Hand Sizes Research Articles

Employing a three-stage procedure to develop a sizing system for medical gloves

There is a need for gloves that are designed based on the dimensions of the hand of each society because the proper size is a key factor that affects performance. This study aimed to design and develop a glove sizing system for Iranian healthcare workers using anthropometric data. This study was conducted on a sample including 540 healthcare workers across Iran classified by ethnicity and gender. Thirty-three dimensions were measured as the anthropometric data. Principal Component Analysis (PCA) and clustering analysis were used to create classifications for glove sizes. The most effective dimensions in defining the hand sizes of Iranian healthcare workers were middle finger length and the handbreadth. The designed six-size system covered 94% of the sample. This system can be used to design suitable gloves for Iranians. The sizes presented can be used to compare size differences in different communities.

A new model for rehabilitation training: a compliant driven hand exoskeleton design

Robot-assisted rehabilitation for limb dysfunction caused by stroke is one of the key research topics today. Some researchers have found that the structure and driving mode of the exoskeleton will produce physiological deviation during training. Therefore, this paper will explore a kind of mechanical exoskeleton with optimized structure and suitableness for the characteristics of the human hand. This paper analyzes and improves the function and composition of the exoskeleton by investigating the physiological structure and movements of human hands. Based on the DH parameters of the model and the relationship between mechanical geometry, the motion trajectory is simulated with MATLAB to verify its motional realizability. The simulation results show that the manipulator can safely realize the movement in line with the characteristics of the human hand, and its installation and alignment can adapt to different human hand sizes. The inverse dynamics analysis of the model with the Jacobin matrix will promote the design of dynamics and control functions of the model.

The role of hand size in body representation: a developmental investigation

Knowledge of one’s own body size is a crucial facet of body representation, both for acting on the environment and perhaps also for constraining body ownership. However, representations of body size may be somewhat plastic, particularly to allow for physical growth in childhood. Here we report a developmental investigation into the role of hand size in body representation (the sense of body ownership, perception of hand position, and perception of own-hand size). Using the rubber hand illusion paradigm, this study used different fake hand sizes (60%, 80%, 100%, 120% or 140% of typical size) in three age groups (6- to 7-year-olds, 12- to 13-year-olds, and adults; N = 229). We found no evidence that hand size constrains ownership or position: participants embodied hands which were both larger and smaller than their own, and indeed judged their own hands to have changed size following the illusion. Children and adolescents embodied the fake hands more than adults, with a greater tendency to feel their own hand had changed size. Adolescents were particularly sensitive to multisensory information. In sum, we found substantial plasticity in the representation of own-body size, with partial support for the hypothesis that children have looser representations than adults.

Reverse Neurocutaneous Flap Based on the Dorsal Branch of the Ulnar Artery for Palm Coverage in Children: Long-Term Results

Although the palm is spared mostly in severe burn injuries, it often is affected in children and requires radical excision of contracting scar tissue to allow normal hand development. Since alternatives are limited for palmar coverage, we primarily use a reverse-perfused, neurocutaneous dorsal ulnar artery flap. We report here our long-term follow-up results. We reviewed the long-term results of 10 postburn palmar contracture release and flap coverage procedures in 10 children. The applied flap was based distally on the dorsal branch of the ulnar artery and harvested along the ulnar aspect of the hand and wrist. The pivot point of the flap was located dorsally, close to the 4th and 5th metacarpal base. Patients were followed for a median period of 6 years (range, 4-20 years). Flap size ranged from 60-130 mm in length and 20-35 mm in width. This variation in flap dimensions resulted from different hand sizes, because of the various patient ages at surgery. All flaps survived, donor site healing was uneventful, and marginal flap necrosis occurred only once. Satisfactory restoration of range of motion without secondary contractures was observed. Moreover, we detected adequate progressive growth, adaptability and sensory recovery in all flaps. Over time, the flaps mostly become hairless and progressively flattened without debulking. The importance of this flap lies in the potential for considerable tissue mobilization to cover palmar defects without sacrificing any major vascular axis. The adequate progressive growth of the flap facilitates functional hand development in children. The predictable vascular anatomy, wide range, and durable, thin, and pliable skin make the reverse neurocutaneous dorsal ulnar artery flap an appealing option for soft tissue reconstruction of the palm in children. Therapeutic V.

