Limb Contractures in Progressive Neuromuscular Disease and the Role of Stretching, Orthotics, and Surgery

Cooperative Goal Generation for Reaching Tasks in Robot-Assisted Rehabilitation

Robot-assisted neurorehabilitation requires automated generation of goal positions for reaching tasks in functional movement therapy. In state-of-the-art solutions, these positions are determined by a motivational therapy game either through constraints on the end-effector (2D or 3D games), or individual arm joints (1D games). Consequently, these positions cannot be adapted to the patients' specific needs by the therapist, and the effectiveness of the training is reduced. We solve this issue by generating goal positions using Gaussian Mixture Models and probability density maps based on the active range of motion of the patient and desired activities, while being compliant with existing game constraints. Therapists can modify the goal generation via an intuitive difficulty and activity parameter. The pipeline was tested on the upper-limb exoskeleton ANYexo 2.0. We have shown that the range of motion exploration rate could be altered from 0.39% to 5.9% per task and that our method successfully generated a sequence of reaching tasks that matched the range of motion of the selected activity, up to an inlier accuracy of 78.9%. Results demonstrate that the responsibilities of the therapy game (i.e., motivating the patient) and the therapists (i.e., individualizing the training) could be distributed properly. We believe that with our pipeline, effective cooperation between the involved agents is achieved, and the provided therapy can be improved.

Computational Mechanics of Form-Fitting 3D-Printed Lattice-Based Wrist-Hand Orthosis for Motor Neuron Disease

Motor neuron disease (MND) patients often experience hand-wrist muscle atrophy resulting in severe social consequences and hampering their daily activities. Although hand-wrist orthosis is commonly used to assist weakened muscles, its effectiveness is limited due to the rapid progression of the disease and the need for customization to suit individual patient requirements. To address these challenges, this study investigates the application of three-dimensional (3D) printing technology to design and fabricate two lattice structures inspired by silkworm cocoons, using poly-ε-caprolactone as feedstock material. Finite element method (FEM) analysis is employed to study the mechanical behavior, enabling control over the geometric configuration incorporated into the hand-wrist orthosis. Through tensile displacement and three-point bending simulations, the stress distribution is examined for both lattice geometries. Geometry-1 demonstrates anisotropic behavior, while geometry-2 exhibits no strict directional dependence due to its symmetry and uniform node positioning. Moreover, the biocompatibility of lattices with human skin fibroblasts is investigated, confirming excellent biocompatibility. Lastly, the study involves semi-structured interviews with MND patients to gather feedback and develop prototypes of form-fitting 3D-printed lattice-based hand-wrist orthosis. By utilizing 3D printing technology, this study aims to provide customized orthosis that can effectively support weakened muscles and reposition the hand for individuals with MND.

Management of arthrofibrosis in neuromuscular disorders: a review

Arthrofibrosis, or rigid contracture of major articular joints, is a significant morbidity of many neurodegenerative disorders. The pathogenesis depends on the mechanism and severity of the precipitating neuromuscular disorder. Most neuromuscular disorders, whether spastic or hypotonic, culminate in decreased joint range of motion. Limited range of motion precipitates a cascade of pathophysiological changes in the muscle-tendon unit, the joint capsule, and the articular cartilage. Resulting joint contractures limit functional mobility, posing both physical and psychosocial burdens to patients, economic burdens on the healthcare system, and lost productivity to society. This article reviews the pathophysiology of arthrofibrosis in the setting of neuromuscular disorders. We describe current non-surgical and surgical interventions for treating arthrofibrosis of commonly affected joints. In addition, we preview several promising modalities under development to ameliorate arthrofibrosis non-surgically and discuss limitations in the field of arthrofibrosis secondary to neuromuscular disorders.

Development of Contractures in DMD in Relation to MRI-Determined Muscle Quality and Ambulatory Function

BACKGROUND

Joint contractures are common in boys and men with Duchenne muscular dystrophy (DMD), and management of contractures is an important part of care. The optimal methods to prevent and treat contractures are controversial, and the natural history of contracture development is understudied in glucocorticoid treated individuals at joints beyond the ankle.

OBJECTIVE

To describe the development of contractures over time in a large cohort of individuals with DMD in relation to ambulatory ability, functional performance, and muscle quality measured using magnetic resonance imaging (MRI) and spectroscopy (MRS).

METHODS

In this longitudinal study, range of motion (ROM) was measured annually at the hip, knee, and ankle, and at the elbow, forearm, and wrist at a subset of visits. Ambulatory function (10 meter walk/run and 6 minute walk test) and MR-determined muscle quality (transverse relaxation time (T2) and fat fraction) were measured at each visit.

RESULTS

In 178 boys with DMD, contracture prevalence and severity increased with age. Among ambulatory participants, more severe contractures (defined as greater loss of ROM) were significantly associated with worse ambulatory function, and across all participants, more severe contractures significantly associated with higher MRI T2 or MRS FF (ρ: 0.40-0.61 in the lower extremity; 0.20-0.47 in the upper extremity). Agonist/antagonist differences in MRI T2 were not strong predictors of ROM.

CONCLUSIONS

Contracture severity increases with disease progression (increasing age and muscle involvement and decreasing functional ability), but is only moderately predicted by muscle fatty infiltration and MRI T2, suggesting that other changes in the muscle, tendon, or joint contribute meaningfully to contracture formation in DMD.

