Quantification of elbow muscle tone from an instrumented manual stretch-reflex test (original) (raw)
Related papers
Elbow spasticity during passive stretch-reflex: clinical evaluation using a wearable sensor system
Journal of NeuroEngineering and Rehabilitation, 2013
Background: Spasticity is a prevalent chronic condition among persons with upper motor neuron syndrome that significantly impacts function and can be costly to treat. Clinical assessment is most often performed with passive stretch-reflex tests and graded on a scale, such as the Modified Ashworth Scale (MAS). However, these scales are limited in sensitivity and are highly subjective. This paper shows that a simple wearable sensor system (angle sensor and 2-channel EMG) worn during a stretch-reflex assessment can be used to more objectively quantify spasticity in a clinical setting. Methods: A wearable sensor system consisting of a fibre-optic goniometer and 2-channel electromyography (EMG) was used to capture data during administration of the passive stretch-reflex test for elbow flexor and extensor spasticity. A kinematic model of unrestricted passive joint motion was used to extract metrics from the kinematic and EMG data to represent the intensity of the involuntary reflex. Relationships between the biometric results and clinical measures (MAS, isometric muscle strength and passive range of motion) were explored. Results: Preliminary results based on nine patients with varying degrees of flexor and extensor spasticity showed that kinematic and EMG derived metrics were strongly correlated with one another, were correlated positively (and significantly) with clinical MAS, and negatively correlated (though mostly non-significant) with isometric muscle strength. Conclusions: We conclude that a wearable sensor system used in conjunction with a simple kinematic model can capture clinically relevant features of elbow spasticity during stretch-reflex testing in a clinical environment.
2004
The objective of this study is to develop a portable device for quantifying the velocity-dependent properties of spastic elbow muscles. Based on a motor-driven system, validation tests of the portable system such as accuracy and response of sensors were first examined. Furthermore, simulated modules (inertia, damper and spring) as well as elbow joints (15 control and 15 hemiplegic subjects) were manually stretched under four different frequencies (1/3, 1/2, 1 and 3/2 Hz) through 60 v range of motion. Joint resistance and displacement during sinusoidal stretch were collected for further analysis. Two quantitative parameters (i.e., viscous components under each frequency and averaged viscosity across four frequencies) were derived to estimate the velocitydependent properties of elbow joint. Tests of simulated modules confirm the manual stretch protocol and data analysis are valid in estimating the velocity-dependent component during a sinusoidal stretch. Compared to normal control, viscous component in each stretch frequency and averaged viscosity were significantly higher in subjects with spasticity (P < 0:001). The viscous component and averaged viscosity were found highly correlated with the modified Ashworth scale. These findings suggest that measurements of viscous component and averaged viscosity during manual sinusoidal stretching using the portable device could be clinically useful in evaluating spasticity. #
2020
Muscular spasticity represents one of the most common motor disorder associated to lesions of the Central Nervous System, such as Stroke, and affects joint mobility up to the complete prevention of skeletal muscle voluntary control. Its clinical evaluation is hence of fundamental relevance for an effective rehabilitation of the affected subjects. Standard assessment protocols are usually manually performed by humans, and hence their reliability strongly depends on the capabilities of the clinical operator performing the procedures. To overcome this limitation, one solution is the usage of mechatronic devices based on the estimation of the Tonic Stretch Reflex Threshold, which allows for a quite reliable and operator-independent evaluation. In this work, we present the design and characterization of a novel mechatronic device that targets the estimation of the Tonic Stretch Reflex Threshold at the elbow level, and, at the same time, it can potentially act as a rehabilitative system. Our device can deliver controllable torque/velocity stimulation and record functional parameters of the musculo-skeletal system (joint position, torque, and multi-channel ElectroMyoGraphyc patterns), with the ultimate goals of: i) providing significant information for the diagnosis and the classification of muscular spasticity, ii) enhancing the recovery evaluation of patients undergoing through therapeutic rehabilitation procedures and iii) enabling a future active usage of this device also as therapeutic tool. Clinical relevance-The contribution presented in this work proposes a technological advancement for a device-based evaluation of motion impairment related to spasticity, with a major potential impact on both the clinical appraisal and the rehabilitation procedures.
Journal of Rehabilitation Medicine
Objective: To assess test-retest reliability and validity of a new diagnostic device, the Shoulder Elbow Perturbator, to quantify muscle weakness, abnormal synergy, (muscle activity-related) spasticity, and changes in viscoelastic joint properties of the elbow.Subjects: Stroke patients, adults with cerebral palsy and healthy controls.Methods: Test-retest reliability was evaluated using intra-class correlations (ICC) and assessment of measurement error. The device’s validity was evaluated by demonstrating differences between patients and healthy controls, and correlations of spasticity and abnormal synergy outcomes using the clinical Modified Tardieu Scale, the Fugl-Meyer Assessment, and the Test of Arm Selective Control.Results: Reliability was excellent, with an ICC > 0.75 for synergy and ICCs > 0.90 for all other impairments, with relatively small measurement errors. Validity was confirmed by group differences between patients and healthy controls for muscle weakness, spasti...
