Joint Of Index Finger Research Articles

Development of a closed-loop system for tremor suppression in patients with Parkinson's disease.

More than 70% of patients suffering Parkinson's disease (PD) exhibit resting tremor in their extremities, hampering their ability to perform daily activities. Based on our earlier studies on corticospinal transmission of tremor signals [10,11], we hypothesize that cutaneous afferents evoked by surface stimulation can produce an inhibitory effect on propriospinal neurons (PN), which in turn will suppress tremor signals passing through the PN. This paper presents the development of a closed-loop system for tremor suppression by transcutaneous electrical nerve stimulation (TENS) of sensory fibers beneath the skin. The closed-loop system senses EMGs of forearm muscles, and detects rhythmic bursting in the EMG signal. When a tremor is detected by the system, a command signal triggers a stimulator to output a train of bi-phasic, current regulated pulses to a pair of surface electrodes. The stimulation electrode is placed on the dorsal hand skin near the metacarpophalangeal joint of index finger, which is innervated by the superficial radial nerve that projects an inhibitory afferent to PNs of forearm muscles. We tested the closed-loop system in 3 normal subjects to verify the algorithm and in 2 tremor dominated PD subjects for feasibility of tremor detecting and suppression. Preliminary results indicate that the closed-loop system can detect tremor in all subjects, and tremor in PD patients was suppressed significantly by electrical stimulation of cutaneous afferents.

Hand rehabilitation after stroke using a wearable, high DOF, spring powered exoskeleton.

Stroke patients often have inappropriate finger flexor activation and finger extensor weakness, which makes it difficult to open their affected hand for functional grasp. The goal was to develop a passive, lightweight, wearable device to enable improved hand function during performance of activities of daily living. The device, HandSOME II, assists with opening the patient's hand using 11 elastic actuators that apply extension torques to finger and thumb joints. Device design and initial testing are described. A novel mechanical design applies forces orthogonal to the finger segments despite the fact that all of the device DOFs are not aligned with human joint DOF. In initial testing with seven stroke subjects with impaired hand function, use of HandSOME II significantly increased maximum extension angles and range of motion in all of the index finger joints (P<;0.05). HandSOME II allows performance of all the grip patterns used in daily activities and can be used as part of home-based therapy programs.

Dislocation of metacarpophalangeal joint of bilateral index finger: A case report

Occurrence of bilateral dislocation of metacarpophalangeal joint of index finger are very uncommon. Most of the dislocation are complex in nature and require surgical open reduction. The need for surgical reduction is primarily due to entrapment of fibrocartilaginous volar plate between proximal phalanx and metacarpal head. The dislocation can be approached by either volar or dorsal approach. We advocates dorsal approach because of its definitive advantage over volar approach like reduced neurovascular injury and direct exposure of volar plate.

Prevalence of sesamoid bones in the hands: 3D-reconstructed CT study

IntroductionThe prevalence of sesamoid bone in hand is known to be variable among populations of various geographic origins. Since counting with radiographs might be inaccurate due to superimposition of adjacent digits, we tried to overcome this obstacle using 3D-reconstructed CT in Korean patients. The purpose was to provide an accurate incidence of sesamoid bones using 3D-CT. MethodsSesamoid bones were examined in 427-CT images. 3D-CT images were analyzed by one observer and parts of hands (411-hands) were evaluated with radiograph to compare with CT results. Statistical analysis between the CT and radiograph results was performed. ResultsSesamoids of metacarpo-phalangeal (MP) joint of the thumb were always present on both radial and ulnar sides, except for 9-cases (2.1%) where they were not present on radial side and 6-cases (1.5%) where they were not present on ulnar side. MP joint of the little finger was the second most prevalent location (62.8%). The sesamoid of the index finger MP joint and thumb interphalangeal joint was observed in 44% and 42.4%, respectively. There was a rare incidence in the MP joints of middle and ring finger (0.7%). The incidence of sesamoid bone was statistically different between the two counting methods for the MP joints of index and little finger and thumb interphalangeal joint (P < 0.005). DiscussionWe could observe five frequent sesamoid bones in the MP joints of the thumb, index, and little finger, and the interphalangeal joint of the thumb in Korean individuals. 3D-CT images revealed the accurate incidences of hand sesamoid bones.

