Joint Of Index Finger Research Articles

Dance-specific eligibility of vocational ballet students - examinations at a governmental training institution for classical ballet

During their training, pre-professional ballet students are confronted with physical stresses comparable to those of competitive sports. In competitive sports, there are mandatory and binding aptitude tests to ensure that the growing athlete meets the requirements. In ballet, there are no such mandatory examinations preceding the start of training. For adult professional dancers, musculoskeletal ideals could be isolated from the dance medicine literature. However, only a few studies describe musculoskeletal characteristics of pre-professional ballet students. It is neither known at what age a student should meet the ideal measurements for an adult nor what deviations from the ideal can be considered normal. This study aims to describe sociodemographic and musculoskeletal characteristics of pre-professional ballet students and discusses to what extent they already meet or deviate from dance-specific eligibility criteria for adult professional ballet dancers. In this study, n = 414 female and n = 192 male students of John Cranko School (JCS) were seen by an experienced orthopaedist and dance physician. Mean age was 13.9 years (SD 3.5, range 5-22 years). Their medical history was taken (age; nationality; start of ballet/training) and a physical examination was performed (height/weight; symmetry of shoulder girdle, spine, waist triangles; pelvic tilt; tibial torsion; range of motion of base of index finger joint, spine, hips, ankle and base of great toe joint). Subsequently, the results of this study were compared with suitability criteria for adult professional ballet dancers that had been isolated from the dance medicine literature for a previous article. Examinees were from 49 different nations. 34.6% of the female subjects (≥16 years) were between 165 and 170 cm and 33.3% of the male subjects (≥18 years) were between 178 and 185 cm tall. 45.0% of those examined showed low body weight (<10th percentile, BMI <18.5 kg/m²). The trunk of 61.0-84.8% of those examined was erect and symmetrical. 25.2% had scoliosis. Half (53.5%) were found to have a bilateral external rotation of the hips of at least 60°, and 68.7% had a bilateral internal rotation between 20 and 50°. 87.3% exhibited a bilateral tibial torsion between 15 and 40°. A bilateral en dehors of 90° was calculated for 25.0%. In 9.1% of those examined, the upper ankle joints presented a dorsiflexion of at least 25°, and in 70.2%, a plantarflexion of at least 70° was seen. In 88.0%, the metatarsophalangeal joint of the great toe was 90° (f) and 80° (m) on both sides. The results of this study showed that pre-professional ballet students fulfil many characteristics of adult professional ballet dancers. High values already among young age groups suggest a ballet-specific selection. Nevertheless, not all students fulfil the theoretical "ideal measurements" for professional classical ballet. These anatomical limits should be considered individually in training to protect the growing pre-professional ballet dancer. The high ballet-specific anatomical demands, but especially the large number of students with a low body weight, underline the necessity of mandatory aptitude tests at the beginning and regular check-ups in the course of training to avert compensatory mechanisms and their consequential damage and to screen for eating disorders and disorders of eating behaviour.

Plexiform Schwannoma of Digital Nerve.

Plexiform schwannoma is an uncommon benign tumour that grows in a plexiform pattern. We report a 47-year-old man with a mass on the palmar aspect of the metacarpophalangeal joint of the right index finger that had been growing gradually for more than 10 years. The mass was palpated from the distal carpal tunnel to the ulnar aspect of the proximal interphalangeal joint of the index finger, with tingling and numbness sensation. The tumour was a multinodular tumour involving the first common palmar digital nerve to the ulnar proper palmar digital nerve. It was resected and reconstructed with a sural nerve graft. Plexiform schwannoma is rare in the digital nerve, with only six cases reported. Generally, classic schwannomas can be enucleated without causing neurologic deficits; however, plexiform schwannoma may require nerve resection. There have been reports of recurrence of plexiform schwannoma; definitive resection and long-term follow-up are necessary. Level of Evidence: Level V (Therapeutic).

