Contribution of thixotropy, spasticity, and contracture to ankle stiffness after stroke

Ankle stiffness asymmetry is associated with balance function in individuals with chronic stroke

Ankle joint is one of important contributors on balance in stroke survivors. This study aimed to investigate the relationships of ankle stiffness symmetry ratios along the talocrural and subtalar axes with clinical balance measures and weight distribution during quiet standing in ambulatory chronic post-stroke survivors. The clinical trials involved 15 ambulatory elderly with chronic post-stroke hemiparesis and 15 healthy controls. Ankle stiffness was evaluated during non-weight-bearing isokinetic passive biaxial ankle movements, and ankle stiffness symmetry ratios between paretic and non-paretic ankle stiffness (SR: Inversion/Eversion SRIE & Dorsi-/Plantarflexion SRDP) were measured. A certified physiotherapist evaluated the Berg Balance Scale (BBS) and weight-distribution ratio (WDR) on bilateral force plates during quiet standing. Correlation coefficients, the factor analysis, and Pearson linear multiple regression were assessed with measured parameters. Correlation coefficients showed significances in-betweens; BBS and SRDP (r = -0.543, p = 0.022), WDR and SRIE (r = -0.667, p = 0.004), SRIE and SRDP (r = -0.604, p = 0.011). The exploratory factor analysis suggested four extracted factors; (1) Balance & Gait, (2) Stroke, (3) Symmetry and (4) Dimension. The first and second factors include general and pathological characteristics in stoke participants respectively. The third factor is associated with symmetrical characteristics explaining up to 99.9% of the variance. Multiple regression analysis showed ankle stiffness ratios predict BBS up to 60% of variance. The biaxial ankle stiffness ratio is a useful clinical variable that assesses balance function, in ambulatory chronic stroke survivors.

Measuring resistance to externally induced movement of the wrist joint in chronic stroke patients using an objective hand-held dynamometer

Objective

We evaluated the resistance to externally induced wrist extension in chronic stroke patients. We aimed to objectively measure and distinguish passive (muscle and soft tissue stiffness) and active (spasticity and spastic dystonia) components of the resistance.

Methods

We used a hand-held dynamometer, which measures torque, joint movement and electromyography (EMG) simultaneously, to assess the resistance to externally induced wrist extension. Slow and fast stretches were applied to the affected and unaffected wrists in 57 chronic stroke patients (57 ± 11 years). We extracted from the data parameters that represent passive and muscle activity components and assessed the validity, test-retest reliability and the clinical utility of the measurement.

Results

The analysis showed (1) a significant difference in the passive and muscle activity components between the affected and unaffected sides; (2) a significant correlation between passive and muscle activity components and the modified Ashworth scale (MAS); (3) a significant difference between the subgroups of patients stratified by the MAS; (4) an excellent intra-rater reliability on each of the passive and muscle activity components with intra-class coefficients between 0.92 and 0.99; (5) and small measurement error.

Conclusions

Using a hand-held dynamometer, we were able to objectively measure the resistance to muscle stretch in the wrist joint in chronic stroke patients and discriminate muscle overactivity components from muscle and soft tissue stiffness. We demonstrated validity, test-retest reliability and the clinical utility of the measurement.

Significance

Quantification of the different components of resistance to externally induced movement enables the objective evaluation of neurorehabilitation effects in chronic stroke patients.

Treatment of spasticity

Spasticity is characterized by an enhanced size and reduced threshold for activation of stretch reflexes and is associated with "positive signs" such as clonus and spasms, as well as "negative features" such as paresis and a loss of automatic postural responses. Spasticity develops over time after a lesion and can be associated with reduced speed of movement, cocontraction, abnormal synergies, and pain. Spasticity is caused by a combination of damage to descending tracts, reductions in inhibitory activity within spinal cord circuits, and adaptive changes within motoneurons. Increased tone, hypertonia, can also be caused by changes in passive stiffness due to, for example, increase in connective tissue and reduction in muscle fascicle length. Understanding the cause of hypertonia is important for determining the management strategy as nonneural, passive causes of stiffness will be more amenable to physical rather than pharmacological interventions. The management of spasticity is determined by the views and goals of the patient, family, and carers, which should be integral to the multidisciplinary assessment. An assessment, and treatment, of trigger factors such as infection and skin breakdown should be made especially in people with a recent change in tone. The choice of management strategies for an individual will vary depending on the severity of spasticity, the distribution of spasticity (i.e., whether it affects multiple muscle groups or is more prominent in one or two groups), the type of lesion, and the potential for recovery. Management options include physical therapy, oral agents; focal therapies such as botulinum injections; and peripheral nerve blocks. Intrathecal baclofen can lead to a reduction in required oral antispasticity medications. When spasticity is severe intrathecal phenol may be an option. Surgical interventions, largely used in the pediatric population, include muscle transfers and lengthening and selective dorsal root rhizotomy.

Measuring Mechanical Properties of Spastic Muscles After Stroke. Does Muscle Position During Assessment Really Matter?

OBJECTIVE

To investigate the influence of muscle position (relaxed vs stretched) on muscle mechanical properties and the ability of myotonometry to detect differences between sides, groups, and sites of testing in patients with stroke. We also analyzed the association between myotonometry and clinical measures of spasticity.

DESIGN

Cross-sectional study.

SETTING

Outpatient rehabilitation units including private and public centers.

PARTICIPANTS

Seventy-one participants (20 subacute stroke, 20 chronic stroke, 31 controls) were recruited (N=71).

INTERVENTION

Muscle mechanical properties were measured bilaterally with a MyotonPRO at muscle belly and musculotendinous sites during 2 protocols (muscle relaxed or in maximal bearable stretched position).

MAIN OUTCOME MEASURES

Muscle tone and stiffness of the biceps brachii and gastrocnemius. Poststroke spasticity was evaluated with the Modified Tardieu Scale (MTS). A mixed-model analysis of variance was used to detect differences in the outcome measures.

RESULTS

The analysis of variance showed a significant effect of muscle position on muscle mechanical properties (higher tone and stiffness with the muscle assessed in stretched position). Measurements with the stretched muscle could help discriminate between spastic and nonspastic sides, but only at the biceps brachii. Overall, there was a significant increase in tone and stiffness in the chronic stroke group and in myotendinous sites compared with muscle belly sites (all, P<.05). No correlations were found between myotonometry and the MTS.

CONCLUSIONS

Myotonometry assessment of mechanical properties with the muscle stretched improves the ability of myotonometry to discriminate between sides in patients after stroke and between people with and without stroke.

Neurorehabilitation in Multiple Sclerosis-A Review of Present Approaches and Future Considerations

Multiple sclerosis is an increasingly prevalent disease, representing the leading cause of non-traumatic neurological disease in Europe and North America. The most common symptoms include gait deficits, balance and coordination impairments, fatigue, spasticity, dysphagia and an overactive bladder. Neurorehabilitation therapeutic approaches aim to alleviate symptoms and improve the quality of life through promoting positive immunological transformations and neuroplasticity. The purpose of this study is to evaluate the current treatments for the most debilitating symptoms in multiple sclerosis, identify areas for future improvement, and provide a reference guide for practitioners in the field. It analyzes the most cited procedures currently in use for the management of a number of symptoms affecting the majority of patients with multiple sclerosis, from different training routines to cognitive rehabilitation and therapies using physical agents, such as electrostimulation, hydrotherapy, cryotherapy and electromagnetic fields. Furthermore, it investigates the quality of evidence for the aforementioned therapies and the different tests applied in practice to assess their utility. Lastly, the study looks at potential future candidates for the treatment and evaluation of patients with multiple sclerosis and the supposed benefits they could bring in clinical settings.

