Movement-related Disorders Research Articles

A porous elastomer with a cavity array for three-dimensional plantar force sensing

Human gait is an important indicator for diagnosis of various movement-related disorders. Three-dimensional (3D) plantar force monitoring enables real-time recording of contact forces in both the normal and tangential directions in each step, providing useful clues for identification of irregular gait patterns or gait-related health issues. Most flexible sensors for gait monitoring focus on contact forces in the normal direction, being limited to detect forces in the tangential direction. Herein we have developed a porous elastomer with a cavity array (PECA) to measure 3D contact forces for gait analysis. The sensor consists of two fabric electrodes and a dielectric layer of porous Ecoflex elastomer containing a 5 × 5 cavity array, forming four parallel-plate capacitor units in a soft construction. Therefore, a 3D force in any arbitrary direction generates four unique capacitive electrical signals. Importantly, the PECA includes a well-designed combination of micrometer-scale pores and millimeter-sized cavities, dramatically improving the detection sensitivity and linear elasticity range. We have demonstrated high sensitivities of 0.41 N−1 and 0.23 N−1 in the normal and tangential directions, respectively. The flexible PECA-based sensors have been tested to sensitively distinguish various standing postures and different stride lengths for gait analysis, promising reliable translation into areas such as healthcare monitoring, sports training, and rehabilitation engineering.

The Serotonin 4 Receptor Subtype: A Target of Particular Interest, Especially for Brain Disorders.

In recent years, particular attention has been paid to the serotonin 4 receptor, which is well expressed in the brain, but also peripherally in various organs. The cerebral distribution of this receptor is well conserved across species, with high densities in the basal ganglia, where they are expressed by GABAergic neurons. The 5-HT4 receptor is also present in the cerebral cortex, hippocampus, and amygdala, where they are carried by glutamatergic or cholinergic neurons. Outside the central nervous system, the 5-HT4 receptor is notably expressed in the gastrointestinal tract. The wide distribution of the 5-HT4 receptor undoubtedly contributes to its involvement in a plethora of functions. In addition, the modulation of this receptor influences the release of serotonin, but also the release of other neurotransmitters such as acetylcholine and dopamine. This is a considerable asset, as the modulation of the 5-HT4 receptor can therefore play a direct or indirect beneficial role in various disorders. One of the main advantages of this receptor is that it mediates a much faster antidepressant and anxiolytic action than classical selective serotonin reuptake inhibitors. Another major benefit of the 5-HT4 receptor is that its activation enhances cognitive performance, probably via the release of acetylcholine. The expression of the 5-HT4 receptor is also altered in various eating disorders, and its activation by the 5-HT4 agonist negatively regulates food intake. Additionally, although the cerebral expression of this receptor is modified in certain movement-related disorders, it is still yet to be determined whether this receptor plays a key role in their pathophysiology. Finally, there is no longer any need to demonstrate the value of 5-HT4 receptor agonists in the pharmacological management of gastrointestinal disorders.

Sports promote brain evolution: a resting-state fMRI study of volleyball athlete.

Long-term skill learning can lead to structure and function changes in the brain. Different sports can trigger neuroplasticity in distinct brain regions. Volleyball, as one of the most popular team sports, heavily relies on individual abilities such as perception and prediction for high-level athletes to excel. However, the specific brain mechanisms that contribute to the superior performance of volleyball athletes compared to non-athletes remain unclear. We conducted a study involving the recruitment of ten female volleyball athletes and ten regular female college students, forming the athlete and novice groups, respectively. Comprehensive behavioral assessments, including Functional Movement Screen and audio-visual reaction time tests, were administered to both groups. Additionally, resting-state magnetic resonance imaging (MRI) data were acquired for both groups. Subsequently, we conducted in-depth analyses, focusing on the amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) in the brain for both the athlete and novice groups. No significant differences were observed in the behavioral data between the two groups. However, the athlete group exhibited noteworthy enhancements in both the ALFF and ReHo within the visual cortex compared to the novice group. Moreover, the functional connectivity between the visual cortex and key brain regions, including the left primary sensory cortex, left supplementary motor cortex, right insula, left superior temporal gyrus, and left inferior parietal lobule, was notably stronger in the athlete group than in the novice group. This study has unveiled the remarkable impact of volleyball athletes on various brain functions related to vision, movement, and cognition. It indicates that volleyball, as a team-based competitive activity, fosters the advancement of visual, cognitive, and motor skills. These findings lend additional support to the early cultivation of sports talents and the comprehensive development of adolescents. Furthermore, they offer fresh perspectives on preventing and treating movement-related disorders. Registration number: ChiCTR2400079602. Date of Registration: January 8, 2024.

