Radial-ulnar Deviation Research Articles

Maximumisometric moments generated by the wrist muscles in flexion-extension and radial-ulnar deviation

Maximum isometric and passive moments about the wrist were measured for a range of flexion-extension and radial-ulnar deviation angles in 10 healthy adult males. Each subject was seated in a test apparatus with his shoulder abducted 90°, elbow flexed 90°, and body and forearm constrained. Peak flexion moments ranged from 5.2 to 18.7 N m (mean = 12.2, SD = 3.7), while peak extension moments ranged from 3.4 to 9.4 N m (mean = 7.1, SD = 2.1). The average flexion moment peaked at 40° of flexion, whereas the average extension moment was relatively constant from 30° flexion to 70° extension. Peak moments generated by the radial and ulnar deviators ranged from 7.9 to 15.3 N m (mean = 11.0, SD = 2.0) and 5.9 to 11.9 N m (mean = 9.5, SD = 2.2), respectively. Passive moments in flexion-extension were near zero in the central 150° of motion, but increased at the end of the range of motion. The average passive moment was 0.5 N m in 90° flexion and 1.2 N m in 90° extension. Average passive moments about the radial-ulnar deviation axis were near zero with the wrist radially deviated and at neutral, but increased to 0.9 N m in full ulnar deviation.

Wrist joint motion simulator

A computer controlled wrist joint motion simulator has been developed that actively moves forearms from cadavers through cyclic planar flexion-extension motions, planar radial-ulnar deviation motions, and combined motions such as circumduction. Hybrid position-force feedback control algorithms are used to determine the wrist flexor and extensor tendon forces necessary to achieve the desired motions. The simulator was used in a series of 12 fresh cadaver forearms to produce both flexion-extension and radial-ulnar deviation motions and was found to cause repeatable, physiological movements. In these experiments, the extensor tendon forces were greater than those of the flexors, typically by a factor of two.

Prevalence of musculoskeletal disorders at the wrist as a function of angles, forces, repetitiveness and movement velocities.

The purpose of this investigation was to study the relationship between the prevalence of musculoskeletal disorders at the wrists and the characteristics of the work conditions in terms of angles, forces, repetitiveness, and movement velocities. Nine workplaces were selected and the prevalence of wrist disorders was determined by means of a questionnaire for both arms separately, along with characteristics of the 335 subjects (age, weight, height, seniority). A work analysis was performed on subjects selected at random from each workplace by recording, for both wrists during a representative number of work cycles, the angles both in radial and ulnar deviations and in flexion-extension and the surface electromyogram on the hand flexors of the forearm. Repetitiveness (defined as the number of transitions per minute) and movement velocities (in deviation and flexion-extension) were derived from the recordings of the angles. All the derived variables were highly correlated, greater angles and greater forces being associated with greater velocities and higher repetitiveness. A multivariate linear regression model for the prediction of the prevalence of musculoskeletal disorders of the wrist was constructed (R = 0.904). Height, weight, seniority, angles in radial-ulnar deviation, and forces were significant and independent predictors of the prevalence. The prevalence of wrist disorders is significantly linked to wrist angles in deviation and to forces exerted. Due to their high correlation with force, the repetitiveness indices and velocities, as defined, do not appear to play an additional role. Further research is needed to find alternative ways of characterizing repetitiveness.

Evaluation of handgrip force from EMG measurements

A series of experiments were performed in order to investigate whether estimates of handgrip force could be derived with fair accuracy from surface EMG levels recorded on the finger flexors of the forearm, taking into account the position of the wrist in the flexion-extension plane and in the ulnar-radial deviation plane. Handgrip forces (on a JAMAR dynamometer) and corresponding surface EMG levels (on the finger flexors of the forearm) were recorded for 20 subjects in 11 postures of the wrist and for 30% and 70% of the MVC in neutral posture. A mathematical empirical model was developed using multiple non-linear regression analysis. Although quite simple, it provides very reliable results, the correlation coefficient between predicted and observed forces being 0.895. Its use must, however, be restricted to work situations where: (a) the hand efforts are of the same type and involve the same muscles as those exerted on the dynamometer; (b) the hand is in neutral pro-supination; and (c) no voluntary effort is exerted by the wrist flexors except for maintaining the wrist posture.

