Cylindrical Handle Research Articles

It is the habit not the handle that affects tooth brushing - a randomised counterbalanced cross over study with young and healthy adults

ObjectiveTo assess the effect of the toothbrush handle on video-observed toothbrushing behaviour and toothbrushing effectiveness.MethodsThis is a randomized counterbalanced cross-over study. N = 50 university students and employees brushed their teeth at two occasions, one week apart, using either a commercial ergonomically designed manual toothbrush (MT) or Brushalyze V1 (BV1), a manual toothbrush with a thick cylindrical handle without any specific ergonomic features. Brushing behaviour was video-analysed. Plaque was assessed at the second occasion immediately after brushing. Participants also rated their self-perceived oral cleanliness and directly compared the two brushes regarding their handling and compared them to the brushed they used at home.ResultsThe study participants found the BV1 significantly more cumbersome than the M1 or their brush at home. (p < 0.05). However, correlation analyses revealed a strong consistency of brushing behavior with the two brushes (0.71 < r < 0.91). Means differed only slightly (all d < 0.36). These differences became statistically significant only for the brushing time at inner surfaces (d = 0.31 p = 0.03) and horizontal movements at inner surfaces (d = 0.35, p = 0.02). Plaque levels at the gingival margins did not differ while slightly more plaque persisted at the more coronal aspects of the crown after brushing with BV1 (d = 0.592; p 0.042).DiscussionThe results of the study indicate that the brushing handle does not play a major role in brushing behavior or brushing effectiveness.

Sensory Factors Influence Dynamic and Static Bi-Manual Finger Grip Strength in a Real-World Task Context

Individual grip strength provides a functional window into somatosensory processes and their effects on motor behaviour in healthy, impaired, and ageing individuals. Variations in grip strength during hand–tool interaction are therefore exploited in a variety of experimental tasks to study the effects of pathology or ageing-related changes on sensory, motor, and cognitive ability. However, many different factors may influence individual grip strength systematically in a given task context without being explicitly identified and controlled for. Grip strength may vary as a function of the location of the measurement device (sensor) on the fingers/hand, the shape, weight and size of object(s) being gripped, the type of grip investigated (static versus dynamic grip), and the hand (dominant versus non-dominant) used for gripping. This study tests for additional factors such as sight, sound, and interactions with/between any of the other factors in a complex task context. A wearable biosensor system, designed for measuring grip strength variations in operators gripping cylindrical objects bi-manually, was used. Grip force signals were recorded from all sensors of the wearable (glove) system, including three directly task-relevant sensors for bi-manually gripping cylindrical objects with the dominant and non-dominant hands. Five young male participants were tested for the effects of sound, movement, and sight on grip strength. The participants had to pick up two cylindrical objects of identical size and weight, then hold them still (static grip) or move them upwards and downwards (dynamic grip) for ten seconds while listening to soft or hard music, with their eyes open or blindfolded. Significant effects of sensor location, hand, movement, sight, and sound on bi-manual grip strength were found. Stronger grip force signals were produced by task-relevant sensors in the dominant hand when moving the cylindrical handles (dynamic grip) in comparison with the static grip condition, depending, as expected, on whether grip signals were measured from the dominant or the non-dominant hand. Significantly stronger grip strength was produced blindfolded (sight condition), and grips were significantly stronger with exposure to harder music (sound factor). It is concluded that grip strength is significantly influenced by sensory factors and interactions between the other factors tested for, pointing towards the need for identifying and systematically controlling such potential sources of variation in complex study task contexts.

Investigating the Haptic Perception of Directional Information Within a Handle.

This paper studies the perception of 2-dimensional directional cues presented on a hand-held tangible interface that resembles a cylindrical handle. The tangible interface is designed to be comfortably held with one hand and houses five custom electromagnetic actuators composed of coils as stators and magnets as movers. We carried out a human subjects experiment enrolling 24 participants, analysing the recognition rate of directional cues using the actuators either to vibrate or tap in sequence across the user's palm. Results show an impact of the positioning/holding of the handle, the mode of stimulation, and the directional indication sent via the handle. There was also a correlation between the score and the confidence of the participants, showing that participants are more confident when recognising vibration patterns. Overall, results supported the potential of the haptic handle to provide accurate guidance, with recognition rates higher than 70 % in all conditions and higher than 75 % in the precane and power wheelchair configurations.

