The effect of body position, leg dominance, and automatic releasing mechanism on quadriceps muscle tone assessed by Pendulum Test in able-bodied persons.

Background and purpose:

Quadriceps femoris muscle spasticity is commonly measured by the Wartenberg pendulum test. It is generally assumed that lower values of the number of swings of the leg and lower relaxation indexes are associated with higher muscle tone and more spasticity. Still, there is incoherence regarding the test’s applications with various body positions and starting mechanisms. This study aims to investigate the influence of body position, leg dominance, and automatic leg-releasing mechanism on muscle tone measured by pendulum test in healthy population whose muscle tone is often compared to the spastic muscle tone of patients with neurologic disorders. 

15 healthy adults (age: 19-32 years, 9 males, 6 females) participated in this study. A Zebris 3D ultrasound-based motion analysis system was used to record kinematic data during the pendulum test. The number of swings of the leg and the relaxation index were computed from the collected data. The pendulum test was completed in eight conditions: in supine and semi-supine positions on the dominant and non-dominant leg separately and with investigator-release and automata-release mechanisms. Paired t-tests and Wilcoxon test with the significance level of .05 were applied in comparison of pairs of the pendulum test condition.

1) Applying automata-release mode, in the non-dominant leg the number of swings (p=0.03) and the relaxation index (p<0.001) were significantly higher in semi-supine than in supine position. 2) The non-dominant leg had significantly more swings than the dominant leg in both body positions with automata-release mode (p=0.009, p<0.001). In investigator-release mode this occurred in supine position (p<0.001). 3). Regarding the number of swings in investigator-release versus automata-release mode, no significant differences were found in any test condition, but the relaxation index showed significant difference for the non-dominant leg (p=0.01, p=0.009). 4) The values of the relaxation index didn’t support in all test conditions the results what the number of swings provided about the muscle tone. In automata-release mode, the dominant leg has a lower number of swings and a higher relaxation index than the non-dominant leg.

The effect of body position on the quadriceps muscle tone can be assessed by applying the pendulum test with an automatic leg-releasing mechanism even when the application of conventional investigator-release mode does not show a significant effect. The pendulum test is more sensitive to assess spasticity with automatic-release than with investigator-release mode. 

Effects of unilateral and bilateral lower extremity fatigue on static stance and postural adjustments response to the externally initiated perturbation.

The study investigated the effects of unilateral and bilateral lower extremity fatigue on both postural stability and postural adjustments. Fourteen young male subjects performed unilateral and bilateral dynamic lower extremity pedaling exercises with 5 sets of 20 times at 50 % maximum voluntary contraction. Center of pressure (COP) signals were recorded before and after the fatigue exercise. Electromyography activities of six trunk and leg muscles were recorded and analyzed during the anticipatory (APAs) and compensatory (CPAs) postural adjustments. The results showed that both fatiguing exercises caused an increase in COP and larger APAs and CPAs in the rectus femoris and tibialis anterior during externally initiated perturbation. However, the observed indicators showed no clear difference between unilateral and bilateral fatigue. These results validated that when enlarged APAs were not sufficient to resist the external perturbation, the central nervous system increased the strength of CPAs to maintain the stability of the body. These findings provided a perspective on the association between APAs and CPAs, which may apply to the athletic training or rehabilitation on postural control.

A portable system to measure knee extensor spasticity after spinal cord injury.

BACKGROUND: The pendulum test is a quantitative method used to assess knee extensor spasticity in humans with spinal cord injury (SCI). Yet, the clinical implementation of this method remains limited. The goal of our study was to develop an objective and portable system to assess knee extensor spasticity during the pendulum test using inertial measurement units (IMU). METHODS: Spasticity was quantified by measuring the first swing angle (FSA) using a 3-dimensional optical tracking system (with external markers over the iliotibial band, lateral knee epicondyle, and lateral malleolus) and two wireless IMUs (positioned over the iliotibial band and mid-part of the lower leg) as well as a clinical exam (Modified Ashworth Scale, MAS). RESULTS: Measurements were taken on separate days to assess test-retest reliability and device agreement in humans with and without SCI. We found no differences between FSA values obtained with the optical tracking system and the IMU-based system in control subjects and individuals with SCI. FSA values from the IMU-based system showed excellent agreement with the optical tracking system in individuals with SCI (ICC > 0.98) and good agreement in controls (ICC > 0.82), excellent test-retest reliability across days in SCI (ICC = 0.93) and good in controls (ICC = 0.87). Notably, FSA values measured by both systems showed a strong association with MAS scores ( ρ  ~ -0.8) being decreased in individuals with SCI with higher MAS scores, reflecting the presence of spasticity. CONCLUSIONS: These findings suggest that our new portable IMU-based system provides a robust and flexible alternative to a camera-based optical tracking system to quantify knee extensor spasticity following SCI.