Knee Strength and Ankle Range of Motion Impacts on Timed Function Tests in Duchenne Muscular Dystrophy: In the Era of Glucocorticoids

BACKGROUND

Duchenne Muscular Dystrophy (DMD) is a neuromuscular disorder that presents in childhood and is characterized by slowly progressive proximal weakness and lower extremity contractures that limit ambulatory ability [1, 2]. Contractures develop in the ankles, knees, and hips due to muscle imbalances, fibrotic changes, loss of strength, and static positioning [2, 5]. Currently, standards of care guidelines emphasize the importance of maintaining good musculoskeletal alignment through stretching, bracing, and glucocorticoid (GC) therapy to preserve strength and function.

METHODS

This is a retrospective analysis of prospectively collected data through the CINRG Duchenne Natural history study (DNHS). The objectives of this analysis are to understand the progression of ankle contractures for individuals with DMD and to investigate the relationship between progressive lower limb contractures, knee strength, and Timed Function Tests.A collection of TFTs including supine to stand (STS), 10 meter walk test (10MWT), and timed stair climbing (4SC) have been used to monitor disease progression and are predictive of loss of ambulation in these patients [4]. Multiple factors contribute to loss of ambulation, including progressive loss of strength and contracture development that leads to changing biomechanical demands for ambulation. A better understanding of the changes in strength and range of motion (ROM) that contribute to loss of function is important in a more individualized rehabilitation management plan. In this longitudinal study, we measured strength using quantitative muscle testing (QMT) with the CINRG Quantitative Measurement System (CQMS)), ROM was measuresed with a goniometer and TFTs were measured using a standard stopwatch and methodology.

RESULTS

We enrolled 440 participants; mean baseline age was 8.9 (2.1, 28.0) years with 1321 observations used for analysis. GC use was stratified based on duration on drug with 18.7%at <  6 months or naïve; 4.3%<1 year; 58.0%1 <  10 years; and 19.3%between 10-25 years of GC use. Ankle ROM was better for those on GC compared to GC naive but did not significantly influence long-term progression rates. QMT, ROM, age and GCs contribute to speed of TFTs. Knee extension (KE) strength and Dorsiflexion (DF) ROM are significant predictors of speed for all TFTs (p <  0.001). Of the variables used in this analysis, KE strength is the primary predictor of walking speed, estimating that every pound increase in KE results in a 0.042 m/s improvement in 10MWT, and a smaller similar increase of 0.009 m/s with every degree of ankle DF ROM.

CONCLUSION

GC use provides an improvement in strength and ROM but does not affect rate of change. Knee strength has a greater influence on speed of TFTs than DF ROM, although both are statistically significant predictors of speed. Results show that retaining knee strength [1, 2], along with joint flexibility, may be important factors in the ability to perform walking, climbing and supine to stand activities.

Design and Implementation of a Robotic Hip Exoskeleton for Gait Rehabilitation

In this paper, a four degrees-of-freedom robotic hip exoskeleton was proposed for gait rehabilitation. The robotic hip exoskeleton was designed with active flexion/extension and passive abduction/adduction at each hip joint to comply with the movement of the thigh. Due to each user’s different lower limbs characteristics and unknown torques at hip joints, model-free linear extended state observer (LESO)-based controllers were proposed for rehabilitation gait control. The prototypes of the robotic hip exoskeleton and controller designs were validated and compared through walking and ascending rehabilitation experiments. Additionally, a motion captured system and EMG signals were used to investigate the walking assistance of the robotic hip exoskeleton.

Compliance to DMD Care Considerations in the Netherlands

BACKGROUND AND OBJECTIVE

To optimize care for patients with DMD, it is essential to know to what extent current care complies with the recommended monitoring frequencies suggested by the DMD care considerations. The objective of this study was to investigate the current care for patients with DMD in the Netherlands and to what extent the care complies with the international care considerations.

METHODS

A cross-sectional questionnaire was carried out among the Dutch DMD patients and caregivers about the patients' functional and health status, visits to healthcare professionals, clinical tests and assessments, therapy, medication use and access to medical aids and devices. Compliance to guidelines was defined by comparing the frequency of visits to health care providers and clinical tests with the recommended frequencies derived from the care considerations of 2010.

RESULTS

Eighty-four participants completed the questionnaire. The majority of participants met the recommended visit frequencies to a neuromuscular specialist and cardiologist. Compliance was suboptimal for respiratory assessments in the non-ambulatory phase, monitoring of side effects of corticosteroid use and neuromuscular assessments. Disease specific information supply was perceived as sufficient and participants were satisfied with the received care.

CONCLUSIONS

This study identifies areas in which compliance is lacking. Countries, such as the Netherlands, working according to a shared care system require easy and low-threshold communication between health care centers and a clear division of roles and responsibilities to reach optimal compliance. In the Netherlands the Duchenne Center Netherlands has the coordinating role.

Passive stiffness of fibrotic skeletal muscle in mdx mice relates to collagen architecture

KEY POINTS

The amount of fibrotic material in dystrophic mouse muscles relates to contractile function, but not passive function. Collagen fibres in skeletal muscle are associated with increased passive muscle stiffness in fibrotic muscles. The alignment of collagen is independently associated with passive stiffness in dystrophic skeletal muscles. These outcomes demonstrate that collagen architecture rather than collagen content should be a target of anti-fibrotic therapies to treat muscle stiffness.