Research on Size Synthesis Optimization Design of a Bionic Exoskeleton for Index Finger Rehabilitation

This paper presents a novel wearable robotic hand exoskeleton named ReHand-II for post-stroke rehabilitation. To ensure the consistency of rotation between exoskeleton joints and index finger joints and to realize reasonable range of movement, the kinematics models of left index finger and the exoskeleton are established. And design variables,constraints and objective function are determined. The size synthesis optimization design is realized. Ultimately the size value of each component parameter is determined. The hand exoskeleton is developed according to the results of the optimization. Finally, ReHand-II shows better bio-imitability and Wearable adaptability by wear experiment results.

Joint-specific prevalence and radiographic pattern of hand osteoarthritis in Korean

We investigated the prevalence and involvement patterns of radiographic osteoarthritis (OA) with hand symptoms among Korean people and compared the difference in prevalence of hand OA between racial groups. Hand radiographs in 299 Korean subjects (266 female, 33 male) ≥40years of age were examined, who had hand arthralgia. The study population was comprised of 206 patients who had radiographic OA at least at one hand joint. Radiographic OA (Kellgren-Lawrence scale≥2 grades) was evaluated for 16 joints of each hand. The most prevalent OA was in the interphalangeal joints (IP) of thumb, followed by the distal interphalangeal joints (DIP) of index finger, DIP of middle and fifth finger in the frequency of order. The involvement of metacarpophalangeal joints (MP) was relatively common in 1st-3rd MP. Hand OA in Korean was higher in the thumb IP and lower in the thumb carpometacarpal joints compared with Caucasian previously reported. Moreover, the higher OA frequency of 1st-3rd MP was not in accordance with other studies in Caucasian and other Asian populations. The patterns of radiographic hand OA were symmetric (OR 15.68), clustered by ray (OR 8.69) and row (OR 6.66). In conclusion, our study showed that thumb IP and 2nd/3rd/5th DIP should be included in the assessment of radiologic hand OA in Koreans.

Analysis of Finger Position During Two- and Three-Fingered Grasp: Possible Implications for Terminal Device Design

INTRODUCTION: Analysis of human hand kinesiology has been used to justify the design characteristics of terminal devices. The human hand is a complex mechanical structure consisting of 15 articulations controlled by over 30 muscles for the 5 fingers. It functions as a communication, sensory, grasp and manipulation structure. Separating essential hand kinesiology that is linked with each hand function might allow for the efficient development of terminal devices where there is one primary function such as grasping. It follows that to develop an effective grasping mechanism for a terminal device there should be a clear understanding of hand motions as they relate directly to the grasping function. The conceptual framework used to characterize grasping functions will most likely influence the development of terminal devices. There is a growing body of literature that is refining the way we think of grasping activities, and may impact the design of terminal devices. For example, researchers have described the simplified coordination of hand motions during grasp as “synergies” or “virtual fingers”, where there are predictable dependencies of one finger on another. Using conceptual approaches such as the “virtual fingers” concept will reduce the complexity of the description of the hand/object/task interaction.[2] Recent studies indicate that only a small part of the hand’s potential motion is used during grasp. Mason et al. [5] concluded that much of reach-to-grasp uses a base posture with small refinements in finger and thumb positions. In another study Baud-Bovy & Soechting [1] found that when two fingers oppose the thumb, there is a predictable singular task that produced a balanced lever. Kamper et al [3] studied a variety of grasping tasks using 5 everyday objects. They found that the thumb, for example, used less than 5% of the available range. If one were to extrapolate these findings, prosthetic grasping mechanisms may only need a portion of the hand’s total range of motion. Grasping patterns of the normal hand should be studied using a wide variety of objects to compare normal grasp patterns with prosthetic devices. The current study examined finger positions during twoand three-fingered grasp of a wide range of geometrical objects. The results from people with normal hands were compared to two terminal devices. METHODS: Seven subjects participated in the study (2 male, 5 female). A 6-camera video motion analysis system (Qualisys, Gothenburg, Sweden) was used to collect marker locations in a calibrated volume approximately 1 m 3 . Fourteen reflective markers were taped to the interphalangeal joints, metacarpophalangeal joints and the carpals of the subjects (Figure 1). Seated subjects were asked to grasp objects, one at a time, using either two fingers or three fingers. The 9 objects were chosen based on standard geometric shapes, sizes and varied mass distribution properties. The smallest object was a 1.9 cm diameter sphere and the largest object was a 9.5 X 12.5 X 1.7 cm rectangular prism. The objects were painted brown to avoid inferring a particular use. Data were collected at 120

