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Objective Kienbock's disease is an unusual disorder caused by osteonecrosis and the collapse of lunate bone which leads to pain and a chronic decrease in wrist function. The treatments in this disease aim to relieve pain and maintain wrist function and movement. Various surgical procedures have been recommended for the subjects with Kienbock's disease; however, the main question posed here is which of the selected procedures are more successful in relief of the pressure applied on lunate. Methods and Materials Computed tomography (CT) scan images of a normal subject were used to create a three-dimensional model of the wrist joint. The effects of several surgical procedures, including radial shortening, capitate shortening, and a combination of both radial and capitate shortening, on the joint contact force of the wrist bones were investigated. Results The pressure applied to the lunate bone in articulation with radius, scaphoid, capitate, hamate, and triquetrum varied between 19.7 and 45.4 MPa. The Von Mises stress, maximum principal stress, and minimum principal stress decreased in the model with a combination of radius and capitate shortening. Conclusion It can be concluded from the results of this study that the combinations of radius and capitate shortening seem to be an effective procedure to decrease joint pressure, if the combined surgery could not be done, shortening of radius or capitate would be recommended. Level of Evidence This is a Level III study.

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Measurement of muscle forces related to aging can help to better identify the gait impairment mechanisms in the elderly. To this end, musculoskeletal modeling has been developed to estimate muscle forces. This study aimed to check the validity of OpenSim modeling (i.e., computed muscle control) approach in elderly subjects. Kinematic and kinetic data and Electromyography (EMG) signals for four different muscles were collected in nine healthy elderly males during walking. Dynamic simulation was done within OpenSim. Correlation analysis was performed to quantitatively compare the maximum estimated muscle forces with maximum measured muscle activities during the first double limb support, single limb support, and the second double limb support phases. The area-time plots of OpenSim and EMG data during gait cycle were obtained for qualitative assessment. In quantitative assessment, a low to moderate correlation was observed for the peak of muscle force and muscle activation of four muscles during sub phases of gait. The muscle forces pattern from OpenSim was found to be relatively similar to the muscle activity pattern from EMG especially for Gastrocnemius Medialis. A low to moderate consistency between OpenSim and EMG in the elderly can be explained by using a single mathematical estimation approach.

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OBJECTIVE: Lower-limb amputation is mainly a result of trauma, vascular disease, diabetes, or congenital disorders. Persons with amputation lose their ability to stand and walk on the basis of the level of amputation. Contribution of level of amputation, type of amputation, or cause of amputation to balance impairment has not been clearly defined. Furthermore, it is controversial how much the mentioned parameters influence standing stability. Therefore, the aim of this review article was to find the relationship between the abovementioned factors and balance impairment in the available literature. It was also aimed to find the possibility of improving standing stability by the use of different prosthesis components. DESIGN: An electronic search was done via the PubMed, EMBASE, and ISI Web of Knowledge databases from 1960 to 2012. Quality of the articles was assessed using the Downs and Black tool. RESULTS: On the basis of the used key words, 100 articles were found, of which 20 articles were selected in accordance with the selection criteria. The scores of reporting, external validity, internal validity (bias), and internal validity (confounding) varied between 4-9, 1-3, 3-5, and 2-6, respectively. CONCLUSIONS: The literature review confirmed that standing stability of amputees depends on level of amputation, type of amputation, and cause of amputation. Moreover, prosthetic characteristics such as prosthetic ankle stiffness have influences on dynamic stability, whereas torsional adaptor does not have any positive influence on stability during level walking and on turning stability. Therefore, it can be concluded that the stability of a person with amputation can be improved by the use of appropriate prosthesis components.

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BACKGROUND: Knee joint osteoarthritis (OA) is one of the most incapacitating diseases affecting older population, which is associated with pain and functional limitation. Various kinds of conservative treatment have been used to decrease knee pain and to improve the quality of life of the subjects suffering from this disease. There are discrepancies in the clinical effects reported for the use of lateral wedge insole in spite of being used as one of the first conservative mechanical treatments for patients with medial compartments of knee OA. METHODS: A total of 36 subjects with medial knee compartment OA were recruited in this research project. Subjects were randomized into two groups to receive 3- and 7-mm lateral wedge insoles based on the date of birth of the participants. Some parameters such as severity of knee pain, Tibiofemoral angle (TFA), severity of OA, and quality of life were selected in this research project. RESULTS: The use of both 3-mm and 7-mm lateral wedge insole improves the quality of life and decreases knee joint pain. However, the effect of 7 mm lateral wedge insole was more than that of 3 mm. CONCLUSION: Using lateral wedge insole is a simple, inexpensive therapy for decreasing pain and improving quality of life; however, most research must be carried out to find the effects of lateral wedge on severity of knee joint OA and aligning TFA.