Distal Movements Research Articles

Motor somatotopy impacts imagery strategy success in human intracortical brain-computer interfaces.

The notion of a somatotopically organized motor cortex, with movements of different body parts being controlled by spatially distinct areas of cortex, is well known. However, recent studies have challenged this notion and suggested a more distributed representation of movement control. This shift in perspective has significant implications, particularly when considering the implantation location of electrode arrays for intracortical brain-computer interfaces (iBCIs). We sought to evaluate whether the location of neural recordings from the precentral gyrus, and thus the underlying somatotopy, has any impact on the imagery strategies that can enable successful iBCI control. Three individuals with a spinal cord injury were enrolled in an ongoing clinical trial of an iBCI. Participants had two intracortical microelectrode arrays implanted in the arm and/or hand areas of the precentral gyrus based on presurgical functional imaging. Neural data were recorded while participants attempted to perform movements of the hand, wrist, elbow, and shoulder. We found that electrode arrays that were located more medially recorded significantly more activity during attempted proximal arm movements (elbow, shoulder) than did lateral arrays, which captured more activity related to attempted distal arm movements (hand, wrist). We also evaluated the relative contribution from the two arrays implanted in each participant to decoding accuracy during calibration of an iBCI decoder for translation and grasping tasks. For both task types, imagery strategy (e.g., reaching vs. wrist movements) had a significant impact on the relative contributions of each array to decoding. Overall, we found some evidence of broad tuning to arm and hand movements; however, there was a clear bias in the amount of information accessible about each movement type in spatially distinct areas of cortex. These results demonstrate that classical concepts of somatotopy can have real consequences for iBCI use, and highlight the importance of considering somatotopy when planning iBCI implantation.

Optimal positions of clear aligner attachments to achieve lower canine tipping and bodily movement using finite element analysis

Background/purposeClear aligners are popular orthodontic tools because of their relatively aesthetic appearance and convenience of use. Nevertheless, bodily tooth movements still present challenges. This study evaluated various configurations of attachments placed on the mandibular canine in terms of the efficiency of canine bodily movement and correction of tipping. Materials and methodsA finite element model of the mandible was constructed to investigate the effects of various attachment configurations on the overall bodily movement and undesirable tipping of a mandibular canine. Canine movements were categorized into four types, namely tipping and bodily movements in the mesial and distal directions. The size and shape of the attachments were fixed, but their placement and orientation were varied. Five and seven attachment configurations were evaluated for their influence on tipping and bodily movements, respectively. ResultsAttachment configuration significantly influenced mandibular canine tipping. The mesial occlusal–distal cervical and mesial occlusal–mesial cervical configurations had notable effects on mesial tipping, and the mesial occlusal–mesial cervical configuration excelled in distal tipping by increasing strain by 33.1%. The mesial occlusal–mesial cervical attachment configuration consistently had superior efficiency in facilitating both mesial and distal bodily movements of the canine. ConclusionThe mesial occlusal–mesial cervical attachment configuration excelled in all four types of canine movement. Irrespective of the attachment configuration, canines tend to move overall with slight tipping due to skeletal resistance and their center of rotation. The attachment configuration is crucial to the success of clear aligner treatment and must be carefully considered in clinical practice.

Congenital Myopathy Due to RyR1 Gene Mutation in a Newborn Masquerading as a Consequence of Hypoxic-ischemic Encephalopathy

Background: Congenital myopathies may be a cause of prolonged and persistent hypotonia and weakness in a newborn, which may be overlooked as a neurological consequence of hypoxic-ischemic encephalopathy. We report such a neonate which turned out to be a case of central core myopathy. Clinical Description: A female neonate born at 38 weeks of gestation suffered birth asphyxia and was referred at 25 days of life due to a persistent need for respiratory support. A review of history revealed that the mother had decreased fetal movements during the third trimester and polyhydramnios. On examination, the baby had a frog-like posture with a paucity of proximal movements with preserved distal movements. Considering the possibility of a congenital myopathy, investigations were carried out. The whole-exome sequencing revealed heterozygous nonsense variation in exon 20 of the RyR1 gene, thus diagnosing the infant as a case of congenital core myopathy. Management and Outcome: The baby was managed with supportive care including ventilatory and nutritional support. Baby remained ventilator dependent, but ultimately succumbed to complications by 2 months of age. Conclusions: A high index of suspicion is required in a newborn with birth asphyxia having unusually persistent hypotonia, thorough clinical examination and appropriate genetic testing can help in identifying an underlying congenital myopathy.