ABSTRACT

Fibrosis is prominent in many skeletal muscle pathologies including dystrophies, neurological disorders, cachexia, chronic kidney disease, sarcopenia and metabolic disorders. Fibrosis in muscle is associated with decreased contractile forces and increased passive stiffness that limits joint mobility leading to contractures. However, the assumption that more fibrotic material is directly related to decreased function has not held true. Here we utilize novel measurement of extracellular matrix (ECM) and collagen architecture to relate ECM form to muscle function. We used mdx mice, a model for Duchenne muscular dystrophy that becomes fibrotic, and wildtype mice. In this model, extensor digitorum longus (EDL) muscle was significantly stiffer, but with similar total collagen, while the soleus muscle did not change stiffness, but increased collagen. The stiffness of the EDL was associated with increased collagen crosslinking as determined by collagen solubility. Measurement of ECM alignment using polarized light microscopy showed a robust relationship between stiffness and alignment for wildtype muscle that broke down in mdx muscles. Direct visualization of large collagen fibres with second harmonic generation imaging revealed their relative abundance in stiff muscles. Collagen fibre alignment was linked to stiffness across all muscles investigated and the most significant factor in a multiple linear regression-based model of muscle stiffness from ECM parameters. This work establishes novel characteristics of skeletal muscle ECM architecture and provides evidence for a mechanical function of collagen fibres in muscle. This finding suggests that anti-fibrotic strategies to enhance muscle function and excessive stiffness should target large collagen fibres and their alignment rather than total collagen.

The Minimal Clinical Important Difference (MCID) in Annual Rate of Change of Timed Function Tests in Boys with DMD

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare x-linked recessive genetic disorder affecting 1 in every 5000-10000 [1, 2]. This disease leads to a variable but progressive sequential pattern of muscle weakness that eventually causes loss of important functional milestones such as the ability to walk. With promising drugs in development to ameliorate the effects of muscle weakness, these treatments must be associated with a clinically meaningful functional change.

OBJECTIVE

The objective of this analysis is to determine both distribution, minimal detectable change (MDC), and anchor-based, minimal clinically important difference, (MCID) of 12 month change values in standardized time function tests (TFT) used to monitor disease progression in DMD.

METHOD

This is a retrospective analysis of prospectively collected data from a multi-center prospective natural history study with the Cooperative International Neuromuscular Research Group (CINRG). This study calculated MDC and MCID values for 3 commonly used timed function tests typically used to monitor disease progression; supine to stand (STS), 10 meter walk/run (10MWT), and 4 stair climb (4SC). MDC used standard error of measurement (SEM) while MCID measurements used the Vignos scale as an anchor to determine clinical change in functional status.

RESULTS

All 3 TFT were significantly important clinical endpoints to detect MDC and MCID changes. MDC and MCID 12 month changes were significant in 10MWT (-0.138, -0.212), Supine to Stand (-0.026, -0.023) and 4 stair climb (-0.034, -0.035) with an effect size greater or close to 0.2.

CONCLUSION

The 3 TFT are clinically meaningful endpoints used to establish change in DMD. MCID values were higher than MDC values indicating that an anchor-based approach using Vignos as a clinically meaningful loss of lower extremity abilities is appropriate to assess change in boys with DMD.

Clinical Management of Duchenne Muscular Dystrophy in the Netherlands: Barriers to and Proposals for the Implementation of the International Clinical Practice Guidelines

BACKGROUND

In order to successfully implement the international clinical care guidelines for Duchenne muscular dystrophy (DMD) in the Netherlands, it is essential to know what barriers are experienced by healthcare practitioners regarding guideline adherence and organization of care. In the Netherlands, academic medical centers provide follow up visits and work together with peripheral hospitals, rehabilitation centers, centers for home ventilation and primary care centers for treatment.

OBJECTIVE

To investigate perceived barriers to international clinical DMD guideline adherence and identify potential areas of improvement for implementation in the Dutch 'shared care' organization.

METHODS

Semi-structured in-depth interviews with healthcare practitioners of academic medical hospitals and questionnaires for healthcare practitioners of rehabilitation centers, based on the framework of Cabana.

RESULTS

The analyses identified 4 barriers for non-adherence to the DMD guideline: (i) lack of familiarity/awareness, (ii) lack of agreement with specific guideline, (iii) lack of outcome expectancy, (iv) external barriers.

CONCLUSIONS

A heterogeneous set of barriers is present. Therefore, a multifaceted intervention strategy is proposed to overcome these barriers, including a clear division of roles, allowing for local (Dutch) adaptations per specialism by local consensus groups, and the facilitation of easy communication with experts/opinion leaders as well as between care professionals.

Implementation of an Upper-Limb Exoskeleton Robot Driven by Pneumatic Muscle Actuators for Rehabilitation

Implementation of a prototype of a 4-degree of freedom (4-DOF) upper-limb exoskeleton robot for rehabilitation was described in this paper. The proposed exoskeleton robot has three DOFs at the shoulder joint and one DOF at the elbow joint. The upper-limb exoskeleton robot is driven by pneumatic muscle actuators (PMA) via steel cables. To implement the passive rehabilitation control, the rehabilitation trajectories expressed in the Fourier series were first planned by the curve fitting. The fuzzy sliding mode controller (FSMC) was then applied to the upper-limb exoskeleton robot for rehabilitation control. Several rehabilitation scenarios were carried out to validate the designed PMA-actuated exoskeleton robot.