Effects of Extensor Digitorum Longus and Tibialis Anterior Taping on Balance and Gait Performance in Patients Post Stroke

The purpose of this study was to investigate the effects of extensor digitorum longus taping (EDLT) and tibialis anterior taping (TAT) on balance and gait performance in patients post-stroke. The study included 40 stroke patients randomly assigned to two intervention groups: the EDLT group and the TAT group. Therapeutic taping was applied to the extensor digitorum in the EDLT group and applied to the tibialis anterior in the TAT group. Balance variables were measured using BioRescue equipment, and gait variables were measured using G-walk equipment. Balance and gait variables were significantly increased in both the EDLT and TAT groups after the intervention, but there were no significant differences between the two groups. Therefore, we concluded that eversion (EDLT) or inversion (TAT) through taping did not affect the outcome. Only dorsiflexion affects gait speed increase post-stroke. As a result of this study, extensor digitorum longus taping and tibialis anterior taping were taping methods with no difference in the improvement of balance ability and gait performance.

Effects of Bobath treatment and specific mobilizations on gait in stroke patients: A randomized clinical trial

BACKGROUND: After a stroke, patients experience sensorimotor damage, balance disorders, loss of selective movement, hypotonia and/or hypertonia, and hypersensitivity, all of which affect gait. OBJECTIVE: The aim of the study was to establish the effectiveness of Bobath therapy with additional specific soft tissue mobilizations versus standard Bobath intervention. METHODS: Subjects were randomly divided into two groups (S1 and S2) of 20 people each. Both groups underwent the same intervention (Bobath concept) over a 5-week period, while the second study group (S2) also received additional, specific soft tissue mobilization. The Berg Balance Scale (BBS), Timed Up and Go Test (TUGT), Active Range of Motion (AROM) of dorsiflexion and knee flexion and extension were used as clinical variables to assess the efficacy of therapy modalities. Data was analysed using a mixed model ANOVA. RESULTS: A significant interaction of group and time was found. The experimental (S2) group had a larger improvement of balance and AROM than the control (S1) group. There was no clear advantage of one group over the other for TUGT. CONCLUSION: The findings demonstrate that a combination of Bobath treatment and additional specific soft tissue mobilizations are more effective in increasing AROM and balance and mobility.

Structural and passive mechanical properties of the medial gastrocnemius muscle in ambulatory individuals with chronic stroke

BACKGROUND

This study aimed to investigate the structural, morphological and passive mechanical properties of the medial gastrocnemius muscle among ambulating chronic stroke survivors using a computational model previously established in healthy individuals without stroke.

METHODS

Individuals with chronic stroke (n = 14, age = 63.4 ± 6.0 years) and healthy controls (n = 15, age = 59.6 ± 8.4 years) participated in the study. The mechanical properties of the medial gastrocnemius were measured during continuous passive ankle motion using ultrasound elastography and a corresponding muscle mechanical property-angle curve was estimated where slack angle and elasticity were determined. Muscle thickness, fascicle length, pennation angle, and echo intensity were also assessed using B-mode ultrasound.

FINDINGS

No significant differences in slack angle (paretic: -16.2° ± 6.13°, non-paretic: -16.93° ± 6.80°, p = 0.82), or slack elasticity (paretic: 4.36 ± 1.94 kPa, non-paretic: 4.54 ± 1.24 kPa, p = 0.64) were found between sides or groups. Lower muscle pennation angle (paretic: 13.6 ± 2.9°, non-paretic: 15.9 ± 2.0°, p = 0.019) and higher echo intensity (paretic: 80.5 ± 13.6, non-paretic: 63.4 ± 17.1, p = 0.003) were observed for paretic muscles. No significant between-sides differences were found for muscle thickness (paretic: 1.5 ± 0.3 cm, non-paretic: 1.6 ± 0.2 cm, p = 0.255) or fascicle length (paretic: 6.6 ± 1.9 cm, non-paretic: 7.1 ± 2.2 cm, p = 0.216). Significant between-groups difference was also observed for fascicle length [non-dominant side (control): 6.2 ± 0.8 cm, paretic side (stroke): 6.6 ± 1.9 cm, p = 0.017].

INTERPRETATION

Although muscle mechanical properties increased exponentially over the slack ankle, measures between paretic and non-paretic sides were similar in ambulating participants with chronic stroke. Side-to-side differences in structural and morphological measures suggest the impact of stroke was relatively more pronounced for these muscle parameters than for passive mechanical properties.

High Doses of Botulinum Toxin Type A for the Treatment of Post-Stroke Spasticity: Rationale for a Real Benefit for the Patients

In the past few years, there was a great interest in the use of higher doses of botulinum toxin type A, especially in case of upper and lower limb severe spasticity. To date, only one prospective, non-randomized, single-arm, multicenter, open-label, dose-titration study with the employment of incobotulinum toxin up to 800 U has been published, and the authors investigated safety and tolerability. Other researches showed efficacy in spasticity reduction, but there is a lack of evidence about the reasons to use high doses of botulinum toxin. This short communication highlights the benefits of higher doses for subjects with upper and lower limb spasticity.

Inter-rater reliability of the Australian Spasticity Assessment Scale in poststroke spasticity

To investigate the inter-rater reliability of the Australian Spasticity Assessment Scale (ASAS) in adult stroke patients with spasticity, two experienced clinicians rated the elbow flexor, wrist flexor, and ankle plantar flexor spasticity by using the ASAS in 85 persons with stroke. Unweighted and weighted (linear and quadratic) kappa statistics were used to calculate the inter-rater reliability for each muscle group. Unweighted kappa coefficients for elbow flexors (n = 83), wrist flexors (n = 80), and ankle plantar flexors (n = 77) were 0.67, 0.60, and 0.55, respectively. Linear and quadratic weighted kappa coefficients, respectively, were 0.77 and 0.87 for elbow flexors, 0.72 and 0.82 for wrist flexors, and 0.72 and 0.85 for ankle plantar flexors. The raters never disagreed by more than a single score in the rating of elbow flexors. On the contrary, the raters disagreed by more than a single score in three patients in the rating of ankle plantar flexors and in one patient in the rating of wrist flexors. The results suggested that inter-rater reliability of the ASAS differed according to the spastic muscle group assessed and the statistical method used. The strength of the agreement on the ASAS, an ordinal scale, ranged from good to very good when the weighted kappa values were considered.

Multivariable passive ankle impedance in stroke patients: A preliminary study

Multivariable ankle mechanical impedance was estimated in four stroke survivors, in coupled dorsi- plantarflexion and inversion-eversion. We applied external torque perturbation with an ankle robot and used multi-input, multi-output stochastic system identification methods to estimate impedance, in both paretic and nonparetic limbs. Subjects were instructed to remain at rest throughout the four trials performed on each leg. Impedance projected onto the directions of maximum and minimum stiffness was fit to a 2nd order linear model, including inertia, viscosity and stiffness. For most trials, stiffness and damping in dorsi-plantarflexion are increased on the paretic side. However, for two subjects, overall impedance is not increased in the absence of sustained involuntary tonic contraction, registering values comparable to the non-paretic side. Thus, we speculate that the intrinsic properties of the paretic ankle remained unaffected at the evaluated pose. Spasticity (hyperflexive stretch reflex) would have systematically increased stiffness and damping, even in the absence of involuntary contraction. Hence, we speculate that these two subjects did not exhibit spasticity, while the remaining two subjects did, since impedance was increased, with no involuntary tonic muscle contraction. Regarding inversion-eversion, impedance in this direction remained unaffected by stroke. We evaluated two volunteers before and after the application of botulinum toxin. Surprisingly, ankle stiffness was not reduced, but anisotropy was normalized.