Automatic determination of the optimal shape of a surface electrode: Selective stimulation

We present a method for automatic determination of the shape and position of the surface electrode for selective control of fingers extension and flexion by means of electrical stimulation. The multi-pad electrodes used in the experiments comprised 24 pads (1 cm diameter) distributed over an area (7 cm × 10 cm) positioned over dorsal and volar aspects of the forearm. The four-channel stimulation system for grasping comprised also an oval reference electrode over the carpal tunnel, and two oval electrodes over the thenar and thumb extensor muscles. We measured seven angles: proximal inter-phalangeal and metacarpal phalangeal index and ring finger joint rotations, wrist extension/flexion and ulnar/radial rotation, and pronation/supination of the forearm. The optimal electrode was determined as the combination of pads that led to fingers, wrist and forearm rotations being similar to the trajectories of healthy individuals when grasping. The similarity of trajectories was assessed by analyzing the aggregate error defined as the sum of squares of differences between the angles measured when stimulating the forearm in tetraplegics and the angles measured in healthy individuals. The aggregate errors were determined from measurements during sequential stimulation of each of the 24 pads. The analysis comprised hand opening and closing for palmar and lateral grasps. The time for determining the optimal electrode was about 10 min. The optimal electrodes had different branched shapes in each of the six tetraplegics; however, once determined they remained unchanged when tested on different days.

Effect of object width on precision grip force and finger posture

This study aimed to define the effect of object width on spontaneous grasp. Participants held objects of various masses (0.75 to 2.25 kg) and widths (3.5 to 9.5 cm) between thumb and index finger. Grip force, maximal grip force and corresponding finger postures were recorded using an embedded force sensor and an optoelectronic system, respectively. Results showed that index finger joints varied to accommodate the object width, whereas thumb posture remained constant across conditions. For a given object mass, grip force increased as a function of object width, although this result is not dictated by the laws of mechanics. Because maximal grip force also increased with object width, we hypothesise that participants maintain a constant ratio between grip force and their maximal grip force at each given width. Altogether we conclude that when the task consists in manipulating objects/tools, the optimal width is different than when maximal force exertions are required.

Robust estimation of dominant axis of rotation

A simple method is developed for robustly estimating a fixed dominant axis of rotation (AoR) of anatomical joints from surface marker data. Previous approaches which assume a model of circular marker trajectories use plane fitting to estimate the direction of the AoR. However, when there is limited joint range of motion and rotation due to a second degree of freedom, minimizing only the planar error can give poor estimates of the AoR direction. Optimizing a cost function which includes the error component within a plane, instead of only the component orthogonal to a plane, leads to improved estimates of the AoR direction for joints which exhibit additional rotational motion from a second degree of freedom. Results from synthetic data validation show the ranges of motion where the new method has lower estimation error compared to plane-fitting techniques. Estimates of the flexion–extension AoR from empirical motion capture data of the knee and index finger joints were also more anatomically plausible.

Sight-Reading Versus Repertoire Performance on the Piano: A Case Study Using High-Speed Motion Analysis

This study was intended to examine whether differences exist in the motions employed by pianists when they are sight-reading versus performing repertoire and to determine whether these differences can be quantified using high-speed motion capture technology. A secondary question of interest was whether or not an improvement in the efficiency of motion could be observed between two sight-reading trials of the same musical excerpt. This case study employed one subject and a six-camera digital infrared camera system to capture the motion of the pianist playing two trials of a repertoire piece and two trials of a sight-reading excerpt. Angular displacements and velocities were calculated for bilateral shoulder, elbow, wrist, and index finger joints. The findings demonstrate the usefulness of high-speed motion capture technology for analyzing motions of pianists during performance, showing that the subject's motions were less efficient in sight-reading tasks than is repertoire tasks.