Conference report on contractures in musculoskeletal and neurological conditions

Limb contractures are debilitating complications associated with various muscle and nervous system disorders. This report summarizes presentations at a conference at the Shirley Ryan AbilityLab in Chicago, Illinois, on April 19-20, 2018, involving researchers and physicians from diverse disciplines who convened to discuss current clinical and preclinical understanding of contractures in Duchenne muscular dystrophy, stroke, cerebral palsy, and other conditions. Presenters described changes in muscle architecture, activation, extracellular matrix, satellite cells, and muscle fiber sarcomeric structure that accompany or predispose muscles to contracture. Participants identified ongoing and future research directions that may lead to understanding of the intersecting factors that trigger contractures. These include additional studies of changes in muscle, tendon, joint, and neuronal tissues during contracture development with imaging, molecular, and physiologic approaches. Participants identified the requirement for improved biomarkers and outcome measures to identify patients likely to develop contractures and to accurately measure efficacy of treatments currently available and under development.

Novel Recessive TNNT1 Congenital Core-Rod Myopathy in French Canadians

OBJECTIVE

Recessive null variants of the slow skeletal muscle troponin T1 (TNNT1) gene are a rare cause of nemaline myopathy that is fatal in infancy due to respiratory insufficiency. Muscle biopsy shows rods and fiber type disproportion. We report on 4 French Canadians with a novel form of recessive congenital TNNT1 core-rod myopathy.

METHODS

Patients underwent full clinical characterization, lower limb magnetic resonance imaging (MRI), muscle biopsy, and genetic testing. A zebrafish loss-of-function model using morpholinos was created to assess the pathogenicity of the identified variant. Wild-type or mutated human TNNT1 mRNAs were coinjected with morpholinos to assess their abilities to rescue the morphant phenotype.

RESULTS

Three adults and 1 child shared a novel missense homozygous variant in the TNNT1 gene (NM_003283.6: c.287T > C; p.Leu96Pro). They developed from childhood very slowly progressive limb-girdle weakness with rigid spine and disabling contractures. They suffered from restrictive lung disease requiring noninvasive mechanical ventilation in 3 patients, as well as recurrent episodes of rhabdomyolysis triggered by infections, which were relieved by dantrolene in 1 patient. Older patients remained ambulatory into their 60s. MRI of the leg muscles showed fibrofatty infiltration predominating in the posterior thigh and the deep posterior leg compartments. Muscle biopsies showed multiminicores and lobulated fibers, rods in half the patients, and no fiber type disproportion. Wild-type TNNT1 mRNA rescued the zebrafish morphants, but mutant transcripts failed to do so.

INTERPRETATION

This study expands the phenotypic spectrum of TNNT1 myopathy and provides functional evidence for the pathogenicity of the newly identified missense mutation. ANN NEUROL 2020;87:568-583.

Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy

Steadily improving management of Duchenne muscular dystrophy (DMD) continues to lead to improved physical and functional status, allowing increasingly successful transitions to independence and self-actualization in adulthood. Rehabilitation principles remain key to overall management for individuals with DMD with increasing options for ever more successful management, reflecting a changing natural history based on the use of glucocorticoids, more consistent comprehensive care, and the emergence of disease-modifying treatments. Advances and expansion in assessment, cardiorespiratory management, preventive management of contracture and deformity, assistive technology, "smart" technology, and robotics with increased emphasis on function, participation, self-advocacy, and independence in decision-making should allow individuals with DMD to experience childhood and transition to adulthood with support that allows for increasing success in the achievement of individual goals and fulfillment across the life span.

Quantitative Evaluation of Lower Extremity Joint Contractures in Spinal Muscular Atrophy: Implications for Motor Function

PURPOSE

To quantitatively describe passive lower extremity range of motion in participants with spinal muscular atrophy (SMA) types 2 and 3, and to establish preliminary thresholds to identify individuals at risk for performing poorly on disease-specific motor function outcome measures.

METHODS

Eighty participants with SMA types 2 and 3, enrolled in an international multicenter natural history study, were evaluated with lower extremity range of motion testing and the Hammersmith Functional Motor Scale-Expanded.

RESULTS

A hip extension joint angle of -7.5° or less for SMA type 2 and 0° or less for SMA type 3 identified diminished motor ability with good sensitivity. For knee extension, a joint angle of -9.0° or less for SMA type 2 or 0° or less for SMA type 3 was similarly sensitive.

CONCLUSIONS

Minimal hip and knee joint contractures were associated with diminished motor ability. Clinical trial designs should consider the effect of contractures on motor function.

Supported Standing in Boys With Duchenne Muscular Dystrophy

PURPOSE

To evaluate the safety, tolerability, and efficacy of supported standing in a small sample of boys with Duchenne muscular dystrophy (DMD).

METHODS

Four 12- to 15-year-old boys with DMD engaged in a home-based supported standing program for 6 to 12 months. A single-subject design was employed to examine muscle length. Bone mineral density was assessed at 4-month intervals using dual-energy x-ray absorptiometry.

RESULTS

Upright, sustained supported standing was tolerated in 3 of the 4 boys. Mean weekly stand times ranged from 1.3 to 3.3 hours. Improved hip or knee flexor muscle length was seen in 3 of the 4 boys. No boys showed improved plantar flexor muscle length or increased lumbar bone mineral density.

CONCLUSIONS

Findings offer preliminary empirical evidence addressing the safety, tolerability, and efficacy of standing in boys with DMD. Additional research with an emphasis on better program adherence is indicated.