Leg Cycling Leads to Improvement of Spasticity by Enhancement of Presynaptic Inhibition in Patients with Cerebral Palsy.

OBJECTIVE: The purpose of this study was to investigate if leg cycling could reduce lower extremity spasticity in patients with cerebral palsy (CP). In addition, we investigated whether the intervention could cause changes in the modulation of presynaptic inhibition. METHODS: This study was a quasi-experimental study, with pretest-posttest for 1 group. Participants in this experiment were eight adult patients with CP with lower extremity spasticity. Spasticity parameters assessed were the amplitude of soleus maximum Hoffmann's reflex (Hmax) and maximum angular velocity (MAV) of knee flexion measured using the pendulum test. D1 inhibition, which seems to be related to the presynaptic inhibition, was recorded by measuring soleus Hoffmann's reflex (H-reflex) with conditioned electric stimuli to the common peroneal nerve. RESULTS: D1 inhibition was significantly enhanced immediately by the cycling intervention. The amplitude of the soleus Hmax was significantly depressed, and there was significant difference in Hmax/maximum M-wave. The MAV was increased due to inhibition of the stretch reflex. CONCLUSION: Leg cycling suppressed stretch reflex and H-reflex, and caused plasticity of inhibitory circuits in patients with CP with lower extremity spasticity. These findings strongly suggest that lower extremity spasticity can be improved by cycling movements.

Assessment of Passive Upper Limb Stiffness and Its Function in Post-Stroke Individuals Wearing an Inertial Sensor during the Pendulum Test.

This article proposes the evaluation of the passive movement of the affected elbow during the pendulum test in people with stroke and its correlation with the main clinical scales (Modified Ashworth Scale, Motor Activity Log, and Fulg Meyer). An inertial sensor was attached to the forearm of seven subjects, who then passively flexed and extended the elbow. Joint angles and variables that indicate viscoelastic properties, stiffness (K), damping (B), E1 amp, F1 amp, and relaxation indices were collected. The results show that the FM scale is significantly correlated with the natural frequency (p = 0.024). The MAL amount-of-use score correlates with the natural frequency (p = 0.024). The variables E1 amp, F1 amp, RI, and ERI are not correlated with the clinical scales, but they correlate with each other; the variable E1 amp correlates with F1 amp (p = 0.024) and RI (p = 0.024), while F1 amp correlates with ERI (p = 0.024). There was also a correlation between the natural frequency and K (r = 0.96, p = 0.003). Non-linear results were found for the properties of the elbow joint during the pendulum test, which may be due to the presence of neural and non-neural factors. These results may serve as a reference for future studies if alternative scales do not provide an accurate reflection.

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.

Efficacy of Transcutaneous Spinal Stimulation versus Whole Body Vibration for Spasticity Reduction in Persons with Spinal Cord Injury.

Transcutaneous spinal stimulation (TSS) and whole-body vibration (WBV) each have a robust ability to activate spinal afferents. Both forms of stimulation have been shown to influence spasticity in persons with spinal cord injury (SCI), and may be viable non-pharmacological approaches to spasticity management. In thirty-two individuals with motor-incomplete SCI, we used a randomized crossover design to compare single-session effects of TSS versus WBV on quadriceps spasticity, as measured by the pendulum test. TSS (50 Hz, 400 µs, 15 min) was delivered in supine through a cathode placed over the thoracic spine (T11-T12) and an anode over the abdomen. WBV (50 Hz; eight 45-s bouts) was delivered with the participants standing on a vibration platform. Pendulum test first swing excursion (FSE) was measured at baseline, immediately post-intervention, and 15 and 45 min post-intervention. In the whole-group analysis, there were no between- or within-group differences of TSS and WBV in the change from baseline FSE to any post-intervention timepoints. Significant correlations between baseline FSE and change in FSE were associated with TSS at all timepoints. In the subgroup analysis, participants with more pronounced spasticity showed significant decreases in spasticity immediately post-TSS and 45 min post-TSS. TSS and WBV are feasible physical therapeutic interventions for the reduction of spasticity, with persistent effects.