Multimodal convergence in the pedunculopontine tegmental nucleus: Motor, sensory and theta-frequency inputs influence activity of single neurons.

The pedunculopontine tegmental nucleus of the brainstem (PPTg) has extensive interconnections and neuronal-behavioural correlates. It is implicated in movement control and sensorimotor integration. We investigated whether single neuron activity in freely moving rats is correlated with components of skilled forelimb movement, and whether individual neurons respond to both motor and sensory events. We found that individual PPTg neurons showed changes in firing rate at different times during the reach. This type of temporally specific modulation is like activity seen elsewhere in voluntary movement control circuits, such as the motor cortex, and suggests that PPTg neural activity is related to different specific events occurring during the reach. In particular, many neuronal modulations were time-locked to the end of the extension phase of the reach, when fine distal movements related to food grasping occur, indicating strong engagement of PPTg in this phase of skilled individual forelimb movements. In addition, some neurons showed brief periods of apparent oscillatory firing in the theta range at specific phases of the reach-to-grasp movement. When movement-related neurons were tested with tone stimuli, many also responded to this auditory input, allowing for sensorimotor integration at the cellular level. Together, these data extend the concept of the PPTg as an integrative structure in generation of complex movements, by showing that this function extends to the highly coordinated control of the forelimb during skilled reach to grasp movement, and that sensory and motor-related information converges on single neurons, allowing for direct integration at the cellular level.

Effects of core stability and feedback music on upper body mediolateral movements during cycling

BackgroundAsymmetry in involuntary trunk motion during voluntary movements of the lower extremities is a risk factor for musculoskeletal injuries and may be related to core stability. Core stability plays a pivotal role in maintaining postural stability during distal segment movements. Because mediolateral head motion partially represents trunk motion during rhythmic movements, controlling it can help ensure symmetric trunk motion. This study aimed to investigate the relationship between core stability and asymmetric trunk motion during rhythmic movements, and to evaluate the effects of feedback music on mediolateral head motion.MethodsWe developed a system that uses a wireless earbud and a high-resolution inertial measurement unit sensor to measure head angle and provide feedback music. When the head angle exceeds a predefined threshold, the music is muted in the earbud on the side of the head tilt. In our lab-based study, we measured head angles during cycling at 70% of maximum speed using this self-developed system, and compared them between individuals with good (Sahrmann core stability test: 2–5 level) and poor core stability (0–1 level). The amplitude of mediolateral head motion was represented by the difference between the left and right peak angles, and the symmetry in mediolateral head motion was represented by the average of left and right peak angles.ResultsIndividuals with poor core stability demonstrated significantly greater amplitude of, and less symmetry in, mediolateral head motion than those with good core stability. Additionally, feedback music significantly reduced the amplitude of mediolateral head motion in both the good- and poor-core-stability groups.ConclusionOur findings indicate that core stability is crucial for maintaining symmetric head motion during rhythmic movements like cycling. Feedback music could serve as an effective tool for promoting symmetry in head motion and thus preventing musculoskeletal injuries.

Biometric analysis hand parameters in young adults for prosthetic hand and ergonomic product applications.

This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

Does Action Observation of the Whole Task Influence Mirror Neuron System and Upper Limb Muscle Activity Better Than Part Task in People With Stroke?

