Wartenberg Pendulum Test Research Articles

Acute Whole-Body Vibration Does Not Alter Passive Muscle Stiffness in Physically Active Males

Whole-body vibration (WBV) is a widely used training method to increase muscle strength and power. However, its working mechanisms are still poorly understood, and studies investigating the effects of WBV on muscle stiffness are scant. Therefore, the aim of this study is to investigate the acute effects of WBV on stiffness and countermovement jump (CMJ). Twenty-four recreationally active males, on separate days and in random order, performed a static squat under two different conditions: with WBV (WBV) or without vibration (CC). Muscle stiffness was assessed through the Wartenberg pendulum test, and CMJ was recorded. RM-ANOVA was employed to test differences between conditions in the above-mentioned variables. In the CC condition, stiffness was significantly lower after the exposure to the static squat (p = 0.006), whereas no difference was observed after the exposure to WBV. WBV and CC did not affect CMJ. No significant correlation was observed between changes in CMJ and changes in stiffness. Our results show that WBV may mitigate the reduction in muscle stiffness observed after static squats. However, current results do not support the notion that WBV exposure may account for an increase in CMJ performance.

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

<p>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&rsquo;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.&nbsp;</p>. <p>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.</p>. <p>1) Applying automata-release mode, in the non-dominant leg the number of swings (p=0.03) and the relaxation index (p&lt;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&lt;0.001). In investigator-release mode this occurred in supine position (p&lt;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&rsquo;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.</p>. <p>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.&nbsp;</p>.

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.

Knee joint kinematics of the pendulum test in children with and without Down syndrome

BackgroundThe Wartenberg pendulum test is a common clinical test that is used to measure stiffness about the knee in persons with and without disabilities such as cerebral palsy and Down syndrome (DS). Adults and adolescents with DS show fewer number of swing cycles and a lower relaxation index than healthy controls. However, it is not clear if children with DS show a similar trend compared to typically developing (TD) children. Research questionWas the knee joint kinematics different between children with and without DS during the pendulum test? MethodsThirteen children with DS and 13 TD children participated in this study. There were two load conditions: no load (NL) and with ankle load (AL) equal to 2 % of the subject’s body weight. Five trials of a pendulum test were collected for each condition. ResultsThe DS group showed a smaller first flexion excursion, a lower relaxation index, lower mean and peak velocities and accelerations during the first and second flexion and extension, and greater variability of acceleration during the first flexion than the TD group across both load conditions. This suggests that the DS group may have greater stiffness of the knee than the TD group to compensate for joint instability. SignificanceThe pendulum test appears to be a valid test to evaluate the passive stiffness of the knee in children with DS. The lower relaxation index in children with DS suggests that larger bursts of quadriceps may be activated during a pendulum test, particularly in the first flexion excursion, to assure the knee joint stability.

Measurement properties of a new wireless electrogoniometer for quantifying spasticity during the pendulum test in ARSACS patients

IntroductionAutosomal recessive spastic ataxia of Charlevoix/Saguenay (ARSACS) is a neuromuscular disorder that induces spasticity in lower limbs. The Wartenberg pendulum test is a classical method of assessing lower limb spasticity based on the dynamics of the pendular leg motion. However, in its original form, this test only provides subjective results and do not allow accurate assessment of spasticity. MethodsThirteen ARSACS patients were assessed using a new wireless electrogoniometer to measure spasticity by quantifying oscillation amplitudes and relaxation indices during the Wartenburg pendulum test. The validity of the instrument was evaluated by comparing its measurements to a known precise goniometer whereas discriminant validity was evaluated by comparing healthy participants and ARSACS patients. Reliability was measured using intraclass correlation (ICC) between pendulum test scores obtained at different moments in time. ResultsData from different tests show that the proposed device is accurate (standard error of measurement of 0.0005°), discriminates healthy and ARSACS patients (most variables have p=0.00) and provides repeatable results (significant ICC usually higher than 0.64 and p<0.05). DiscussionThe proposed tool allows the clinician to analyze pendulum oscillation amplitudes and ratios and thus, provide an index of spasticity for the patients affected by ARSACS. This is important as the original procedure is only evaluated visually and the progression cannot be detected until the condition changes drastically. Thus, the system proposed meets the requirements of being useful, precise and user-friendly in the evaluation of patients in a research as well as a clinical environment.