P17 A bend in the road: a patient with rheumatoid arthritis developing multicentric reticulohistiocytosis

P17 A bend in the road: a patient with rheumatoid arthritis developing multicentric reticulohistiocytosis

Development of a Human-Robot Interaction System for Industrial Applications

The use of robots is increasing day by day. In this study, it was aimed to develop manufacturing-assistant robot software for small production plants involving non-mass production. The main purpose of this study is to eliminate the difficulty of recruiting an expert robot operator thanks to the developed software and to facilitate the use of robots for non-experts. The developed software consists of three parts: the convolutional neural network (CNN), process selection-trajectory generation, and trajectory regulation modules. Before the operations in these modules are executed, operators record the desired process and the trajectory of the process in the video by hand gestures and index finger. Then recorded video is separated into images. The separated images are classified by the CNN module and the positions of landmarks (joint and fingernail of index finger) were calculated by the same module and using the images. Eight different pre-trained CNN structures were tested in the CNN module, and the best result Xception structure (test loss = 0.0051) was used. The desired process was determined and the trajectory of the process was created with the CNN output data. The connection of the generated trajectory with the object was detected by the trajectory regulation module, and unnecessary trajectory parts were cleaned. Regulated trajectory and desired tasks such as welding or sealing were simulated via an industrial robot in a simulation environment. As a result, an industrial robot could be programmed by non-expert operators for companies whose production line is not standard by using the developed software.

Mechanical design and feasibility of a finger exoskeleton to support finger extension of severely affected stroke patients.

In this paper we presented the mechanical design and evaluation of a low-profile and lightweight exoskeleton that supports the finger extension of stroke patients during daily activities without applying axial forces to the finger. The exoskeleton consists of a flexible structure that is secured to the index finger of the user while the thumb is fixed in an opposed position. Pulling on a cable will extend the flexed index finger joint such that objects can be grasped. The device can achieve a grasp size of at least 7 cm. Technical tests confirmed that the exoskeleton was able to counteract the passive flexion moments corresponding to the index finger of a severely affected stroke patient (with an MCP joint stiffness of k = 0.63Nm/rad), requiring a maximum cable activation force of 58.8N. A feasibility study with stroke patients (n=4) revealed that the body-powered operation of the exoskeleton with the contralateral hand caused a mean increase of 46° in the range of motion of the index finger MCP joint. The patients (n=2) who performed the Box & Block Test were able to grasp and transfer maximally 6 blocks in 60 sec. with exoskeleton, compared to 0 blocks without exoskeleton. Our results showed that the developed exoskeleton has the potential to partially restore hand function of stroke patients with impaired finger extension capabilities. An actuation strategy that does not involve the contralateral hand should be implemented during further development to make the exoskeleton suitable for bimanual daily activities.

Role of Low-Level Laser Therapy as an Adjuvant in Functional Rehabilitation of Patients with Joint Stiffness in Post-Burn Contracture

Introduction Post-burn contracture is a known sequelae of burn injuries involving neck, axilla, elbow, and hand. There are many methods which are used as adjuvant in rehabilitation of post-burn contracture patients. The low-level laser therapy (LLLT) is one of the methods that can be used as an adjuvant in rehabilitation of joint stiffness following burns and but with very few data available from India. In this article we share our experience of using LLLT for functional rehabilitation of a patient with joint stiffness following postburn contracture. Materials and Methods This study was conducted in a burns centre in a tertiary care institute in South India. Informed consent and departmental ethical committee clearance were obtained prior to study. The subject was a young boy with no known co-morbidities with stiffness of metacarpophalangeal and interphalangeal joint of index and middle finger of right hand. Patient was treated with contracture release with full thickness skin graft. The patient received low-level laser therapy to induce collagenolysis and to increase the movement of the joints. Each joint received laser therapy for duration of 125-second every time for 15-minutes for 2 sessions in a span of 4-days. Result LLLT has been found to be useful in early rehabilitation of post-burn contracture patients with joint stiffness. No side effects were observed during the study. Conclusion The LLLT is an effective, safe, and non-invasive adjuvant in functional rehabilitation of our patient with joint stiffness following post-burn contracture. We suggest further study including multiple subjects and a control group for validation of the result.