Background: Task-based action observation and imitation (AOI) is a promising intervention to enhance upper limb (UL) motor function poststroke. However, whether whole/part task must be trained in the AOI therapy needs further substantiation. Objective: The objective of this study is to assess and compare the mirror neuron activity and UL muscle activity during AOI of reaching task in terms of whole task (complete movement) and part task (proximal arm movements and distal arm movements). Methods: In this cross-sectional study, 26 participants with first-time unilateral stroke were asked to observe the prerecorded videos of a reaching task in terms of a whole task and proximal and distal components, followed by imitation of the task, respectively. Electroencephalographic (EEG) mu rhythm suppression and electromyographic amplitude of six UL muscles were measured during the task. Results: The analysis of EEG revealed a statistically significant mu suppression score, indicating mirror neuron system activity, during AOI of the whole task in C3 (p = <0.001) and C4 (p = <0.001) electrodes compared to the part task. Percentage maximum voluntary contraction amplitudes of the deltoid (p = 0.002), supraspinatus (p = <0.001), triceps brachii (p = 0.002), brachioradialis (p = 0.006), and extensor carpi radialis (p = <0.001) muscles showed a significant increase in muscle activity during AOI of the whole task. Also, there seems to be a task observation-specific activation of muscles following AOI of proximal or distal tasks. Conclusion: The practice of the whole task should be given emphasis while framing the AOI treatment module to enhance reaching in people with stroke. Trial registration: Clinical Trials Registry-India (CTRI) identifier: CTRI/2018/04/013466.

Terminal organization of the corticospinal projection from the arm/hand region of the rostral primary motor cortex (M1r or old M1) to the cervical enlargement (C5-T1) in rhesus monkey.

High-resolution anterograde tracers and stereology were used to study the terminal organization of the corticospinal projection (CSP) from the rostral portion of the primary motor cortex (M1r) to spinal levels C5-T1. Most of this projection (90%) terminated contralaterally within laminae V-IX, with the densest distribution in lamina VII. Moderate bouton numbers occurred in laminae VI, VIII, and IX with few in lamina V. Within lamina VII, labeling occurred over the distal-related dorsolateral subsectors and proximal-related ventromedial subsectors. Within motoneuron lamina IX, most terminations occurred in the proximal-related dorsomedial quadrant, followed by the distal-related dorsolateral quadrant. Segmentally, the contralateral lamina VII CSP gradually declined from C5-T1 but was consistently distributed at C5-C7 in lamina IX. The ipsilateral CSP ended in axial-related lamina VIII and adjacent ventromedial region of lamina VII. These findings demonstrate the M1r CSP influences distal and proximal/axial-related spinal targets. Thus, the M1r CSP represents a transitional CSP, positioned between the caudal M1 (M1c) CSP, which is 98% contralateral and optimally organized to mediate distal upper extremity movements (Morecraft etal., 2013), and dorsolateral premotor (LPMCd) CSP being 79% contralateral and optimally organized to mediate proximal/axial movements (Morecraft etal., 2019). This distal to proximal CSP gradient corresponds to the clinical deficits accompanying caudal to rostral motor cortex injury. The lamina IX CSP is considered in the light of anatomical and neurophysiological evidence which suggests M1c gives rise to the major proportion of the cortico-motoneuronal (CM) projection, while there is a limited M1r CM projection.

Neural Substrates for Hand and Shoulder Movement in Healthy Adults: A Functional near Infrared Spectroscopy Study

Characterization of cortical activation patterns during movements in healthy adults may help our understanding of how the injured brain works. Upper limb motor tasks are commonly used to assess impaired motor function and to predict recovery in individuals with neurological disorders such as stroke. This study aimed to explore cortical activation patterns associated with movements of the hand and shoulder using functional near-infrared spectroscopy (fNIRS) and to demonstrate the potential of this technology to distinguish cerebral activation between distal and proximal movements. Twenty healthy, right-handed participants were recruited. Two 10-s motor tasks (right-hand opening-closing and right shoulder abduction-adduction) were performed in a sitting position at a rate of 0.5 Hz in a block paradigm. We measured the variations in oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) concentrations. fNIRS was performed with a 24-channel system (Brite 24®; Artinis) that covered most motor control brain regions bilaterally. Activation was mostly contralateral for both hand and shoulder movements. Activation was more lateral for hand movements and more medial for shoulder movements, as predicted by the classical homunculus representation. Both HbO2 and HbR concentrations varied with the activity. Our results showed that fNIRS can distinguish patterns of cortical activity in upper limb movements under ecological conditions. These results suggest that fNIRS can be used to measure spontaneous motor recovery and rehabilitation-induced recovery after brain injury. The trial was restropectively registered on January 20, 2023: NCT05691777 (clinicaltrial.gov).

