The purpose of this study is to evaluate the kinematic effects on the distal radioulnar joint of performing a distal radius osteotomy for treatment of Kienbok's disease. Method: Fourteen normal human cadaveric forearm were used. PQ, PT, Supinator, Biceps, FCR, FCU, ECU, FDP, ECRL, and ECRB tendons were prepared and loaded. Just static loading and dynamic resistive muscle loading conditions were simulated throughout a complete pronation-supination motion on a forearm simulator. A torque cell was used to measure the torque required to create and resist motion of the Forearm. Surgical models were simulated for radius shortening osteotomy(RSO), lateral open(LOO), lateral closing(LCO), and medial closing(MCO) wedge osteotomies. Radius length, radius inclination control and stable maintenance, two types of external-fixators were used. The torque and positional data were recorded continuously during pronation and supination with the torque cell and potentiometer. The data were filtered and interpolated using Matlab. We compared torque values at 80% and 100% of the full range of motion, in both supination, and in pronation. The specimens were divided into 4 groups based on the anatomy of the DRUJ. Specifically, the articulation of the DRUJ (flat or tilted), and the variance of the ulna. A three factors analysis of variances with repeated measures was performed to test for significant differences. Results: When looking at all 14 specimens with static loading, the LCO condition statistically significant more torque was required to achieve 80% and 100% pronation when compared to control (p<0.05). 80% and 100% of supination also affected, however, these results were not statistically significant. The LOO, RSO, and MCO did not have a statistically significant effect on the required torque. The resistive loading conditions showed the same tendencies as the unloaded conditions. With static loading, when all 14 cadavers were divided into the 4 groups, all 4 groups showed same tendency. Conclusion: We investigated the effects of the radius shortening and three variations of radius wedge osteotomies on forearm kinematics. From our result, we can't conclude which methods will be good for treating Kienbok's disease, however, this study provided information regarding the effects of the current surgical treatment options on forearm mechanics. If all osteotomies are essentially equal in their efficacy to decompress the lunate, one would like to use the osteotomy that has the least effect on otherwise normal forearm mechanics.We found the LCO to be the least favorable with respect to the functioning of the forearm.