Evaluating Viscoelastic Properties of the Wrist Joint During External Perturbations: Influence of Velocity, Grip, and Handedness

In this study, we designed a robot-based method to compute a mechanical impedance model that could extract the viscoelastic properties of the wrist joint. Thirteen subjects participated in the experiment, testing both dominant and nondominant hands. Specifically, the robotic device delivered position-controlled disturbances in the flexion-extension degree of freedom of the wrist. The external perturbations were characterized by small amplitudes and fast velocities, causing rotation at the wrist joint. The viscoelastic characteristics of the mechanical impedance of the joint were evaluated from the wrist kinematics and corresponding torques. Since the protocol used position inputs to determine changes in mean wrist torque, a detailed analysis of wrist joint dynamics could be made. The scientific question was whether and how these mechanical features changed with various grip demands and perturbation velocities. Nine experimental conditions were tested for each hand, given by the combination of three velocity perturbations (fast, medium, and slow) and three hand grip conditions [self-selected grip, medium and high grip force, as percentage of the maximum voluntary contraction (MVC)]. Throughout the experiments, electromyographic signals of the extensor carpi radialis (ECR) and the flexor carpi radialis (FCR) were recorded. The novelty of this work included a custom-made soft grip sensor, wrapped around the robotic handle, to accurately quantify the grip force exerted by the subjects during experimentation. Damping parameters were in the range of measurements from prior studies and consistent among the different experimental conditions. Stiffness was independent of both direction and velocity of perturbations and increased with increasing grip demand. Both damping and stiffness were not different between the dominant and nondominant hands. These results are crucial to improving our knowledge of the mechanical characteristics of the wrist, and how grip demands influence these properties. This study is the foundation for future work on how mechanical characteristics of the wrist are affected in pathological conditions.

Ultrasound Elastography in the Assessment of the Stiffness of Spastic Muscles: A Systematic Review

The incidence of muscle spasticity is high in patients with diseases of the central nervous system. This condition leads to significant limitations in movement and impaired functional capacities. Muscle spasticity manifests as changes in the mechanical properties of the muscles. This muscle disorder is generally assessed using qualitative methods, whose validity, reliability and sensitivity are questionable. In recent years, ultrasound elastography (USE) has been used as a non-invasive technique for characterizing the stress response and mechanical properties of individual muscles in the evaluation of spasticity. This article presents a systematic review of the USE techniques, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration guidelines, used for the evaluation of muscle stiffness caused by spasticity. The articles selected in this study were evaluated using the Quality Appraisal of Diagnostic Reliability (QAREL) tool. Mainly, studies on the assessment of spasticity involving the evaluation of muscle stiffness with USE techniques (i.e., shear-wave elastography [SWE] or compression elastography [CE]) were selected. Then, common topics related to the assessment of spastic muscles and the statistical results of these studies were classified. Of 21 articles, nine used only CE, 10 used only SWE and two used both techniques. In the studies, statistically significant differences were observed in the measurements of muscle stiffness between the paretic and non-paretic sides as well as between patients and healthy patients. The clinical measurements obtained, devices used and assessment and probe positions for both techniques were discussed. The most frequently studied muscles were the biceps (n = 7) and gastrocnemius (n = 11). On applying the QAREL tool, we found that only two studies showed compliance at 80%-90%, seven studies at 50%-70% and the remaining 12 at 10%-40%. The results showed that USE techniques have limitations in spasticity assessment, such as subjectivity because of the lack of standardized protocols. A deficit of studies on intra-operator and inter-operator measurements indicates that this technique is not yet mature for spasticity diagnosis, although it is a promising diagnostic tool for designing treatment plans and monitoring the effectiveness of therapeutic modalities.

The Use of Botulinum Toxin for Treatment of Spasticity

Spasticity is one component of the upper motor neuron (UMN) syndrome resulting from a multitude of neurologic conditions, such as stroke, brain injury, spinal cord injury, multiple sclerosis, and cerebral palsy. It is clinically recognized as a phenomenon of velocity-dependent increase in resistance, i.e., hypertonia. Recent advances in the pathophysiology of spasticity improve our understanding of mechanisms underlying this complex phenomenon and its relations to other components of UMN syndrome (weakness and disordered motor control), as well as the resultant clinical problems. This theoretical framework provides a foundation to set up treatment goals and to guide goal-oriented clinical assessment and treatment. Among a spectrum of treatment options, botulinum toxin (BoNT) therapy is the preferred treatment for focal spasticity. The evidence is very robust that BoNT therapy effectively reduces spasticity; however, it does not improve voluntary movement. In this chapter, we highlight a few issues on how to achieve the best clinical outcomes of BoNT therapy, such as dosing, dilution, guidance techniques, adjunctive therapies, early treatment, repeated injections, and central effects, as well as the ways to improve motor function in selected subgroups of patients with spasticity. We also discuss the reasons of poor responses to BoNT therapy and when not to use BoNT therapy.

Quantitative Modeling of Spasticity for Clinical Assessment, Treatment and Rehabilitation

Spasticity, a common symptom in patients with upper motor neuron lesions, reduces the ability of a person to freely move their limbs by generating unwanted reflexes. Spasticity can interfere with rehabilitation programs and cause pain, muscle atrophy and musculoskeletal deformities. Despite its prevalence, it is not commonly understood. Widely used clinical scores are neither accurate nor reliable for spasticity assessment and follow up of treatments. Advancement of wearable sensors, signal processing and robotic platforms have enabled new developments and modeling approaches to better quantify spasticity. In this paper, we review quantitative modeling techniques that have been used for evaluating spasticity. These models generate objective measures to assess spasticity and use different approaches, such as purely mechanical modeling, musculoskeletal and neurological modeling, and threshold control-based modeling. We compare their advantages and limitations and discuss the recommendations for future studies. Finally, we discuss the focus on treatment and rehabilitation and the need for further investigation in those directions.

Experimental and numerical investigation of a polypropylene orthotic device for assistance in level ground walking

This study investigates the use of an orthotic device for improving pathologic gait lacking a heel-strike and its effect on the joint loads. The orthosis is fabricated from 10-mm thick polypropylene sheets joined together using a bolted joint. The gait trials are recorded using a Qualisys motion capture system and Kistler's force platform. The data recorded in this study comprise five male and five female participants, executing level ground gait under barefoot, shod and orthotic conditions. Computed tomography reconstructed foot bone-tissue model and computer-aided design model of the orthosis are used to predict the mechanical behaviour with and without orthosis under static loading. A one-way analysis of variance is conducted to compare the peak gait parameters in the early and late stance phase between the three walking conditions. The experimental results show that the orthosis reduces the peak joint forces and the rate of change of moment at the hip, knee and ankle joints. The finite element analysis results present a decrease in foot plantar pressure from 0.74 to 0.32 MPa with orthotic usage. The results of this study indicate that the orthosis can eliminate the heel-ground gap while retaining sufficient ankle motion and providing peak joint force reduction.

Effectiveness of Physiotherapy Interventions on Spasticity in People With Multiple Sclerosis: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of the study was to examine the effectiveness of physiotherapy (PT) interventions on spasticity in people with multiple sclerosis.

DESIGN

A systematic search was performed using PRISMA guidance. Studies evaluate the effect of PT interventions on spasticity were included. People with multiple sclerosis, spasticity, disability and PT interventions characteristics were extracted in included studies. Level of evidence was synthesized by the Grade of Recommendation, Assessment, Development and Evaluation approach. Meta-analyses were performed by calculating Hedges g at 95% confidence interval.