Rehabilitative technology use among individuals with Duchenne/Becker muscular dystrophy

PURPOSE

To document use of rehabilitative technology among individuals with Duchenne/Becker muscular dystrophy (DBMD) among sites of the Muscular Dystrophy Surveillance, Tracking, and Research network (MD STARnet).

METHODS

Data from 362 caregivers who participated in the MD STARnet caregiver interview between April 2006 and March 2012 (54.7% response rate) were analyzed to assess the type, frequency and duration of use of assistive technology.

RESULTS

Caregiver reports of technology use by individuals with DBMD across five MD STARnet sites in the US demonstrated significant regional differences in the proportion of individuals who had ever used night splints (36.9%-73.0%), standers (3.1%-22.2%) and scooters (10.7%-54.5%). Among individuals who used night splints 59.7% stopped using them at a mean age of 10.3 years after a mean duration of 2.9 years in spite of the current recommendation to continue using them through the non-ambulatory phase.

DISCUSSION

Results of this comprehensive survey document the frequency of assistive device use by individuals with DBMD in the USA and also provides data on differences across the sites. Further research is needed to understand the reasons for and the impact of these differences on clinical outcomes and health related quality of life of individuals with DBMD.

Noninflammatory Joint Contractures Arising from Immobility: Animal Models to Future Treatments

Joint contractures, defined as the limitation in the passive range of motion of a mobile joint, can be classified as noninflammatory diseases of the musculoskeletal system. The pathophysiology is not well understood; limited information is available on causal factors, progression, the pathophysiology involved, and prediction of response to treatment. The clinical heterogeneity of joint contractures combined with the heterogeneous contribution of joint connective tissues to joint mobility presents challenges to the study of joint contractures. Furthermore, contractures are often a symptom of a wide variety of heterogeneous disorders that are in many cases multifactorial. Extended immobility has been identified as a causal factor and evidence is provided from both experimental and epidemiology studies. Of interest is the involvement of the joint capsule in the pathophysiology of joint contractures and lack of response to remobilization. While molecular pathways involved in the development of joint contractures are being investigated, current treatments focus on physiotherapy, which is ineffective on irreversible contractures. Future treatments may include early diagnosis and prevention.

Upper extremity orthoses use in amyotrophic lateral sclerosis/motor neuron disease: three case reports

BACKGROUND

Central to the armamentarium of a hand therapist is evaluation for successful orthotic use. Orthoses can have a profound effect on quality of life in persons with amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND). The purposes of orthoses are to decrease the effects of muscle imbalance, provide assistance in performance of activities of daily living (ADLs), prevent joint contracture, and relieve pain. There are few published accounts on the usefulness of orthoses and ALS. The purpose of this paper is to expand the body of literature by describing three successful cases.

METHODS

Three cases illustrate effects on weakened proximal muscles, wrist extensors, thenar musculature, and intrinsic muscles. The primary outcome measure is patient report, but functional rating scales, goniometry, quality of life scores, and pinch strength when obtainable are described.

RESULTS

Due to the progressive nature of the disease, outcome measures can be inconclusive. Patient report of increased life satisfaction and ability to participate in daily life is the critical outcome in these case examples. In all cases, satisfaction increased. Some of the stated changes include the following: ability to manipulate objects, grip, eat, wipe face, hold phone, use iPad®, and adjust hat.

CONCLUSIONS

Upper extremity orthotic use can be a beneficial adjunct contributing to the quality of life for individuals with ALS/MND. We have observed positive responses in pain control, contracture management, functional positioning, and increased independence with the use of orthoses. Designing appropriate means of studying effects of orthosis intervention is deficient in the current scientific literature.

Current treatment and management of dystrophinopathies

OPINION STATEMENT

• Duchenne muscular dystrophy (DMD), the most common and severe type of dystrophinopathy, is a progressive disease affecting primordially skeletal and cardiac muscle. A coordinated multidisciplinary approach is required to address its multisystemic manifestations and secondary problems.• Treatment with glucocorticosteroids (GCS) is accepted as standard of care in ambulant DMD. Daily and intermittent administrations are both in common use with different efficacy and different side effect profile.• There are no established guidelines for age/stage at initiation and treatment duration of GCS. Common practice is initiation of GCS before the child is starting to decline (between age 3 and 6 years) and continuation of monitored treatment after loss of ambulation, aiming at delaying cardiac and respiratory manifestations and preventing the development of scoliosis.• Prevention, monitoring, and treatment of the side effects of long-term chronic GCS use, such as excessive weight gain, hypertension, osteoporosis, impairment of glucose metabolism, delayed puberty, and cataract, should be integrated in the standards of care.• Noninvasive ventilatory support associated with cough assisting techniques has significantly improved the longevity in DMD.• Pharmacologic treatment for cardiac manifestations includes the standard treatments of dilated cardiomyopathy and arrhythmia such as the use of angiotensin converting enzyme (ACE) inhibitors, beta-blockers and diuretics. The lack of robust controlled data hampers clear recommendations about preventive treatment with ACE inhibitors.• DMD is associated with low bone mineral content, which is aggravated by the use of corticosteroids. The use of biphosphonates can be considered in the treatment of painful vertebral fractures. The use of biphosphonates as a preventive treatment should be investigated in randomized controlled studies.• DMD has evolved from a pediatric disease to an adult condition. This underscores the need to prepare adult neurologists for the optimal surveillance and management of patients with a severe chronic disease that have outgrown the pediatric care and that may develop new disease manifestations with improved longevity.

