Integration of marker and force data to compute three-dimensional joint moments of the thumb and index finger digits during pinch

This manuscript describes three-dimensional force data collected during postural shifts performed by individuals simulating rock-climbing skills. Starting from a quadrupedal vertical posture, 6 expert climbers had to release their right-hand holds and maintain the tripedal posture for a few seconds. The vertical and contact forces (lateral and anteroposterior forces) applied on the holds were analyzed in two positions: an “imposed” position (the trunk far from the supporting wall) and an “optimized” position (the trunk close to the wall and lower contact forces at the holds). The tripedal postures performed in the two positions were achieved by the same pattern of vertical and contact forces exerted by the limbs on the holds. In the optimized position, the transfer of the forces was less extensive than in the imposed position, so that the forces were exerted primarily on the ipsilateral hold. Moreover, a link between the contact force values and the couple due to body weight with respect to the feet was shown.

Download Full-text

A Three-dimensional Finger Motion Measurement System of a Thumb and an Index Finger Without a Calibration Process

Sensors ◽

10.3390/s20030756 ◽

2020 ◽

Vol 20 (3) ◽

pp. 756 ◽

Cited By ~ 1

Author(s):

Yeongyu Park ◽

Joonbum Bae

Keyword(s):

Index Finger ◽

Three Dimensional ◽

Length Change ◽

Measuring Method ◽

Finger Joint ◽

Joint Angles ◽

Calibration Process ◽

Hand Motion ◽

Wearable Systems ◽

Cmc Joint

Various wearable systems have been investigated to measure hand motion, but some challenges remain. Many systems require a calibration process to map sensor signals to actual finger joint angles by the principle of measuring the length change of the finger, or bending sensors. Also, few studies have investigated how to measure thumb motion accurately using the wearable systems. This paper proposes an exoskeleton system with linear Hall sensors to measure three-dimensional hand motion without a calibration process. The calibration process is avoided by measuring finger joint angles through an absolute rotation measurement. A new wearing method with lower parts underneath the hand joints and rubber bands is proposed to fix the structure to the hand and adapt it for various hand sizes. As the thumb has a complex biomechanical feature at carpometacarpal (CMC) joint, a new measuring method of the CMC joint is proposed to directly calculate the orientation of the metacarpal. The prototype of the thumb and index finger was manufactured, and the performance was verified experimentally by using an optical motion capture system.

Download Full-text

Flexion Angles of Finger Joints in Two-Finger Tip Pinching Using 3D Bone Models Constructed from X-Ray Computed Tomography (CT) Images

Applied Bionics and Biomechanics ◽

10.1155/2020/8883866 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Satoshi Shimawaki ◽

Yoshiaki Nakamura ◽

Masataka Nakabayashi ◽

Hideharu Sugimoto

Keyword(s):

Index Finger ◽

Three Dimensional ◽

High Mobility ◽

Ct Images ◽

Flexion Angle ◽

Normal Hand ◽

Distal Interphalangeal ◽

X Ray Computed ◽

Different Diameters ◽

Finger Tip

The motion analysis of two-finger tip pinching using the thumb and index finger provides crucial data for designing the motion mechanism of electric prosthetic hands. The purpose of this study is to determine the joints that have high mobility during two-finger tip pinching by measuring the flexion angle of each joint. Ten Japanese men with normal hand were selected. CT images were obtained while the hands adopted the following four postures: a basic posture not pinching a cylinder, and three postures pinching wooden cylinders with different diameters (2, 10, and 30 mm). Three-dimensional bone models of the thumb and index finger were created using the CT images and used to measure the flexion angles of the joints. The flexion angles of the proximal interphalangeal and metacarpophalangeal joints of the index finger significantly decreased as the diameter of the cylinder increased. However, even when the diameter of the cylinder changed, the flexion angle of the distal interphalangeal joint of the index finger, and the flexion and rotation angles of all of the thumb joints did not change. When pinching objects of different sizes with a two-finger tip pinch, the posture of the thumb is fixed, and only the posture of the index finger changes. When designing the two-finger tip pinch motion for an electric prosthetic hand, it is sufficient to drive the joints of the index finger only.