The Controller Is the Problem: Endoscopic Proficiency Is Affected by Hand Size When Controlling for Dexterity

INTRODUCTION: Surgical specialties are historically male dominated. Endoscope controllers are traditionally a one-size-fits-all design for the average male hand size of 7.5 inches. However, female specialists, who often have smaller hand sizes, are becoming more prevalent in endoscopy-related fields, yet instrument engineering has not reflected this shift. Our study aims to determine if hand size, independent of innate ability, affects endoscopic and bronchoscopic proficiency. METHODS: A total of 54 medical students without previous endoscopic experience participated in a manual dexterity test as a control, followed by large-controller endoscopic and small-controller bronchoscopic simulation exercises. Outer surgical glove sizes were recorded, completion times were corrected for wall contact, and participants were stratified by glove size (<7.5 inches and ≥ 7.5 inches). Data analysis included independent Student’s t-test and multivariate models by linear regression. RESULTS: Mean endoscopic completion time was significantly longer in participants with <7.5-inch size gloves (p = 0.01). However, participants with glove size <7.5 inches had better dexterity measures (p = 0.04). Multivariate analysis supported these findings, as hand size correlated with endoscopy speed (p = 0.003). Conversely, there was no significant difference in mean bronchoscopy completion time based on hand size (p = 0.61), which was reiterated on multivariate analysis. CONCLUSION: Participants with larger hand size had a clear advantage with the larger endoscopic controller, irrespective of dexterity. Meanwhile, there was no difference in time among hand size using the smaller bronchoscopic controller. Our results suggest that controller size affects endoscopic proficiency, thus emphasizing the need to change endoscope controller design to account for hand size variability as the population of operators becomes more diverse.

Low-Cost Self-Calibration Data Glove Based on Space-Division Multiplexed Flexible Optical Fiber Sensor.

Wearable devices such as data gloves have experienced tremendous growth over the past two decades. It is vital to develop flexible sensors with fast response, high sensitivity and high stability for intelligent data gloves. Therefore, a tractable low-cost flexible data glove with self-calibration function based on a space-division multiplexed flexible optical fiber sensor is proposed. A simple, stable and economical method was used to fabricate flexible silicone rubber fiber for a stretchable double-layered coaxial cylinder. The test results show that the fiber is not sensitive to the temperature range of (20~50 °C) and exhibits excellent flexibility and high stability under tensile, bending and torsional deformation. In addition, the signal detection part of the data glove enables compact and efficient real-time information acquisition and processing. Combined with a self-calibration function that can improve the accuracy of data acquisition, the data glove can be self-adaptive according to different hand sizes and bending habits. In a gesture capture test, it can accurately recognize and capture each gesture, and guide the manipulator to make the same action. The low-cost, fast-responding and structurally robust data glove has potential applications in areas such as sign language recognition, telemedicine and human–robot interaction.

The Current State of Surgical Ergonomics.

Work-related musculoskeletal disorders are widespread among surgeons, causing significant disability and career modification. Gender plays a role, as female surgeons have a two-fold greater risk for discomfort during certain operations due to generally smaller hand sizes and height as compared to male surgeons. There is a lack of appropriate surgical instrumentation geared toward smaller hand sizes. Maintaining a neutral position while operating, frequent changes in position, and increased awareness can contribute to decreasing the detrimental impact on surgeons' bodies from performing operations.

Towards Unsupervised Rehabilitation: Development of a Portable Compliant Device for Sensorimotor Hand Rehabilitation.

Sensorimotor impairments of the hand after stroke can drastically reduce the ability to perform activities of daily living. Recently, there has been an increased interest in minimally supervised and unsupervised rehabilitation to increase therapy dosage and to complement conventional therapy. Several devices have been developed that are simple to use and portable. Yet, they do not incorporate diversified somatosensory feedback, which has been suggested to promote sensorimotor recovery. Here we present the prototype of a portable one-degree-of-freedom hand trainer based on a novel compliant shell mechanism. Our solution is safe, intuitive, and can be used for various hand sizes. Importantly, it also provides rich sensory feedback through haptic rendering. We complement our device with a rehabilitation game, where we leverage interactive tangible game elements with diverse haptic characteristics to provide somatosensory training and foster recovery.