Is there any relationship between orthotic usage and functional activities in children with neuromuscular disorders?

BACKGROUND

Contractures of Achilles tendons and gastrocnemius muscle deteriorate the performance in daily living activities of patients with neuromuscular diseases. Ankle-foot orthoses help to prevent the progression of deformities and to obtain optimal position of the joints to support standing and walking.

OBJECTIVE

To investigate the relationship between orthotic usage and functional activities in pediatric patients with different neuromuscular diseases.

STUDY DESIGN

Retrospective study.

METHODS

A total of 127 subjects' physical assessment forms were analyzed. Functional level, type of orthoses, falling frequencies, ankle joint range of motion, and timed performance tests were examined in two consecutive dates with an interval of 3 months.

RESULTS

A total of 91 patients were using orthoses while 36 patients were not within assessment dates. A total of 64 of 91 (70.3%) patients were diagnosed with Duchenne muscular dystrophy. A total of 81 (89.0%) subjects were using plastic ankle-foot orthoses for positioning at nights and 10 (11%) were using different types of the orthoses (knee-ankle-foot orthoses, dynamic ankle-foot orthoses, and so on) for gait in the study group.

CONCLUSIONS

Night ankle-foot orthoses were not found to be effective directly on functional performance in children with neuromuscular diseases, although they protect ankle from contractures and may help to correct gait and balance.

CLINICAL RELEVANCE

This retrospective study shows that the positive effects of using an ankle-foot orthosis at night are not reflected in the functional performance of children with neuromuscular diseases. This may be due to the progressive deteriorating nature of the disease.

Systematic review and evidence-based clinical recommendations for dosing of pediatric supported standing programs

PURPOSE

There is a lack of evidence-based recommendations for effective dosing of pediatric supported standing programs, despite widespread clinical use.

METHODS

Using the International Classification of Functioning, Disability, and Health (Child and Youth Version) framework, we searched 7 databases, using specific search terms.

RESULTS

Thirty of 687 studies located met our inclusion criteria. Strength of the evidence was evaluated by well-known tools, and to assist with clinical decision-making, clinical recommendations based on the existing evidence and the authors' opinions were provided.

CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE

Standing programs 5 days per week positively affect bone mineral density (60 to 90 min/d); hip stability (60 min/d in 30° to 60° of total bilateral hip abduction); range of motion of hip, knee, and ankle (45 to 60 min/d); and spasticity (30 to 45 min/d).

Physical therapy evaluation and management in neuromuscular diseases

Neuromuscular disorders (NMDs) are a group of myopathic or neuropathic diseases that directly or indirectly affect the functioning of muscle. Physical therapists (PTs) have extensive specialized training in musculoskeletal evaluation and assessment that gives them the tools to meet the significant needs of this population. This article reviews the role of PTs in treating the NMD population with a discussion of available evaluation techniques and interventions and with an effort to differentiate between treatments known to apply to this population and conventional practice of PTs. The status of currently available outcome measures used for research and their applicability to clinics are presented.

Consensus treatment recommendations for late-onset Pompe disease

INTRODUCTION

Pompe disease is a rare, autosomal recessive disorder caused by deficiency of the glycogen-degrading lysosomal enzyme acid alpha-glucosidase. Late-onset Pompe disease is a multisystem condition, with a heterogeneous clinical presentation that mimics other neuromuscular disorders.

METHODS

Objective is to propose consensus-based treatment and management recommendations for late-onset Pompe disease.

METHODS

A systematic review of the literature by a panel of specialists with expertise in Pompe disease was undertaken.

CONCLUSIONS

A multidisciplinary team should be involved to properly treat the pulmonary, neuromuscular, orthopedic, and gastrointestinal elements of late-onset Pompe disease. Presymptomatic patients with subtle objective signs of Pompe disease (and patients symptomatic at diagnosis) should begin treatment with enzyme replacement therapy (ERT) immediately; presymptomatic patients without symptoms or signs should be observed without use of ERT. After 1 year of ERT, patients' condition should be reevaluated to determine whether ERT should be continued.

Plantarflexion contracture in the mdx mouse

OBJECTIVE

Contractures are a major clinical issue for patients with muscular dystrophies. However, it is unknown whether contractures are present in the widely used mdx mouse model of Duchenne muscular dystrophy. Therefore, the objectives of this study were to develop methods to measure muscle contractures in mice, to determine whether plantarflexion contractures are present in mdx mice, and to analyze the composition of the major muscles involved.

DESIGN

Hindlimbs of eight wild type and six mdx mice were assessed every 2 wks during the course of a 12-wk study. Assessments included range of motion and in vivo torques about the ankle. At the end of the study, mice were euthanized, and muscles were analyzed for composition.

RESULTS

The mdx mice had ∼10 degrees less dorsiflexion, increased passive torque moving the ankle into dorsiflexion, and an increased passive-to-active torque ratio relative to wild type mice. Gastrocnemius muscle composition alterations included increased wet mass, decreased protein content, and increased collagen.

CONCLUSIONS

The results indicate that mdx mice have plantarflexion contractures similar to those seen in children with Duchenne muscular dystrophy. In future studies, these measures can be used to assess strategies to slow the progression of contractures that occur with muscular dystrophies.

