Wrist joint motion

Arthroplasty is one of the treatments for severe deformity case of Rheumatoid Arthritis, intended to preserve wrist joint motion while removing pain or any other problems associated with the wrist joint [6]. However, there are several problems associated with the wrist arthroplasty. Loosening effect was commonly occurred due to lack of bony support towards the implant [7-8]. Jay Menon et al. claimed that the wrist arthroplasty experienced with a earpal component fixed with three screws could successfiilly result a good bony support [8]. Bone graft was needed in order to enhance the fusion between bones and implant [9]. Hence, the aim of this project was to analyse the biomechanical effect of bone graft in enhancing distal component fixation of the wrist implant. 

The wrist functions by allowing changes of orientation of the hand relative to the forearm. The wrist joint complex consists of multiple articulations of eight carpal bones with the distal radius, the structures of the ulnocarpal space, the metacarpals, and each other. This collection of bones and soft tissues is capable of a substantial arc of motion that augments hand and finger function. 

The complexity of joint motion at the wrist makes it difficult to calculate the instant center of motion. However, the trajectories of the hand during radioulnar deviation and fiexion/extension, when they occur in a fixed plane, are circular, and the rotation in each plane takes place about a fixed axis. These axes are located within the head of the capitate and are not altered by the position of the hand in the plane of rotation [Youm et al, 1978]. During radioulnar deviation, the instant center of rotation lies at a point in the capitate situated distal to the proximal end of this bone by a distance equivalent to approximately one-quarter of its total length (Figure 49.28). During fiexion/extension, the instant center is close to the... 

With single-piece silicone implants for the finger and wrist, the stems of the implant are free to move and therefore silicone wear debris is generated as the silicone abrades against the bone. These silicone wear particles can cause an inflammatory response that results in pain, joint stiffness, loss of joint motion and soft tissue swelling (Shepherd, 2002 Shepherd and Johnstone, 2002). 

Wu, G., van der Helm, EC.T., (Dirkjan) Veeger, H.E.J., Makhsous, M. et al., ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion—Part II Shoulder, elbow, wrist and hand. J. Biomech., 38, pp. 981-992,2005. 

The range of joint motion should be tested both passively and actively, with any restrictions noted. A general motion screening is performed by asking the patient to raise both arms slowly and touch the backs of his hands over the head. The physician observes scapular motion and symmetry of shoulder, elbow, and wrist angles. The inability to perform this test indicates motion restriction in the upper extremity. The areas of restriction must then be identified. 

Besides flexion and extension, the forearm can rotate around its longitudinal axis. Rotation involves the proximal radioulnar joint of the elbow and the distal radioulnar joint, which lies above the wrist. These motions are observed with the forearm flexed to 90 degrees. 

The close-packed position of the wrist is full extension. Falling on the wrist in this position will readily cause fracture. In a relaxed, loosely packed position, the joints are relatively mobile. For the performance of any task involving wrist action, the articulations must enter into a combination of interdependent locked positions, creating a solid structure that can bear the strain of torsional motion. In turning a doorknob, for example, the wrist joint changes from a sack of... 

Somatic dysfunction of the wrist permits motion toward the dysfunction motion away from the dysfunction will be restricted. The technique described may be used to test motion of the ra-dionavicular joint and each of the intercarpal joints. It may also be used to test the carpometacarpal and metacarpophalangeal joints. 

Joint replacements, 45-10-45-13 Joint structure modehng, 15-6 Joint-articulating surface motion, 49-1-49-34 ankle joint, 49-2—49-4 elbow joint, 49-20-49-23 hand joint, 49-27-49-32 hip joint, 49-10-49-15 knee joint, 49-4 9-10 shoulder joint, 49-15—49-20 wrist joint, 49-23—49-27 Jones, D., 74-7... 

The joints affected most frequently by rheumatoid arthritis are the small joints of the hands, wrists, and feet (Fig. 89-3). In addition, elbows, shoulders, hips, knees, and ankles may be involved. Patients usually experience joint stiffness that typically is worse in the morning. The duration of stiffness tends to be correlated directly with disease activity, usually exceeds 30 minutes, and may persist all day. Chronic inflammation with lack of an adequate exercise program results in loss of range of motion, atrophy of muscles, weakness, and deformity. 