RESULTS

A total of 29 studies were included in the review, and 25 were included in the meta-analyses. The included PT interventions were exercise therapy, electrical stimulation, radial shock wave therapy, vibration, and standing. The review and meta-analyses showed different evidences of benefits and nonbenefits for PT interventions on some spasticity outcomes. The best quality evidences were for beneficial effects of exercise therapy especially robot gait training and outpatient exercise programs on self-perceived spasticity and muscle tone respectively. The review results were positive regarding the acute effects, follow-up measurements, safety, progressive MS, and nonambulatory people with multiple sclerosis. The included articles were heterogeneous and badly reported in PT interventions and people with multiple sclerosis characteristics.

CONCLUSIONS

Physiotherapy interventions can be a safe and beneficial option for spasticity in people with multiple sclerosis. No firm conclusion can be drawn on overall spasticity. Further researches in different spasticity aspects are needed.

In vivo muscle morphology comparison in post-stroke survivors using ultrasonography and diffusion tensor imaging

Skeletal muscle architecture significantly influences the performance capacity of a muscle. A DTI-based method has been recently considered as a new reference standard to validate measurement of muscle structure in vivo. This study sought to quantify muscle architecture parameters such as fascicle length (FL), pennation angle (PA) and muscle thickness (tm) in post-stroke patients using diffusion tensor imaging (DTI) and to quantitatively compare the differences with 2D ultrasonography (US) and DTI. Muscle fascicles were reconstructed to examine the anatomy of the medial gastrocnemius, posterior soleus and tibialis anterior in seven stroke survivors using US- and DTI-based techniques, respectively. By aligning the US and DTI coordinate system, DTI reconstructed muscle fascicles at the same scanning plane of the US data can be identified. The architecture parameters estimated based on two imaging modalities were further compared. Significant differences were observed for PA and tm between two methods. Although mean FL was not significantly different, there were considerable intra-individual differences in FL and PA. On the individual level, parameters measured by US agreed poorly with those from DTI in both deep and superficial muscles. The significant differences in muscle parameters we observed suggested that the DTI-based method seems to be a better method to quantify muscle architecture parameters which can provide important information for treatment planning and to personalize a computational muscle model.

Unilateral Strength Training and Mirror Therapy in Patients With Chronic Stroke: A Pilot Randomized Trial

OBJECTIVE

The aim of the study was to investigate the feasibility and potential effectiveness of mirror-aided cross-education compared with cross-education alone in poststroke upper limb recovery.

DESIGN

A pilot randomized controlled parallel group study was carried out. Thirty-two patients with chronic stroke followed a 4-wk isometric strength training program performed with the less-affected upper limb three times per week. Participants in the mirror and strength training group observed the reflection of the exercising arm in the mirror. Participants in the strength training only group exercised without a mirror entirely. Participant compliance, adverse effects, and suitability of outcome measures assessed feasibility. Effectiveness outcomes included maximal isometric strength measured with the Biodex Dynamometer, the Modified Ashworth Scale, and the Chedoke Arm and Hand Activity Inventory.

RESULTS

Compliance was high with no adverse effects. The use of the Biodex Dynamometer must be reviewed. Mirror therapy did not augment the cross-education effect (P > 0.05) in patients with chronic stroke when training isometrically.

CONCLUSIONS

This pilot trial established the feasibility of a randomized controlled trial comparing mirror-aided cross-education with cross-education alone for poststroke upper limb recovery. Mirror therapy did not augment cross-education when training isometrically. However, results indicate that the combination of interventions should be investigated further applying an altered training protocol.

Development of muscle contractures and spasticity during subacute rehabilitation after severe acquired brain injury: a prospective cohort study

Objective: This study investigated the development of contractures, passive stiffness, and spasticity in the ankle joint in patients with severe acquired brain injury (ABI) from admission to rehabilitation unit until 1-year post-injury compared to healthy controls. Design: An observational longitudinal cohort study Methods and procedures: Nineteen patients (26 affected ankle joints) with severe ABI >17 years old and with paresis of a lower limb admitted to sub-acute neurorehabilitation were compared to 14 healthy controls (28 ankle joints). Passive and reflex-mediated ankle joint stiffness was obtained measuring torque, range of motion, velocity and acceleration of the ankle movements. Data was collected at inclusion, after 4-5 weeks, after 8-9 weeks and at 1-year follow-up. Outcomes and results: At admittance to rehabilitation range of motion and stiffness was significantly lower compared to controls. Range of motion decreased by one degree in three weeks and passive ankle joint stiffness increased significantly by 1% per week. More patients than controls had no stretch reflex. Conclusion: Patients with severe ABI show reduced mobility and increased passive stiffness despite less spasticity in the ankle joint compared to healthy controls. Research and clinical practice should therefore focus intensively on the prevention of contractures in the ankle joint. ISRCTN17910097.

Unilateral dorsiflexor strengthening with mirror therapy to improve motor function after stroke: A pilot randomized study

BACKGROUND

Independently, cross-education, the performance improvement of the untrained limb following unilateral training, and mirror therapy have shown to improve lower limb functioning poststroke. Mirror therapy has shown to augment the cross-education effect in healthy populations. However, this concept has not yet been explored in a clinical setting.

OBJECTIVES

This study set out to investigate the feasibility and potential efficacy of applying cross-education combined with mirror therapy compared with cross-education alone for lower limb recovery poststroke.

METHODS

Thirty-one chronic stroke participants (age 61.7 ± 13.3) completed either a unilateral strength training (ST; n = 15) or unilateral strength training with mirror-therapy (MST; n = 16) intervention. Both groups isometrically strength trained the less-affected ankle dorsiflexors three times per week for 4 weeks. Only the MST group observed the mirror reflection of the training limb. Patient eligibility, compliance, treatment reliability, and outcome measures were assessed for feasibility. Maximal voluntary contraction (MVC; peak torque, rate of torque development, and average torque), 10-m walk test, timed up and go (TUG), Modified Ashworth Scale (MAS), and the London Handicap Scale (LHS) were assessed at pretraining and posttraining.

RESULTS

Treatment and assessments were well tolerated without adverse effects. No between group differences were identified for improvement in MVC, MAS, TUG, or LHS. Only the combined treatment was associated with functional improvements with the MST group showing an increase in walking velocity.

CONCLUSION

Cross-education plus mirror therapy may have potential for improving motor function after stroke. This study demonstrates the feasibility of the combination treatment and the need for future studies with larger sample sizes to investigate the effectiveness of the treatment.

Effects of stroke injury on the shear modulus of the lower leg muscle during passive dorsiflexion

Contractures are common complications of a stroke. The spatial location of the increased stiffness among plantar flexors and its variability among survivors remain unknown. This study assessed the mechanical properties of the lower leg muscles in stroke survivors during passive dorsiflexions. Stiffness was estimated through the measurement of the shear modulus. Two experiments were independently conducted, in which participants lay supine: with the knee extended ( experiment 1, n = 13 stroke survivors and n = 13 controls), or with the knee flexed at 90° ( experiment 2, n = 14 stroke survivors and n = 14 controls). The shear modulus of plantar flexors [gastrocnemius medialis (three locations), gastrocnemius lateralis (three locations), soleus (two locations), flexor digitorum longus, flexor hallucis longus), peroneus longus] and dorsiflexors (tibialis anterior and extensor digitorum longus) was measured using ultrasound shear wave elastography during passive dorsiflexions (2°/s). At the same ankle angle, stroke survivors displayed higher shear modulus than controls for gastrocnemius medialis and gastrocnemius lateralis (knee extended) and soleus (knee flexed). Very low shear modulus was found for the other muscles. The adjustment for muscle slack angle suggested that the increased shear modulus was arising from consequences of contractures. The stiffness distribution between muscles was consistent across participants with the highest shear modulus reported for the most distal regions of gastrocnemius medialis (knee extended) and soleus (knee flexed). These results provide a better appreciation of stiffness locations among plantar flexors of stroke survivors and can provide evidence for the implementation of clinical trials to evaluate targeted interventions applied on these specific muscle regions.