Effects of Functional Electrical Stimulation Cycling of Different Duration on Viscoelastic and Electromyographic Properties of the Knee in Patients with Spinal Cord Injury.

The benefits of functional electrical stimulation during cycling (FES-cycling) have been ascertained following spinal cord injury. The instrumented pendulum test was applied to chronic paraplegic patients to investigate the effects of FES-cycling of different duration (20-min vs. 40-min) on biomechanical and electromyographic characterization of knee mobility. Seven adults with post-traumatic paraplegia attended two FES-cycling sessions, a 20-min and a 40-min one, in a random order. Knee angular excursion, stiffness and viscosity were measured using the pendulum test before and after each session. Surface electromyographic activity was recorded from the rectus femoris (RF) and biceps femoris (BF) muscles. FES-cycling led to reduced excursion (p < 0.001) and increased stiffness (p = 0.005) of the knee, which was more evident after the 20-min than 40-min session. Noteworthy, biomechanical changes were associated with an increase of muscle activity and changes in latency of muscle activity only for 20-min, with anticipated response times for RF (p < 0.001) and delayed responses for BF (p = 0.033). These results indicate that significant functional changes in knee mobility can be achieved by FES-cycling for 20 min, as evaluated by the pendulum test in patients with chronic paraplegia. The observed muscle behaviour suggests modulatory effects of exercise on spinal network aimed to partially restore automatic neuronal processes.

Objective assessment of spasticity by pendulum test: a systematic review on methods of implementation and outcome measures.

BACKGROUND: Instrumented pendulum test is an objective and repeatable biomechanical method of assessment for spasticity. However, multitude of sensor technologies and plenty of suggested outcome measures, confuse those interested in implementing this method in practice. Lack of a standard agreement on the definition of experimental setup and outcome measures adds to this ambiguity and causes the results of one study not to be directly attainable by a group that uses a different setup. In this systematic review of studies, we aim to reduce the confusion by providing pros and cons of the available choices, and also by standardizing the definitions. METHODS: A literature search was conducted for the period of 1950 to the end of 2019 on PubMed, Science Direct, Google Scholar and IEEE explore; with keywords of "pendulum test" and "Spasticity". RESULTS: Twenty-eight studies with instrumented pendulum test for assessment of spasticity met the inclusion criteria. All the suggested methods of implementation were compared and advantages and disadvantages were provided for each sensor technology. An exhaustive list categorized outcome measures in three groups of angle-based, angular velocity-based, and angular acceleration-based measures with all different names and definitions. CONCLUSIONS: With the aim of providing standardized methodology with replicable and comparable results, sources of dissimilarity and ambiguity among research strategies were found and explained with the help of graphical representation of pendulum movement stages and corresponding parameters on the angular waveforms. We hope using the provided tables simplify the choices when implementing pendulum test for spasticity evaluation, improve the consistency when reporting the results, and disambiguate inconsistency in the literature.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days.

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.

Comparison of Spasticity in Spinal Cord Injury and Stroke Patients Using Reflex Period in Pendulum Test.

Spasticity is a motor impairment present in patients with both stroke and spinal cord injury. In this research, the results from the Wartenberg pendulum test, performed on stroke and spinal cord injury patients using goniometers and electromyogram recordings of the quadriceps, were reviewed and a new parameter to quantify spasticity was extracted. The Reflex Period (RP) of the pendulum test was defined as the time span from 50% of the maximum velocity of the leg swing to the activation of muscle contraction in the quadriceps, determined from the EMG. The results suggest that the reflex period in stroke patients is generally shorter than in those suffering from spinal cord injury.

Comparison of Single-Session Dose Response Effects of Whole Body Vibration on Spasticity and Walking Speed in Persons with Spinal Cord Injury.