Determination of wrist kinematics using a magnetic tracking device

The objective of this work is to present a method to determine the three-dimensional kinematics of the human wrist joint under physiological loading conditions using a magnetic tracking device. Euler angles were used to determine wrist extension-flexion, radial-ulnar deviation and supination-pronation. The screw displacement axis (SDA) method was used to describe the relative motion between carpal bones. Computer graphics were also used to obtain a better visualization of the three-dimensional motions of the carpal bones. This was accomplished by combining motion data and digitization data describing the geometry of the articular surfaces of the carpal bones. Geometric data included the locations of several points located on the articular surfaces forming the radio-scaphoid and radio-lunate joints. The SDA axes describing the motions of the capitate or the lunate or the scaphoid with respect to the radius during flexion-extension were found almost parallel to the medial-lateral direction. Translations along any SDA did not exceed 2 mm. One can thus consider the motion of each carpal bone as a pure rotation about a screw axis. Also, the SDA axis describing the motion of the capitate with respect to the radius was found to pass through the proximal end of the capitate. The graphical display of carpal motions shows that, as the wrist is flexed, the surface of the lunate within the radio-lunate articulation moves from palmar to dorsal. On the other hand, the palmar-dorsal location of the proximal surface of the scaphoid within the radio-scaphoid articulation remains almost unchanged.

A biomechanical comparison of four methods of fixation of the trapeziometacarpal joint

Four methods of internal fixation for trapeziometacarpal arthrodesis were evaluated for biomechanical stability under axial compression, torsion, and cantilever bending in either flexion-extension or radial-ulnar deviation. The techniques tested included crossed Kirschner wires, cerclage wiring, cup and cone with a single oblique Kirschner wire, and a tension band technique that has not previously been reported. Results reported included stiffness (load/deformation) of the construct and toggle (displacement without load applied, after cyclic loading). The tension band and cerclage techniques provided greater construct stiffnesses in axial loading than crossed Kirschner wire or cup-and-cone fixation, and toggle was significantly lower than for specimens fixed by the cup-and-cone technique. In torsion the tension band technique produced fixation that was significantly stiffer than cup-and-cone fixation. In cantilever bending the differences between fixation systems were not significant, except between cerclage and cup-and-cone techniques in flexion-extension. On the basis of our results in a biomechanical model, the tension band technique offers superior fixation in torsion, the cerclage technique in flexion-extension, and both in axial loading.

Kinematic analysis of relative motion within the proximal carpal row

The motions of the scaphoid and triquetrum relative to the Innate have been studied on cadaver specimens. The helical axis concept was applied. The wrist motions performed were flexionextension and radial-ulnar deviation. The results showed increased relative motion of the scaphoid towards terminal extension, and to a lesser amount in the case of the triquetrum, towards terminal flexion. The Innate might be considered as a keystone in the proximal carpal row when wrist stability is considered. It is doubly intercalated: longitudinally and transversely. Wrist ligaments co-ordinate the positioning of the bones in the mid-range of carpal motions, and restrict further motion in extreme positions of the wrist joint.

A non-exoskeleton optoelectric wrist goniometer

Highly repetitive wrist motion and extreme wrist posture can result in carpal tunnel syndrome. To study the association between wrist motion and posture and carpal tunnel syndrome, a hand/wrist goniometer is indispensable. This paper describes the development of an optoelectric goniometer. The goniometer utilized a fluid-based absolute angle sensor to transduce wrist posture into electrical signals. A geometric relationship and 6 nonlinear equations were used to calculate relative wrist angles. The result was an easy-to-use and non-exoskeleton hand/wrist goniometer which measures radial-ulnar deviation and flexion-extension of the wrist. Validation results showed that the average error of the absolute angle transducer was 4.5% of the full scale output (180°). Correlation between the output from the sensor and the standard motion was 0.977. Repeatability tests showed that the variation was 6.02% of the input value. The resolution of the sensor was 0.036°.