Kinematic and Dynamic Synergies of Human Precision-Grip Movements

We analyzed the adaptability of human thumb and index finger movement kinematics and dynamics to variations of precision grip aperture and movement velocity. Six subjects performed precision grip opening and closing movements under different conditions of movement velocity and movement aperture (thumb and index finger tip-to-tip distance). Angular motion of the thumb and index finger joints was recorded with a CyberGlove and a three-dimensional biomechanical model was used for solving the inverse dynamics problem during precision grip movements, i.e., for calculating joint torques from experimentally obtained angular variations. The time-varying joint angles and joint torques were analyzed by principal-component analysis to quantify the contributions of individual joints in kinematic and dynamic synergies. At the level of movement kinematics, we found subject-specific angular contributions. However, the adaptation to large aperture, achieved by an increase of the relative contribution of the proximal joints, was subject-invariant. At the level of movement dynamics, the adaptation of thumb-index finger movements to task constraints was similar among all subjects and required the linear scaling of joint torques, the synchronization of joint torques under high velocity conditions, and a flexible redistribution of joint torques between the proximal joint of the thumb and that of the index finger. This work represents one of the first attempts at calculating the joint torques during human precision-grip movements and indicates that the dynamic synergies seem to be remarkably simple compared with the synergies found for movement kinematics.

A biomechanical analysis of the rheumatoid index finger after joint arthroplasty

Objective. To determine the mechanisms responsible for the recurrence of ulnar drift after metacarpophalangeal joint arthroplasty in the rheumatoid hand. Design. A three-dimensional biomechanical model of the index finger joints was used to predict the implant loads during several activities of daily living. Background. Post-operative clinical evaluation of Sutter metacarpophalangeal prostheses shows a high incidence of fracture and recurrent deformity. Methods. A six-component force transducer in conjunction with a six-camera motion analysis system were used to obtain kinematic and external loading data from eight patients with rheumatoid arthritis during several simulated activities. These data were used as input into a three-dimensional biomechanical model of the implant and interphalangeal joints of the index finger. Tendon lines of action and moment arms were obtained using a series of MRI scans and CAD modelling techniques. Results. Implant forces were oriented in a radial and dorsal direction to resist the ulnarpalmarly pull of tendons associated with the metacarpophalangeal joint. Conclusions. The recurrence of ulnar drift is attributable to fatigue failure of the prostheses. After fracture the implant is unable to support the repetitive loading patterns experienced during activities of daily living. Relevance Understanding the mechanisms responsible for the recurrence of ulnar drift and implant failure is a step towards improving the prosthesis design, surgical procedures and ultimately the patient's prognosis.

Impedance Charactheristics of Human Finger Joints.

This paper describes impedance characteristics of human finger joints. Five joints of thumb and index finger are taken into consideration one by one our experiment. While subject keeps the joint angle of the finger to which the moment of rotation is applied as initial condition, small external disturbance is given to the finger joint. From the time trajectories of the joint angle and the moment of rotation caused by the disturbance, impedance parameters of each joint are estimated. Inertia of finger joint depends on position from MP joint or root of finger, and MP joints of thumb and index finger have large viscosity and stiffiness. Especially, MP joint of thumb has very strong stiffness compared with all joints of index finger, and it plays an important roll for stable gripping motions. On the other hand, DIP joint of index finger has small viscosity and stiffness, which is appropriate to perform active probing motion based on touch sense of fingertips. Moreover, we investigate how initial moment of rotation has influence on impedance of the finger joints. It is shown that stiffness of each joint increases in proportion to the initial moment of rotation.

異常虫様筋が関与したと思われる手根管症候群の１例

A rare case of carpal tunnel syndrome caused by an anomalous lumbrical muscle, associated with ipsilateral pronator syndrome, is reported.An 18-year-old male was operated on for left carpal tunnel syndrome and pronator syndrome.Upon division of the transverse carpal ligament, very slight changes due to compression could be seen on the surface of the median nerve and an abnormal muscle was seen on the medial side of the median nerve. The muscle arose from the radial aspect of the flexor profundus tendon to the index finger and the distal margin of the origin was 2cm proximal to the transverse crase of the wrist but portions more proximal of the origin and insertion of the muscle could not be identified. On traction of this muscle, the metacarpo-phalangeal joint of index finger was flexed. In the proximal forearm, the median nerve was compressed by abnormal accessory insertion of the brachialis muscle, bicipital aponeurosis and hypertrophied humeral head of the pronator teres muscle. We assume that the carpal tunnel syndrome was caused not only by the abnormal lumbrical muscle but also by the compression in the proximal forearm (multiple crush).