NEW & NOTEWORTHY The shear modulus of 13 muscle regions was assessed in stroke patients using elastography. When compared with controls, shear modulus was increased in the gastrocnemius muscle (GM) when the knee was extended and in the soleus (SOL) when the knee was flexed. The distal regions of GM and SOL were the most affected. These changes were consistent in all the stroke patients, suggesting that the regions are a potential source of the increase in joint stiffness.

Extracorporeal Shock Waves Versus Botulinum Toxin Type A in the Treatment of Poststroke Upper Limb Spasticity: A Randomized Noninferiority Trial

OBJECTIVE

To investigate whether extracorporeal shock wave therapy (ESWT) is noninferior to botulinum toxin type A (BoNT-A) for the treatment of poststroke upper limb spasticity.

DESIGN

Randomized noninferiority trial.

SETTING

Referral medical center.

PARTICIPANTS

Patients (N=42) with chronic stroke (28 men; mean age, 61.0±10.6y).

INTERVENTIONS

Patients received either ESWT or BoNT-A. During the study period, all patients continued their regular rehabilitation.

MAIN OUTCOME MEASURES

Assessments were performed at baseline and at 1, 4, and 8 weeks after the intervention. The primary outcome was the change from baseline of the modified Ashworth scale (MAS) score of the wrist flexors at week 4. Secondary outcomes included the change of the MAS scores, Tardieu angles of the wrist and elbow flexors, wrist and elbow passive range of motion (PROM), and upper extremity Fugl-Meyer Assessment (UE-FMA) score during the study period, as well as the treatment response rate.

RESULTS

The primary outcome result in the ESWT group (-0.80±0.41) was similar to that in the BoNT-A group (-0.90±0.44), with a higher confidence limit (0.4) for the difference between groups within the prespecified margin of 0.5, indicating the noninferiority of ESWT to BoNT-A. The response rate was not significantly different between the 2 groups. Both groups showed significant improvement in secondary outcomes relative to baseline; however, the ESWT group yielded greater improvement in wrist and elbow PROM and UE-FMA score.

CONCLUSION

Our results suggest that ESWT is a noninferior treatment alternative to BoNT-A for poststroke upper limb spasticity. ESWT and BoNT-A caused similar reduction in spasticity of the wrist and elbow flexors; however, ESWT yielded greater improvement in wrist and elbow PROM and UE-FMA score.

Quantitative Evaluation of Post-stroke Spasticity Using Neurophysiological and Radiological Tools: A Pilot Study

Objective

To determine the possibility of a new measurement tool using electromyography and ultrasonography for quantitative spasticity assessment in post-stroke patients.

Methods

Eight hemiplegic stroke patients with ankle plantarflexor spasticity confirmed by a Modified Ashworth Scale (MAS) were enrolled. Spasticity was evaluated using the MAS and Modified Tardieu Scale (MTS). Each subject underwent surface electromyography (sEMG) using the Brain Motor Control Assessment (BMCA) protocol and was compared with a healthy control group. Using ultrasonography, muscle architecture and elasticity index were measured from the medial gastrocnemius muscle (GCM) on the affected and unaffected sides.

Results

MAS and MTS revealed significant correlation with sEMG activity. The fascicle length and pennation angle were significantly decreased in the medial GCM on the hemiplegic side compared with the unaffected side. The elasticity index of the spastic medial GCM was significantly increased compared with the unaffected side. The MTS X and R²–R1 values were significantly correlated with the elasticity index in the hemiplegic GCM. The relationship between clinical evaluation tools and both BMCA and sonoelastography was linear, but not statistically significant in the multiple regression analysis.

Conclusion

The BMCA protocol and ultrasonographic evaluation provide objective assessment of post-stroke spasticity. Further studies are necessary to conduct accurate assessment and treatment of spasticity.

Benefits and Risks of Non-Approved Injection Regimens for Botulinum Toxins in Spasticity

Spasticity with muscle paresis and loss of dexterity is a common feature of upper motor neuron syndrome due to injuries or the pyramidal tract in several neurological conditions. Botulinum toxin type A has been considered the gold standard treatment for spasticity and movement disorders, with efficacy, reversibility, and low prevalence of complications. During the last 30 years, thousands of studies of its use have been performed, but few guidelines are available. Therefore, there is great variability in both the doses and intervals of administration and the approaches taken by clinicians with considerable experience in spasticity and movement disorder treatment. In the present review article, we provide a short overview of the benefits and risks of non-approved injection regimens and doses for botulinum toxins, focusing on the treatment of post-stroke spasticity, where there is great interest in the potential for increasing the number of treatment/years and the dose of botulinum toxin treatment for subjects with upper and lower limb spasticity. However, many doubts exist regarding antibody development and possible adverse effects.

Early manifestation of spasticity after first stroke in the territory of the internal carotid artery: A prospective multicenter study

AIMS

The main aim of this study was to provide an estimate of the incidence and prevalence of spasticity following stroke in the internal carotid artery territory for Regional Stroke Centers in the Czech Republic. A secondary goal was to identify predictors for the development of spasticity.

METHODS

In a prospective cohort study, 256 consecutive patients with clinical signs of central paresis due to a first-ever stroke were examined in the acute stage. All patients had primary stroke of carotid origin and paresis of the upper and/or lower limb for longer than 7 days after stroke onset. All were examined between 7-10 days after the stroke. We evaluated the degree and pattern of paresis, spasticity using the Modified Ashworth scale and the Barthel Index, baseline characteristics and demographic data.

RESULTS

Of 256 patients (157 males; mean age 69.9±12.4 years), 115 (44.9%) patients developed spasticity during the first 10 days after stroke onset. Eighty-three (32.5%) patients presented with mild neurological deficit (modified Rankin Scale 0 - 2) and 69 (27.0%) patients were bedridden.

CONCLUSION

Spasticity was noted in 44.9% patients with neurological deficit due to first-ever stroke in the carotid territory in the first 10 days after stroke onset. Severe spasticity was rare.

Simulation of variable impedance as an intervention for upper extremity motor exploration

Current methods in robot-assisted therapy are limited in providing predictions of the effectiveness of interventions. Our approach focuses on how robotic interaction can impact the distribution of movements expressed in the arm. Using data from a previous study with stroke survivors (n=10), we performed simulations to examine how changes in hand endpoint impedance would alter exploratory motion. We present methods for designing a custom training intervention, by relating the desired change in acceleration covariance in planar motion with a corresponding change in inertia matrix. We first characterized motor exploration in terms of overall covariance in acceleration, and secondly as covariance that varies with position in the workspace. Using a forward dynamics simulation of the hand endpoint impedance, we found that the variable change in endpoint inertia resulted in better recovery of acceleration covariance compared to the fixed change in inertia method. These results could significantly impact rehabilitation firstly in terms of design principles for altering coordination patterns through direct assistance. Furthermore, our work might serve to improve therapy by facilitating access to repeated practice of independent joint motion.