Stereoradiogrammetric technique for estimating alignment of the joints in the hand and wrist

A method and apparatus for quantitative measurement of the alignment and motion of the joints of the hand in three dimensions has been developed using stereoradiogrammetric principles. Alignment in planes of flexion-extension and radial-ulnar deviation can be determined to within 2.5°; rotation about the long axis of the metacarpals or phalanges is more difficult to determine, and can be measured to within 7°. Stereo views subtending angles in the range of 40° were found to optimize the total system accuracy.

Functional ranges of motion of the wrist joint

We have examined 40 normal subjects (20 men and 20 women) to determine the ideal range of motion required to perform activities of daily living. The amount of wrist flexion and extension, as well as radial and ulnar deviation, was measured simultaneously by means of a biaxial wrist electrogoniometer. The entire battery of evaluated tasks could be achieved with 60 degrees of extension, 54 degrees of flexion, 40 degrees of ulnar deviation, and 17 degrees of radial deviation, which reflects the maximum wrist motion required for daily activities. The majority of the hand placement and range of motion tasks that were studied in this project could be accomplished with 70 percent of the maximal range of wrist motion. This converts to 40 degrees each of wrist flexion and extension, and 40 degrees of combined radial-ulnar deviation. This study provides normal standards for the functional range of motion of the wrist.

The SLAC wrist: Scapholunate advanced collapse pattern of degenerative arthritis

Four thousand wrist x-ray films were reviewed to establish the pattern of sequential changes in degenerative arthritis of the wrist. After eliminating all other arthritides, we studied 210 cases of degenerative arthritis. The most common pattern (57%) was arthritis between the scaphoid, lunate, and radius; 27% of cases occurred between the scaphoid, trapezium, and trapezoid; a combination of these two patterns occurred in 15%. Twenty operations were performed on 19 patients with the scapholunate advanced collapse pattern. Eighteen of 19 patients had less pain postoperatively and none required pain medication. Flexion-extension and radial-ulnar deviation motions showed considerable improvement after the operation.

An in-vivo study of normal wrist kinematics.

The motion of the hand relative to a reference frame embedded in the radius is described using the screw displacement axis (SDA) concept. A three-dimensional sonic digitizer was utilized in a study of the dominant wrist of 15 normal subjects to determine the location and orientation of the SDAs based on the endpoints of flexion-extension motion (FEM) and radial-ulnar deviation (RUD) of the hand. The length of the common perpendicular between the SDAs of FEM and RUD was as large as 6 mm in some individuals; however, in some subjects the FEM SDA was distal of the RUD SDA while in others it was proximal. Considering the group of 15 subjects, the SDAs of FEM and RUD for the normal group nearly intersect in the head of the capitate in the neutrally positioned wrist and forearm.

The Three-dimensional Rotational Behaviors of the Carpal Bones

The rotational behaviors of the carpal bones of ten fresh cadaver forearms were determined using a three-dimensional sonic digitizer, as the hands were passively moved through planar constrained motions. Changing forearm orientation from supination to pronation results in an increase in the magnitudes of extension of the proximal and distal carpal row bones and a reduction in the magnitudes of flexion of the distal carpal row bones. The included angles between each carpal bone screw displacement axis (SDA) and third metacarpal SDA for corresponding intervals of motion are significantly greater than zero, regardless of forearm orientation. The included angles of the proximal carpal row bones are significantly greater than those of the distal carpal row bones during third metacarpal radial-ulnar deviation. The carpal bone rotation magnitudes are significantly attenuated relative to the prescribed rotation magnitudes of the third metacarpal, with the exception of the trapezoid during third metacarpal extension. The rotational attenuation is greatest in the proximal carpal row bones and is most pronounced during third metacarpal flexion-extension motion and ulnar deviation. Evidence from this investigation favors a carpal row concept of wrist motion, as opposed to a carpal column model.