Three-dimensional changes after maxillary molar distalization with a miniscrew-anchored cantilever.

To evaluate the changes after maxillary molar distalization in Class II malocclusion using the miniscrew-anchored cantilever with an extension arm. The sample included 20 patients (9 male, 11 female; mean age 13.21 ± 1.54 years) with Class II malocclusion, treated with the miniscrew-anchored cantilever. Lateral cephalograms and dental models obtained before (T1) and after molar distalization (T2) were evaluated using Dolphin software and 3D Slicer. Superimposition of digital dental models using regions of interest on the palate was performed to evaluate three-dimensional displacement of maxillary teeth. Intragroup change comparisons were performed using dependent t-test and Wilcoxon test (P < 0.05). The maxillary first molars were distalized to overcorrected Class I. The mean distalization time was 0.43 ± 0.13 years. Cephalometric analysis demonstrated significant distal movement of the maxillary first premolar (-1.21 mm, 95% confidence interval [CI]: -0.45, -1.96) and maxillary first (-3.38 mm, 95% CI: -2.88, -3.87) and second molars (-2.12 mm, 95% CI: -1.53, -2.71). Distal movements increased progressively from the incisors to the molars. The first molar showed small intrusion (-0.72 mm, 95% CI: 0.49, -1.34). In the digital model analysis, the first and second molars showed a crown distal rotation of 19.31° ± 5.71° and 10.17° ± 3.84°, respectively. The increase in maxillary intermolar distance, evaluated at the mesiobuccal cusps, was 2.63 ± 1.56 mm. The miniscrew-anchored cantilever was effective for maxillary molar distalization. Sagittal, lateral, and vertical movements were observed for all maxillary teeth. Distal movement was progressively greater from anterior to posterior teeth.

A cross-sectional study of the scapular muscles’ endurance in young healthy smartphone addicts and smartphone non-addicts, using scapular muscle endurance test

Background: Mobile phones have become an indispensable part of our day-to-day lives. The increasing dependency of people on smartphones has led to smartphone addiction among people. Extended use of smartphones in awkward postures with neck bent and arms unsupported requires significant stability of the scapular muscles to produce distal hand movements. The scapular muscles are thus under constant tension to achieve stability while transferring forces and motions along the kinetic chain requiring good endurance in the long run. The present study was thus aimed to compare the scapular muscle endurance of smartphone addicts versus non - addicts. Methodology: Smartphone Addiction Scale - Short Version (SAS - SV) scores were used to categorize 242 subjects into two groups (121 subjects in each group); Group 1 - Smartphone Addicts and Group 2 - Smartphone Non - Addicts. Scapular muscles’ endurance was assessed for all the subjects using the Scapular Muscle Endurance test and the time duration was noted. Results: Independent t-test was used to test the statistical significance of Scapular Muscle Endurance in Group 1 and Group 2. The observed difference between Group 1 and Group 2 was 24.07 seconds (p-value = 0.000). Conclusion: The scapular muscle endurance was significantly reduced in smartphone addicts as compared to smartphone non - addicts.