Degradable and stretchable bio-based strain sensor for human motion detection

In recent years, flexible strain sensors have attracted considerable attention for the great application potential in the emerging fields of wearable devices, electronic skin and health monitoring. However, most of flexible strain sensors are nondegradable, and the produced numerous electronic wastes after uselessness will seriously threaten environment and ecology. Herein, we propose a new strategy to fabricate degradable and stretchable bio-based strain sensor using candle soot (CS) particles to construct conductive pathways and chitosan, potato starch (PS), and polyvinyl alcohol (PVA) to form stretchable matrix in the presence of Fe3+ ions. Owing to the formation of multiple hydrogen bonding constructed by chitosan, PS and PVA as well as coordination bonding by Fe3+ ions, the obtained strain sensor showed high elongation at break up to 200% and good fatigue resistance. Furthermore, the firm embedding of the CS particles into the surface of the stretchable matrix endowed the strain sensor with steady sensitivity (gauge factors of 1.49 at 0–60% strain and 2.71 at 60–100% strain), fast response (0.22 s) and good repeatability even after 1000 stretching-releasing cycles. In addition, the strain sensor was successfully applied to detect various human motions including finger and wrist bending, swallowing and pronunciation. Interestingly, after connecting to an Arduino microcontroller circuit with a Bluetooth module, the strain sensor was able to wirelessly detect real-time movements of index finger joints. Different from most previously reported sensors, the prepared strain sensor in this work was completely degraded in 2 wt% CH3COOH solution at 90 °C only within 10 min, thus effectively avoiding the production of electrical waste after the updating and upgrading of the sensors. The findings conceivably stand out as a new methodology to prepare environmental-friendly sensors in the field of flexible electronics, which is very beneficial for the sustainable development of environment and society.

Design of flexible resistance sensor based on mesh convex microstructure

To solve the problems of large volume and poor flexibility of the traditional pressure sensor prepared by rigid materials, a flexible pressure resistance sensor with mesh convex platform microstructure has been prepared by using polydimethylsiloxane (PDMS) as a substrate and graphene as a conductive functional layer. The preparation process of the graphene conductive layer of the flexible sensor and PDMS substrate are optimized. And the effect of the concentration of graphene on the sensitivity of the sensor is investigated. The experimental results show that the addition of polyurethane to graphene and the hydrophilic treatment of the PDMS can improve the stability of the sensitivity of the sensor. Excessive graphene blocks microstructural gaps, leading to enhanced microstructural resistance to deformation which will reduce sensitivity. The experimental results show that the thicker the PDMS, the smaller the microstructural deformation, resulting in lower sensitivity. Based on the theoretical basis of elastic mechanics, the calculated results show that the microstructural strain decreases with the thickness of PDMS, consistent with the experimental results. Finally, the performance of PDMS microstructure sensor with thickness of 0.2 mm has been tested. The sensor has a high linear sensitivity (0.152 kPa−1) and a wide linear dynamic response range (0–4 kPa), along with a fast response time of 83 ms and reliable stability. The sensor has been attached to the index finger joint for bending test and fixed to the left hand pulse detection beat, which shows the sensor is able to detect human physiological activity.

Selective Drive and Control of Index Finger Joint Using Multipoint Functional Electrical Stimulation

Functional electrical stimulations (FES) drive human joints by stimulating peripheral nerves electrically. FES is applied to the rehabilitation of paralyzed patients or force feedback applications. However, exerting a large force to a specified finger using FES is difficult, because high-intensity stimulation can cause low selectivity. This problem is remarkable for the index finger because its fascicles are distributed deep in the forearm with a small area close to the skin. This paper describes a method for simultaneously stimulating multiple points to solve the problem. We conducted experiments focusing on selectivity and exerting torque to the index finger. The phase difference between stimulation waveforms and electrode isolation states were varied in the experiments. The proposed method was confirmed to induce a larger force than one-point stimulation and did not deteriorate selectivity if appropriate parameters were selected. Moreover, a finger angle control experiment considering selectivity was conducted. The selectivity problem makes selective control difficult. The proposed method was advantageous for finger controlling.

Development and comprehensive evaluation of a new spring-steel-driven glove for grasping assistance during activities of daily living.