Modification of spasticity by transcutaneous spinal cord stimulation in individuals with incomplete spinal cord injury

Context/objectiveTo examine the effects of transcutaneous spinal cord stimulation (tSCS) on lower-limb spasticity.DesignInterventional pilot study to produce preliminary data.SettingDepartment of Physical Medicine and Rehabilitation, Wilhelminenspital, Vienna, Austria.ParticipantsThree subjects with chronic motor-incomplete spinal cord injury (SCI) who could walk ≥10 m.InterventionsTwo interconnected stimulating skin electrodes (Ø 5 cm) were placed paraspinally at the T11/T12 vertebral levels, and two rectangular electrodes (8 × 13 cm) on the abdomen for the reference. Biphasic 2 ms-width pulses were delivered at 50 Hz for 30 minutes at intensities producing paraesthesias but no motor responses in the lower limbs.Outcome measuresThe Wartenberg pendulum test and neurological recordings of surface-electromyography (EMG) were used to assess effects on exaggerated reflex excitability. Non-functional co-activation during volitional movement was evaluated. The timed 10-m walk test provided measures of clinical function.ResultsThe index of spasticity derived from the pendulum test changed from 0.8 ± 0.4 pre- to 0.9 ± 0.3 post-stimulation, with an improvement in the subject with the lowest pre-stimulation index. Exaggerated reflex responsiveness was decreased after tSCS across all subjects, with the most profound effect on passive lower-limb movement (pre- to post-tSCS EMG ratio: 0.2 ± 0.1), as was non-functional co-activation during voluntary movement. Gait speed values increased in two subjects by 39%.ConclusionThese preliminary results suggest that tSCS, similar to epidurally delivered stimulation, may be used for spasticity control, without negatively impacting residual motor control in incomplete SCI. Further study in a larger population is warranted.

Lower limb spasticity assessment using an inertial sensor: a reliability study

Spasticity is a common motor impairment in patients with neurological disorders that can prevent functional recovery after rehabilitation. In the clinical setting, its assessment is carried out using standardized clinical scales. The aim of this study was to verify the applicability of inertial sensors for an objective measurement of quadriceps spasticity and evaluate its test–retest and inter-rater reliability during the implementation of the Wartenberg pendulum test. Ten healthy subjects and 11 patients in vegetative state with severe brain damage were enrolled in this study. Subjects were evaluated three times on three consecutive days. The test–retest reliability of measurement was assessed in the first two days. The third day was devoted to inter-rater reliability assessment. In addition, the lower limb muscle tone was bilaterally evaluated at the knee joint by the modified Ashworth scale. The factorial ANOVA analysis showed that the implemented method allowed us to discriminate between healthy and pathological conditions. The fairly low SEM and high ICC values obtained for the pendulum parameters indicated a good test–retest and inter-rater reliability of measurement. This study shows that an inertial sensor can be reliably used to characterize leg kinematics during the Wartenberg pendulum test and provide quantitative evaluation of quadriceps spasticity.

Functional assessments of the knee joint biomechanics by using pendulum test in adults with Down syndrome.

In this study, we assessed kinematics and viscoelastic features of knee joint in adults with Down syndrome (DS) by means of the Wartenberg pendulum test. This test allows the measuring of the kinematics of the knee joint during passive pendular motion of leg under the influence of gravity. In addition, by a combination of kinematic and anthropometric data, pendulum test provides estimates of joint viscoelastic properties by computing damping and stiffness coefficients. To monitor the occurrences of muscle activation, the surface electromyogram (EMG) of muscle rectus femoris was recorded. The experimental protocol was performed in a group of 10 adults with DS compared with 10 control adults without DS. Joint motion amplitude, velocity, and acceleration of the leg during the first knee flexion significantly decreased in persons with DS with respect to those without DS. This behavior was associated with the activation of rectus femoris in subjects with DS that resulted in increasing of joint resistance shortly after the onset of the first leg flexion. The EMG bursts mostly occurred between 50 and 150 ms from the leg flexion onset. During the remaining cycles of pendular motion, persons with DS exhibited passive leg oscillations with low tonic EMG activity and reduced damping coefficient compared with control subjects. These results suggest that adults with DS might perform preprogrammed contractions to increase joint resistance and compensate for inherent joint instability occurring for quick and unpredictable perturbations. The reduction of damping coefficients observed during passive oscillations could be a predictor of muscle hypotonia.