Download Full-text

Modeling of the Holding Force in an Electromagnetic Chuck

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1286259 ◽

1999 ◽

Vol 122 (3) ◽

pp. 569-575 ◽

Cited By ~ 4

Author(s):

Alejandro Felix ◽

Shreyes N. Melkote ◽

Yoichi Matsumoto

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Three Dimensional ◽

Element Model ◽

Prediction Errors ◽

Modeling And Prediction ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element ◽

Force Data ◽

The Finite Element Model

This paper addresses the modeling and prediction of the normal holding force in an electromagnetic chuck used in precision machining applications. Knowledge of the normal holding force is necessary to determine if a given chuck is capable of preventing workpiece slip during machining. First, an analytic model termed the magnetic circuit model was developed and compared with experimental holding force data. It was found that this model, although simple in form, was limited in its ability to accurately predict the holding force over the entire range of conditions investigated. The discrepancies in the model were attributed to its inability to accurately model the leakage flux and nonuniform distribution of the magnetic flux. A three-dimensional finite element model was then developed to overcome these limitations. Predictions with this model were found to be in better agreement with experiments, yielding prediction errors within 25 percent in most cases. The finite element model also provided an explanation for the observed decrease in the measured holding force at current values beyond a certain threshold. [S1087-1357(00)01503-3]

Download Full-text

Temporal Influences of Functional Knee Bracing on Torque Production of the Lower Extremity

Journal of Sport Rehabilitation ◽

10.1123/jsr.15.3.215 ◽

2006 ◽

Vol 15 (3) ◽

pp. 215-227

Author(s):

Brian Campbell ◽

James Yaggie ◽

Daniel Cipriani

Keyword(s):

Lower Extremity ◽

Outcome Measures ◽

Repeated Measures ◽

Exercise Intervention ◽

Three Dimensional ◽

Exercise Program ◽

Joint Moments ◽

Repeated Measures Design ◽

Reaction Forces ◽

Vertical Ground Reaction Forces

Context:Functional knee braces (FKB) are used prophylactically and in rehabilitation to aide in the functional stability of the knee.Objective:To determine if alterations in select lower extremity moments persist throughout a one hour period in healthy individuals.Design:2X5 repeated measures design.Setting:Biomechanics Laboratory.Subjects:Twenty subjects (14 male and 6 female, mean age 26.5±7 yrs; height 172.4±13 cm; weight 78.6±9 kg), separated into braced (B) and no brace (NB) groups.Intervention:A one-hour exercise program divided into three 20 minute increments.Main Outcome Measures:Synchronized three-dimensional kinematic and kinetic data were collected at 20-minute increments to assess the effect of the FKB on select lower extremity moments and vertical ground reaction forces.Results:Increase in hip moment and a decrease in knee moment were noted immediately after brace application and appeared to persist throughout a one hour bout of exercise.Conclusions:The FKB and the exercise intervention caused decreases in knee joint moments and increases in hip joint moments.

Download Full-text

Joint angle, moment and power compensations in dogs with fragmented medial coronoid process

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-07-04-0038 ◽

2008 ◽

Vol 21 (02) ◽

pp. 110-118 ◽

Cited By ~ 24

Author(s):

J. A. Dobney ◽

M. R. Owen ◽

G. R. Colborne ◽

N. J. Burton

Keyword(s):

Dynamic Analysis ◽

Stance Phase ◽

Coronoid Process ◽

Joint Moments ◽

Inverse Dynamic ◽

Inverse Dynamic Analysis ◽

Affected Side ◽

Custom Software ◽

Stance Time ◽

Force Data

SummaryFragmented medial coronoid process (FMCP) is the most common cause of forelimb lameness in juvenile medium and large breed dogs; however methods of assessing the disruption to their gait remain subjective. The purpose of this study was to objectively quantify the mechanical disruptions to gait in dogs with arthroscopically confirmed unilateral FMCP. Seven dogs underwent full inverse dynamic analysis at the time of diagnosis. Kinematic and force data were collected from both forelimbs at trot. Stance phase joint angles, net joint moments and net joint powers were calculated using custom software. There were gross differences in kinetic and kinematic patterns between FMCP affected and compensating forelimbs. Stance time was 0.24 sec on the lame side and 0.26 sec on the compensating side. The shoulder and the elbow were more flexed at ground contact, and elbow, carpal and MCP joints had smaller ranges of motion on the lame side. Net joint moments were significantly reduced (P<0.05) in the elbow, carpal and MCP joints of the FMCP affected limb. Net joint powers were likewise significantly smaller (P<0.05). However, the overall moment and power patterns persisted. Total limb support moment was significantly smaller on the affected side (P<0.05). Total limb power was significantly reduced on the affected side (P<0.05) being most affected in its propulsive phase in the second half of stance. Inverse dynamic analysis of this clinical condition is an objective means by which to assess the mechanical disruption to gait.