Global joint information extraction convolution neural network for Parkinson’s disease diagnosis

Parkinson’s Disease (PD) is a prevalent neurodegenerative condition, ranking second in incidence only to Alzheimer’s disease. Presently, the diagnosis of PD using sensors and computer vision can recognize characteristics like speech, respiration, and gait in patients. However, these methods typically require the use of complex hardware systems or extensive data analysis when collecting or processing motion data from various joints of the patients. In this research, an efficient diagnostic system for PD is introduced, which utilizes common smartphones to capture videos of 42 healthy volunteers and 30 Parkinson’s patients walking under different conditions. The system utilizes human pose estimation technology to extract three-dimensional joint coordinates, simplifying the data collection process. Afterward, joint coordinates are transformed into two-dimensional images using color mapping techniques, thus converting the diagnosis into an image recognition challenge. In contrast to video processing, this approach reduces 6.51 million parameters (22%) and reduces testing time by 62.92%. Finally, by combining ResNet50 and random forest algorithms, decision accuracy is improved using two-dimensional images. Experimental evidence substantiates the system’s capability to efficiently identify Parkinsonian gait. The recognition rate for the leg joint group is 88.89%, and it would increase to 91.67% when factoring in the four-limb joint group. The system provides the potential for preliminary at-home diagnosis, holding significant clinical application potential, and diagnostic value for other movement-related disorders.

Medical and social characteristics of people with disability and neuromuscular, skeletal, and movement-related disorders

BACKGROUND:Measures of growth are important for creating a construction and expansion system of opportunities for the constituents of the Russian Federation. The need for complex rehabilitation in people with impaired neuromuscular, skeletal, and movement-related functions is still not fully understood.
 AIM:This pilot study aimed to determine the need for comprehensive rehabilitation of adults with neuromuscular, skeletal, and movement-related functions according to the main indicators of primary disability.
 MATERIALS AND METHODS:The comparative analysis of the dynamics of newly detected (primary) disabilities in the Russian Federation due to all causes and disorders of neuromuscular, skeletal, and movement-related functions (categories b710b799 according to the International Classification of Functioning, Disabilities and Health) was conducted. Indicators in the Leningrad region were analyzed from 2016 to 2020.
 RESULTS:The need for rehabilitation in the Leningrad region is lower than that in the whole country. Individuals with neuromuscular, skeletal, and movement-related disorders aged 1844 years need the most intensive rehabilitation.
 CONCLUSIONS:The results of this study revealed that the decrease in overall primary disability is faster than the decrease in primary disability in the target group. The prevention and rehabilitation of neuromuscular and statodynamic disorders were slower, whereas the need for rehabilitation was higher in the specific-cause group than in the all-cause group.

Human CSF movement influenced by vascular low frequency oscillations and respiration.

