distinguished as one of the most significant positive clinical signs of upper motor neuron syndrome, constituting a clinical feature that has great impact in the neurorehabilitation setting. Thus, the current study aimed to determine the prevalence, onset, evolution, and prediction of spasticity after a stroke. Materials and Methods: A correlational, longitudinal design was used. A total of 136 patients were evaluated at the following times: 10 days (T1), 3 months (T2), and 12 months (T3) poststroke. The initial evaluation included sociodemographic and clinical data (T1). Muscle tone was measured (T1, T2, and T3) using the Modified Ashworth Scale. Results: The prevalence of poststroke spasticity in the elbow was 37.5% at T1 and 57.4% at T2 and T3. Among patients with motor damage, the onset of spasticity occurred at T1 in 44.7%, between T1 and T2 in 23.7%, and between T2 and T3 in 0.9%. Significant predict...
Clinical Rehabilitation, 2008
Objective: To quantify agreement between three clinically usable methods of measuring spasticity. Methods: Patients with a first stroke who had no useful functional movement in the upper limb within six weeks from stroke onset were eligible to participate. Spasticity at the wrist joint was simultaneously measured using three methods, during an externally imposed passive stretch at two (uncontrolled) displacement velocities. The measures used were a common clinical measure (modified Ashworth Scale), a biomechanical measure (resistance to passive movement) and a neurophysiological measure (muscle activity). Results: One hundred patients (54 men and 46 women) with a median age of 74 years (range 43-91) participated. Median time since stroke was three weeks (range 1-6), the right side was affected in 52 patients and the left in 48 patients. Based on muscle activity measurement, 87 patients had spasticity. According to the modified Ashworth score 44 patients had spasticity. Sensitivity of modified Ashworth score, when compared with muscle activity recordings, was 0.5 and specificity was 0.92. Based on muscle activity patterns, patients could be classified into five subgroups. The biomechanical measures showed no consistent relationship with the other measures. Conclusion: The presentations of spasticity are variable and are not always consistent with existing definitions. Existing clinical scales that depend on the quantification of muscle tone may lack the sensitivity to quantify the abnormal muscle activation and stiffness associated with common definitions of spasticity. Neurophysiological measures may provide more clinically useful information for the management and assessment of spasticity.
Association of spasticity and motor dysfunction in chronic stroke
Annals of physical and rehabilitation medicine, 2019
Abnormal muscle tone and spasticity are consequences of injury to the central nervous system. High muscle tone has serious consequences in terms of financial cost and quality of life[1]. It is a commonly encountered impairment that coexists with motor deficits poststroke [2,3]. However, its prevalence in the chronic phase (> 3 months) shows inconsistencies. Studies assessing muscle tone, typically measured with the modified Ashworth Scale 20 (MAS), describe a varied prevalence among stroke survivors, with 21 values from 17% [4] to 79% [5,6] and the most frequently reported 22 prevalence 19% to 43% [3,7-12]. Similarly, according to other 23 clinical measures (Tone Assessment Scale), the prevalence of 24 abnormal tone was 36% to 38% [10,13]. Some studies have 25 indicated that higher rates of spasticity are more likely when 26 patients exhibit paresis [14]. However even then, rates were below 27 45% [14]. To date, the prevalence of increased tone among chronic 28 stroke survivors with moderate/severe motor deficits remains 29 undetermined. 30 The presence of increased muscle tone can have a negative 31 impact on motor control [6,9,10] and motor learning [15] after 32 stroke. Impaired muscle tone is often associated with abnormal 33 posture and abnormal co-activation of agonist and antagonist 34 muscles [16]. Increased tone, especially within zones of spasticity,
Evaluation of upper-limb spasticity after stroke: A clinical and neurophysiologic study
Archives of Physical Medicine and Rehabilitation, 2005
Pizzi A, Carlucci G, Falsini C, Verdesca S, Grippo A. Evaluation of upper-limb spasticity after stroke: a clinical and neurophysiologic study. Arch Phys Med Rehabil 2005;86:410-5. Objectives: To assess upper-limb spasticity after stroke by means of clinical and instrumental tools and to identify possible variables influencing the clinical pattern. Design: Descriptive measurement study of a consecutive sample of patients with upper-limb spasticity after stroke. Setting: Neurorehabilitation hospital. Participants: Sixty-five poststroke hemiplegic patients. Interventions: Not applicable. Main Outcome Measures: Upper-limb spasticity, as assessed clinically (Modified Ashworth Scale [MAS], articular goniometry) and neurophysiologically (maximum H-reflex [Hmax], maximum M response [Mmax], Hmax/Mmax ratio).
Validation of a New Biomechanical Model to Measure Muscle Tone in Spastic Muscles
Neurorehabilitation and Neural Repair, 2011
Background. There is no easy and reliable method to measure spasticity, although it is a common and important symptom after a brain injury. Objective. The aim of this study was to develop and validate a new method to measure spasticity that can be easily used in clinical practice. Methods. A biomechanical model was created to estimate the components of the force resisting passive hand extension, namely ( a) inertia (IC), ( b) elasticity (EC), ( c) viscosity (VC), and ( d) neural components (NC). The model was validated in chronic stroke patients with varying degree of hand spasticity. Electromyography (EMG) was recorded to measure the muscle activity induced by the passive stretch. Results. The model was validated in 3 ways: ( a) NC was reduced after an ischemic nerve block, ( b) NC correlated with the integrated EMG across subjects and in the same subject during the ischemic nerve block, and ( c) NC was velocity dependent. In addition, the total resisting force and NC correlated wi...