Spasticity affects approximately 65% of persons with spinal cord injury (SCI) and negatively impacts function and quality of life. Whole body vibration (WBV) appears to reduce spasticity and improve walking function; however, the optimal dose (frequency/duration) is not known. We compared single-session effects of four different WBV frequency/duration dose conditions on spasticity and walking speed, in preparation for a planned multi-session study. Thirty-five participants with motor-incomplete SCI received four different doses of WBV: high frequency (50 Hz)/short duration (180 s), high frequency/long duration (360 s), low frequency (30 Hz)/short duration, and low frequency/long duration, plus a control intervention consisting of sham electrical stimulation. In all conditions, participants stood on the WBV platform for 45-s bouts with 1 min rest between bouts until the requisite duration was achieved. The frequency/duration dose order was randomized across participants; sessions were separated by at least 1 week. Quadriceps spasticity was measured using the pendulum test at four time points during each session: before, immediately after, 15 min after, and 45 min after WBV. Walking speed was quantified using the 10-m walk test at three time points during each session: baseline, immediately after, and 45 min after WBV. In the full group analysis, no frequency/duration combination was significantly different from the sham-control condition. In participants with more severe spasticity, a greater reduction in stretch reflex excitability was associated with the high frequency/long duration WBV condition. The sham-control condition was associated with effects, indicating that the activity of repeated sitting and standing may have a beneficial influence on spasticity. TRIAL REGISTRATION: NCT02340910 (assigned 01/19/2015).

Predictive value of the pendulum test for assessing knee extensor spasticity.

BACKGROUND: The pendulum test is commonly used to quantify knee extensor spasticity, but it is currently unknown to what extent common pendulum test metrics can detect spasticity in patients with neurological injury or disease, and if the presence of flexor spasticity influences the test outcomes. METHODS: A retrospective analysis was conducted on 131 knees, from 93 patients, across four different patient cohorts. Clinical data included Modified Ashworth Scale (MAS) scores for knee extensors and flexors, and years since diagnosis. BioTone™ measures included extensor strength, passive and active range of motion, and pendulum tests of most affected or both knees. Pendulum test metrics included the relaxation index (RI), 1st flexion amplitude (F1amp) and plateau angle (Plat), where RI=F1amp/Plat. Two-way ANOVA tests were used to determine if pendulum test metrics were influenced by the degree of knee flexor spasticity graded by the MAS, and ANCOVA was used to test for confounding effects of age, years since injury, strength and range of motion (ROM). In order to identify the best pendulum test metrics, Receiver Operator Characteristic analysis and logistic regression (LR) analysis were used to classify knees by spasticity status (none or any) and severity (low/moderate or high/severe). RESULTS: Pendulum test metrics for knee extensors were not influenced by degree of flexor spasticity, age, years since injury, strength or ROM of the limb. RI, F1amp and Plat were > 70% accurate in classifying knees by presence of clinical spasticity (from the MAS), but were less accurate (< 70%) for grading spasticity level. The best classification accuracy was obtained using F1amp and Plat independently in the model rather than using RI alone. CONCLUSIONS: We conclude that the pendulum test has good predictive value for detecting the presence of extensor spasticity, independent of the existence of flexor spasticity. However, the ability to grade spasticity level as measured by MAS using the RI and/or F1amp may be limited. Further study is warranted to explore if the pendulum test is suitable for quantifying more severe spasticity.

Flexor and extensor muscle tone evaluated using the quantitative pendulum test in stroke and parkinsonian patients.

The aim of this study was to evaluate the flexor and extensor muscle tone of the upper limbs in patients with spasticity or rigidity and to investigate the difference in hypertonia between spasticity and rigidity. The two experimental groups consisted of stroke patients and parkinsonian patients. The control group consisted of age and sex-matched normal subjects. Quantitative upper limb pendulum tests starting from both flexed and extended joint positions were conducted. System identification with a simple linear model was performed and model parameters were derived. The differences between the three groups and two starting positions were investigated by these model parameters and tested by two-way analysis of variance. In total, 57 subjects were recruited, including 22 controls, 14 stroke patients and 21 parkinsonian patients. While stiffness coefficient showed no difference among groups, the number of swings, relaxation index and damping coefficient showed changes suggesting significant hypertonia in the two patient groups. There was no difference between these two patient groups. The test starting from the extended position constantly manifested higher muscle tone in all three groups. In conclusion, the hypertonia of parkinsonian and stroke patients could not be differentiated by the modified pendulum test; the elbow extensors showed a higher muscle tone in both control and patient groups; and hypertonia of both parkinsonian and stroke patients is velocity dependent.