Neurorehabilitation
The aim of this study was to investigate the intra-rater reliability of the Modified Modified Ashworth Scale (MMAS) in the upper limb of patients with hemiparesis and to determine the effect of pain and contracture presence on the reliability of the MMAS. For this test-retest study 30 patients with hemiparesis were included. One physiotherapist using the MMAS, randomly rated the spasticity of shoulder adductors, elbow flexors, and wrist flexors in the affected upper limb of each patient with hemiparesis twice with at least a 1 week interval between testing sessions. The presence of pain and contracture during passive stretch was recorded. The magnitude of the contracture was measured by a goniometer. The quadratic weighted kappa statistics was very good for the upper limb spasticity (κw= 0.84). Intra-rater reliability was good for shoulder adductors (κw=0.75), and very good for elbow flexors and wrist flexors (κw 0.86 and 0.90, respectively). There were no differences between the we...
Spasticity measurement based on tonic stretch reflex threshold in stroke using a portable device
Clinical Neurophysiology, 2008
Objectives: We investigated intra-and inter-evaluator reliability to quantify spasticity based on the tonic stretch reflex threshold (TSRT) and the correlation between TSRT and resistance to stretch. Methods: Spasticity was evaluated in 20 subjects with chronic stroke-related spasticity using a portable device and the Modified Ashworth Scale (MAS). Evaluations were done on 2 days, by three evaluators. Biceps brachii EMG signals and elbow displacement were recorded during 20 elbow stretches applied at different velocities for each evaluation. Velocity-dependent dynamic stretch reflex thresholds (angle where EMG signal increased in the biceps for a given velocity of stretch) were recorded. These values were used to compute TSRT (excitability of motoneurons at 0°/s). Spasticity was also measured with MAS. Results: Reliability was moderately good for subjects with moderate to high spasticity (intra-evaluator: 0.46-0.68, and inter-evaluator: 0.53-0.68). The TSRT measure of spasticity did not correlate with resistance to stretch (MAS). Conclusions: TSRT may be a more representative measure for subjects with moderate to high spasticity. Further improvements are suggested for the portable device in order to quantify all the levels of spasticity. Significance: TSRT may be an alternative clinical measure to current clinical scales.
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.
Journal of neuroengineering and rehabilitation, 2014
The current methods of assessing motor function rely primarily on the clinician's judgment of the patient's physical examination and the patient's self-administered surveys. Recently, computerized handgrip tools have been designed as an objective method to quantify upper-extremity motor function. This pilot study explores the use of the MediSens handgrip as a potential clinical tool for objectively assessing the motor function of the hand. Eleven patients with cervical spondylotic myelopathy (CSM) were followed for three months. Eighteen age-matched healthy participants were followed for two months. The neuromotor function and the patient-perceived motor function of these patients were assessed with the MediSens device and the Oswestry Disability Index respectively. The MediSens device utilized a target tracking test to investigate the neuromotor capacity of the participants. The mean absolute error (MAE) between the target curve and the curve tracing achieved by the par...
Quantifying muscle tone in spinal cord injury patients using isokinetic dynamometric techniques
Spinal Cord, 1996
The torque generated during a passive movement of the knee joint was used to quantify muscle tone in normal able-bodied subjects and spastic and flaccid spinal cord injury (SCI) subjects using a computerized isokinetic dynamometer. Maximum peak (Tmax) and the sum of four consecutive peaks (Tsum) were calculated for each velocity (30, 60, 120° Is) and for each phase (flexing or extending) separately and compared statistically using a one-way ANOV A. Statistical significance between groups was found in T max FLEXION (FLX) at 60 and 1200/s. Scheffe's tests revealed that the spastic group was significantly less than both the flaccid and normal groups, although the flaccid and normal groups were not significantly different from each other. The slopes of the linear regression curve of the torque-velocity data were found and compared statistically using a t-test for parallelism. In all parameters, the data increased in a linear fashion with increasing velocity of knee motion. The slope of the regression curve for the spastic group was significantly lower than that of the normal group for T max and was significantly lower than that of the flaccid group for Tsum while the slopes for the flaccid and normal groups were not significantly different. The ability of the entire set of variables to classify subjects into three groups (normal, spastic, and flaccid) was tested using discriminant analysis. By taking into account 7 of the 12 original variables, this multivariate technique correctly classified 100% of the spastic, 90% of the normal, but only 67% of the flaccid subjects. Separation of observations was between spastic and normal subjects was good, except for only one case. This feature could be useful when dealing with assessment of individual responses to therapeutic interventions aimed at modification of spasticity.