A Modified Cannulated Cancellous Bone Impactor Is a Helpful Tool During Acetabular Fractures ORIF, a Technical Note

A Modified Cannulated Cancellous Bone Impactor Is a Helpful Tool During Acetabular Fractures ORIF, a Technical Note

Influence of Coupling Forces and Body Posture on the Rotational Hand–Arm Impedance in yh Direction

This manuscript investigates the rotational mechanical impedance of the human hand–arm system with respect to vibration excitation around the gripping axis of the hand under the influence of body posture, gripping force, and push force. Knowledge of rotational mechanical impedance is required for deriving models of hand–arm biodynamics. These models are used in the validation of power tools to predict further vibrational human–machine interactions. In the current state of research, such models exist for translational but not rotational vibration excitation. Consequently, this study investigates the properties of a hand–arm system with respect to rotational vibration excitation. In the study, the rotational impedance of the hand–arm systems of 13 adults was measured at various gripping and push forces applied in different body postures. The setup of the test used in this study consisted of a shaker that applied rotational vibrations at certain frequencies to the subjects’ hand–arm systems via a cylindrical handle. The results of the study indicate a spring–damper dynamic of the hand–arm system. The gripping force strongly influences the magnitude of rotational impedance across the frequency spectrum. Regarding push force and posture, no corresponding influence could be determined. The results suggest that the frictional contact between the hand and handle might confer a damping effect.

Retention of different all ceramic endocrown materials cemented with two different adhesive techniques.

The purpose of this in vitro study was to evaluate the influence of two adhesive techniques on the retentive force of four all ceramic endocrowns. Forty maxillary first molars of approximately similar size and shape were collected. The teeth were all decoronated 2 mm above the level of proximal cement-enamel junction (CEJ) and were all endodontically treated. The teeth were then randomly divided equally into four groups (10 each) according to all ceramic material used, as follows: Group I (VE) - Ten prepared molars were restored with hybrid ceramic (Vita Enamic); Group II (LU) - Ten prepared molars were restored with resin Nano-ceramic (Lava Ultimate). Group III (CD) - Ten prepared molars were restored with zirconia-reinforced lithium di-silicate ceramic material (Celtra Duo); Group IV (LZ) - Ten prepared molars were restored with zirconia ceramic (Lava Zirconia). Each group was then subdivided into two equal subgroups (n=5) according to the type of cement (adhesive technique) used for cementation. Subgroup A (RX ARC): the endocrowns were cemented with a total-etch adhesive resin cement (RelyX ARC). Subgroup B (RXU): the endocrowns were cemented with self-adhesive resin luting cement (RelyX UniCem). The restorations were designed with an outer cylindrical handle located on buccal and palatal surfaces to provide a mean for the removal of the endocrowns during the pull-out testing. The cemented endocrowns were thermocycled and then removed along the path of insertion using a universal testing machine at 0.5 mm/min. The retentive force was recorded, and the stress of dislodgement was calculated using the surface area of each preparation. The highest mean dislodgement stresses were 64.3 MPa for Group I (VE), whereas there was no statistically significant difference between Group I, II and III and LZ showed the lowest values with significant difference between the other three groups. Regarding the type of cement, there was a statistically significant difference between RelyX ARC (mean=60.09 MPa) and RelyX Unicem (mean=49.73 MPa). Retention of Vita Enamic, Lava Ultimate, and Celtra Duo are significantly higher than Lava Zirconia.

A Modular Magnetic Resonance Imaging-Compatible Pipette Simulator to Evaluate How Design Affects the Basilar Thumb Joint Mechanics

Abstract People who frequently use micropipettes experience hand and upper limb disorders. The basilar thumb joint, also known as the first carpometacarpal or trapeziometacarpal joint, is commonly affected by osteoarthritis (OA). Mechanical factors are associated with OA initiation and progression. We developed a magnetic resonance imaging (MRI)-compatible modular micropipette simulator to improve understanding of how micropipette design affects basilar thumb joint contact mechanics. The micropipette simulator also addresses limitations of current techniques for studying pipetting and basilar thumb joint mechanics. Its modularity will allow future studies to examine handle design parameters such as handle diameter, cross-sectional shape, and other features. A micropipette simulator with a cylindrical handle (length 127 mm, diameter 25 mm) was used with one subject to demonstrate the system's feasibility. Contact areas were within the range of prior data from basilar thumb joint models in power grasp and lateral pinch, and contact pressures were the same order of magnitude.