Millions of people suffer from a decline in grip strength and hand function due to conditions such as chronic disease, injuries, and aging. Hand function decline results in difficulties with performing activities of daily living, where grasping, lifting, and releasing objects are essential. There is an increasing demand for assistive gloves to enhance users' hand function and improve their independence. This paper presents the design of a new bidirectional lightweight assistive glove and demonstrates its capabilities through comprehensive experiments using human subjects. The developed glove can provide adequate power augmentation for grasping and releasing objects due to its simple yet effective design using spring steel strips and linear actuators. The glove directly transfers assistive forces to users' fingertips without any complex intermediate mechanism, and its low weight of 196 g promotes its usability. The rigorous experiment design provided a thorough assessment of the developed glove by accounting for both parameters of size and weight of objects and by including subjects with different hand sizes. To quantify the glove's performance, the subjects' muscle activity, their finger and thumb joints' trajectories, and their grasping forces while using the glove were investigated. The glove could generate the necessary grasping forces to assist with lifting common-household objects. The subjects' muscle activity significantly decreased when using the glove for object manipulation. The trajectories of the index finger and thumb joints when using the glove were dependent on the size of objects similar to natural unassisted grasping. The obtained results demonstrate the glove's ability for grip power augmentation of individuals with declining hand strength.

AMRTA-X: Grasp Kinematic Analysis during Myoelectric Prehension Orthosis and Body Powered Prehension Orthosis's Usage on Brachial Plexus Injury Patients

Brachial Plexus Injury (BPI) results in decreased motor function in upper extremity and leads to reduced hand grasping movement. Orthotic prehension is designed to create artificial grasp movements in paralyzed hand. This study was to compare grasp kinematic improvement between body powered and myoelectric prehension orthosis usage in patients with BPI. This study was a single group without control and post test with experimental study. The subjects of the study (n = 11) were brachial plexus injury patients with non-functional hand strength. Joint motion and angular velocity of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joint of index finger were evaluated. There was an improvement in joint motion and angular velocity after both orthosis usage. Joint motion in MCP and PIP, Angular velocity in MCP were not significantly different between myoelectric and body powered and myoelectric prehension orthosis usage. PIP angular velocity improvement were better after body powered prehension orthosis usage (p= 0.03).In conclusion, body powered and myolectric prehension orthosis usage improved kinematic parameter of index finger’s MCP and PIP joint. PIP angular velocity was better after body powered prehension orthosis usage.

The Effect of Rhythmic Tactile Stimuli Under the Voluntary Movement on Audio-Tactile Temporal Order Judgement.

The simultaneous perception of multimodal sensory information is important for effective reactions to the external environment. In relation to the effect on time perception, voluntary movement and rhythmic stimuli have already been identified in previous studies to be associated with improved accuracy of temporal order judgments (TOJs). Here, we examined whether the combination of voluntary movement and rhythmic stimuli improves the just noticeable difference (JND) in audio-tactile TOJ Tasks. Four different experimental conditions were studied, involving two types of movements (voluntary movement, involuntary movement) and two types of stimulus presentation (rhythmic, one-time only). In the voluntary movement condition (VM), after the auditory stimulus (cue sound) participants moved their right index finger voluntarily and naturally, while in the involuntary movement condition (IM), their right index finger was moved by the tactile device. The stimuli were provided in a rhythmic or one-time only manner by hitting inside the first joint of the participants' right index finger using a tactile device. Furthermore, in the rhythmical tactile (RT) conditions, tactile stimuli were presented rhythmically to the right index finger 5 times consecutively. On the other hand, in the one-time tactile (1T) conditions, tactile stimuli was presented one-time only to the right index finger. Participants made an order judgment for the fifth tactile stimuli and the first and only auditory stimuli. In our TOJ tasks, auditory-tactile stimulus pairs were presented to participants with varying stimulus-onset asynchronies (SOAs; intervals between the within-pair onsets of the auditory and tactile stimuli). For the two stimuli presented at a time that were shifted by the SOA, the participants were asked to judge which one was presented first, and they were given a two-choice answer. Using a non-parametric test, our results showed that voluntary movement and rhythmic tactile stimuli were both effective in improving the JNDs in TOJ Tasks. However, in the combination of voluntary movement and rhythmic tactile stimuli, we found that there was no significant difference in JNDs in our experiments.

The Effect of the Waveform of the Functional Electrical Stimulation on the Movement of MP Joint in Index Finger

Recently, many types of Functional Electrical Stimulation (FES) devices have been developed for rehabilitation and neural prosthesis. The effect on human motion by changing the waveform pattern of electrical stimulation was evaluated for suitable parameters for the precise control of MP joint of index finger, In this study, we use a combination of square wave waveforms and then we focused on the stimulation period, stimulation amplitude, and pulse width. The results showed that the stimulus amplitude and pulse width had a strong linear correlation with MP joint angle increase. However, the stimulation period may have nonlinearity. These results suggest that the voltage and pulse width are possible parameters for the precious human hand motion control with FES.