Spatial and Temporal Muscle Synergies Provide a Dual Characterization of Low-dimensional and Intermittent Control of Upper-limb Movements

Muscle synergy analysis investigates the neurophysiological mechanisms that the central nervous system employs to coordinate muscles. Several models have been developed to decompose electromyographic (EMG) signals into spatial and temporal synergies. However, using multiple approaches can complicate the interpretation of results. Spatial synergies represent invariant muscle weights modulated with variant temporal coefficients; temporal synergies are invariant temporal profiles that coordinate variant muscle weights. While non-negative matrix factorization allows to extract both spatial and temporal synergies, the comparison between the two approaches was rarely investigated targeting a large set of multi-joint upper-limb movements. Spatial and temporal synergies were extracted from two datasets with proximal (16 subjects, 10M, 6F) and distal upper-limb movements (30 subjects, 21M, 9F), focusing on their differences in reconstruction accuracy and inter-individual variability. We showed the existence of both spatial and temporal structure in the EMG data, comparing synergies with those from a surrogate dataset in which the phases were shuffled preserving the frequency content of the original data. The two models provide a compact characterization of motor coordination at the spatial or temporal level, respectively. However, a lower number of temporal synergies are needed to achieve the same reconstruction R2: spatial and temporal synergies may capture different hierarchical levels of motor control and are dual approaches to the characterization of low-dimensional coordination of the upper-limb. Last, a detailed characterization of the structure of the temporal synergies suggested that they can be related to intermittent control of the movement, allowing high flexibility and dexterity. These results improve neurophysiology understanding in several fields such as motor control, rehabilitation, and prosthetics.

The relationship of trunk control with balance, upper extremity and lower extremity functions in stroke patients

The center of the body is the trunk. For distal extremity movements, balance, and functional tasks, proximal trunk control is crucial. The aim of the study is to examine the relationship of trunk control with balance, upper extremity and lower extremity functions in stroke patients. Thirty-six stroke patients were included in this cross-sectional descriptive study. Trunk control was assessed using the Trunk Impairment Scale (TIS), Berg Balance Scale (BBS) was used for balance evaluation, Fugl-Meyer Lower Extremity Scale (FML) was used for lower extremity function evaluation, Fugl-Meyer Upper Extremity Scale (FMU) was used for upper extremity function evaluation. The mean age of the included stroke patients was 62±11 years. There was a moderate negative correlation between TIS and BBS (r=-0.610, p&lt;0.01). A moderate negative correlation was found between TIS and FML (r=-0.520, p=0.001). A low negative correlation was found between TIS and FMU (r=-0.372, p=0.025). Trunk control affects balance, lower extremity and upper extremity function. In the treatment of stroke patients, exercise approaches for trunk control should be added to rehabilitation programs in addition to basic neurophysiological approaches.

A rare case of congenital upper limb deformity in a neonate

Radial club hand or radial dysplasia is an uncommon congenital anomaly. It is a longitudinal deficiency along the preaxial or the radial aspect of the upper extremity. It includes a wide spectrum of disorders that encompass an absent thumb, thumb hypoplasia, a thin first metacarpal and an absent radius. A 20-day-old male child, a baby of Vishakha Pravin Dongare was brought to the out-patient department at Acharya Vinoba have rural hospital, Wardha, Maharashtra with complaints of fever since 2 days. There was a history of a deformed left upper limb in the form of a short, curved, left forearm and an absent thumb since birth. The movements of the left elbow were limited. All the distal movements including the rotatory movements of the forearm and the wrist and the fine finger movements were not elicited. Only flickering movements of the fingers were elicited. The thumb had not developed at all. On clinico-radiological examination it was found that there was a complete deficiency of radius and the thumb with hyperflexion and radial side deviation at the wrist joint. Currently, the patient is under observation and will be followed up at monthly intervals for further evaluation and management.

Correlation Between Hand Grip Strength and Scapular Muscle Strength of Affected Upper Extremity in Female Breast Cancer Survivors Post Modified Radical Mastectomy