Cerebrospinal fluid (CSF) movement through the pathways within the central nervous system is of high significance for maintaining normal brain health and function. Low frequency hemodynamics and respiration have been shown to drive CSF in humans independently. Here, we hypothesize that CSF movement may be driven simultaneously (and in synchrony) by both mechanisms and study their independent and coupled effects on CSF movement using novel neck fMRI scans. Caudad CSF movement at the fourth ventricle and hemodynamics of the major neck blood vessels (internal carotid arteries and internal jugular veins) was measured from 11 young, healthy volunteers using novel neck fMRI scans with simultaneous measurement of respiration. Two distinct models of CSF movement (1. Low-frequency hemodynamics and 2. Respiration) and possible coupling between them were investigated. We show that the dynamics of brain fluids can be assessed from the neck by studying the interrelationships between major neck blood vessels and the CSF movement in the fourth ventricle. We also demonstrate that there exists a cross-frequency coupling between these two separable mechanisms. The human CSF system can respond to multiple coupled physiological forces at the same time. This information may help inform the pathological mechanisms behind CSF movement-related disorders.

A-274 A Case Study of Progressive Supranuclear Palsy in a 68-year-old with Pronounced Frontal-Executive Deficits Complicated by Cerebrovascular Disease

Abstract Objective: Individuals with Progressive Supranuclear Palsy (PSP) often experience cognitive decline, repeated falls, restricted gaze, bradykinesia, and depression/behavioral changes. Despite having certain distinguishing features neuroanatomically and neurologically, PSP continues to be difficult to classify and distinguish from some other more well-known neurodegenerative and movement-related disorders. Method: A 68-year-old white male presented for a neuropsychological evaluation (2022) initially after his neurologist became suspicious of him having cerebellar degeneration or multisystem atrophy. He reported a progressive one-year decline in memory, motor abilities, and executive functions, along with having personality changes and a loss of independence in his activities of daily living (ADLs). To complicate the differential diagnosis, an MRI of his brain from six months prior simply concluded “age-related changes”. Upon revisiting this MRI and closer visual inspection, focal atrophy of the midbrain became apparent on a sagittal section, in addition to bilateral ischemic changes in the white matter. He was later diagnosed with PSP. Results: Despite demonstrating adequate performance on simple cognitive screening measures, he displayed marked behavioral disinhibition, executive/attention problems, visuospatial concerns, decreased motor abilities, and variable memory functioning that were found to impact his ability to carry out instrumental and even some basic ADLs. Conclusions: Cases such as this one requiring diagnostic clarification lend support to the “hummingbird sign” (midbrain atrophy) being a useful imaging marker in distinguishing PSP from other clinical disorders. Additionally, in contrast to other neurodegenerative disorders, frontal-executive deficits (e.g., disinhibition) were a particularly pronounced feature in his PSP neurocognitive profile, followed by milder difficulties in memory, language, and visuospatial functions.

Rhythm and Music-Based Interventions in Motor Rehabilitation: Current Evidence and Future Perspectives.

Research in basic and clinical neuroscience of music conducted over the past decades has begun to uncover music’s high potential as a tool for rehabilitation. Advances in our understanding of how music engages parallel brain networks underpinning sensory and motor processes, arousal, reward, and affective regulation, have laid a sound neuroscientific foundation for the development of theory-driven music interventions that have been systematically tested in clinical settings. Of particular significance in the context of motor rehabilitation is the notion that musical rhythms can entrain movement patterns in patients with movement-related disorders, serving as a continuous time reference that can help regulate movement timing and pace. To date, a significant number of clinical and experimental studies have tested the application of rhythm- and music-based interventions to improve motor functions following central nervous injury and/or degeneration. The goal of this review is to appraise the current state of knowledge on the effectiveness of music and rhythm to modulate movement spatiotemporal patterns and restore motor function. By organizing and providing a critical appraisal of a large body of research, we hope to provide a revised framework for future research on the effectiveness of rhythm- and music-based interventions to restore and (re)train motor function.

Chronic Alcoholism and HHV-6 Infection Synergistically Promote Neuroinflammatory Microglial Phenotypes in the Substantia Nigra of the Adult Human Brain.