A Randomized, Double-Blinded, Crossover Pilot Study Assessing the Effect of Nabilone on Spasticity in Persons With Spinal Cord Injury

Pooyania S, Ethans K, Szturm T, Casey A, Perry D. A randomized, double-blinded, crossover pilot study assessing the effect of nabilone on spasticity in persons with spinal cord injury. Objectives To determine whether nabilone, a synthetic cannabinoid, alleviates spasticity in people with spinal cord injury (SCI). Design A double-blind, placebo-controlled crossover study. Setting Outpatient rehabilitation clinics. Participants We recruited volunteers (N=12) with SCI and spasticity. One subject, a paraplegic man, dropped out of the study because of an unrelated cause. Eleven subjects completed the study; all subjects were men with an average age of 42.36 years; 6 of them were persons with tetraplegia, and 5 were persons with paraplegia. Interventions The subjects received either nabilone or placebo during the first 4-week period (0.5mg once a day with option to increase to 0.5mg twice a day), and then outcome measures were assessed. After a 2-week washout, subjects were crossed over to the opposite arm. Main Outcome Measures The primary outcome was the Ashworth Scale for spasticity in the most involved muscle group, in either the upper or lower extremities, chosen by the subject and clinician. The secondary outcomes included the sum of the Ashworth Scale in 8 muscle groups of each side of the body measured by the clinician; Spasm Frequency Scale and visual analog scale, reported by the subject; Wartenberg Pendulum Test, in order to quantify severity of spasticity; and the Clinician's and Subject's Global Impression of Change. Results One subject dropped out during the placebo arm because of an unrelated urinary stricture, and 11 subjects completed the study. There was a significant decrease on active treatment for the Ashworth in the most involved muscle (mean difference ± SD, .909±.85; P=.003), as well as the total Ashworth score ( P=.001). There was no significant difference in other measures. Side effects were mild and tolerable. Conclusions Nabilone may be beneficial to reduce spasticity in people with SCI. We recommend a larger trial with a more prolonged treatment period and an option to slowly increase the dosage further.

Neuromuscular and psychological influences on range of motion recovery in anterior cruciate ligament reconstruction patients

To identify distinguishing characteristics for knee surgery patients who experience a protracted recovery process, we sought to determine if there is an association between the neuromuscular stretch reflex and psychological factors of pain perception and anxiety on the range of motion (ROM) recovery rate of post-operative anterior cruciate ligament reconstruction (ACLR) rehabilitation patients. The ACLR participants were categorized into a slow recovery group (SRG: >6 weeks to recover 0–125° knee flexion [ n = 10]) and a normal recovery group (NRG: <6 weeks to recovery 0–125° knee flexion [ n = 12]). Control participants ( n = 22) were age, gender and activity-level matched to the surgical participants. Neuromuscular testing consisted of sagittal plane video kinematics of the Wartenberg Pendulum Test for determining lower limb stiffness indices and electromyography-monitored patellar tendon tap reflex responses. Psychological and health status assessments consisted of the State–Trait Anxiety Inventory and SF-36™ Health Survey. Data revealed that neuromuscular reflex profiles, lower limb stiffness indices, pain, anxiety and SF-36™ indices of function were not significantly different between the two surgical groups (SRG and NRG). The surgical groups exhibited significantly greater pain (2.67 ± 2.27 SRG, 1.49 ± 1.15 NRG) than the control group ( p ⩽ .05). SF-36™ indices were significantly lower for the surgical groups for total score (546.55 ± 94.70 SRG, 577.57 ± 125.58 NRG), function 69.00 ± 20.24 SRG, 67.08 ± 19.12 NRG), role physical (53.75 ± 22.85 SRG, 53.12 ± 23.15 NRG), social (76.24 ± 25.31 SRG, 65.62 ± 27.24 NRG), and emotional (82.49 ± 19.81 SRG, 81.38 ± 23.02 NRG) subscales ( p ⩽ .05). These results suggest that neuromuscular reflex responses, visual analogue scale (VAS) pain, and anxiety are not distinguishing factors for ROM recovery rate between the SRG and NRG. Decreased SF-36™ indices, including pain as it influences function, though clinically relevant factors, were not statistically associated with post-operative ROM recovery rate.