Investigating the Relationship between Coupling Forces and Hand-Transmitted Vibration under Varying Excitation Levels

In this study, the vibration total value of the acceleration transmitted to the wrist and elbow was measured in the laboratory with a group of 13 male subjects holding a cylindrical handle while modifying the coupling force under varying levels of vibration. The results were used to establish the relationship between hand-transmitted vibration and coupling forces and to compare with the relations proposed as part of an ISO Technical Specification, ISO/TS 15230-2. This was done to determine the suitability of the proposed relationships when variations are introduced on the level of vibration on the handle. While tracing back the origins of the relations proposed in ISO/TS 15230-2, this paper further brings in evidence of the importance of considering the role of coupling forces when evaluating the exposure to hand-transmitted vibration and provides additional evidence to support the relationships which are proposed as part of the ISO Technical Specification. Irrespective of the level of broadband random vibration excitation considered, the agreement with these relationships was found to be best when setting the reference coupling force at 50, 75, 100 and 125 N and whenever the coupling forces applied on the handle were maintained below 150 N.

Force Control Strategy of Five-Digit Precision Grasping With Aligned and Unaligned Configurations

To investigate the digit force control during a five-digit precision grasp in aligned (AG) and unaligned grasping (UG) configurations. The effects of various cylindrical handles for tools on power grasp performance have been previously investigated. However, there is little information on force control strategy of precision grasp to fit various grasping configurations. Twenty healthy young adults were recruited to perform a lift-hold-lower task. The AG and UG configurations on a cylindrical simulator with force transducers were adjusted for each individual. The applied force and moment, the force variability during holding, and force correlations between thumb and each finger were measured. No differences in applied force, force correlation, repeatability, and variability were found between configurations. However, the moments applied in UG were significantly larger than those in AG. The force control during precision grasp did not change significantly across AG and UG except for the digit moment. The simulator is controlled efficiently with large moment during UG, which is thus the optimal configuration for precision grasping with a cylindrical handle. Further research should consider the effects of task type and handle design on force control, especially for individuals with hand disorders. To design the handle of specific tool, one should consider the appropriate configuration according to the task requirements of precision grasping to reduce the risk of accumulating extra loads on digits with a cylindrical handle.

A Preliminary Study on Ergonomic Contribution to the Engineering Design Approach of a Wheel Loader Control Lever System

Studies show that heavy machinery operators are exposed to risk factors of musculoskeletal diseases. However, there has yet to be a study investigating the grip analysis of heavy machinery control levers. This preliminary study aims to investigate the grip analysis of a system that emulates the push–pull operations, handle shapes, and resistance of wheel loader control lever systems. The system was designed, analysed, and optimised using Autodesk Inventor 2019 before fabrication and testing. It underwent usability testing for estimated and perceived grip force analysis (ergonomics analysis). The tests measured estimated force using a sensor glove, and perceived force using the Borg CR10 scale. The data were analysed using regression and paired t-tests. The findings suggested that pulling and high resistance factors required higher estimated force (339.50 N) and perceived force (5.625) than pushing and low resistance factors in manoeuvring the system (p &lt; 0.05). The cylindrical handle required more estimated force (339.50 N) but less perceived force (4.5) than the spherical handle due to ergonomic design considerations (p &lt; 0.05). Although there were inaccuracies in force measurement methods, the perceived method was still effective for data collection, since it is challenging to measure grip force in a real situation with heavy machinery. While this study was only a simulation, it provided researchers with ideas that may solve problems in the manipulation of heavy machinery control levers.