Background: Proximal joint stability is required to perform distal movements. Good grip strength might require adequate shoulder stability which will be dependent upon its musculature. Purpose: To find the relation of hand grip strength with scapular muscle strength in breast cancer survivors post modified radical mastectomy (MRM). Methodology: An observational cross sectional study was conducted in a tertiary care hospital. A total of 33 breast cancer survivors who underwent MRM before 6 months or more were included. Their affected side hand grip strength along with serratus anterior muscle strength and strength of upper, middle and lower fibers of trapezius was measured using hand held dynamometer. Results: Karl pearson’s correlation coefficient was used to find the correlation between hand grip strength and scapular muscle strength. Strong positive correlation was found between hand grip strength and serratus anterior muscle (r = 0.848) as well as lower trapezius (r = 0.868) strength. Whereas moderate positive correlation was found between hand grip strength and upper trapezius (r = 0.665) as well as middle trapezius (r = 0.444) muscle strength which was statistically significant (p&lt;0.05). Conclusion: Hand grip strength was significantly correlated with the scapular muscle strength in breast cancer survivors post MRM. Keywords: Breast cancer survivors, hand grip strength, hand held dynamometer, Modified Radical Mastectomy, Scapular muscle.

Identification of key determinant for predicting feasible mandibular molars distalization

Background/purposeThe distal movement of mandibular molar is effective treatment strategy, while it is still difficult to determine if the posterior available space is sufficient or not for mandibular molar distalization before treatment. Thus, this study aimed to identify the measurement items of lateral cephalograms with the potential to accurately predict the posterior anatomical limit of mandibular molar distalization. Materials and methodsCephalometric images of 26 patients were used. We establish five landmarks: the distal contact point (D7), the distal root apex (R7), the distal tooth cervix (TC) of the mandibular second molar, the anterior border of the ramus (ABR) and the external oblique line of the mandible (E). The D7-ABR and the vertical height between TC and E (TC-V), the distal movements of D7 and R7 during treatment (D7D, R7D) were measured. The subjects were divided into bodily-like and tipping movement group, according to the ratio D7D/R7D. ResultsSignificant differences in D7D and R7D were found between the bodily-like movement and tipping movement groups (P < 0.01). Moreover, TC-V was significantly larger in the bodily-like movement group (P < 0.01). A positive correlation was found between TC-V and D7D (r = 0.68) and between TC-V and R7D (r = 0.69), indicating that TC-V has the potential to make accurate predictions for D7D and R7D. D7-ABR did not show a positive correlation with R7D. ConclusionUsing TC-V can strengthen the prediction of available posterior space for mandibular molar distalization.

Optimized Simulation of Upper Body Timing on the Production of Bat-Head Speed in Baseball Batting

The objectives of this study were to (1)investigate the effect of the timing of the upper body joint motions in baseball batting on the bat-head speed and (2)develop and evaluate a simulation model inputting the individual hand forces on the bat. Twenty-three male collegiate baseball players performed tee batting set at waist height. A 10-segment angle-driven simulation model consisting of a bat and upper body was driven using the coordinate data of the standard motion. Performance optimization was conducted by changing the timing of the joint angle time histories of the upper body to increase the maximum bat-head speed. The optimization simultaneously estimated the individual hand forces by polynomial approximation dependent on the total bat forces to assess joint torques of the upper body. The bat-head speed increased to 39.2m/s from 35.6m/s, and the optimized timings were characterized by the earlier timing of the barrel-side elbow supination, wrist radial flexion, torso right lateral flexion, and the later timing of the barrel-side shoulder abduction. It is concluded that the skillful coordination of the individual joint movements for the upper body can produce a higher bat-head speed through effective sequencing of proximal to distal movements.

The Effects of Increased Maxillary Canine Bracket Angulation on Tooth Movement and Alignment Efficiency: A Prospective Clinical Study.