Both chronic alcoholism and human herpesvirus-6 (HHV-6) infection have been identified as promoters of neuroinflammation and known to cause movement-related disorders. Substantia Nigra (SN), the dopaminergic neuron-rich region of the basal ganglia, is involved in regulating motor function and the reward system. Hence, we hypothesize the presence of possible synergism between alcoholism and HHV-6 infection in the SN region and report a comprehensive quantification and characterization of microglial functions and morphology in postmortem brain tissue from 44 healthy, age-matched alcoholics and chronic alcoholics. A decrease in the perivascular CD68+ microglia in alcoholics was noted in both the gray and white matter. Additionally, the CD68+/Iba1− microglial subpopulation was found to be the dominant type in the controls. Conversely, in alcoholics, dystrophic changes in microglia were seen with a significant increase in Iba1 expression and perivascular to diffuse migration. An increase in CD11b expression was noted in alcoholics, with the Iba1+/CD11b− subtype promoting inflammation. All the controls were found to be negative for HHV-6 whilst the alcoholics demonstrated HHV-6 positivity in both gray and white matter. Amongst HHV-6 positive alcoholics, all the above-mentioned changes were found to be heightened when compared with HHV-6 negative alcoholics, thereby highlighting the compounding relationship between alcoholism and HHV-6 infection that promotes microglia-mediated neuroinflammation.

Lumbar Movement Dysfunction Based on Movement Control Impairment Classification System in Those Who Do and Do Not Develop Transient Low Back Pain During Prolonged Sitting

ObjectiveLong-term sitting triggers movement-related disorders. We used a movement control impairment (MCI) system to investigate lumbar movement dysfunction in those who did and did not develop transient low back pain (LBP) during prolonged sitting. MethodsTwelve patients who did and did not develop transient LBP during sitting for 2 hours were enrolled. We tested the movement control abilities of the 2 groups using 6 MCI tests (12 test items). ResultsThe mean MCI test score in the transient LBP developer group was significantly higher than that in the LBP non-developer group (P = .03). Lumbar flexion movement control as the backward rocking test was significantly more common in the transient LBP developer than in the LBP non-developer group (P < .027). Pelvic shifting and asymmetry during side-bending of the trunk were evident in both groups (all P > .05). However, pelvic shifting during side-bending of the trunk was evident only in the LBP group (33%; P = .093). ConclusionThe group exhibiting transient LBP had higher positive MCI test scores and exhibited more asymmetry than the other group. Even the non-LBP group exhibited poor lumbar flexion and rotation. Therefore, subjects with subclinical dysfunction caused by prolonged sitting may require homogenous subgroups classification for the early detection of mechanical risk factors and health and functional interventions.

Concurrent validity of a wearable IMU for objective assessments of functional movement quality and control of the lumbar spine

Inertial measurement units (IMUs) are being recognized in clinical and rehabilitation settings for their ability to assess movement-related disorders of the spine for better guidance of treatment-planning and tracking of recovery. This study evaluated the Mbientlab MetaMotionR IMUs, relative to Vicon motion capture equipment in measuring local dynamic stability of the spine (quantified using maximum finite-time Lyapunov exponent; λmax), lumbopelvic coordination (quantified using mean absolute relative phase; MARP), and intersegmental motor variability (quantified using deviation phase; DP) of lumbopelvic segments in 10 participants during 35 cycles of repetitive spine flexion–extension (FE). Intraclass correlations were strong between systems when using both the FE angle time-series and the sum of squares (SS) time-series to measure local dynamic stability (0.807 ≤ICC2,1λmax,FE ≤ 0.919; 0.738 ≤ ICC2,1λmax,SS ≤ 0.868), sagittal-plane lumbopelvic coordination (0.961 ≤ICC2,1MARP ≤ 0.963), and sagittal-plane lumbopelvic variability (0.961 ≤ICC2,1DP ≤ 0.963). It was concluded that the MetaMotionR IMUs can be reliably used for measuring features associated with spine movement quality and motor control during a repetitive FE task. Future work will assess the reliability of sensor placement, performance during multi-directional movements, and ability to discern clinical and healthy populations based on assessment of movement quality and control.

Effects of 99mTc-TRODAT-1 drug template on image quantitative analysis.