Effectiveness of Faradic and Russian currents on plantar flexor muscle spasticity, ankle motor recovery, and functional gait in stroke patients

BACKGROUND AND PURPOSE

Spasticity is a major disabling symptom in patients post stroke. Though studies have demonstrated that electrical stimulation (ES) can reduce spasticity and improve passive ankle range of motion (ROM), not many studies have evaluated the effectiveness of ES on active ankle ROM. The purpose of this study was to determine the effectiveness of Faradic and Russian currents in the reduction of ankle plantar-flexor spasticity and improving motor recovery in patients post stroke.

METHODS

Eighty-three patients (29 females and 54 males; mean age of 57.12 years) were randomly assigned to Group 1 (task-oriented exercises), Group 2 (Faradic current for 10 min and task-oriented exercises), and Group 3 (Russian current for 10 min and task-oriented exercises) for a period of 5 sessions per week for 6 weeks. All patients were assessed for soleus and gastrocnemius muscles spasticity measured by modified modified Ashworth scale; active and passive range ROM measured by goniometer; and functional ambulation measured by modified Emory Functional Ambulation Profile at the time of recruitment to study and after 6 weeks.

RESULTS

Both the types of stimulation and exercises were not associated with improvements in modified Emory Functional Ambulation Profile (p > 0.05). The results showed that all the groups are effective in improving passive ankle ROM (p < 0.05) and reducing soleus and gastrocnemius muscles spasticity (p < 0.05). Though all the groups were effective in improving active ankle ROM, no group was found to be superior to another after treatment CONCLUSION: Adding ES to exercises are associated with low to medium effect sizes (<0.5) in reducing spasticity and improving ankle ROM.

A historical review of the evolution of the Tardieu Scale

There are many clinical assessment tools that can be used to quantify spasticity, one feature of the Upper Motor Neurone (UMN) syndrome. The focus of this short paper is on three; the Tardieu Scale, the Modified Tardieu Scale and the Australian Spasticity Assessment Scale, because a fundamental concept of these tests is their velocity dependent nature. Other bedside assessments such as the Modified Ashworth Scale examine hypertonicity, another feature of the UMN syndrome, but in this instance, the stretching movement is not velocity dependent. The Tardieu Scale, while not officially named until 1997, was conceived in the 1950s and since that time it has been revised by multiple authors and it is these additions that will be discussed in this article. The advantages and disadvantages of these assessment tools will be discussed with the ultimate aim of identifying one that has greater clinical utility.

Biomechanical investigation of the modified Tardieu Scale in assessing knee extensor spasticity poststroke

OBJECTIVE

The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke.

METHODS

Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)].

RESULTS

The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was -0.83 (SD 0.73, range -2.6-0.3). There was no significant relationship between the R₂ -R₁ and the slope of work-velocity curve (r = 0.09, p = .62).

CONCLUSIONS

The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.

Relationship between spasticity and spinal neural circuits in patients with chronic hemiparetic stroke

Spasticity is a common problem in patients with stroke that contributes to motor dysfunction. However, the pathophysiological mechanisms underlying spasticity are not fully understood. The purpose of the present study was to explain the relationship between features of spinal neural circuits assessed using electrophysiological techniques and the clinical manifestations of stroke. The participants were 71 patients with chronic hemiparetic stroke. To assess spinal neural circuits, Hmax/Mmax of the forearm flexor muscles and reciprocal inhibition (RI) between forearm extensor and flexor muscles with the H reflex conditioning-test paradigm were measured. The relationships between electrophysiological parameters and clinical variables (age, time from stroke onset, upper extremity functional scores, and spasticity) were then analyzed. It was found that the third phase of RI (RI-3) correlated with the modified Ashworth scores of the wrist and finger flexors. No other correlations were found between electrophysiological and clinical measures. These results suggest that RI-3 is associated with spasticity and may be helpful to understand the basis of post-stroke spasticity.

Quantification of a single score (1+) in the Modified Ashworth Scale (MAS), a clinical assessment of spasticity

The Modified Ashworth Scale (MAS) is an assessment that is often used by clinicians to grade spasticity in the affected limbs of stroke survivors. The MAS is a function of the angle at which the clinician perceives a resistance to stretch and/or a `catch' during a passive joint rotation. The qualitative nature of the assessment in combination with the low resolution of the scale could result in varied grouping of spastic patients, even for a single score. The objective of this pilot study was to develop a method for the quantification of the MAS, which could provide greater resolution and could eventually guide better informed therapeutic interventions. The MAS assessment at the elbow joint for four stroke survivors with the same clinical MAS score of 1+ was performed by a clinician and quantified using signals from surface electromyography (EMG) and an electrogoniometer. The subjects were tested on both the affected and contralateral upper limbs. The findings from this study show a varied set of signal outputs across four stroke survivors, all graded at 1+. The quantification provides insight as to the mechanisms underlying the passive resistance.

Different Effects of Cold Stimulation on Reflex and Non-Reflex Components of Poststroke Spastic Hypertonia

OBJECTIVE

To use an established biomechanical approach to quantify reflex and non-reflex responses from spastic-paretic elbow flexors in response to controlled cold and heat stimulation.

METHODS

Thirteen spastic-hemiplegic stroke subjects were tested in the experiment. The spastic elbow joint was stretched into extension for 50° at two speeds (5°/s and 100°/s) in a customized apparatus. Thermal stimulation (HEAT at heat pain threshold, COLD at 0°C, or BASELINE at room temperature) was applied to the thenar eminence of the contralateral hand immediately prior to stretching for at least 30 s.

RESULTS

Total torque was greater at 100°/s than at 5°/s. Total torque was significantly increased after COLD, but not HEAT as compared to BASELINE. When normalized to total torque at baseline, HEAT decreased total torque by 6.3%, while COLD increased total torque by 11.0%. There was no significant difference in the reflex torque among three thermal conditions.

CONCLUSION

The findings demonstrate differentiated effects of cold stimulation on the total resistance from spastic muscles. They provide objective evidence for anecdotal clinical observations of increased muscle spasticity by cold exposure.

Assessing muscle spasticity with Myotonometric and passive stretch measurements: validity of the Myotonometer

Spasticity of the biceps brachii muscle was assessed using the modified Ashworth Scale (MAS), Myotonometry and repeated passive stretch techniques, respectively. Fourteen subjects with chronic hemiplegia participated in the study. Spasticity was quantified by muscle displacements and compliance from the Myotonometer measurements and resistive torques from the repeated passive stretch at velocities of 5 °/s and 100 °/s, respectively. Paired t-tests indicated a significant decrease of muscle displacement and compliance in the spastic muscles as compared to the contralateral side (muscle displacement: spastic: 4.84 ± 0.33 mm, contralateral: 6.02 ± 0.49 mm, p = 0.038; compliance: spastic: 1.79 ± 0.12 mm/N, contralateral: 2.21 ± 0.18 mm/kg, p = 0.048). In addition, passive stretch tests indicated a significant increase of total torque at the velocity of 100 °/s compared with that of 5 °/s (T_t5 = 2.82 ± 0.41 Nm, T_t100 = 6.28 ± 1.01 Nm, p < 0.001). Correlation analysis revealed significant negative relationships between the stretch test and the Myotonometer measurements (r < −0.5, p < 0.05). Findings of this study provided validation of the Myotonometry technique and its high sensitivity in examination of spasticity in stroke.