Revolute. In this case the robot s movements are exclusively rotational (Fig. 9.1b). The essential difference from the other three is that, in addition to the rotatory motion of the base, the arm is jointed in the human style and includes a shoulder, an elbow and a wrist, ali of which can perform angular movements. 

Robotic Arm The main body of most industrial robots is stationary. The robot has a joint that allows the body to rotate in place. The shoulder is the first joint connected to the main body, and it allows the arm to raise and lower. An industrial robotic arm with six joints can imitate the motion of a human arm. Fortunately, we only need a shoulder, elbow, and wrist to accomplish the same movements. This is because some of our joints can move in two or three directions, whereas each robotic joint can only move in one direction. 

The primary sources of control for body-powered devices are biomechanical in nature. Movement, or force, from a body joint or multiple joints is used to change position, or develop a force/ pressure that can be transduced by a harness and Bowden cable and/or mechanical switches. Typically, inputs such as chin and head force/movement, glenohumeral flexion/extension or abduction/ adduction, biscapular and scapular abduction, shoulder elevation and depression, chest expansion, and elbow or wrist movements are used. However, direct force/motion from muscle(s) has also been used by way of surgical procedures such as muscle tunnel cinepiasty (Sauerbruch, 1916) and the Krukenberg cinepiasty (Krukenberg, 1917). 

Kinematic models are also used in designs of smart hand and hand prostheses in order to track independently the motion in each degree of freedom. For example, fingers as a part of serial kinematic chain are composed of revolute joints. Different motions are considered, such as abduction/adduction and flexion/extension, together with pronation/ supination of the wrist and fingers for the better manipulation and grasping motion of the hand [31-33]. Most of actual motion-tracking models represent the joint as a spherical joint. 

The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, and skeletal muscles. The articular ligaments and tendons are the main parts holding together the joint(s). hr respect to the movement, there are freely moveable, partially moveable, and immovable joints. Synovial joints, the freely moveable ones, allow for a large range of motion and encompass wrists, knees, ankles, shoulders, and hips. 

As with many of the arthritic conditions, the primary dysfunction of the wrist and hand occur with the secondary motions more than the primary motions. Some dysfunctions of the carpal joints occur involving multiple joints. One of the most typical of the carpal dysfunctions involves restriction of glide of the lunate bone. It tends to have a preferential glide into the ventral direction and can contribute to the narrowing of the space of the carpal tunnel. The dysfunctions of... 

Other restricted motions of the wrist or hand may be treated in a similar fashion by taking the joint to the barrier to motion, having the patient push against isometric resistance toward the freedom of motion, relax, and repeat the process three times. Any muscle energy technique may be followed by a passive stretch. 

Rheumatoid arthritis and osteoarthritis may involve the joints of the wrist and hand. Psoriatic arthritis and gouty arthritis may also affect this area. Many of the findings and specific deformities were mentioned previously. In the arthriti-des, the small accessory motions of the joint are lost first. The osteopathic physician must articulate all joints once the acute inflammation has subsided. Placing traction on the joint as it is articulated decreases the discomfort for the patient. The patient should be encouraged to exercise the joints gently to maintain mobility. 

Figure 12 represents a human body model with 39 bodies and 45 degrees of freedom. The degrees of freedom are distributed as follows 3 at the neck, 2 at each collar bone, 3 at each shoulder, 2 at each elbow, 2 at each wrist, 1 for finger motion on each hand, 2 at the waist, 3 at each hip, 1 at each knee and 3 at each foot. In addition, there are 6 degrees of freedom of the base body, which is taken to be the hips. The 3, 2 and 1 degrees of freedom motions at the joints have been represented with spherical, universal and revolute joints, respectively. For convenience, the model used for computation used only revolute joints. Universal joints were represented as two perpendicular revolute joints and spherical joints as three mutually perpendicular revolute joints. 

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