Novel application of a Wii remote to measure spasticity with the pendulum test: Proof of concept.

BACKGROUND: The pendulum test is a standard clinical test for quantifying the severity of spasticity. In the test, an electrogoniometer is typically used to measure the knee angular motion. The device is costly and difficult to set up such that the pendulum test is normally time consuming. OBJECTIVE: The goal of this study is to determine whether a Nintendo Wii remote can replace the electrogroniometer for reliable assessment of the angular motion of the knee in the pendulum test. METHODS: The pendulum test was performed in three control participants and 13 hemiplegic stroke patients using both a Wii remote and an electrogoniometer. The correlation coefficient and the Bland-Altman difference plot were used to compare the results obtained from the two devices. The Wilcoxon signed-rank test was used to compare the difference between hemiplegia-affected and nonaffected sides in the hemiplegic stroke patients. RESULTS: There was a fair to strong correlation between measurements from the Wii remote and the electrogoniometer (0.513

Posture Influence on the Pendulum Test of Spasticity in Patients with Spinal Cord Injury.

The study aims to investigate the influence of different postures on spasticity results by pendulum test in patients with spinal cord injury (SCI). The setting was at the University of Campinas (UNICAMP), Campinas, SP, Brazil. Five individuals with SCI and five individuals in the control group were included. All individuals went through the pendulum test in three different positions: supine, semi-supine at an angle of 30°, and sitting up at an angle of 60°. An electrogoniometer was attached to the right leg for measurement of knee joint angles. All situations were performed five times. Blood pressure was monitored during tests. Relaxation index (RI), normalized relaxation index (RIn), test duration in seconds, initial flexion angle, and resting angle were analyzed at three different positions. Results were compared between different positions, and statistically no differences were found. In individuals with SCI, RI (1.83 ± 0.2), RIn (1.14 ± 0.13), and test duration values (13.95 ± 4.14), in sitting up position, were similar to the control group results. In sitting up position, patients showed spasticity reduction. However, the other two postures produce pain and increase blood pressure in patients with tetraplegia. Therefore, these postures should be avoided in patients with lesions above T6, due to possible autonomic dysreflexia symptoms.

Assessment of passive knee stiffness and viscosity in individuals with spinal cord injury using pendulum test.

OBJECTIVE: Stiffness and viscosity represent passive resistances to joint motion related with the structural properties of the joint tissue and of the musculotendinous complex. Both parameters can be affected in patients with spinal cord injury (SCI). The purpose of this study was to measure passive knee stiffness and viscosity in patients with SCI with paraplegia and healthy subjects using Wartenberg pendulum test. DESIGN: Non-experimental, cross-sectional, case-control design. SETTING: An outpatient physical therapy clinic, University of social welfare and Rehabilitation Science, Iran. PATIENTS: A sample of convenience sample of 30 subjects participated in the study. Subjects were categorized into two groups: individuals with paraplegic SCI (n = 15, age: 34.60 ± 9.18 years) and 15 able-bodied individuals as control group (n = 15, age: 30.66 ± 11.13 years). INTERVENTIONS: Not applicable. MAIN MEASURES: Passive pendulum test of Wartenberg was used to measure passive viscous-elastic parameters of the knee (stiffness, viscosity) in all subjects. RESULTS: Statistical analysis (independent t-test) revealed significant difference in the joint stiffness between healthy subjects and those with paraplegic SCI (P = 0.01). However, no significant difference was found in the viscosity between two groups (P = 0.17). Except for first peak flexion angle, all other displacement kinematic parameters exhibited no statistically significant difference between normal subjects and subjects with SCI. CONCLUSIONS: Patients with SCI have significantly greater joint stiffness compared to able-bodied subjects.

Cardiac autonomic status is associated with spasticity in post-stroke patients.