Aging with muscular dystrophy: pathophysiology and clinical management

Major advances in the fields of medical science and physiology, molecular genetics, biomedical engineering, and computer science have provided individuals with muscular dystrophy (MD) with more functional equipment, allowing better strategies for improvement of quality of life. These advances have also allowed a significant number of these patients to live much longer. As progress continues to change management, it also changes patients' expectations. A comprehensive medical and rehabilitative approach to management of aging MD patients can often fulfill expectations and help them enjoy an enhanced quality of life.

Interventions for increasing ankle range of motion in patients with neuromuscular disease

BACKGROUND

Reduced ankle dorsiflexion range of motion, or ankle equinus, is a common and disabling problem for patients with neuromuscular disease. Clinicians devote considerable time and resources implementing interventions to correct this problem although few of these interventions have been subject to rigorous empirical investigation.

OBJECTIVES

To assess the effect of interventions to reduce or resolve ankle equinus in people with neuromuscular disease.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Specialized Register (August 2009), Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2009), MEDLINE (1966 to August 2009), EMBASE (1980 to August 2009), CINAHL 1982 to August 2009), AMED (1985 to August 2009) and The Physiotherapy Evidence Database (PEDro) (1929 to August 2009). We searched the reference lists of identified articles and also contacted known experts in the field to identify additional or unpublished data.

SELECTION CRITERIA

Randomised controlled trials evaluating interventions for increasing ankle dorsiflexion range of motion in neuromuscular disease. Outcomes included ankle dorsiflexion range of motion, functional improvement, foot alignment, foot and ankle muscle strength, health-related quality of life, satisfaction with the intervention and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently selected papers, assessed trial quality and extracted data.

MAIN RESULTS

Four studies involving 149 participants met inclusion criteria for this review. Two studies assessed the effect of night splinting in a total of 26 children and adults with Charcot-Marie-Tooth disease type 1A. There were no statistically or clinically significant differences between wearing a night splint and not wearing a night splint. One study assessed the efficacy of prednisone treatment in 103 boys with Duchenne muscular dystrophy. While a daily dose of prednisone at 0.75 mg/kg/day resulted in significant improvements in some strength and function parameters compared with placebo, there was no significant difference in ankle range of motion between groups. Increasing the prednisone dose to 1.5 mg/kg/day had no significant effect on ankle range of motion. One study evaluated early surgery in 20 young boys with Duchenne muscular dystrophy. Surgery resulted in increased ankle dorsiflexion range at 12 months but functional outcomes favoured the control group. By 24 months, many boys in the surgical group experienced a relapse of achilles tendon contractures.

AUTHORS' CONCLUSIONS

There is no evidence of significant benefit from any intervention for increasing ankle range of motion in Charcot-Marie-Tooth disease type 1A or Duchenne muscular dystrophy. Further research is required.

Diagnosis and management of Duchenne muscular dystrophy, part 2: implementation of multidisciplinary care

Optimum management of Duchenne muscular dystrophy (DMD) requires a multidisciplinary approach that focuses on anticipatory and preventive measures as well as active interventions to address the primary and secondary aspects of the disorder. Implementing comprehensive management strategies can favourably alter the natural history of the disease and improve function, quality of life, and longevity. Standardised care can also facilitate planning for multicentre trials and help with the identification of areas in which care can be improved. Here, we present a comprehensive set of DMD care recommendations for management of rehabilitation, orthopaedic, respiratory, cardiovascular, gastroenterology/nutrition, and pain issues, as well as general surgical and emergency-room precautions. Together with part 1 of this Review, which focuses on diagnosis, pharmacological treatment, and psychosocial care, these recommendations allow diagnosis and management to occur in a coordinated multidisciplinary fashion.

[Importance of the muscular system in the development of neuromuscular deformities: new diagnostic and therapeutic aspects ]

The term neuromuscular disorders covers a multitude of diagnoses which are of peculiar interest to the orthopaedic surgeon due to their impact upon the musculoskeletal system. The development of changes in muscle structure, muscle properties and muscle function carries the risk for the development of deformities and a deterioration in physical functions. Diagnostic and therapeutic measures should focus on muscular changes in particular. An interdisciplinary approach is recommended. The traditional orthopaedic management of deformity correction by muscle or tendon lengthenings always involves the risk of additional weakness. A more functional view of neuromuscular disorders should look at the 4 "M"s, i.e. muscle power, muscle excursion, muscle balance and muscle structure. Whenever possible, functionally important muscles should be preserved by correcting deformities primarily at the skeletal level. Re-establishing muscle balance reduces the risk of recurrent deformities. Contractures show different structural substrates that must be addressed individually. Orthotic treatment plays an important role in the conservative and surgical management of muscle dysfunction in neuromuscular disorders. This should include preventive as well as therapeutic splinting both for functional improvement and for postural management purposes.

Pompe disease: a review of the current diagnosis and treatment recommendations in the era of enzyme replacement therapy

Pompe disease, or glycogen storage disease type II, is a rare autosomal recessive disorder caused by mutations in the gene that encodes for alpha-glucosidase. Presentation in infancy is associated with respiratory failure, cardiomyopathy, and severe muscle weakness. Juvenile- or adult-onset cases typically present with proximal muscle weakness and are associated with respiratory insufficiency or exertional dyspnea. Treatment, until recently, was focused on supportive measures, and infants diagnosed with Pompe disease usually died within the first year of life. The recent development of recombinant alpha-glucosidase has dramatically improved the life expectancy and quality of life of infantile-onset disease with improvements in respiratory and motor function observed in juvenile- or adult-onset cases. This review focuses on the presentation, pathogenesis, diagnosis, and treatment recommendations for Pompe disease in this new era of enzyme replacement therapy.

