A measure of spasticity based on the exponential fit of the knee joint torque estimated from the goniogram during the pendulum test

Pendulum test is a method to quantify the spasticity. We used the goniogram recorded during the pendulum test to estimate the knee joint torque based on the model which considers spastic reflex activity. We fitted the exponential curve Th = ae-bt to the estimated knee joint torque to calculate the parameters a and b. We compared the scaled value log a/b with the modified Ashworth score. We used 8 sets of data collected in a clinical study with six complete paraplegic subjects. The comparison shows that the ratio a/b correlates with the MAS scores; thereby, can be used as a measure of spasticity. The advantage of using the ratio a/b is that this score is not rater dependent and that the scores are real numbers compared the MAS scores; thereby, providing better resolution of the level of spasticity

The assessment of spasticity: Pendulum test based smart phone movie of passive markers

The pendulum test is the method for quantification of the level of spasticity in persons with spinal cord and brain injuries/diseases. The data for the assessment comes from the analysis of lower leg rotation in the sagittal plane while sitting caused by gravity. We built a simple instrument that uses the smart phone and passive markers for studying the pendulum movement of the leg. We compared the results of the new device with the results acquired with the conventional apparatus which uses a knee joint angle encoder and inertial sensors mounted on the upper and lower leg. The differences of parameters estimated from the test between the two systems are in the range of 5%, which is in the same range as the precision of the positioning of the pendulum apparatus on the leg. The new system is simple for the application (donning, doffing, setup time, accuracy, repeatability) and allows a straightforward interpretation to a clinician. © Serbian Journal of Electrical Engineering. 2018

Validation of the pendulum test in the assessment of muscle tone in persons with cerebral palsy

Introduction: Cerebral palsy (CP) is often accompanied by motor limitations, abnormal movements and spasticity. Precise and reproducible assessment of spasticity is essential for the selection and follow up of the therapeutic protocol. In clinics the spasticity is most often characterized with the estimate of resistance to a manual flexion and extension of a particular joint and use of a modified Ashworth scale (MAS). The MAS grading depends on the subjective assessment by the examiner. Aim: The possible alternative is to use the pendulum test (PT) determined parameters for the quantitative assessment of the spasticity. Material and Methods: We used a new instrument from the company 3F - Fit Fabricando Faber comprising inertial measurement units at the shank and thigh, and two EMG recording units to record electromyographic signals from the hamstrings and quadriceps muscles. The study included 48 subjects diagnosed with cerebral palsy. Results: The analysis of results showed that the new measure based on the PT recordings is highly corelated with the muscle tone in CP patients, and automatically distinguishes the type of spasticity (flexion or extension), relaxation rate and spasticity strength. Conclusion: The new measure showed sensitivity of the PT and indicates great potential of using the PT in the protocols for better control of spasticity in CP patients.The conference took place in the Anatomy Institute of Padova Universit

A new method and instrumentation for analyzing spasticity

The assessment of spasticity is an important indicator of the course of the recovery in humans with central nervous system lesion. This recovery may be augmented by optimal ergonomic design of wheelchairs, beds, transferring devices and other devices used in activities of daily life. To quantify the influence of different aids and methods in reduction or increase of spasticity, an objective measure is required. The pendulum test was introduced to induce the stretch of the muscle, thereby, trigger spastic response, and the amplitudes of first sinusoidal movements are used as the measure of spasticity. We present a new model of the lower leg during the pendulum test which includes the nonlinear characteristics of the muscles, and a model of the shank and foot that are customized to the patient. The spastic torque component is calculated based on acquired values of angular acceleration, angular velocity, and angle. We developed a new analysis methodology and tool to describe the level and course of reflexive behavior. We describe the instrumentation for data acquisition. The kinematics is captured by two accelerometers, one gyroscope, and a Hall-effect joint angle encoder. Muscle activities of prime knee flexors and extensors are synchronously recorded. The simulation uses user's particular inertial parameters and data from repeated pendulum movements of the lower leg and outputs the reflexive torque. We developed the user-friendly software in MatLab for the analysis of data recorded with the new instrument. We present the application of the method in representative healthy subject and two spastic SCI patients. The main finding is that this method allows distinction between the flexion and extensions types of spasticity and the level of reflexive behavior

Assessment of Spasticity by a Pendulum Test in SCI Patients Who Exercise FES Cycling or Receive only Conventional Therapy