A rare case report of bilateral distal radius fractures including bilateral isolated metacarpophalangeal joint dislocations in a piano artist

Bilateral distal radius fractures are rare injuries and only a small number of case reports exist. Literature reports of low velocity as well as high velocity injuries. It has been found that high velocity injuries are frequently associated with injury to carpals, metacarpals and phalanges. No case has yet been reported in medical literature with respect to bilateral distal radius fractures associated with bilateral single finger Metacarpophalangeal (MCP) joint dislocation. The aim of this case report is to emphasize the rarity of this injury and the associated trauma which are sometimes missed or diagnosed late. This case also highlights the role of skilful urgent reduction and stabilisation of such injuries followed by an early aggressive hand and wrist rehabilitation program to ensure an excellent outcome for the patient. Case Report: We report a case of bilateral distal radius fracture with MCP joint dislocation of the right index finger and MCP joint dislocation left thumb in a professional pianist following a high energy trauma due to a road traffic accident. The patient underwent surgery in the form of closed reduction and a wrist spanning radial distractor application with pinning of bilateral wrist. Closed reduction was done for the MCP joint dislocation left thumb and open reduction for the MCP joint dislocation right index finger. Patient was on an aggressive physiotherapy regime from the early postoperative period. Both the distal radius fractures united adequately by three months as well as the MCP joint dislocations restored with a satisfactory DASH functional scores. Conclusion: High energy traumas to the hand and wrist can result in ipsilateral or even bilateral injuries of the distal radius, ulna, carpals, metacarpals and phalanges. Hence, it is important not to miss any associated injury in the small bones of the hand when there is a fracture in the forearm and arm bones. Initiation of an early and intense rehabilitation program requires immediate reduction and fixation of the fractures and dislocations in order to gain the best functional outcome for the patient.

Finger Grasp Kinematics Towards Exoskeleton Development

This paper investigates the relationships between index finger joint rotations to determine whether a one degree of freedom (DOF) exoskeleton could produce natural finger motions for a range of different users and grasping conditions.Four healthy subjects each performed ten trials involving the grasp of two cylindrical objects with diameters of 66.5mm and 47mm. Finger trajectories for each trial were recorded using a motion capture system and were used to obtain joint rotational trajectories for the Metacarpo-phalangeal (MCP) Proximal-interphalangeal (PIP) and Distal-interphalangeal (DIP) joints.Joint ranges of motion (ROM) were largest for all subjects when grasping the smaller diameter object. This effect was also seen where subjects with longer fingers tended to use a larger MCP ROM for the same object. Subject 2 was an exception to this, using the smallest MCP and PIP ROM of all subjects when grasping the large diameter object: this anomaly is thought be caused by difference in palmar engagement with the object.The profile of the MCP-PIP trajectories were similar when normalised to their range of motion, with a maximum y-axis error of 22%. This implies that the MCP-PIP relationship for a cylindrical grasp can be approximated be a general scalable polynomial. We conclude that through parabolic coupling between MCP and PIP joints, a one-DOF exoskeleton is capable of producing functional grasping movements. Through an adjustable coupling mechanism between MCP and PIP, it is also believed that an exoskeleton can be successfully adapted for differing object and finger sizes.

Context-dependent relationship in high-resolution micro-ECoG studies during finger movements.