Physical therapy management of Pompe disease

Pompe disease (Glycogen storage disease type II, GSDII, or acid maltase deficiency) is an autosomal recessive disorder characterized by deficiency of acid alpha-glucosidase resulting in intra-lysosomal accumulation of glycogen and leading to progressive muscle dysfunction. The natural history of infantile-onset Pompe disease is characterized by hypertrophic cardiomyopathy and profound generalized weakness presenting in the first few months of life, with rapid progression and death usually occurring by one year of age. Late-onset Pompe disease is characterized by onset of symptoms after one year of age, less severe or absence of cardiac involvement and slower progression, with symptoms primarily related to progressive dysfunction of skeletal muscles and respiratory muscle involvement. Recent clinical trials of enzyme replacement therapy have begun to allow greater opportunity for potential improvement in motor status, function, and survival than ever before, with hopes of moving toward maximizing physical function for individuals with Pompe disease. Children are living longer with some achieving independent sitting, creeping, and walking-milestones typically never achieved in the untreated natural history of the disorder. With increased survival, clinical management based on an understanding of the pathology and pathokinesiology of motor function gains importance. This article reviews current knowledge regarding the motor system in Pompe disease and provides an overview of physical therapy management of Pompe disease, including management strategies for individuals on enzyme replacement therapy.

Twelve weeks of nightly stretch does not reduce thumb web-space contractures in people with a neurological condition: a randomised controlled trial

QUESTION

What is the effectiveness of 12 weeks of nightly stretch in reducing thumb web-space contracture in people with neurological conditions?

DESIGN

Assessor-blinded, randomised controlled trial.

PARTICIPANTS

Forty-four (one dropout)community-dwelling patients with a neurological condition (14 stroke, 7 traumatic brain injury, 23 spinal cord injury) who had uni or bilateral thumb web-space contractures (60 thumbs).

INTERVENTION

The experimental thumbs were splinted into a stretched,abducted position each night for 12 weeks. The control thumbs were not splinted.

OUTCOME MEASURES

Thumb web-space was measured as the carpometacarpal angle during the application of a 0.9 Nm abduction torque before and after intervention.

RESULTS

The mean increase in thumb web-space after 12 weeks was 1 deg (95% CI, -1 to 2).

CONCLUSION

Intensive stretch administered regularly over three months does not reduce thumb web-space contractures in neurological conditions.

Localized and adaptive synoviocyte proliferation characteristics in rat knee joint contractures secondary to immobility 11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To investigate the proliferative activity of synoviocytes in joint contracture.

DESIGN

Experimental controlled trial.

SETTING

Laboratory in vivo study.

ANIMALS

Adult male Sprague-Dawley rats (avg weight, 340g).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We immobilized the knee joints of 24 rats, in 135 degrees of flexion, for up to 32 weeks. Controls were 24 sham-operated and 5 unoperated rats. On sagittal sections, synoviocytes that stained with a proliferating cell nuclear antigen antibody were counted over the anterior and posterior synovial intima. The length of the synovial intima was also measured.

RESULTS

The absolute number of proliferating synoviocytes decreased markedly in the posterior capsule of knee joints immobilized for more than 2 weeks (2.4+/-1.0 vs 22.7+/-7.1 at week 16, P<.05), and so did the synovial intima length (1.4+/-0.1mm vs 8.6+/-0.5mm at week 16, P<.05). No change occurred anteriorly.

CONCLUSION

A decreased number of proliferating synoviocytes and increased intima adhesion in the posterior capsule characterized joint contractures. The data further suggest that the synovial intima adapted to the new position of the joint. Phenomena of mechanotransduction could explain the fact that adaptations were restricted to the posterior synovial intima.

Sensory adaptation after a 2-week stretching regimen of the rectus femoris muscle

OBJECTIVE

To study the effects of a muscle stretching regimen for the rectus femoris muscle on subjective stretch sensation and range of motion (ROM).

DESIGN

A 2 x 2 crossover design comprising 2 treatments and 2 intervention periods.

SETTING

A military base in Sweden.

PARTICIPANTS

A volunteer sample of 29 male military conscripts divided into 2 groups, with each group subjected to both experimental and control treatments at different time periods.

INTERVENTION

Two weeks of supervised stretching (4 times/wk) of the rectus femoris muscle (experimental treatment) and the calf muscles (control treatment).

MAIN OUTCOME MEASURES

Subjective rating of the stretch sensation for the anterior aspect of the thigh determined on a category ratio scale. Passive knee flexion ROM determined on each test with the same applied torque, specific for each subject.

RESULTS

An additive analysis of variance revealed that the stretch sensation after the experimental treatment was decreased, compared with the control treatment (p <.01). The knee flexion, however, remained the same regardless of the treatment.

CONCLUSION

Sensory adaptation seems to be an important mechanistic factor in the effect stretching has on ROM changes. The lack of change in knee flexion suggests that the stretching, as performed in this study, did not influence stiffness of the rectus femoris muscle. Sensory adaptation may also be an underlying mechanism in the alleviating effect of stretching when applied to tired, tender, and painful muscles.