This study aimed to evaluate the effects of a 10° angulation of a maxillary canine (Mx3) bracket on Mx3 and maxillary central incisor (Mx1) tooth movements and alignment efficiency in treatments involving maxillary premolar extraction. This split-mouth study included 29 individuals in a +10° angulation study group and a 0° angulation control group. The initial (T0) and 12th week (T1) orthodontic models were prepared and digitized with a three-dimensional scanner and superimposed using the OrthoAnalyzer analysis program. The movements of Mx3 and Mx1 were measured, and the alignment efficiency was assessed using Little's Irregularity Index. The Shapiro-Wilk test was used to test the data for a normal distribution. T1 and T0 measurements within the group and T1 and T0 differences between groups were compared using a paired samples t-test. The significance level was set to P < .05. The linear movements of Mx3 in the distal direction significantly increased, and Little's Irregularity Index values statistically significantly decreased in both groups. Distal movements of Mx3 were significantly higher in the control group than in the study group (P< 0.01 and P< 0.05). The movements of Mx1 and Little's Irregularity Index measurements did not show statistically significant differences between the groups (P > 0.05). A +10° Mx3 bracket angulation increased the inclination of Mx3 to the mesial, but it decreased the Mx3 distal linear movement and the retraction of Mx1, with no difference in terms of alignment efficiency between the+10° and 0° Mx3 bracket angulations.

Developing and assessing a new web-based tapping test for measuring distal movement in Parkinson\u2019s disease: a Distal Finger Tapping test

Disability in Parkinson’s disease (PD) is measured by standardised scales including the MDS-UPDRS, which are subject to high inter and intra-rater variability and fail to capture subtle motor impairment. The BRadykinesia Akinesia INcoordination (BRAIN) test is a validated keyboard tapping test, evaluating proximal upper-limb motor impairment. Here, a new Distal Finger Tapping (DFT) test was developed to assess distal upper-limb function. Kinetic parameters of the test include kinesia score (KS20, key taps over 20 s), akinesia time (AT20, mean dwell-time on each key) and incoordination score (IS20, variance of travelling time between key taps). To develop and evaluate a new keyboard-tapping test for objective and remote distal motor function in PD patients. The DFT and BRAIN tests were assessed in 55 PD patients and 65 controls. Test scores were compared between groups and correlated with the MDS-UPDRS-III finger tapping sub-scores. Nine additional PD patients were recruited for monitoring motor fluctuations. All three parameters discriminated effectively between PD patients and controls, with KS20 performing best, yielding 79% sensitivity for 85% specificity; area under the receiver operating characteristic curve (AUC) = 0.90. A combination of DFT and BRAIN tests improved discrimination (AUC = 0.95). Among three parameters, KS20 showed a moderate correlation with the MDS-UPDRS finger-tapping sub-score (Pearson’s r = − 0.40, p = 0.002). Further, the DFT test detected subtle changes in motor fluctuation states which were not reflected clearly by the MDS-UPDRS-III finger tapping sub-scores. The DFT test is an online tool for assessing distal movements in PD, with future scope for longitudinal monitoring of motor complications.

Bayesian optimization of peripheral intraneural stimulation protocols to evoke distal limb movements

Objective. Motor neuroprostheses require the identification of stimulation protocols that effectively produce desired movements. Manual search for these protocols can be very time-consuming and often leads to suboptimal solutions, as several stimulation parameters must be personalized for each subject for a variety of target motor functions. Here, we present an algorithm that efficiently tunes peripheral intraneural stimulation protocols to elicit functionally relevant distal limb movements. Approach. We developed the algorithm using Bayesian optimization (BO) with multi-output Gaussian Processes (GPs) and defined objective functions based on coordinated muscle recruitment. We applied the algorithm offline to data acquired in rats for walking control and in monkeys for hand grasping control and compared different GP models for these two systems. We then performed a preliminary online test in a monkey to experimentally validate the functionality of our method. Main results. Offline, optimal intraneural stimulation protocols for various target motor functions were rapidly identified in both experimental scenarios. Using the model that performed best, the algorithm converged to stimuli that evoked functionally consistent movements with an average number of actions equal to 20% of the search space size in both the rat and monkey animal models. Online, the algorithm quickly guided the observations to stimuli that elicited functional hand gestures, although more selective motor outputs could have been achieved by refining the objective function used. Significance. These results demonstrate that BO can reliably and efficiently automate the tuning of peripheral neurostimulation protocols, establishing a translational framework to configure peripheral motor neuroprostheses in clinical applications. The proposed method can also potentially be applied to optimize motor functions using other stimulation modalities.