BACKGROUND: Whether post-stroke spasticity is associated with autonomic status is unclear. The purpose of our study was to determine whether spasticity in post-stroke patients is associated with heart rate variability (HRV), an indicator of sympathetic and parasympathetic regulation. OBJECTIVE: To determine whether HRV is associated with spasticity in post-stroke patients. METHODS: Our cross-sectional observational study included 21 post-stroke patients with varying degrees of knee spasticity. We measured patients' heart rate variability (HRV) during the morning and afternoon of the same day using the modified Ashworth assessment and the pendulum test. The relationship between HRV and the spasticity parameters was evaluated based on the Pearson correlation coefficient (r). RESULTS: The data for the morning measurements showed that the relaxation index negatively correlated with the high frequency (HF) power of HRV (r = -0.47, P < 0.05), and positively correlated with the low frequency (LF) power of HRV (r = 0.47, P < 0.05) and the LF/HF power ratio (r = 0.55, P < 0.05). Similar correlations were observed between the diurnal differences of HRV and the relaxation index. No correlation was observed among the data for the afternoon measurements. CONCLUSIONS: Higher parasympathetic tone and lower sympathetic tone are associated with a higher degree of knee spasticity in post-stroke patients. Further studies are warranted to confirm our findings and investigate the pathological mechanisms involved.

Clinical usefulness of the pendulum test using a NK table to measure the spasticity of patients with brain lesions.

. [Purpose] The purpose of the present study was to investigate the clinical usefulness (reliability and validity) of the pendulum test using a Noland-Kuckhoff (NK) table with an attached electrogoniometer to measure the spasticity of patients with brain lesions. [Subjects] The subjects were 31 patients with stroke or traumatic brain injury. [Methods] The intraclass correlation coefficient (ICC) was used to verify the test-retest reliability of spasticity measures obtained using the pendulum test. Pearson's product correlation coefficient was used to examine the validity of the pendulum test using the amplitude of the patellar tendon reflex (PTR) test, an objective and quantitative measure of spasticity. [Results] The test-retest reliability was high, reflecting a significant correlation between the test and the retest (ICCs = 0.95-0.97). A significant negative correlation was found between the amplitude of the PTR test and the four variables measured in the pendulum test (r = -0.77- -0.85). [Conclusion] The pendulum test using a NK table is an objective measure of spasticity and can be used in the clinical setting in place of more expensive and complicated equipment. Further studies are needed to investigate the therapeutic effect of this method on spasticity.

The Quantitative Measurement of Spasticity Using Change of Muscle Length during Pendulum Test

OBJECTIVE: The aim of this study was to develop objective evaluation method of spasticity which reflects the characteristics of lengthening velocity-dependent stretch reflex of spasticity. METHOD: Kinematic analysis for knee angle and rectus femoris muscle lengthening parameters, and dynamic EMG were performed simultaneously during pendular movement of spastic lower leg for thirty two patients with spasticity and ten normal control subjects. Angular parameters consist of angular relaxation index (ARI), maximal angular velocity (MAV), angular threshold (AT) and angular velocity threshold (AVT). And lengthening parameters consist of lengthening relaxation index (LRI), maximal lengthening velocity (MLV), lengthening threshold (LT) and lengthening velocity threshold (LVT). RESULTS: 1) ARI, MAV, AT, and AVT according to Modified Ashworth scale (MAS) were 1.32+/-0.11, 303.84+/-45.11 deg/sec, 44.19+/-13.81 deg, 262.15+/-33.54 deg/sec in MAS I, 1.16+/-0.16, 279.92+/-42.94 deg/sec, 30.33+/-6.02 deg, 247.65+/-35.92 deg/sec in MAS II, and 0.95+/-0.14, 241.31+/-19.98 deg/sec, 20.55+/-2.68 deg, 209.11+/-48.11 deg/sec in MAS III (P<0.05). 2) LRI, MLV, LT, and LVT according to MAS were 1.27+/-0.11, 0.58+/-0.07, 1.164+/-0.14, 0.53+/-0.05 in MAS I, 1.12+/-0.09, 0.53+/-0.05, 1.150+/-0.08, 0.42+/-0.04 in MAS II, and 0.99+/-0.10, 0.44+/-0.01, 1.137+/-0.15, 0.36+/-0.02 in MAS III (P<0.05). 3) There were significant correlation between various pendulum test parameters and MAS. CONCLUSION: Muscle lengthening parameters as well as knee angular parameters were sensitive parameters reflecting the degree of spasticity. LVT is the most sensitive parameter among all parameters (p<0.01).