Quantifying repeatability of the Wartenberg pendulum test parameters in children with spasticity

The Wartenberg (pendulum) test is commonly used in a variety of studies involving healthy subjects, patients with CP, stroke patients, and other neurological conditions. There is some evidence that the Wartenberg test may be able to differentiate healthy people from patients with spasticity. The aim of the study was to explore the within-session repeatability of primary outcome measures, i.e. relaxation indices derived from the Wartenberg test when test was performed by single investigator.Patients were lying supine, thigh along the horizontal line. The lower legs were allowed to hang freely over the table edge, and the knee motion in response to leg drop from the horizontal position was measured using motion system VICON with external markers attached to each leg at greater trochanter, lateral knee epicondyle, and lateral malleolus. Data from four consecutive trials were collected at 1min intervals. The set of relaxation indices and maximum velocity was calculated for each trial. Data of 21 children (42 limbs) who underwent the evaluation due to spasticity problem were analysed.The repeated measure ANOVA test, one way analysis of variance, coefficients of correlation and determination were used to determine the repeatability of the relaxation indices, the association between the indices in time, and influence of the spasticity origin on the variability.The results show that relaxation indices, did not differ between the trails in statistically significant way in our group of patients with spasticity, however they exhibited high within-session variability in the individual patients (16–90%). Therefore the variability of the relaxation indices may restrict the clinical usefulness of the indices to monitor the changes of spasticity over time. Further, our findings do not seem to conform to the earlier reports demonstrating a systematic, time-dependent, change in the relaxation indices when repeated measures were taken within a session. In conclusion, this study demonstrates that although the Wartenberg test is repeatable in groups of patients, it does not provide us with repeatable measures in individual patients, thus if it is to be used as a replacement for other clinical tests of spasticity further investigations are needed to explain the substantial variability of the indices.

Spasticity outcome measures in spinal cord injury: psychometric properties and clinical utility

Comprehensive review and systematic analyses. Assess published psychometric evidence for spinal cord injury (SCI) spasticity outcome measures. Considerations about the influence of spasticity on function have also been identified to understand treatment effects and guide service delivery. London, Ontario and Vancouver, British Columbia, Canada. Review of measures was based on availability of psychometric data, application in clinical settings and evaluated in SCI patients. Ashworth and Modified Ashworth Scales (AS, MAS), Penn Spasm Frequency Scale (PSFS), Spinal Cord Assessment Tool for Spasticity (SCATS), Visual Analogue Scale self-rated scale of spasticity (VAS) and the Wartenberg Pendulum Test (WPT) were included in this review. The most frequently used tools for SCI spasticity measurement include the AS, MAS, PSFS and VAS, of which the latter two are self-report spasticity measures. The SCATS has been partially validated for SCI, but is not widely used. The WPT has been minimally validated despite its use in a large-scale SCI spasticity randomized controlled trial. Since spasticity is multidimensional, focusing on one or two spasticity outcome measures can misrepresent the extent and influence of spasticity on SCI patients. Different scales measure different aspects of spasticity and individual tools correlate weakly with each other. Spasticity may be better measured with an appropriate battery of tests, including the AS or MAS, along with PSFS. These tools would benefit from further reliability and responsiveness testing. Tools that assess the influence of spasticity on patient activities, participation and quality of life are important, but lacking.