The activation of the sensorimotor cortex as measured by electrocorticographic (ECoG) signals has been correlated with contralateral hand movements in humans, as precisely as the level of individual digits. However, the relationship between individual and multiple synergistic finger movements and the neural signal as detected by ECoG has not been fully explored. The authors used intraoperative high-resolution micro-ECoG (µECoG) on the sensorimotor cortex to link neural signals to finger movements across several context-specific motor tasks. Three neurosurgical patients with cortical lesions over eloquent regions participated. During awake craniotomy, a sensorimotor cortex area of hand movement was localized by high-frequency responses measured by an 8 × 8 µECoG grid of 3-mm interelectrode spacing. Patients performed a flexion movement of the thumb or index finger, or a pinch movement of both, based on a visual cue. High-gamma (HG; 70-230 Hz) filtered µECoG was used to identify dominant electrodes associated with thumb and index movement. Hand movements were recorded by a dataglove simultaneously with µECoG recording. In all 3 patients, the electrodes controlling thumb and index finger movements were identifiable approximately 3-6-mm apart by the HG-filtered µECoG signal. For HG power of cortical activation measured with µECoG, the thumb and index signals in the pinch movement were similar to those observed during thumb-only and index-only movement, respectively (all p > 0.05). Index finger movements, measured by the dataglove joint angles, were similar in both the index-only and pinch movements (p > 0.05). However, despite similar activation across the conditions, markedly decreased thumb movement was observed in pinch relative to independent thumb-only movement (all p < 0.05). HG-filtered µECoG signals effectively identify dominant regions associated with thumb and index finger movement. For pinch, the µECoG signal comprises a combination of the signals from individual thumb and index movements. However, while the relationship between the index finger joint angle and HG-filtered signal remains consistent between conditions, there is not a fixed relationship for thumb movement. Although the HG-filtered µECoG signal is similar in both thumb-only and pinch conditions, the actual thumb movement is markedly smaller in the pinch condition than in the thumb-only condition. This implies a nonlinear relationship between the cortical signal and the motor output for some, but importantly not all, movement types. This analysis provides insight into the tuning of the motor cortex toward specific types of motor behaviors.

Correlates between magnetic resonance imaging and X-ray abnormalities and hand symptoms in older adults

Purpose: The clinical relevance of abnormal features seen on hand magnetic resonance imaging (MRI) have been investigated in patients with hand osteoarthritis (HOA). However, whether these relationships are similar in the general population and if they are independent of features seen on radiographs is not known. Therefore, we aimed to describe cross-sectional associations between presence of MRI-detected effusion-synovitis, bone marrow lesions, erosions, collateral ligaments (CL), osteophytes; radiograph-detected osteophytes and joint space narrowing (JSN) with joint symptoms and grip strength in community-based older adults. Methods: Distal and proximal interphalangeal index finger joints (n=221, mean age= 72, 44% females) were imaged using MRI, conventional radiographs (XR) and assessed using the Oslo HOA score and OARSI atlas, respectively. Joints were assessed clinically for pain and tenderness. Hand pain, function, and stiffness were assessed using the Australian/Canadian HOA index (AUSCAN) questionnaire; grip strength was assessed using a dynamometer. Data was analysed using log binomial, ordinal logistic, and linear regression and adjusted for age, sex, and other MRI or XR abnormalities. Results: Participants with above average (worse) AUSCAN pain scores had higher proportions of women (55%), met clinical HOA criteria (92%), and have poorer grip strength (9psi), and quality of life (AQoL utility 0.66) than those with mild or no pain. Absent CL’s on MRI (RR=3.33 (95% confidence interval; 1.45, 7.61)) and JSN on X-ray (RR=2.47 (1.06, 5.74)) were associated with higher risk of having a painful joint after adjustment for age, sex, and other structures. Participants with JSN had higher odds of moving to a higher category of AUSCAN pain (OR=1.59 (1.08, 2.35)) while effusion, surprisingly, inferred lower odds (OR=0.51 (0.28, 0.91)) of pain. JSN was also associated with lower grip strength independent of pain and other features (β=-0.95 (-1.74, -0.15)). No abnormalities were independently associated with tender joints, AUSCAN function limitation or stiffness. Conclusions: Absence of CL’s, and JSN were independently associated with painful joints; JSN was also associated with weak grip strength. Unexpectedly, effusions were associated with reduced odds of pain. This data does not support using MRI to identify potential targets for therapeutic interventions for hand pain.Tabled 1Associations of presence of MRI and radiographic abnormalities and HOA symptoms and grip strength.Presence of painful joint RR (95% CI)Presence of tender joint OR (95% CI)AUSCAN pain OR (95% CI)AUSCAN physical function limitation OR (95% CI)AUSCAN stiffness OR (95% CI)Grip strength beta (95% CI)MRI abnormalitiesEffusion0.65 (0.16, 2.57)0.46 (0.15, 1.43)0.51 (0.28, 0.91)1.03 (0.40, 2.61)0.72 (0.33, 1.56)0.35 (-0.85, 1.55)Absence of collateral ligament3.33 (1.45, 7.61)0.69 (0.10, 5.01)1.74 (0.82, 3.65)2.66 (0.79, 9.02)2.26 (0.84, 6.05)-1.46 (-2.96, 0.04)BML1.32 (0.34, 5.16)1.31 (0.42, 4.06)1.20 (0.79, 1.81)0.89 (0.50, 1.57)1.40 (0.81, 2.40)0.09 (-0.73, 0.91)Erosion1.80 (0.60, 5.33)1.01 (0.37, 2.76)0.92 (0.62, 1.38)0.61 (0.34, 1.10)0.97 (0.58, 1.63)0.09 (-0.73, 0.91)Osteophytes2.55 (0.33, 19.56)1.02 (0.28, 3.62)1.14 (0.74, 1.75)1.10 (0.61, 1.98)1.25 (0.68, 2.27)0.62 (-0.23, 1.47)X-ray abnormalitiesOstephytes0.58 (0.24, 1.41)0.82 (0.31, 2.19)0.79 (0.52, 1.20)1.07 (0.59, 1.94)1.11 (0.66, 1.87)0.16 (-0.68, 1.00)Joint space narrowing2.47 (1.06, 5.74)1.97 (0.84, 4.58)1.59 (1.08, 2.35)1.37 (0.79, 2.36)1.04 (0.64, 1.68)-0.95 (-1.74, -0.15) Open table in a new tab