Etude radiologique des centres de rotation du poignet

To ensure the total replacement of wrist, it seems necessary to determine the main kinematic specifications of mobility and stability of this joint. After a review of the literature, the authors have determined, by the classical X-rays graphic method, the positions of both radial-ulnar deviation and flexion-extension centers, on 26 alive normal wrists. The data, in some ways different from Youm's, introduce to the conditions of stability of any wrist in a functional situation. The center locus (on the forearm axis in a front view, quite anterior in a lateral view) is, in some ways, an answer to the question of muscular equilibrium during prehensile efforts, so to the amount of strains the joint must bear, and consequently to the design of a total wrist prosthesis.

Biomechanics of the Wrist

The wrist joint is a complex linkage between forearm and hand which is capable of an impressive arc of motion yet retaining a remarkable degree of stability. Carpal stability is derived from numerous intra-and intercarpal ligaments in addition to closely approximated wrist flexors and extensors. Motion occurring at the carpus is predominantly biplane--radial ulnar deviation and palmar flexion and extension. The center of motion for these planes of movement is located within the proximal and palmar pole of the capitate. When painful conditions arise at the wrist, a loss of wrist motion usually follows. Occasionally a loss of volitional control over wrist extensors is noted with the abnormal recruitment of wrist flexors with finger flexor activity. When instability and pain co-exist at the wrist, deformity can arise as a result of the inherent motor imbalance noted between the 6 wrist motors. Vector force analyses disclose that the flexor carpi ulnaris is the dominant wrist motor with the least significant force being supplied by the extensor carpi radialis longus. Although wrist motion is not essential for most activities of daily living, the preservation of wrist motion is for some individuals essential for the performance of specific occupational or recreational activities.

Fractures of the Scaphoid

Fractures of the scaphoid can be classified into either undisplaced, stable fractures or displaced, unstable fractures by their roentgenographic appearance. When there is greater than 1 mm of fracture offset or an instability collapse pattern (dorsal lunate rotation) on the lateral view, an unstable, displaced fracture is present. When doubt exists after reviewing routine films, special X-rays, such as radial-ulnar deviation stress views, traction oblique views, or trispiral tomography should be obtained. In acute scaphoid fractures, where no displacement of the fracture fragments or lunate dorsal tilting can be seen, a short-arm thumb spica cast provides satisfactory support for fracture union. A wrist position of volar flexion-radial deviation is preferred to the more traditional positions of wrist extension with radial deviation or wrist extension with ulnar deviation with 100% union rate and no malunions. In displaced scaphoid fractures, a long-arm cast is recommended, with reduction of the fracture by wrist flexion and radial deviation. If accurate reduction is not obtained or is lost during the course of treatment, open reduction and internal fixation should be strongly considered. In scaphoid nonunions, undisplaced fractures can be treated satisfactorily by an inlay bone graft, using either a dorsal or a volar approach. For displaced scaphoid nonunions, either a dorsal approach with internal fixation should be done (particularly if there is evidence of radioscaphoid arthrosis), or a volar approach with internal fixation can be performed. Peg graft techniques had a higher rate of nonunion and secondary arthritis. Nonunions should be immobilized a minimum of 4 months or until roentgenographic union is present.