Acute Effects of Stretching on Muscle Stiffness After a Bout of Exhaustive Eccentric Exercise

With the aim to analyze the influence of stretching on muscle stiffness after eccentric exercise, 30 young men (18 - 32 years old), were divided into three groups: STR, undergoing a stretching program (SP) of the dominant quadriceps muscle, ECC, undergoing exhaustive eccentric exercise, and ECC/STR, undergoing eccentric exercise, followed by SP. Muscle stiffness (MS) was assessed immediately before the respective programs, and 1 and 24 hours after, measuring the following parameters during Wartenberg pendulum test: angle and angular velocity of first knee flexion (FKF) and following oscillating extension, time of oscillating movements and final resting knee angle (FRKA). Despite the slight (2%) but significant increase of FRKA, all further parameters did not change over time in STR. MS in ECC was documented by the reduced range of motion (ROM) and the slower angular velocity. Reduction in FRKA (10%) was still present after 24 hours, while other variables tended to recover eventually. Similar reduction in FKF was observed for ECC/STR, but with significantly less impairment in the range of pendulum movement one hour after the exercise and in tendency still remained less impaired 24 hours after. The results suggest that SP conducted after exhaustive eccentric exercise alleviated reductions in ROM induced by exercise.

Wartenberg Part 3: Relaxation training, centration and skeletal opposition: A conceptual model

Some people are unable to relax even in a resting position. Undoubtedly, this interferes with manual therapy. Presumably, letting go requires a feeling of safety. If so, for those without neuromusculoskeletal pathology, all that may be needed is encouragement. But this must move beyond words; safety and comfort must be experienced somatically. Safety requires stability. In those unable to relax, stability is purchased through persistent and, sometimes, wide-ranging muscular co-activation. Skeletal opposition, a different stabilization strategy, permits more relaxation and is more efficient since it uses only bursts of muscular co-activation. To reach maximal efficiency of movement there must be trust in the safety of unstable equilibrium. Creating suitable conditions for this somatic learning is the subject of this paper. Introduced are two concepts useful in describing movement excellence; each with two sub-divisions. Skeletal opposition is discussed in two forms: centrifugal and centripetal. Secondly, centration strategies, either expansile or load-bearing, are discussed with examples. Described in earlier installments was Wartenberg's pendulum test (Wartenberg, R., 1952. Knee dropping test. This test, designed for diagnosing spasticity, can assess relaxation. Also presented were four other tests: abrupt relaxation test, supine head–ankle oscillation test, isometric tense-relax testing and ballistic perturbation testing, the last three recumbent. Four telltale signs of extraneous muscle effort were outlined, as were four signs of relaxation. Myofascial techniques, at three levels of scale, were illustrated. Torsional oscillation, scalable in application, was introduced as both test and treatment. Speculations regarding oscillation as therapy were presented. These include the simultaneous use of two asymmetric oscillations to reach deeper using reflection and refraction; force collimation using bridge points; standing waves and oscillatory still points. Some people are unable to relax even in a resting position. Undoubtedly, this interferes with manual therapy. Presumably, letting go requires a feeling of safety. If so, for those without neuromusculoskeletal pathology, all that may be needed is encouragement. But this must move beyond words; safety and comfort must be experienced somatically. Safety requires stability. In those unable to relax, stability is purchased through persistent and, sometimes, wide-ranging muscular co-activation. Skeletal opposition, a different stabilization strategy, permits more relaxation and is more efficient since it uses only bursts of muscular co-activation. To reach maximal efficiency of movement there must be trust in the safety of unstable equilibrium. Creating suitable conditions for this somatic learning is the subject of this paper. Introduced are two concepts useful in describing movement excellence; each with two sub-divisions. Skeletal opposition is discussed in two forms: centrifugal and centripetal. Secondly, centration strategies, either expansile or load-bearing, are discussed with examples. Described in earlier installments was Wartenberg's pendulum test (Wartenberg, R., 1952. Knee dropping test. This test, designed for diagnosing spasticity, can assess relaxation. Also presented were four other tests: abrupt relaxation test, supine head–ankle oscillation test, isometric tense-relax testing and ballistic perturbation testing, the last three recumbent. Four telltale signs of extraneous muscle effort were outlined, as were four signs of relaxation. Myofascial techniques, at three levels of scale, were illustrated. Torsional oscillation, scalable in application, was introduced as both test and treatment. Speculations regarding oscillation as therapy were presented. These include the simultaneous use of two asymmetric oscillations to reach deeper using reflection and refraction; force collimation using bridge points; standing waves and oscillatory still points.