Intra-rater reliability of the Modified Tardieu Scale in patients with multiple sclerosis

The reliability of the Modified Tardieu Scale (MTS) has not been examined in patients with multiple sclerosis (MS). This study aimed to assess intra-rater reliability of the MTS in the assessment of lower limb spasticity in patients with MS. Data from 30 patients with MS (18 women, mean age = 41.5) were used to assess intra-rater reliability. An inexperienced physiotherapist in the scale randomly examined the hip adductors, knee extensors, and ankle plantar flexors on each subject twice with at least a 7-day interval. Kappa statistics (κ) were calculated for MTS quality of muscle reactions. Intraclass correlation coefficients (ICC_agreement) and smallest detectable change (SDC) were calculated for R2, R1, and R2-R1. Qualitative rating of spasticity demonstrated moderate or good agreement, with an overall moderate κ of 0.72. Intra-rater reliability for all angle components of MTS was poor to good (ICC_agreement range 0.45-0.83). The SDC for all the MTS components across the muscle groups was unacceptably large (range 14.6-55.6). Results did not establish good intra-rater reliability for the MTS when assessing lower limb muscle spasticity in patients with MS by a physiotherapist with no previous experience in the scale and with limited training.

Effects of 8 weeks of mat-based Pilates exercise on gait in chronic stroke patients

[Purpose] The purpose of this study was to investigate the effects of an 8-week program of Pilates exercise on gait in chronic hemiplegia patients and to determine whether or not it can be used for rehabilitation in postsrtoke patients. [Subjects and Methods] Twenty individuals with unilateral chronic hemiparetic stroke (age, 66.1 ± 4.4 yrs; height, 162.3 ± 8.3 cm; weight, 67.4 ± 12.3 kg) participated in this study and were randomly allocated equally to either a Pilates exercise group or a control group. To identify the effects of Pilates exercise, a 3-D motion analysis with 8 infrared cameras was performed. [Results] For the gait parameters, improvements were found in the Pilates exercise group for all variables, and statistical significance was observed for stride length, gait velocity, knee range of motion and hip range of motion. For the asymmetry indexes, insignificant improvements were found for all variables in the Pilates exercise group. [Conclusion] In conclusion, an 8-week program of Pilates exercise had a positive influence on improving the gait ability of poststroke patients, and the intervention could be applied to poststroke patients with various levels of physical disability by adjusting the intensity of training.

Ankle Intrinsic Stiffness in Subcortical Poststroke Subjects

The authors' purpose was to evaluate bilateral ankle intrinsic stiffness in subcortical poststroke subjects. Ten subcortical poststroke subjects and 10 healthy controls participated in this study. The ankle passive stiffness at 3 different speeds and the electromyographic activity of the soleus, the gastrocnemius, and the tibialis anterior muscles of poststroke contralesional (CONTRA) and ipsilesional (IPSI) limbs and of one limb of healthy subjects were assessed. Ankle electromyographic activity was collected to ensure that reflexive or voluntary muscle activity was not being elicited during the passive movements. A significant interaction was observed between the effects of the limb (IPSI vs. CONTRA vs. control) and ankle position, F(4, 28) = 3.285, p = .025, and between the effects of the limb and the velocity of stretch, F(2, 14) = 4.209, p = .037. While increased intrinsic stiffness was observed in the CONTRA limb of poststroke subjects at ankle neutral position when the passive stretch was applied with a velocity of 1°/s (p = .021), the IPSI limb of poststroke subjects presented increased stiffness at 20º of plantar flexion when the stretch was applied with a velocity of 5°/s (p = .009) when compared to healthy group. Subcortical poststroke subjects present increased intrinsic stiffness in both the CONTRA and IPSI limbs in specific ankle amplitudes.

Changes of Achilles tendon properties via 12-week PNF based robotic rehabilitation of ankle joints with spasticity and/or contracture

Ankle joint with spasticity and/or contracture can severely affect mobility and independence of stroke survivors. Due to that, the Achilles tendon(AT) is affected. In this paper, we aim to study changes of AT properties via proprioceptive neuromuscular facilitation (PNF) treatment. A robotic ankle-foot rehabilitation system has been proposed, which consists of a robotic ankle-foot platform and a graphic user interface. In this pilot study, two post-stroke patients participated and carried out a 12-week PNF treatment with the robotic system. The treatment is evaluated quantitatively in AT properties. The evaluation shows that after the PNF treatment, the average decrease of AT length is 4.1 mm (6.5%) and the recovery ratio is 30.4%, while the thickness has no change. The results indicate that the PNF based robotic rehabilitation for ankle joints with spasticity and/or contracture is effective to improve the ankle spasticity/contracture.

A pilot randomized controlled trial of a daily muscle stretch regime to prevent contractures in the arm after stroke

Objective: To evaluate the feasibility and effects of daily stretch positioning for prevention of contractures in stroke patients without arm function.

Design: Randomized controlled pilot study.

Setting: Stroke rehabilitation ward, UK.

Subjects: Twenty-five subjects drawn from an initial pool of 126 presenting with loss of arm function, all within four weeks of stroke.

Interventions: In addition to usual care, subjects in the experimental group (n =13) were prescribed two 30-min stretches for wrist and finger flexors and two 30-min stretches targeting shoulder adductors and internal rotators, per day for up to 12 weeks post stroke. Stretches were carried out by therapists and nursing staff.

Main measures: Passive range of wrist extension and shoulder external rotation to standard force or to pain at four, eight and twelve weeks after stroke.

Results: Compliance was variable. Frequency of positioning was fair from four to eight weeks post stroke but declined after that. Mean (SD) frequency of stretch positions completed between four and eight weeks was 36.5 (13.0) for the wrist, 31.2 (14.1) for the shoulder, out of 56 prescribed. There were no significant effects of treatment. By eight weeks post stroke the mean range of wrist extension and shoulder external rotation lost on the affected side in both groups was 30 degrees.

Conclusions: The stretch treatment was not well tolerated over many weeks. Statistical power was low due to the large degree of variability of range of motion and small sample size. The regime tested cannot be recommended as a workable treatment to prevent contractures.

Contracture preventive positioning of the hemiplegic arm in subacute stroke patients: a pilot randomized controlled trial

Objective: To investigate the effectiveness of a contracture preventive positioning procedure for the hemiplegic arm in subacute stroke patients in addition to conventional physio and occupational therapy.

Design: A single-blind pilot randomized controlled trial.

Setting: Inpatient neurological units from three rehabilitation centres in the Netherlands.

Subjects: Nineteen subacute stroke patients (minus two drop-outs) with a severe motor deficit of the arm.

Interventions: All subjects underwent conventional rehabilitation care. Nine subjects additionally received a positioning procedure for two 30-min sessions a day, five days a week, for five weeks.

Main measures: Passive range of motion of five arm movements using a hydrogoniometer and resistance to passive movement at the elbow using the Ashworth Scale. Secondary outcome measures were pain at the end range of passive motions, the arm section of the Fugl-Meyer Assessment and Barthel Index scores for ADL-independence. Outcome measures were taken after five weeks and additional measurements after 10 weeks by two assessors blinded to group allocation.

Results: Comparison of the experimental ( n = 9) with the control subjects ( n = 8) after five weeks showed that additional positioning significantly slowed down development of shoulder abduction contracture ( P = 0.042, −5.3 degrees versus −23 degrees). No other differences were found between the groups.

Conclusions: Applying a contracture preventive positioning procedure for the hemiplegic arm slowed down the development of shoulder abduction contracture. Positioning did not show significant additional value on other outcome measures. Since the sample size was small, results of this study need future verification.

The effect of exercise of the affected foot in stroke patients-a randomized controlled pilot trial

Objective: To evaluate the effect of treatment with a portable device called Stimulo on range of motion, muscle strength and spasticity in the ankle joint and its effect on walking ability, balance, activities of daily living (ADL) and health-related quality of life in stroke patients.