99mTc-TRODAT-1 is a type of drug that can bind to dopamine transporters in living organisms and is often used in SPCT imaging for observation of changes in the activity uptake of dopamine in the striatum. Therefore, it is currently widely used in studies on clinical diagnosis of Parkinson’s disease (PD) and movement-related disorders. In conventional 99mTc-TRODAT-1 SPECT image evaluation, visual inspection or manual selection of ROI for semiquantitative analysis is mainly used to observe and evaluate the degree of striatal defects. However, these methods are dependent on the subjective opinions of observers, which lead to human errors, have shortcomings such as long duration, increased effort, and have low reproducibility. To solve this problem, this study aimed to establish an automatic semiquantitative analytical method for 99mTc-TRODAT-1. This method combines three drug templates (one built-in SPECT template in SPM software and two self-generated MRI-based and HMPAO-based TRODAT-1 templates) for the semiquantitative analysis of the striatal phantom and clinical images. At the same time, the results of automatic analysis of the three templates were compared with results from a conventional manual analysis for examining the feasibility of automatic analysis and the effects of drug templates on automatic semiquantitative analysis results. After comparison, it was found that the MRI-based TRODAT-1 template generated from MRI images is the most suitable template for 99mTc-TRODAT-1 automatic semiquantitative analysis.

High-accuracy detection of early Parkinson's Disease using multiple characteristics of finger movement while typing.

Parkinson’s Disease (PD) is a progressive neurodegenerative movement disease affecting over 6 million people worldwide. Loss of dopamine-producing neurons results in a range of both motor and non-motor symptoms, however there is currently no definitive test for PD by non-specialist clinicians, especially in the early disease stages where the symptoms may be subtle and poorly characterised. This results in a high misdiagnosis rate (up to 25% by non-specialists) and people can have the disease for many years before diagnosis. There is a need for a more accurate, objective means of early detection, ideally one which can be used by individuals in their home setting. In this investigation, keystroke timing information from 103 subjects (comprising 32 with mild PD severity and the remainder non-PD controls) was captured as they typed on a computer keyboard over an extended period and showed that PD affects various characteristics of hand and finger movement and that these can be detected. A novel methodology was used to classify the subjects’ disease status, by utilising a combination of many keystroke features which were analysed by an ensemble of machine learning classification models. When applied to two separate participant groups, this approach was able to successfully discriminate between early-PD subjects and controls with 96% sensitivity, 97% specificity and an AUC of 0.98. The technique does not require any specialised equipment or medical supervision, and does not rely on the experience and skill of the practitioner. Regarding more general application, it currently does not incorporate a second cardinal disease symptom, so may not differentiate PD from similar movement-related disorders.

Prevalence and Predisposing Factors of Parkinson Disease: A Community-Based Study In Barangay Mangilag Sur, Candelaria, Quezon: A Research Protocol

Parkinson Disease is a neurodegenerative disorder affecting the central nervous system caused by the death of dopaminergic cells in the ventral region of the pars compacta of the substancia nigra. The subsequent lack of dopamine causes movement-related disorders including tremors, rigidity, hypokinesia, and postural instability. The clinical diagnosis of PD is hinged on the triad of asymmetric bradykinesia, rest tremors and rigidity, with an expert (usually a Neurologist) eliminating those cases having mimics of the symptomatology. Development of the disease is through certain environmental, hereditary, and genetic factors. In the Philippines, PD is a rarely seen disorder and establishing of a prevalence study has been difficult for neurologists. Prevalence of the disease in the country has been estimated to be less than 1% based on a 2007 study conducted by the Philippine Neurologic Association but without ascertainment of cases. The researchers aim to determine the disease’s prevalence in a locale and explore on the possible predisposing factors on the development of the disease. Keywords: Parkinson’s Disease, Prevalence, Community Survey, Rural

Changes in brain activity during action observation and motor imagery: Their relationship with motor learning.