Gender-differences of proceduralists in perception of hand-held surgical instrument fit – A cross-sectional survey

ObjectiveDetermining perception of hand size as it relates to instrument use and ability to perform a procedure in a diverse population of proceduralists across surgical and medical specialties. MethodsCross-sectional survey was distributed via electronic format to a convenience sample of surgeons/physicians. Secondary analysis included identified instrument use and choice of/perception of ability to learn and perform procedures. Results488 respondents, 84.4% (female), 75.8% (glove size ≤6.5), and 82.2% (surgical specialties). 67.8% reported trouble using surgical instruments, primarily endoscopes, laparoscopic instruments, and needle drivers. Latent class analysis identified two groups of female respondents with similar hand sizes but differ in the perception of their hand's abilities. Conclusions and relevanceInstruments beyond laparoscopic instruments do not fit all hands. Even among female with physicians with similar hand size, there is a sub-set who struggle using surgical tools. Beyond gender and hand size, the operator's perception of their hand and their ability is critical in determining the viability of instrument mastery.

Problems Using Data Gloves with Strain Gauges to Measure Distal Interphalangeal Joints' Kinematics.

Data gloves with strain gauges are a widely used technology to record hand kinematics. Several researchers have experienced problems when using data glove models to record distal interphalangeal (DIP) joints, mainly in relation to bad glove fitting. The aim of this work is to report the problems that arise when using one of these gloves (CyberGlove) and to determine an appropriate hand size to avoid these problems. First, static controlled postures of DIP joints and dynamic recordings while closing/opening the fist were taken using the data gloves on participants with different hand sizes, in order to establish the minimum hand length that does not pose recording problems. The minimum obtained hand length that allowed proper recording was 184 mm. Then, validation was performed, which consisted of recording the functional range of motion of the DIP joints in a sample of eight healthy participants with hand lengths longer than the minimum obtained one. These results were then compared to the results found in the literature. Although the glove fit properly, some problems remained: difficulty to record small flexion angles or a diminished touch sensitivity. Its usability would improve if two or three different glove sizes were commercially available.

A smart ball sensor fabricated by laser kirigami of graphene for personalized long-term grip strength monitoring

Grip strength is an important indicator of health conditions and needs to be monitored for health management. However, different populations (e.g., babies and rehabilitation patients) have different hand sizes and different levels of grip strengths, requiring a personalized sensor to monitor grip strength. In this paper, we developed a smart ball sensor by laser kirigami of graphene for personalized grip strength monitoring. To realize the rational utilization of space, a transparent pill shell embedding all electronic accessories is installed in the center of the ball sensor with a spiral-sensing unit fabricated by laser kirigami of graphene on the surface. Furthermore, we assessed the influence of contact area between hand and ball on grip strength using finite-element analysis (FEA), which was then considered in our results readout. The grip strength can be continuously read by a mobile phone in a wireless manner. The smart ball sensor demonstrated a high performance in vitro against gold-standard method in diseased and healthy subjects. It would be a powerful tool for personalized long-term monitoring of grip strength, especially suitable for specific populations such as babies and sensitive enough for samll grip strength.

Exodex Adam-A Reconfigurable Dexterous Haptic User Interface for the Whole Hand.

Applications for dexterous robot teleoperation and immersive virtual reality are growing. Haptic user input devices need to allow the user to intuitively command and seamlessly “feel” the environment they work in, whether virtual or a remote site through an avatar. We introduce the DLR Exodex Adam, a reconfigurable, dexterous, whole-hand haptic input device. The device comprises multiple modular, three degrees of freedom (3-DOF) robotic fingers, whose placement on the device can be adjusted to optimize manipulability for different user hand sizes. Additionally, the device is mounted on a 7-DOF robot arm to increase the user’s workspace. Exodex Adam uses a front-facing interface, with robotic fingers coupled to two of the user’s fingertips, the thumb, and two points on the palm. Including the palm, as opposed to only the fingertips as is common in existing devices, enables accurate tracking of the whole hand without additional sensors such as a data glove or motion capture. By providing “whole-hand” interaction with omnidirectional force-feedback at the attachment points, we enable the user to experience the environment with the complete hand instead of only the fingertips, thus realizing deeper immersion. Interaction using Exodex Adam can range from palpation of objects and surfaces to manipulation using both power and precision grasps, all while receiving haptic feedback. This article details the concept and design of the Exodex Adam, as well as use cases where it is deployed with different command modalities. These include mixed-media interaction in a virtual environment, gesture-based telemanipulation, and robotic hand–arm teleoperation using adaptive model-mediated teleoperation. Finally, we share the insights gained during our development process and use case deployments.

A Genomic Perspective Across Earth's Microbiomes Reveals That Genome Size in Archaea and Bacteria Is Linked to Ecosystem Type and Trophic Strategy.