Increased muscle tone and exaggerated tendon reflexes characterize most of the individuals after a spinal cord injury (SCI). We estimated seven parameters from the pendulum test and used them to compare with the Ashworth modified scale of spasticity grades in three populations (retrospective study) to assess their spasticity. Three ASIA B SCI patients who exercised on a stationary FES bicycle formed group F, six ASIA B SCI patients who received only conventional therapy were in the group C, and six healthy individuals constituted the group H. The parameters from the pendulum test were used to form a single measure, termed the PT score, for each subject. The pendulum test parameters show differences between the F and C groups, but not between the F and H groups, however, statistical significance was limited due to the small study size. Results show a small deviation from the mean for all parameters in the F group and substantial deviations from the mean for the parameters in the C group. PT scores show significant differences between the F and C groups and the C and H groups and no differences between the F and C groups. The correlation between the PT score and Ashworth score was 0.88. © 2017 IEEE.This is the peer-reviewed version of the article: Popovic-Maneski, L., Aleksic, A., Metani, A., Bergeron, V., Cobeljic, R., Popovic, D.B., 2018. Assessment of Spasticity by a Pendulum Test in SCI Patients Who Exercise FES Cycling or Receive only Conventional Therapy. IEEE Transactions on Neural Systems and Rehabilitation Engineering 26, 181–187. [https://doi.org/10.1109/TNSRE.2017.2771466

Development and testing of the method for quantified assessment of spasticity

Spasticitet ili stanje ukrućenosti mišića je motorni poremećaj koji prati bolest ili povredu centralnog nervnog sistema. Pojačan mišićni tonus i povećani tetivni refleksi su jedna od glavnih karakteristika spasticiteta. Spasticitet smanjuje preciznost voljnih pokreta, ograničava opseg pokreta, doprinosi zamoru i značajno smanjuje kvalitet života. Kontrolisani umereni spasticitet je povoljan jer mišići koji se aktiviraju smanjuju verovatnoću sekundarnih posledica paralize. Kao metoda za kvantifikaciju spasticiteta sa analizom kretanja potkolenice u vertikalnoj ravni uveden je pendulum test i set parametara koji se koriste u proceni spasticiteta. U ovoj tezi su istražene mogućnosti smanjenja spasticiteta kod pacijenata posle povrede kičmene moždine i cerebralne paralize. Istraživanje je doprinelo unapređenju instrumentacije i obrade rezultata pri pendulum testu. U tezi su prikazani: 1) novi instrument za snimanje kinematike i sistem za merenje aktivnosti mišića čiji se spasticitet procenjuje, 2) metoda procene spasticiteta na osnovu obrade slike, 3) modeli fizičkog klatna koji uključuju momente generisane pasivnim i aktivnim otporom spastičnih mišića, 4) tri nove mere spasticiteta (pendulum test (PT) skor, Spasticity Score (SPAS) i Smeasure). Osnovni naučni doprinos istraživanja jeste uvođenje novih objektivnih, kvantitativnih mera nezavisnih od subjektivnog osećaja, razumevanje spastičnosti na osnovu pendulum testa, kao i određivanje tipa spasticiteta. Detaljnom analizom rezultata merenja na pacijentima je pokazano da su nove mere spasticiteta (PT skor i SPAS) korelisane sa modifikovanom Ašvort skalom koja se često koristi u literaturi i praksi kao indikator intenziteta spasticiteta. PT skor i SPAS daju detaljniju gradaciju u odnosu na Ašvort skalu koja ima samo šest nivoa.Spasticity or a condition of muscle stiffness is a motor disorder that accompanies a disease or injury to the central nervous system. Increased muscle tone and tendon reflexes are the main characteristics of spasticity. It reduces the precision of voluntary movements, limits the range of motion, contributes to fatigue and reduces the quality of life. Controlled spasticity is beneficial because it reduces the secondary consequences of paralysis. Pendulum test with a set of parameters is introduced as a method for quantifying spasticity by analyzing the movement of the lower leg in the vertical plane. In this thesis, the possibilities of reducing spasticity in patients after spinal cord injury and cerebral palsy were investigated. The research contributed to the improvement of instrumentation and processing of results in the pendulum test. The thesis presents: 1) a new instrument for recording kinematics and a system for measuring muscle activity whose spasticity is assessed, 2) a method of assessing spasticity based on image processing, 3) physical pendulum models that include moments generated by passive and active resistance of spastic muscles, 4 ) three new measures of spasticity (pendulum test (PT) score, Spasticity Score (SPAS) and Smeasure). The main contribution are new mathematically quantified measures of spasticity, that are independent of the subjective feeling. We introduced a methodology how to define the type of spasticity and understand spasticity using pendulum test. New measures of spasticity (PT score and SPAS) are correlated with modified Ashworth scale, which is often used in literature and practice as an indicator of spasticity intensity. The PT score and SPAS give a more detailed gradation compared to the Ashworth scale which has only six levels