Many studies have demonstrated that training utilizing action observation and/or motor imagery improves motor performance. These two techniques are widely used in sports and in the rehabilitation of movement-related disorders. Motor imagery has also been used for brain-machine/computer interfaces (BMI/BCI). During both action observation and motor imagery, motor-related regions such as the premotor cortex and inferior parietal lobule are activated. This is common to actual execution and are involved with the underlying mechanisms of motor learning without execution. Since it is easier to record brain activity during action observation and motor imagery than that during actual sport movements, action observation, and motor imagery of sports skills or complex whole body movements have been utilized to investigate how neural mechanisms differ across the performance spectrum ranging from beginner to expert. However, brain activity during action observation and motor imagery is influenced by task complexity (i.e., simple vs complex movements). Furthermore, temporal changes in brain activity during actual execution along the long time course of motor learning are likely nonlinear and would be different from that during action observation or motor imagery. Activity in motor-related regions during action observation and motor imagery is typically greater in experts than in nonexperts, while the activity during actual execution is often smaller in experts than in nonexperts.

A Medical Approach to the Monoamine Oxidase Inhibition by Using 7Hbenzo[ e]perimidin-7-one Derivatives

A series of perimidinone derivatives (7H-benzo[e]perimidin-7-one) were synthesized and assessed by means of in vitro assays as human MAO inhibitors. These compounds inhibited reversibly the enzymes with inhibitory constants in the range of 2 to 20 μM. In addition, the selectivity of inhibition of the MAO isoforms seems to be significantly dependent of the presence either of heteroatom or electron donating and withdrawing groups on the perimidinone framework, which was verified by using molecular docking simulation with the crystallized MAO receptors. Most of these inhibitors were highly selective: 9 and 11 inhibited selectively the MAO-B isoform while 12 had 10-fold selectivity for MAO-A isoform. Moreover, the compound 12 was both the most selective and potent MAO-A inhibitor among perimidinones. These results have important implications for the drug design of molecules targeting depression and movement-related disorders.

Clinical Exercise Pathophysiology for Physical Therapy: Examination, Testing, and Exercise Prescription for Movement-Related Disorders

Dr. Debra Coglianese and her team of 22 contributing authors have put together a comprehensive clinical exercise physiology textbook for physical therapists. This book covers the spectrum of physiology and pathophysiology, from the cellular to the whole-body level, and elegantly captures the importance of exercise for assessing and managing clients with different clinical conditions. The authors, all of whom have degrees in physical therapy, provide a unique and clinically relevant perspective on exercise pathophysiology.

Evaluation of an Educational Program for Clinical Pharmacists to Conduct Standardized Assessments for Medication-Induced Movement-Related Disorders.

Movement disorders and tardive dyskinesia are common adverse effects of first-generation antipsychotic medications. Although the atypical agents are less likely to result in movement disorders, they are not entirely devoid of this risk. Movement disorders such as akathisia continue to be associated with newer antipsychotics like risperidone and aripiprazole,1,2 and all currently available antipsychotics carry a risk of tardive dyskinesia.3,4 In addition, the anticipated benefits of atypical antipsychotics have been tempered, and they come with their own unique set of adverse effects, factors that together have led to a re-evaluation of the use of conventional antipsychotics.5 Antipsychotic-induced movement disorders and tardive dyskinesia are often underrecognized in clinical practice, with potentially damaging implications for patient care.6 Despite the availability of validated rating scales, evidence of their use remains scarce. Studies have revealed a lack of documentation (both quantity and quality) of movement disorder assessment, as well as challenges associated with accurate detection and management of these adverse effects.7-9 Distinguishing one movement disorder from another continues to be challenging and requires careful evaluation by experienced raters.10 Pharmacists are well positioned to fill this role. Pharmacists build their practice according to a pharmaceut ical care model in which they are held accountable for providing rational drug therapy with the goal of optimizing patient outcomes.11 This goal is achieved by regularly monitoring patient-specific medical data, evaluating the management of medication, and providing pharmaceutical care for the purpose of identifying and resolving drug therapy problems.12,13 Numerous published reports have shown that the provision of clinical pharmacy services, including medication interventions, has resulted in better patient care, shorter hospital stays, and health care cost savings.14 The success of pharmacists in managing diabetes mellitus, lipid abnormalities, anticoagulation, and complex HIV drug regimens has been well documented.15,16 Despite these expanded roles in some settings, pharmacists have been found to represent an underutilized health care resource.17 In the field of mental health, research related to the provision of specific pharmaceutical care services is limited. As such, there is a unique opportunity to study the impact of training pharmacists to assess movement disorders. Pharmacists are in an excellent position to conduct such assessments, as they have regular contact with patients and are experts in medication management, which includes the evaluation and management of adverse effects. At the authors’ clinical site, formal training for such assessments is currently unavailable to pharmacists who routinely work with patients receiving antipsychotic therapy. The value of formal clinician training to better identify antipsychotic-induced movement disorders is emphasized in the literature, including the benefits of having trained pharmacists screen patients for the purpose of identifying and managing these adverse effects.18-20 In this study, investigators developed a new program to train clinical pharmacists to assess medication-related movement disorders. This research functioned as a pilot study, with only a small number of participants, with the intention to provide broader implementation of the program if successful.