Our view of genome size in Archaea and Bacteria has remained skewed as the data has been dominated by genomes of microorganisms that have been cultivated under laboratory settings. However, the continuous effort to catalog Earth’s microbiomes, specifically propelled by recent extensive work on uncultivated microorganisms, provides an opportunity to revise our perspective on genome size distribution. We present a meta-analysis that includes 26,101 representative genomes from 3 published genomic databases; metagenomic assembled genomes (MAGs) from GEMs and stratfreshDB, and isolates from GTDB. Aquatic and host-associated microbial genomes present on average the smallest estimated genome sizes (3.1 and 3.0 Mbp, respectively). These are followed by terrestrial microbial genomes (average 3.7 Mbp), and genomes from isolated microorganisms (average 4.3 Mbp). On the one hand, aquatic and host-associated ecosystems present smaller genomes sizes in genera of phyla with genome sizes above 3 Mbp. On the other hand, estimated genome size in phyla with genomes under 3 Mbp showed no difference between ecosystems. Moreover, we observed that when using 95% average nucleotide identity (ANI) as an estimator for genetic units, only 3% of MAGs cluster together with genomes from isolated microorganisms. Although there are potential methodological limitations when assembling and binning MAGs, we found that in genome clusters containing both environmental MAGs and isolate genomes, MAGs were estimated only an average 3.7% smaller than isolate genomes. Even when assembly and binning methods introduce biases, estimated genome size of MAGs and isolates are very similar. Finally, to better understand the ecological drivers of genome size, we discuss on the known and the overlooked factors that influence genome size in different ecosystems, phylogenetic groups, and trophic strategies.

아동용 장갑의 치수 규격 설계를 위한 손 치수 분석

Most apparel products have national standards for sizing; however, for gloves, national sizing standards have not yet been established. This study aims to analyze children''s hand dimensions and propose a size specification for children''s gloves that shows children''s hand-related size information. Among the 3D measurements of sixth Size Korea Project, the measurement data of 19 dimensions related to the hands of 1,057 boys and girls aged 7-13 years old were analyzed. The distribution and growth trend of hand measurements for boys and girls demonstrated considerable mean differences and distribution trends by gender and age as per hand dimensions, which leads to the conclusion that it is necessary to show these results in the children''s glove design. Based on these results, the cross-distribution maps of children''s hand length and hand circumference were drafted; furthermore, the distribution relationship with an adult hand size was identified. Based on the distribution of hand sizes, the distribution of adult hand sizes overlapped with children''s hand sizes was verified, and children''s glove size specifications were presented. The results can be used as useful data such as measures for setting the size range and sizing system for children''s gloves.

A Novel Clinical-Driven Design for Robotic Hand Rehabilitation: Combining Sensory Training, Effortless Setup, and Large Range of Motion in a Palmar Device.

Neurorehabilitation research suggests that not only high training intensity, but also somatosensory information plays a fundamental role in the recovery of stroke patients. Yet, there is currently a lack of easy-to-use robotic solutions for sensorimotor hand rehabilitation. We addressed this shortcoming by developing a novel clinical-driven robotic hand rehabilitation device, which is capable of fine haptic rendering, and that supports physiological full flexion/extension of the fingers while offering an effortless setup. Our palmar design, based on a parallelogram coupled to a principal revolute joint, introduces the following novelties: (1) While allowing for an effortless installation of the user's hand, it offers large range of motion of the fingers (full extension to 180° flexion). (2) The kinematic design ensures that all fingers are supported through the full range of motion and that the little finger does not lose contact with the finger support in extension. (3) We took into consideration that a handle is usually comfortably grasped such that its longitudinal axis runs obliquely from the metacarpophalangeal joint of the index finger to the base of the hypothenar eminence. (4) The fingertip path was optimized to guarantee physiologically correct finger movements for a large variety of hand sizes. Moreover, the device possesses a high mechanical transparency, which was achieved using a backdrivable cable transmission. The transparency was further improved with the implementation of friction and gravity compensation. In a test with six healthy participants, the root mean square of the human-robot interaction force was found to remain as low as 1.37 N in a dynamic task. With its clinical-driven design and easy-to-use setup, our robotic device for hand sensorimotor rehabilitation has the potential for high clinical acceptance, applicability and effectiveness.

