Quantitative evaluations of ankle spasticity and stiffness in neurological disorders using manual spasticity evaluator.
ABSTRACT Spasticity and contracture are major sources of disability in people with neurological impairments that have been evaluated using various instruments: the Modified Ashworth Scale, tendon reflex scale, pendulum test, mechanical perturbations, and passive joint range of motion (ROM). These measures generally are either convenient to use in clinics but not quantitative or they are quantitative but difficult to use conveniently in clinics. We have developed a manual spasticity evaluator (MSE) to evaluate spasticity/contracture quantitatively and conveniently, with ankle ROM and stiffness measured at a controlled low velocity and joint resistance and Tardieu catch angle measured at several higher velocities. We found that the Tardieu catch angle was linearly related to the velocity, indicating that increased resistance at higher velocities was felt at further stiffer positions and, thus, that the velocity dependence of spasticity may also be position-dependent. This finding indicates the need to control velocity in spasticity evaluation, which is achieved with the MSE. Quantitative measurements of spasticity, stiffness, and ROM can lead to more accurate characterizations of pathological conditions and outcome evaluations of interventions, potentially contributing to better healthcare services for patients with neurological disorders such as cerebral palsy, spinal cord injury, traumatic brain injury, and stroke.
- SourceAvailable from: apta.org[show abstract] [hide abstract]
ABSTRACT: We undertook this investigation to determine the interrater reliability of manual tests of elbow flexor muscle spasticity graded on a modified Ashworth scale. We each independently graded the elbow flexor muscle spasticity of 30 patients with intracranial lesions. We agreed on 86.7% of our ratings. The Kendall's tau correlation between our grades was .847 (p less than .001). Thus, the relationship between the raters' judgments was significant and the reliability was good. Although the results were limited to the elbow flexor muscle group, we believe them to be positive enough to encourage further trials of the modified Ashworth scale for grading spasticity.Physical Therapy 03/1987; 67(2):206-7. · 2.78 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: A portable teleassessment system was designed for remote evaluation of elbow impairments in patients with neurological disorders. A master device and a slave device were used to drive a mannequin arm and the patient's arm, respectively. The elbow flexion angle and torque were measured at both the master and slave devices, and sent to each other for teleoperation. To evaluate spasticity/contracture of the patient's elbow remotely, the clinician asked the patient to relax the elbow, moved the mannequin arm at a selected velocity, and haptically felt the resistance from the patient's elbow. In other tasks, the patient moved his/her elbow voluntarily and the clinician observed the corresponding mannequin arm movement and determined the active range of motion (ROM). The clinician could also remotely resist the patient's movement and evaluate the muscle strength. To minimize the effect of network latency, two different teleoperation schemes were used depending on the speed of the tasks. For slow movement tasks, real-time teleoperations were performed using control architectures that considered causality of the tasks, with performance similar to that during an in-person examination. For tasks involving fast movements, a teach-and-replay teleoperation scheme was used which provided the examiner with transparent and stable haptic feeling. Overall, the teleassessment system allowed the clinician to remotely evaluate the impaired elbow of stroke survivors, including assessment of the passive ROM, active ROM, muscle strength, velocity-dependent spasticity, and catch angle.IEEE transactions on neural systems and rehabilitation engineering: a publication of the IEEE Engineering in Medicine and Biology Society 07/2008; 16(3):245-54. · 2.42 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: This study aimed to explore the limitations of the Ashworth scale for measuring spasticity. An isokinetic dynamometer to quantify resistance to passive stretch and surface EMG was used to verify if a stretch response occurred and, if so, at what joint angle. The authors sought to determine which components of passive resistance (magnitude, rate of change, onset angle of stretch, or velocity dependence) were most related to Ashworth scores and which were related to motor function in cerebral palsy (CP). Twenty-two individuals with spastic CP (11 males, 11 females; mean age 11.9 years, SD 4.3) and a comparison group of nine children without CP (four males, five females; mean age 11.3 years, SD 2.5) participated in the study. The group with CP included those with a diagnosis of spastic diplegia, hemiplegia, or quadriplegia, distributed across Gross Motor Functional Classification Levels. Procedures included: (1) clinical assessment at the knee joint, (2) functional assessments, and (3) isokinetic assessment of passive resistance torque in hamstrings and quadriceps at three velocities. EMG data were recorded simultaneously to identify stretch responses. Detecting stretch responses using the Ashworth scale compared with instrumented measures showed near complete agreement at extremes of the scale, with marked inconsistencies in mid-range values. Ashworth scores were correlated with instrumented measures, particularly for the quadriceps, with higher correlations to the rate of change in resistance (stiffness) and onset angle of stretch than to peak resistance torque. Those with greater resistance tended to have poorer function with isokinetic relations typically stronger.Developmental Medicine & Child Neurology 03/2002; 44(2):112-8. · 2.68 Impact Factor