Open-Source Software in Medical Imaging: Case-Based Study with Interdisciplinary Innovative Product Design

Purpose: Recently, comprehensive open-source software (OSS) solutions for medical images have been developed. They offer powerful tools for the management, visualization, storage and analysis of images. The purpose of the present study was to present the features and use of OSS in comparison with commercial software solutions when evaluating medical images.&#x0D; Methods: A case study of the development of a tool handle of optimal size and shape using the free OSS “3D Slicer” is presented. Many authors recommend cylindrical-shaped handles to increase comfort, performance and to avoid cumulative trauma, but none have considered the optimal shape of the handle. Hence, we derived a method for obtainingan optimally shaped tool handle based on the power grip hand posture and non-deformed soft tissue. During magnetic resonance imaging (MRI), an outer hand mold was used to maintain the optimal hand posture. 3D Slicer was used for segmentation and 3D reconstruction of MRI. A three-dimensional (3D) hand model was exported to a commercial program for computer-aided design for the optimal tool handle.&#x0D; Results: Measurements of the diameters on 3D reconstruction showed that the position of fingers wasere withheld within small deviations, which maximized maximum finger force exertion. An optimally shaped handle this way provided 25% higher contact area compared with the optimal cylindrical handle. It therefore reduced contact pressure, increased performance and comfort and could probably prevent disorders due to cumulative trauma.&#x0D; Conclusion: This case study supported the use of OSS for medical imaging as a powerful and (mostly) free tool comparable with (usually expensive) commercial solutions.

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.

Effects of ergonomic clip-on handles on upper-body vibration transmissibility and muscular activity during pedalling with vibrations

Mountain bikers often report impaired finger sensitivity caused by mechanical vibrations and misalignment between the wrist and the forearm when using traditional (cylindrical) handles. The aim of this study was to evaluate the acute effects of ergonomic clip-on handles that allowed the hand to rest on the medial carpal bone, on muscular activity, vibration transmissibility between the cycle ergometer and body segments, and handgrip strength. Sixteen cyclists performed two pedalling exercises at ~200 W lasting 20 minutes on a cycle ergometer that delivered vibrations under the fork (vertical amplitude: 4-25 mm; frequency: 4-17 Hz) whilst using cylindrical handles and ergonomic clip-on handles with a randomized order. Compared to cylindrical handles, ergonomic clip-on handles decreased significantly vibration transmissibility to the extensor digitorum, triceps brachii and flexor carpi radialis muscles by 10, 10 and 7%, respectively. The surface electromyography activity of the flexor carpi radialis decreased by 45%, while that of the triceps brachii increased by 12% (both significantly). Unlike the cylindrical handles, the ergonomic clip-on handles did not involve a significant decrease in the maximal handgrip force after the pedalling exercise. The ergonomic clip-o handles may prevent symptoms of hand-arm vibration syndrome in mountain bikers and could preserve their ability to effectively manoeuvre and brake the bike.

PUI 사용성 개선을 위한 의료기기 손잡이의 인간공학적 평가: 이비인후과 진료장치를 중심으로

Objective: The purpose of this study is to ergonomically evaluate subjective usability according to handle shape, diameter, angle and button position for endoscope, and spray of the Ear, Nose, and Throat (ENT) medical device to suggest optimal design guidelines.<BR>Background: As medical demand increases, the prevalence of occupational diseases among doctors is high such as musculoskeletal and cerebral cardiovascular diseases. Therefore, it is required to design an ergonomic PUI (physical user interface) to minimize human mistakes and errors of a doctor in the medical system.<BR>Method: Forty subjects participated in this study. This study produced a mock-up of an endoscope and spray with various handle types, angles, and diameter. For the pen-type endoscope, the shape of the handle (cylindrical, rectangular) and diameter (32, 35, 38㎜) were considered as independent variables. For the pistol-type endoscope, the shape of the handle (cylindrical, rectangular) and angle (90°, 100°, 110°, 120°, 130°) were considered as independent variables. For the spray, the position of the button (upper-top, middle-front, middle-side, lower-front, lower-side) was considered as the independent variable. As a dependent variable, this study evaluated the subjective usability using by the visual analog scale on a scale of 0 to 100.<BR>Results: The ANOVA result of a pen-type endoscope, there were significant differences in handle shape and diameter. The handle shape of rectangular and 32mm diameter had the significantly highest usability. The ANOVA result of the pistol-type endoscope, the handle angle had the significantly highest usability at 120°. As the angle increased up to 120°, subjective usability also tended to increase, but the angle of 130° decreased the trend. The ANOVA result of spray, the position of push button had the significantly highest subjective usability on bottom-front.<BR>Conclusion: Based on the results of this study, the endoscope and spray should be designed to have a pistol-type cylindrical handle with a diameter of 32 to 35mm and an adjustable angle. If the adjustable design is difficult, it is suggested to design with an angle of about 120°. And also, it is suggested that the spray’s button be positioned in the front, which can be pressed with the thumb.<BR>Application: This study can apply ergonomic handle design guidelines for endoscopy and spray. Furthermore, it could contribute to the prevention of occupational musculoskeletal disorders.