Poster 218: Velocity Versus Position Dependent Spasticity: A Case Report

Setting: Tertiary care rehabilitation hospital. Patient: A 50-year-old man with a C6 American Spinal Injury Association grade B spinal cord injury. Case Description: The subject was positioned with both legs hanging over the edge of a therapeutic bed. A MiniBird 6 degree-of-freedom direct-current magnetic motion sensor from Ascension Technology (18×8×8mm) was secured to skin on the leg a consistent distance from the joint line of the knee. The examiner extended the knee and released the foot, allowing the leg to swing through a complete range of motion. This procedure was followed on both legs in sitting and then supine lying. Assessment/Results: The motion sensor was interfaced to a computer that recorded angular 3-dimensional coordinates at a sample rate of 100Hz. The magnitude of angular displacement (in degrees) in sitting was 77.4° and 54.2° on the right and left legs, respectively. In lying, the magnitude of angular displacement was 6.1° (right) and 9.6° (left). The mean velocity (in deg/s) in sitting was recorded to be 407.5°/s (right) and 387.1°/s (left). In lying, the mean velocity was 33.8°/s (right) and 30.09°/s (left). Thus, we recorded over a 10-fold decrease in angular displacement and mean angular velocity in the supine position. Discussion: People with a spinal cord injury often report differences in spasticity in lying versus sitting. The Wartenberg Pendulum Test (WPT) can be used to assess spasticity. These data suggest that positional effects may have a greater impact on spasticity than velocity-dependent effects alone. Possible segmental mechanisms to explain the substantial difference in spasticity between lying and sitting include: increased stretching of 2-joint extensor muscles in supine and/or increased reciprocal 1a inhibition from the hamstrings in sitting. Conclusions: The significance of body position when performing WPT must be standardized.

Wartenberg's pendulum, repose and the ‘gripped’ patella—part 1: quadriceps normotonia

Summary This paper, the first of a three part series, explores the principle of least effort applied to the quadriceps. The next installment describes manual therapy of the anterior thigh, in particular, the freeing of benign patello-femoral tension. The concluding installment describes a movement therapy approach aiding the patient in awareness and in the exercise of choice in levels of exertion. Quadriceps contraction is necessary in many activities of daily living, but only in bursts. The need for sustained effort is rare. In fact, quadriceps activity is extraneous in most stationary recumbent, standing and sitting positions. Despite the current belief that it is prudent to conserve resources, uninterrupted yet subtle quadriceps contraction is commonplace. Such effort is easy to learn but difficult to correct. This pattern may be demonstrated using the Wartenberg pendulum test. The test may also be used as a self-awareness procedure for re-training relaxation. For the clinician, valuable information may be gained by observing foot trajectory, shin carriage, extraneous exertion and quality of motion. Inquiry after these features may sharpen diagnosis and improve treatment.

Outcome measures of spasticity.

Spasticity is characterized by a velocity-dependent increase in muscle resistance, in response to a passive stretch. Whilst clinical scales probably represent the most common approach to its measurement, these are limited by poor reliability and difficulties with some definitions. However, recently, a simple system has been used to provide the clinician with a measure of the force applied during the Ashworth Test. The Wartenberg Pendulum Test has been devised for measuring spasticity at the knee, but has been shown to be unsuitable for measuring more severe spasticity. Powered systems have been used in research studies, but are rarely considered suitable for routine clinical use. However, one method of interest, using a low inertia torque motor to measuring stiffness at the wrist, has been shown to provide rapid measurements which correspond to the degree of spasticity defined by other scales. Clinical gait analysis may have an important role to play in assessing spasticity - since there are clear associations between lower limb spasticity and gait problems - but it does not provide a true measure of the condition. In summary, while scales remain the most common method of measuring spasticity, there is considerable potential in instrumented techniques that can provide greater reliability and precision of measurement.