Design: A randomized controlled pilot study.

Setting: A research centre.

Subjects: Ambulatory or partly ambulatory chronic stroke patients with remaining spasticity and/or decreased range of motion in the hemiparetic leg/ankle.

Interventions: Standardized and individualized programme including active and passive range of motion of the ankle with a portable device (Stimulo), performed three times a week for 30 min, over a six-week period.

Main measures: Range of motion, muscle strength, spasticity, gait variables, balance, ADL and health-related quality of life.

Results: Eighteen subjects were included in the study with a mean age of 75 years. The compliance rate was 94-99%. There were no significant differences between the groups.

Conclusion: The study showed no significant effect of an ankle-exercise intervention programme with Stimulo. Further studies with a larger sample size are of importance before any further conclusions can be drawn.

Reliability of metatarsophalangeal and ankle joint torque measurements by an innovative device

The toe flexor muscles maintain body balance during standing and provide push-off force during walking, running, and jumping. Additionally, they are important contributing structures to maintain normal foot function. Thus, weakness of these muscles may cause poor balance, inefficient locomotion and foot deformities. The quantification of metatarsophalangeal joint (MPJ) stiffness is valuable as it is considered as a confounding factor in toe flexor muscles function. MPJ and ankle joint stiffness measurement is still largely depended on manual skills as current devices do not have good control on alignment, angular joint speed and displacement during measurement. Therefore, this study introduces an innovative dynamometer and protocol procedures for MPJ and ankle Joint torque measurement with precise and reliable foot alignment, angular joint speed and displacement control. Within-day and between-day test-retest experiments on MPJ and ankle joint torque measurement were conducted on ten and nine healthy male subjects respectively. The mean peak torques of MPJ and ankle joint of between-day and within-day measurement were 1.50±0.38Nm/deg and 1.19±0.34Nm/deg. The corresponding torques of the ankle joint were 8.24±2.20Nm/deg and 7.90±3.18Nm/deg respectively. Intraclass-correlation coefficients (ICC) of averaged peak torque of both joints of between-day and within-day test-retest experiments were ranging from 0.91 to 0.96, indicating the innovative device is systematic and reliable for the measurements and can be used for multiple scientific and clinical purposes.

Contributions of voluntary activation deficits to hand weakness after stroke

BACKGROUND

Hemiparetic stroke survivors often exhibit profound weakness in the digits of the paretic hand, but the relative contribution of potential biomechanical and neurological impairment mechanisms is not known. Establishing sources of impairment would help in guiding treatment.

OBJECTIVE

The present study sought to quantify the role of diminished capacity to voluntarily active finger flexor and extensor muscles as one possible neurological mechanism.

METHODS

Two groups of stroke survivors with "severe" (N = 9) or "moderate" (N = 9) hand impairment and one group of neurologically intact individuals (N = 9) participated. Subjects were asked to create isometric flexion force and extension force, respectively, with the tip of the middle finger. The maximum voluntary force (MVF) and the maximum stimulated force (MSF) produced by an applied train of electrical current pulses (MSF) were recorded for flexion and extension. Percent voluntary activation (PVA) was computed from MVF and MSF.

RESULTS

Significant deficits in both MVF and PVA were observed for stroke subjects compared to control subjects. For example, activation deficits were >80% for extensor digitorum communis (EDC) for the "severe" group. Maximum voluntary force and PVA deficits were greater for EDC than for flexor digitorum superficialis (FDS) for stroke subjects with severe impairment. Maximum voluntary force and PVA correlated significantly for stroke subjects but not for control subjects.

CONCLUSIONS

Although extrinsic finger muscles could be successfully recruited electrically, voluntary excitation of these muscles was substantially limited in stroke survivors. Thus, finger weakness after stroke results predominantly from the inability to fully activate the muscle voluntarily.

Interobserver reliability of the Australian Spasticity Assessment Scale (ASAS)

AIM

The aim of this paper is to present the Australian Spasticity Assessment Scale (ASAS) and to report studies of its interrater reliability. The ASAS identifies the presence of spasticity by confirming a velocity-dependent increased response to rapid passive movement and quantifies it using an ordinal scale.

METHOD

The rationale and procedure for the ASAS is described. Twenty-two participants with spastic CP (16 males; age range 1y 11mo-15y 3mo) who had not had botulinum neurotoxin-A within 4 months, or bony or soft tissue surgery within 12 months, were recruited from the spasticity management clinic of a tertiary paediatric teaching hospital. Fourteen muscles in each child were assessed by each of three experienced independent raters. ASAS was recorded for all muscles. Interrater reliability was calculated using the weighted kappa statistic (quadratic weighting; κqw) for individual muscles, for upper limbs, for lower limbs, and between raters.

RESULTS

The weighted kappa ranged between 0.75 and 0.92 for individual muscle groups and was 0.87 between raters.

INTERPRETATION

The ASAS complies with the definition of spasticity and is clinically feasible in paediatric settings. Our estimates of interrater reliability for the ASAS exceed that of the most commonly used spasticity scoring systems.

Deep soft-tissue massage applied to healthy calf muscle has no effect on passive mechanical properties: a randomized, single-blind, cross-over study

Background

Massage is often applied with the intention of improving flexibility or reducing stiffness in musculotendinous tissue. There is, however, a lack of supporting evidence that such mechanical effects occur. The purpose of the study was to investigate the effect of massage on the passive mechanical properties of the calf muscle complex.

Methods

Twenty nine healthy volunteers aged between 18 and 45 years of age had their calf muscle compliance and ankle joint dorsiflexion range of motion (ROM) measured using an instrumented footplate before, immediately and 30 minutes after a ten minute application of deep massage or superficial heating to the calf muscle complex. Repeated measures analysis of variance was used to determine differences between testing sessions and the types of intervention. Reliability testing for the measurement method was conducted using analysis of variance both within and between testing sessions.

Results

There was no significant change in calf muscle stiffness or ankle dorsiflexion range of motion with or without the application of calf massage. Inter- and intra-session reliability were very high, ICC > 0.88 (p < 0.001).

Conclusions

Although individuals’ perception of a change in tissue characteristics following massage has been reported, there was no evidence that soft tissue massage led to a change in the passive mechanical properties of the calf muscle complex. The findings of this study suggest that the use of massage to increase tissue flexibility prior to activity is not justified.

NeuroControl of movement: system identification approach for clinical benefit

Progress in diagnosis and treatment of movement disorders after neurological diseases like stroke, cerebral palsy (CP), dystonia and at old age requires understanding of the altered capacity to adequately respond to physical obstacles in the environment. With posture and movement disorders, the control of muscles is hampered, resulting in aberrant force generation and improper impedance regulation. Understanding of this improper regulation not only requires the understanding of the role of the neural controller, but also attention for: (1) the interaction between the neural controller and the "plant", comprising the biomechanical properties of the musculaskeletal system including the viscoelastic properties of the contractile (muscle) and non-contractile (connective) tissues: neuromechanics; and (2) the closed loop nature of neural controller and biomechanical system in which cause and effect interact and are hence difficult to separate. Properties of the neural controller and the biomechanical system need to be addressed synchronously by the combination of haptic robotics, (closed loop) system identification (SI), and neuro-mechanical modeling. In this paper, we argue that assessment of neuromechanics in response to well defined environmental conditions and tasks may provide for key parameters to understand posture and movement disorders in neurological diseases and for biomarkers to increase accuracy of prediction models for functional outcome and effects of intervention.