Hand tool handle size and shape determination based on hand measurements using a contour gauge

AbstractThe purpose of this study is to provide a novel approach to tool handle design and development based on measurements of hand shape using a contour gauge. In general, traditional design techniques, designing based on anthropometric data, and derived mathematical models do not incorporate enough subject data to design a customized product. First, anthropometric measurements on the right hand of 60 participants were collected with a contour gauge to manufacture matching handles. A curved handle fitting the human hand was constructed with common computer‐aided design software, and cylindrical handles and elliptical handles were added for comparison. All of the handles were used to record the participants' grip force to evaluate the operating efficiency of the handles. Finally, the participants completed a comfort‐rating questionnaire. The results show that contours based on the hand provided the highest operating performance and the best overall comfort‐rating compared to cylindrical handles and elliptical cylindrical handles. The newly developed handles in the grip force tasks have the highest push performance and the best comfort ratings compared to traditional cylindrical and elliptical handles. The developed handles could provide the hand tool industry information on developing and manufacturing many other similar handle designs (such as those for saws and electric screwdrivers).

Mangos figurativos de hueso romanos procedentes de &lt;em&gt;Mursa&lt;/em&gt;

El artículo analiza cuatro mangos figurativos de la Colección de objetos romanos de hueso del Museo Arqueológico de Osijek, Croacia. Esta Colección consiste en 19 mangos de hueso romanos divididos en cuatro tipos diferentes: mangos figurativos, mangos de cuchillos de doble filo, varios mangos completos y mangos cilíndricos. Tres de los mangos figurativas de hueso son mangos de cuchillos de resorte (cultellus) y en dos de ellos aparecen representaciones antropomórficas – un gladiador murmillo y Hércules, y en el tercero aparece una representación zoomórfica de un cerdo. Los tres objetos están hechos de tejido óseo compacto de hueso largo de mamíferos medianos o grandes. El cuarto artefacto, probablemente un mango patera con la cabeza de león en la punta, también está hecho de tejido óseo compacto de hueso largo de mamíferos de tamaño medio y grande. Este artefacto es obviamente una pieza de alta calidad y creemos que llegó a Mursa como una importación, mientras los otros mangos podrían haber sido manufacturados localmente.

Development of a finger adapter method for testing and evaluating vibration-reducing gloves and materials

The objective of this study was to develop a convenient and reliable adapter method for testing and evaluating vibration-reducing (VR) gloves and VR materials at the fingers. The general requirements and technical specifications for the design of the new adapter were based on our previous studies of hand-held adapters for vibration measurement and a conceptual model of the fingers-adapter-glove-handle system developed in this study. Two thicknesses (2 mm and 3 mm) of the adapter beam were fabricated using a 3-D printer. Each adapter is a thin beam equipped with a miniature tri-axial accelerometer (1.1 g) mounted at its center, with a total weight ≤ 2.2 g. To measure glove vibration transmissibility, the adapter is held with two gloved fingers; a finger is positioned on each side of the accelerometer. Each end of the adapter beam is slotted between the glove material and the finger. A series of experiments was conducted to evaluate this two-fingers-held adapter method by measuring the transmissibility of typical VR gloves and a sample VR material. The experimental results indicate that the major resonant frequency of the lightweight adapter on the VR material (≥800 Hz) is much higher than the resonant frequencies of the gloved fingers grasping a cylindrical handle (≤300 Hz). The experimental results were repeatable across the test treatments. The basic characteristics of the measured glove vibration transmissibility are consistent with the theoretical predictions based on the biodynamics of the gloved fingers-hand-arm system. The results suggest that VR glove fingers can effectively reduce only high-frequency vibration, and VR effectiveness can be increased by reducing the finger contact force. This study also demonstrated that the finger adapter method can be combined with the palm adapter method prescribed in the standardized glove test, which can double the test efficiency without substantially increasing the expense of the test.