Involuntary Neuromuscular Coupling between the Thumb and Finger of Stroke Survivors during Dynamic Movement.

Finger–thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being controlled independently, the index finger and thumb especially must work in concert to perform a variety of tasks requiring lateral or palmar pinch. The impact of stroke on this functionally critical sensorimotor control during dynamic tasks has been largely unexplored. In this study, we explored finger–thumb coupling during close–open pinching motions in stroke survivors with chronic hemiparesis. Two types of perturbations were applied randomly to the index with a novel Cable-Actuated Finger Exoskeleton: a sudden joint acceleration stretching muscle groups of the index finger and a sudden increase in impedance in selected index finger joint(s). Electromyographic signals for specific thumb and index finger muscles, thumb tip trajectory, and index finger joint angles were recorded during each trial. Joint angle perturbations invoked reflex responses in the flexor digitorum superficialis (FDS), first dorsal interossei (FDI), and extensor digitorum communis muscles of the index finger and heteronymous reflex responses in flexor pollicis brevis of the thumb (p < 0.017). Phase of movement played a role as a faster peak reflex response was observed in FDI during opening than during closing (p < 0.002) and direction of perturbations resulted in shorter reflex times for FDS and FDI (p < 0.012) for extension perturbations. Surprisingly, when index finger joint impedance was suddenly increased, thumb tip movement was substantially increased, from 2 to 10 cm (p < 0.001). A greater effect was seen during the opening phase (p < 0.044). Thus, involuntary finger–thumb coupling was present during dynamic movement, with perturbation of the index finger impacting thumb activity. The degree of coupling modulated with the phase of motion. These findings reveal a potential mechanism for direct intervention to improve poststroke hand mobility and provide insight on prospective neurologically oriented therapies.

Correction: Measuring 3D Hand and Finger Kinematics-A Comparison between Inertial Sensing and an Opto-Electronic Marker System.

[This corrects the article DOI: 10.1371/journal.pone.0164889.].

Normative study of paediatric hand in an Indian population and a novel method of measurement of first web space arc radius

The aesthetic appearance of the thumb hasn’t been analysed to a similar extent as thumb function which would aid during reconstructive surgeries of the thumb and first web space and analyse its outcome. The purpose of this study is to determine the relative length, girth, nail width of thumb with respect to the index finger and intermetacarpal distance. Measurement of the 1st web space arc radius has been done to tackle the problem of webbing which is not addressed by IMD and palmar abduction angles. A total of 482 hands in 241 subjects were studied to measure the relative length of the thumb with respect to the index finger, the relative nail width of thumb with respect to index finger, the relative girth of IP joint of thumb with respect to PIP joint of index finger and Intermetacarpal distance was calculated. The 1st web space arc radius was calculated by the “best arc fit” with the thumb in maximum radial abduction using a radius gauge. The data collected was analysed by age, gender, laterality of the hand and the height and weight of the child. Hands of subjects of which with a mean age of years were analysed. The relative Thumb length, girth and nail width remained independent of age. It has been observed that the reliability of the measurements between the right and left web space arc radius measurement is significant [ICC– p value