Age-related changes in spatiotemporal characteristics of gait accompany ongoing lower limb linear growth in late childhood and early adolescence

Walking gait is generally held to reach maturity, including walking at adult-like velocities, by 7–8 years of age. Lower limb length, however, is a major determinant of gait, and continues to increase until 13–15 years of age. This study used a sample from the Fels Longitudinal Study (ages 8–30 years) to test the hypothesis that walking with adult-like velocity on immature lower limbs results in the retention of immature gait characteristics during late childhood and early adolescence. There was no relationship between walking velocity and age in this sample, whereas the lower limb continued to grow, reaching maturity at 13.2 years in females and 15.6 years in males. Piecewise linear mixed models regression analysis revealed significant age-related trends in normalized cadence, initial double support time, single support time, base of support, and normalized step length in both sexes. Each trend reached its own, variable-specific age at maturity, after which the gait variables’ relationships with age reached plateaus and did not differ significantly from zero. Offsets in ages at maturity occurred among the gait variables, and between the gait variables and lower limb length. The sexes also differed in their patterns of maturation. Generally, however, immature walkers of both sexes took more frequent and relatively longer steps than did mature walkers. These results support the hypothesis that maturational changes in gait accompany ongoing lower limb growth, with implications for diagnosing, preventing, and treating movement-related disorders and injuries during late childhood and early adolescence.

Diagnosis of Primary Task-Specific Lower Extremity Dystonia in a Runner

Resident's case problem. A 56-year-old man was referred to physical therapy for analysis of unusual gait, first noticed 3 years previously when running. Prior to this evaluation, the patient had seen multiple orthopaedic, sports medicine, and neurological specialists while undergoing repeated and extensive testing. Ten months of testing and treatment, including conservative and surgical management, did not provide an explanation for the gait abnormality or result in improvement of the patient's condition. The patient's physical examination was relatively unremarkable, considering the severity of the gait abnormality. Distinct abnormalities were apparent with computerized gait analysis and dynamic electromyography, and, when combined with the physical examination findings, led to a suspicion of the task-specific disorder of runner's dystonia. The patient was referred to a neurologist specializing in movement-related disorders, with a final confirmed diagnosis of primary task-specific dystonia with first onset during running (ie, runner's dystonia). Idiopathic, task-specific dystonia of the lower extremity is documented as a very rare occurrence, yet increasing trends in running participation may result in a higher incidence of this condition. Improved awareness of runner's dystonia in the present case might have enhanced the clinical decision-making process and resulted in more timely and effective treatment solutions. Clinical examination findings, including computerized gait analysis and electromyography, in conjunction with imaging, blood, and genetic testing, can aid in the diagnosis of runner's dystonia. Differential diagnosis, level 4.