An investigation of carpal bone motion using a three-dimensional sonic digitizer

Normal carpal kinematics were studied in 22 cadaver specimens using a biplanar radiography method. The kinematics of the trapezium, capitate, hamate, scaphoid, lunate, and triquetrum were determined during wrist motion in sagittal and coronal planes. The results were expressed using the concept of the screw displacement axis and converted to describe the magnitude of rotation about and translation along three axes (X-axis: pronation-supination axis, Y-axis; flexion-extension axis, and Z-axis: radial-ulnar deviation axis) commonly used for the wrist. The orientation of these axes is expressed relative to the radius.Within the proximal carpal row, considerable differences of carpal behavior around the Y-axis were observed during sagittal plane motion of the wrist. The scaphoid exhibited the greatest magnitude of rotation, and the lunate the least. The magnitude of rotation of the carpal bones around the X-axis during sagittal plane motion of the wrist was small. The proximal carpal bones exhibited some ulnar deviation in 60° of wrist flexion. During coronal plane motion of the wrist, the magnitude of radial-ulnar deviation of the distal carpal bones was mutually similar and generally of a greater magnitude than that of the proximal carpal bones. The proximal carpal bones experienced some flexion during radial deviation of the wrist and extension during ulnar deviation of the wrist. Translation was generally minimal in all carpal bones throughout wrist motion.This study reports results from the largest cadaver wrist kinematics study completed to date. The accuracy of the current method was improved when compared to previous studies. A sufficient number of specimens to allow statistical comparison was used and minimal interspecimen variability was noted. This study enabled a precise description of quantitative analyses of normal carpal kinematics relative to the radius.

A biomechanical investigation of wrist kinematics

This paper describes a biomechanical investigation to determine the overall kinematic behavior of the human wrist or carpus. The hand and forearm segments are modeled as rigid bodies, and the three-dimensional kinematic characteristics of the wrist are obtained by studying two clinically significant planar motions of the hand relative to the forearm: flexion-extension motion, and radial-ulnar deviation. The three mechanical quantities used to describe the kinematic behavior of the wrist are the functional range of motion, the looseness locus, and the instantaneous center of rotation locus. In vivo and in vitro experimental data are collected using biplanar X-ray films, and a three-dimensional sonic digitizer interfaced with a small laboratory computer. Validation tests using a metal universal joint with known kinematic properties indicate the accuracy and reliability of the experimental results. Data for one normal subject and one rheumatoid patient, examined both pre and post operatively, are presented and discussed.

Kinematics of the wrist. I. An experimental study of radial-ulnar deviation and flexion-extension.

The kinematics of the wrist during radial-ulnar deviation and flexion-extension were studied in several ways. In six fresh cadaver wrists, the forearm was fixed in full pronation, each motion was constrained to one plane, and two metal markers were placed in each of the finger metacarpals, as well as in the radius and all of the carpal bones except the pisiform and greater multangular. Radial ulnar and flexion-extension movements in these wrists were studied roentgenographically. In the wrists of six normal volunteers, a similar roentgenographic analysis was carried out and the trajectories of wrist motions also were studied using light-emitting diodes. Finally, roentgenographic measurements were made on 100 wrists of normal subjects. From these studies, it was concluded that: (1) during each of these motions, rotation occurs about a fixed axis located within the head of the capitate, and the location of each axis is not changed by the position of the hand in either plane; (2) the distance from the base of the third metacarpal to the distal articular surface of the radius (the carpal height), measured along the proximally projected axis of the third metacarpal on posteroanterior roentgenograms, is constant throughout radial-ulnar deviation of the normal wrist and can be used as a measure of carpal collapse; and (3) the perpendicular distance of the fixed axis of rotation for radial-ulnar deviation from the distally projected longitudinal axis of the ulna can be used as a quantitative measurement of the amount of translation of the carpus in pathological conditions.

Kinematic investigation of normal MCP joint

This investigation is an analytical and experimental study to quantitatively determine the kinematic behavior of the human metacarpophalangeal (MCP) joint. An in vivo study of the range of motion, and an in vitro study of the center of rotation, moment arm and tendon excursions are described. Various experimental techniques were employed. A specially designed finger experimenting apparatus was used in this investigation. Assuming the MCP joint to be an unknown joint mechanism which connects two rigid bodies, finger and metacarpal, the analysis of two rigid link kinematics is developed. In the study of kinematic behavior of the MCP joint, two motions are considered clinically significant: radial-ulnar deviation and flexion-extension motion.