Development and testing of the method for quantified assessment of spasticity

Spasticitet ili stanje ukrućenosti mišića je motorni poremećaj koji prati bolest ili povredu centralnog nervnog sistema. Pojačan mišićni tonus i povećani tetivni refleksi su jedna od glavnih karakteristika spasticiteta. Spasticitet smanjuje preciznost voljnih pokreta, ograničava opseg pokreta, doprinosi zamoru i značajno smanjuje kvalitet života. Kontrolisani umereni spasticitet je povoljan jer mišići koji se aktiviraju smanjuju verovatnoću sekundarnih posledica paralize. Kao metoda za kvantifikaciju spasticiteta sa analizom kretanja potkolenice u vertikalnoj ravni uveden je pendulum test i set parametara koji se koriste u proceni spasticiteta. U ovoj tezi su istražene mogućnosti smanjenja spasticiteta kod pacijenata posle povrede kičmene moždine i cerebralne paralize. Istraživanje je doprinelo unapređenju instrumentacije i obrade rezultata pri pendulum testu. U tezi su prikazani: 1) novi instrument za snimanje kinematike i sistem za merenje aktivnosti mišića čiji se spasticitet procenjuje, 2) metoda procene spasticiteta na osnovu obrade slike, 3) modeli fizičkog klatna koji uključuju momente generisane pasivnim i aktivnim otporom spastičnih mišića, 4) tri nove mere spasticiteta (pendulum test (PT) skor, Spasticity Score (SPAS) i Smeasure). Osnovni naučni doprinos istraživanja jeste uvođenje novih objektivnih, kvantitativnih mera nezavisnih od subjektivnog osećaja, razumevanje spastičnosti na osnovu pendulum testa, kao i određivanje tipa spasticiteta. Detaljnom analizom rezultata merenja na pacijentima je pokazano da su nove mere spasticiteta (PT skor i SPAS) korelisane sa modifikovanom Ašvort skalom koja se često koristi u literaturi i praksi kao indikator intenziteta spasticiteta. PT skor i SPAS daju detaljniju gradaciju u odnosu na Ašvort skalu koja ima samo šest nivoa.Spasticity or a condition of muscle stiffness is a motor disorder that accompanies a disease or injury to the central nervous system. Increased muscle tone and tendon reflexes are the main characteristics of spasticity. It reduces the precision of voluntary movements, limits the range of motion, contributes to fatigue and reduces the quality of life. Controlled spasticity is beneficial because it reduces the secondary consequences of paralysis. Pendulum test with a set of parameters is introduced as a method for quantifying spasticity by analyzing the movement of the lower leg in the vertical plane. In this thesis, the possibilities of reducing spasticity in patients after spinal cord injury and cerebral palsy were investigated. The research contributed to the improvement of instrumentation and processing of results in the pendulum test. The thesis presents: 1) a new instrument for recording kinematics and a system for measuring muscle activity whose spasticity is assessed, 2) a method of assessing spasticity based on image processing, 3) physical pendulum models that include moments generated by passive and active resistance of spastic muscles, 4 ) three new measures of spasticity (pendulum test (PT) score, Spasticity Score (SPAS) and Smeasure). The main contribution are new mathematically quantified measures of spasticity, that are independent of the subjective feeling. We introduced a methodology how to define the type of spasticity and understand spasticity using pendulum test. New measures of spasticity (PT score and SPAS) are correlated with modified Ashworth scale, which is often used in literature and practice as an indicator of spasticity intensity. The PT score and SPAS give a more detailed gradation compared to the Ashworth scale which has only six levels

New scale for assessing spasticity based on the pendulum test

Quantified assessment of spasticity is essential for the rehabilitation of persons with paralysis. We introduce the new SPAsticity Scale (SPAS), which we found highly correlated with the Modified Ashworth Score (MAS); yet, with a delicate gradation of spasticity compared to the MAS. The parameters defining the SPAS show the level and the type of spasticity (flexion or extension). The SPAS is based on a complex model of the pendulum type oscillations of the lower leg, which includes the spastic torques. The data to calculate SPAS were collected by a wearable instrument with two inertial measurement units and two EMG recording units in subjects with a complete chronic spinal cord injury

The assessment of spasticity: Pendulum test based smart phone movie of passive markers

The pendulum test is the method for quantification of the level of spasticity in persons with spinal cord and brain injuries/diseases. The data for the assessment comes from the analysis of lower leg rotation in the sagittal plane while sitting caused by gravity. We built a simple instrument that uses the smart phone and passive markers for studying the pendulum movement of the leg. We compared the results of the new device with the results acquired with the conventional apparatus which uses a knee joint angle encoder and inertial sensors mounted on the upper and lower leg. The differences of parameters estimated from the test between the two systems are in the range of 5%, which is in the same range as the precision of the positioning of the pendulum apparatus on the leg. The new system is simple for the application (donning, doffing, setup time, accuracy, repeatability) and allows a straightforward interpretation to a clinician. © Serbian Journal of Electrical Engineering. 2018

The assessment of spasticity: Pendulum test based smart phone movie of passive markers

The pendulum test is the method for quantification of the level of spasticity in persons with spinal cord and brain injuries/diseases. The data for the assessment comes from the analysis of lower leg rotation in the sagittal plane while sitting caused by gravity. We built a simple instrument that uses the smart phone and passive markers for studying the pendulum movement of the leg. We compared the results of the new device with the results acquired with the conventional apparatus which uses a knee joint angle encoder and inertial sensors mounted on the upper and lower leg. The differences of parameters estimated from the test between the two systems are in the range of 5%, which is in the same range as the precision of the positioning of the pendulum apparatus on the leg. The new system is simple for the application (donning, doffing, setup time, accuracy, repeatability) and allows a straightforward interpretation to a clinician. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 35003 and Grant no. III 44008