Wartenberg pendulum test: objective quantification of muscle tone in children with spastic diplegia undergoing selective dorsal rhizotomy

The aim of this study was to investigate the reliability and sensitivity of the Wartenberg pendulum test for quantification of muscle tone in young children with spastic diplegia undergoing selective dorsal rhizotomy (SDR). Fourteen non‐disabled children (mean age of 5.5 years, age range 2.3 to 8.8 years, one female and one male in each year) were tested twice. Twenty children with spastic diplegia (12 males, eight females; mean age of 4.3 years, age range 2.5 to 6.3 years) consecutively selected for SDR, were assessed before and 6 months after SDR. Parameters of the pendulum test: R2, R1, maximal velocity, and swing time were correlated with clinical assessments for spasticity (modified Ash worth scale, quadriceps reflex) and measurements of gross motor function: the Gross Motor Function Classification System and the Gross Motor Function Measure. The Wartenberg pendulum test was found to be an objective and sensitive method for quantifying spasticity in knee extensor muscles in children as young as 2.5 years old. The method was responsive to changes after SDR. The only correlation with clinical measurements of spasticity was between the R2 ratio and the quadriceps reflex. Swing time was the most reliable and sensitive variable; it showed a weak correlation with measurements for gross motor function.

The Effect of Common Peroneal Nerve Stimulation on Quadriceps Spasticity in Hemiplegia

Summary Contemporary physiotherapy for neurologically impaired patients puts emphasis on the management of spasticity. A randomised controlled trial of the Odstock dropped foot stimulator (ODFS), a common peroneal stimulator used to correct drop-foot during walking, showed a reduction in spasticity of the quadriceps muscles in a sample of 32 chronic hemiplegic subjects. Both treatment (FES) and control groups received a course of ten physiotherapy sessions during the first four weeks of the trial period. The treatment group used the stimulator as part of the physiotherapy sessions and independently each day as they found useful. Both groups received the same amount of therapy contact time. The treatment group continued to use the stimulator for the 12-week period. Assessments also included measurement of walking speed and effort of walking, gait analysis and mobility and quality of life questionnaires. Results of these tests are not presented in this paper but are referred to in relation to changes in spasticity. Spasticity of the quadriceps muscles was measured using the Wartenberg pendulum test. Results showed that during the first four-week period both groups had a reduction in spasticity which was statistically significant in the control group; measured by both the relaxation index (p = 0.005) and the area beneath the curve (p = 0.036) and in the FES group only as the area beneath the curve (p = 0.028) At 12 weeks, reduction in spasticity in the control group was no longer statistically significant in either of these parameters, whereas in the treatment group reduction measured as area beneath the curve was statistically significant (p = 0.001). There was no statistically significant difference between the two groups. These results are discussed in relation to the subject of measurement of spasticity, the effect of physiotherapy on spasticity and observations made on changes in speed and effort of walking.

Muscle damping measured with a modified pendulum test in patients with fibromyalgia, lumbago, and cervical syndrome.

Muscle tension with tenderness may be localized or generalized as in fibromyalgia. Wartenberg's pendulum test might be appropriate for quantitating muscle damping, at least in generalized cases. Damping values provide a quantitative measure of muscle tension and of the response to various treatments. According to recent anatomic and experimental works, intrafusal muscle fibers are double-innervated by gamma motoneurons and sympathetic fibers. With electromyograph recording, the activity of extrafusal fibers and gamma motoneurons (reflexes) can be assessed and separated from the action of the sympathetic system. An electrogoniometer registers the movements of the freely swinging leg. On the oscilloscope, the patient's nodular curve is compared with an ideal calculated dampened curve to find the damping value. Electromyograph surface electrodes from the knee extensors and flexors detect the activity of extrafusal fibers and the occurrence of reflexes. In longstanding severe fibromyalgia, damping values are almost always elevated, at least in one leg. Half or more of patients with chronic lumbago and cervical syndrome present with increased damping. The surface electromyograph remains silent (in contrast to spastic patients). The findings support the hypothesis that muscle tension in rheumatic patients results from overactivity of the sympathetic system (or part of it). Even in clinically localized pain syndromes, muscle damping is often increased in the legs. The test is valuable for quantitating muscle tension and the effectiveness of therapeutic methods.