Download Full-text

Hip Abductors and Lumbar Lateral Flexors act as Energy Generators in Running Single-leg Jumps

International Journal of Sports Medicine ◽

10.1055/a-0749-8846 ◽

2018 ◽

Vol 39 (13) ◽

pp. 1001-1008 ◽

Cited By ~ 5

Author(s):

Natsuki Sado ◽

Shinsuke Yoshioka ◽

Senshi Fukashiro

Keyword(s):

Reaction Force ◽

Three Dimensional ◽

Knee Extensors ◽

Plantar Flexors ◽

Positive Power ◽

Flexor Muscles ◽

Hip Abduction ◽

Hip Abductor ◽

Force Data ◽

Positive Work

AbstractIn humans, hip abductor and lumbar lateral flexor muscles are well-developed as side-to-side lumbopelvic stabilizers. We hypothesized that the hip abductors and lumbar lateral flexors act as energy generators during a running single-leg jump, although they are generally recognized as stabilizers. We collected kinematics and ground reaction force data in running single-leg jumps by 13 male high jumpers and calculated three-dimensional kinetic variables. Hip abduction and lumbosacral lateral flexion towards free leg side torques were exerted during almost the entire take-off phase, exerting positive power during the terminal 2/3 of the phase. The positive work of the hip abductors (1.08±0.30 J/kg) was as large as that of the ankle plantar-flexors, suggesting that the energy-generating potential of the hip abductors compares with that of the extensors of the stance-leg joints. The lumbosacral lateral flexors also performed positive work (0.36±0.18 J/kg), which was 47±25% of the knee extensors, albeit less than the extensors of the stance leg joints. The results implied that the hip abductors and lumbar lateral flexors have substantial potentials not only as stabilizers but also as energy generators and that they act as substantial energy generators during running single-leg jumps.

Download Full-text

Kinematic and Dynamic Synergies of Human Precision-Grip Movements

Journal of Neurophysiology ◽

10.1152/jn.01310.2004 ◽

2005 ◽

Vol 94 (4) ◽

pp. 2284-2294 ◽

Cited By ~ 71

Author(s):

I. V. Grinyagin ◽

E. V. Biryukova ◽

M. A. Maier

Keyword(s):

Inverse Dynamics ◽

Index Finger ◽

Precision Grip ◽

Three Dimensional ◽

Biomechanical Model ◽

Principal Component ◽

Movement Kinematics ◽

Movement Velocity ◽

Joint Torques ◽

Relative Contribution

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.

Download Full-text

Sagittal plane kinematics and kinetics of the pastern joint during the stance phase of the trot

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1632707 ◽

2002 ◽

Vol 15 (01) ◽

pp. 15-17 ◽

Cited By ~ 8

Author(s):

W. H. Singleton ◽

J. L. Lanovaz ◽

Marta Prades ◽

Hilary M. Clayton

Keyword(s):

Energy Absorption ◽

Stance Phase ◽

Sagittal Plane ◽

Joint Moments ◽

Maximal Extension ◽

Peak Energy ◽

Force Data ◽

Kinetics Of ◽

Kinematics And Kinetics ◽

Palmar Aspect

SummaryThe objectives were to measure sagittal plane kinematics and kinetics of the forelimb pastern joint during the stance phase at the trot. Sagittal plane video (200 Hz) and force (1,000 Hz) recordings were analyzed from four trials of six sound horses trotting in hand. Kinematic and force data were used to calculate net joint moments and joint powers. The pastern joint showed maximal flexion (155.3 ± 11.0°) at 34% stance and maximal extension (190.2 ± 3.8°) at 93% stance. Energy was absorbed on the palmar aspect throughout stance, with peak energy absorption occurring in the second half of the stance. It was concluded that the primary function of the pastern joint was to act as an energy damper.

Download Full-text