Coordination of index finger movements

The purpose of this investigation was to describe the patterns of coordination among the joint motions of the index finger, and among the EMGs of index finger muscles. Index finger movements involving all three joints were varied in speed and direction. Joint motions were recorded along with finewire EMG from all the muscles that insert into the index finger. We observed nearly linear relationships for angular position between the two interphalangeal (IP) joints, and between the metacarpophalangeal (MP) and proximal IP (PIP) joints regardless of movement, speed and direction. The activities of the extrinsic flexors were of similar magnitude and were highly correlated when they acted as agonists but were poorly correlated when they acted as antagonists to the movement. Extrinsic extensor muscles behaved in this way also. The activation patterns of the intrinsic musculature correlated weakly except for extension movements voluntarily limited to the IP joints. We conclude that the highly coordinated action of the extrinsic flexors during flexion contribute importantly to the linked motions of the IP joints in part because these muscles span two or all the three index finger joints. Hence, interjoint movement patterns appear not to arise solely from restraints imposed by passive tissues, especially for fast flexion movements. The weakly correlated intrinsic mucle activity does not uncouple the flexion motions at the PIP and DIP joints because these muscles exert extensor torques at both IP joints. However, the actions of the intrinsic muscles are necessary for stabilizing the MP joint in flexion postures during IP motion and in producing motions voluntarily limited to the MP joint.

The functional significance of the long extensors and juncturae tendinum in finger extension

To determine the role of the long extensors and soft tissues in the extension and interaction of the fingers, we applied traction to the extensors and measured the angles of the finger joints. The tendons, juncturae tendinum and intertendinous fascia, and the web between the fingers were sequentially sectioned, and the effects on the joints were again determined with tendon traction. Traction produced hyperextension of the metacarpophalangeal joints and some extension of the interphalangeal joints, although the latter remained partially flexed, producing a clawhand. Cutting the long extensor tendons had no effect on the interaction between adjacent fingers. Traction on the extensor digitorum communis to the index and the extensor indicis proprius produced the same extension of index finger joints and adjacent digits. Traction on the extensor digitorum communis to the index produced 32% of the maximal extension of the long finger MP joint. We reduced this to 22% by cutting the juncturae and intertendinous fascia and to 5% by cutting the web. The interaction between fingers was greater on the ulnar half of the hand because of the juncturae but was similarly reduced by ablative cuts of these structures.

The effect of loading on position sense at the proximal interphalangeal joint of the human index finger.

1. Proprioceptive acuity was tested at the proximal interphalangeal joint of the index finger of normal subjects. 2. Examination of the ability of the subjects to match finger positions (position matching procedure) revealed that digital nerve block (DNB) of the finger resulted in characteristic alignment errors at the extremes in all subjects. 3. When one finger (target finger) is positioned close to full extension, all subjects hyperextended the anaesthetized matching finger, whilst target finger positioning towards full flexion resulted in hyperflexion of the matching finger. At intermediate positions the pattern of matching errors was more variable but tended to be consistent for a given subject. 4. When the matching finger was isotonically loaded into flexion, there was little change in matching performance for most subjects. However, when the matching finger was anaesthetized, such loading now produced clear alteration in performance in all subjects. This indicates that muscle receptors contribute to proprioceptive sensations at this joint, but require other afferent sources to optimally resolve position when the finger is loaded. 5. Two other test procedures (angle reproduction and assigned positions) were assessed and compared with the results obtained by the position matching technique. Although alterations in proprioceptive performance during DNB could be detected with these procedures, they tended to be less sensitive than the position matching procedure.

The effect of digital nerve block on position sense at the proximal interphalangeal joint of the human index finger

Position matching at the proximal interphalangeal joint of the index finger in human subject was tested by passive displacement of the right (target) finger and active matching of the left index finger. In 5 subjects it was found that position matching was grossly impaired after digital nerve block of the matching finger. Typically, subjects hyperextended the matching finger when the target finger was held in extension and hyperflexed the matching finger when the target finger was held in flexion. These results suggest that even with active positioning, joint and cutaneous receptors importantly contribute to the awareness of position at this joint.

Forensic Investigation of Electrostatic Shock Injury

This investigation, undertaken in 1983, involved the occurrence of an injury of a sort hitherto unreported in the technical journals. However, forensic investigation of a personal injurys causations requires a complete and open-minded determination of the circumstances of the occurrence. It can be equally as important to eliminate what did not happen as well as to reconstruct with validity how the injury took place. Thereupon, the causations of the occurrence can be identified. The injury resulted in the amputation of part of the first joint of the subjects left index finger and was followed by tissue grafts and by retarded healing and hyper sensitization of the entire hand. As an electrical systems engineer, the writer was engaged by the subjects attorney to investigate the occurrence of the injury believed to have been caused electrically.