Finite element analysis to assess the biomechanical behavior of a finger model gripping handles with different diameters

Summary Study aim: Interactions between the fingers and a handle can be analyzed using a finite element finger model. Hence, the biomechanical response of a hybrid human finger model during contact with varying diameter cylindrical handles was investigated numerically in the present study using ABAQUS/CAE. Materials and methods: The finite element index finger model consists of three segments: the proximal, middle, and distal phalanges. The finger model comprises skin, bone, subcutaneous tissue and nail. The skin and subcutaneous tissues were assumed to be non-linearly elastic and linearly visco-elastic. The FE model was applied to predict the contact interaction between the fingers and a handle with 10 N, 20 N, 40 N and 50 N grip forces for four different diameter handles (30 mm, 40 mm, 44mm and 50 mm). The model predictions projected the biomechanical response of the finger during the static gripping analysis with 200 incremental steps. Results: The simulation results showed that the increase in contact area reduced the maximal compressive stress/strain and also the contact pressure on finger skin. It was hypothesized in this study that the diameter of the handle influences the stress/strain and contact pressure within the soft tissue during the contact interactions. Conclusions: The present study may be useful to study the behavior of the finger model under the static gripping of hand-held power tools.

Adding Handles to Optimize Manual Box Handling.

The risk factors for developing musculoskeletal disorders in material handling tasks are well known. Among strategies for controlling risks, modifying boxes by adding handles is suggested. However, there are no clear recommendations regarding box modification as an approach to improve musculoskeletal health. In this study, we investigated the main literature databases to identify effects of box modification on reducing physical load. Electronic and manual searches were performed to identify studies that evaluated effects of boxes handles on physical exposure during handling tasks. The included studies were very heterogeneous (methods of assessment, types of handles used, and methodological quality), jeopardizing synthesis of evidence. Despite the mentioned limitations, we could suggest some features that could improve manual handling in practical settings, like the use of cylindrical handles forms with intermediate diameters (between 31 and 51 mm) and 30° inclination. Those characteristics demonstrated positive results on physical exposure. Regular cut-outs were indicated as a beneficial approach when boxes are handled in high surfaces. When handling occurs in medium heights or in the floor level, handles positioned on the top of the box might bring better results. Efforts to standardize methods are important to support both objective and subjective assessment of box handle design, as well to improve the internal validity of studies.

Assessment of ergonomically designed handle shapes for low-frequency vibration responses

Hand-operated tool handles transmit a large magnitude of vibration to the hand-arm system during low-frequency operations. Therefore, the precise design of a hand tool is very important to overcome musculoskeletal disorders, hand-arm vibration, etc. This study was aimed at developing optimal tool handles with an increased contact area and to overcome the contact pressure, which causes discomfort and pain. Six different human hand-based optimal handles (handles B to G) and one optimal cylindrical handle (handle A) were designed and fabricated using 3D printing technology, in order to assess the effect of low-frequency vibrations. The effect of handle shapes was evaluated with objective and subjective measurements using 15 subjects. Objective measurements were performed to assess the vibration transmissibility by experimental study at the frequency range of 0–100 Hz, and subjective measurements were performed to rate the handles based on comfort descriptors and overall comfort of the handles. Root mean square vibration accelerations were recorded at the wrist, elbow, and shoulder of each subject and at the base of the handle fixture to evaluate the vibration transmissibility for each handle. The mean vibration transmissibility was found to be minimum for handle B and was rated to be more comfortable by the subjects. The results indicated that all the human hand-based handles transmit less vibration and were rated to be more comfortable than the optimal cylindrical handle.