Skeleton-aware Multi-scale Heatmap Regression for 2D Hand Pose Estimation

Hand pose estimation plays an essential role in sign language understanding and human-computer interaction. Existing RGB-based 2D hand pose estimation methods learn the joint locations from a single resolution, which is not suitable for different hand sizes. To tackle this problem, we propose a new deep learning-based framework that consists of two main modules. The first one presents a segmentation-based approach to detect the hand skeleton and localize the hand bounding box. The second module regresses the 2D joint locations through a multi-scale heatmap regression approach that exploits the predicted hand skeleton as a constraint to guide the model. Moreover, we construct a new dataset that is suitable for both hand detection and pose estimation tasks. It includes the hand bounding boxes, the 2D keypoints, the 3D poses and their corresponding RGB images. We conduct extensive experiments on two datasets to validate our method. Qualitative and quantitative results demonstrate that the proposed method outperforms the state-of-the-art and recovers the pose even in cluttered images and complex poses.

Smaller hands and less experience are associated with greater ergonomic strain during endoscopic procedures.

Up to 89% of physicians who routinely perform endoscopy experience some type of musculoskeletal pain. In this study, we sought to quantitatively analyze provider factors that influence ergonomic strain during live endoscopic procedures. Surface electromyography (sEMG) was used to measure ergonomic strain on physicians while performing upper and lower endoscopies. EMG data were normalized to a maximal voluntary contraction (MVC) recording for each muscle group, yielding a %MVC value. Subgroup analyses were performed based on glove size, physician training level, specialty, and handedness. A total of 165 upper (n = 68) and lower (n = 97) endoscopies were recorded. Endoscopists with small hand sizes had significantly higher ergonomic strain in the left anterior and posterior forearm muscle compartments as compared to endoscopists with medium or large hands (%MVC L-anterior: small: 9.1 ± 1.1; medium: 6.4 ± 1.2; large: 5.9 ± 1.6; p < 0.001); (%MVC L-posterior: small: 12.0 ± 0.8; medium: 9.4 ± 1.3; large: 8.8 ± 1.4; p < 0.001). Additionally, upper body muscle groups had significantly higher ergonomic strain in endoscopists with less lifetime endoscopic experience (%MVC R-trapezius: expert: 8.4 ± 1.2; novice: 9.3 ± 1.2; p < 0.05); (%MVC R-deltoid: expert: 6.1 ± 1.4; novice: 8.5 ± 1.3; p < 0.001). There were no significant ergonomic differences between surgeons or gastroenterologists and no differences between right- and left-handed dominant individuals. Endoscopists with small hands experienced great ergonomic strain in their left forearm. Our data support the widely held belief that "one size does not fit all" and will hopefully spark change in the design of future endoscopes by device manufacturers. Our data also support that the experience level of the endoscopist contributed significantly to ergonomic performance, likely due to postural differences leading to decreased upper body strain. Therefore, it remains critically important to educate young proceduralists on strategies for ergonomic relief early in his or her endoscopic training program that can ameliorate ergonomic strain that accrues over the lifetime of a physician's career.

사용자 인터페이스 유형별 스마트폰 파지 자세에 대한 우세손, 손 크기, 그리고 기기 크기의 영향 파악

Objective: This study aims to identify the effects of hand size, hand dominance, and device size on the grip posture of smartphones for physical and graphical UIs.<BR>Background: An inappropriate user interface (UI) causes an inappropriate grip posture and is a cause of lowering smartphone usability. Although studies on smartphone UI elements affecting the gripping posture have been conducted in various fields, there has been no study on the effect of hand dominance for physical and graphical UIs together.<BR>Method: Forty participants with different hand sizes simulated texting and web-surfing tasks using smartphone mock-ups with screen sizes of 3.0

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.

Features of Index-Ring Finger Pair’s Force Contribution in Multi-Finger Force-Following Tasks

New types of cylindrical handles such as pushrims with force signal sensors under four fingers (excluding the thumb) enable real-time gripping-status assessment. The mirrored change phenomenon of the index and ring fingers observed in linear grip tasks offers a new perspective on finger grouping. To evaluate the force contribution of index-ring finger pair in multi-finger force, 10 right-handed male participants with similar hand sizes were recruited to participate in sinusoidal function force-following tasks involving a cylindrical handle. The real-time signal of the grip force and individual finger force were recorded to analyze real-time changes in the finger force contribution (FC). Subsequently, the time-FC curves of individual and paired fingers were analyzed. Results show are as follows: (1) When the FC of the index-ring finger pair exceeded that of the middle-little finger pair, the gripping load was relatively low, and a smaller difference between the FCs of the index-ring finger pair and the middle-little finger pair indicated a smaller following error. (2) The FC of index-ring finger pair is a better (higher-linearity) parameter to assess gripping status. These findings show that the paired-finger FC is an adequate parameter for the gripping-status assessment.