Measuring Three-dimensional Knee Kinematics Using a Femoral Clamp: Accuracy, Repeatability and Reproducibility in Gait.

The ability to measure full six degrees-of-freedom knee joint kinematics is critical in the diagnosis of knee pathology. Soft tissue artifact (STA) remains the greatest source of error in measurement knee kinematics. The purpose of this study is to present a new femoral clamp to reduce STA at the thigh while preserving the natural gait pattern. Knee joint kinematics during gait was measured for six healthy subjects by using the femoral clamp and a rigid cluster-based technique. Performance was assessed in terms of accuracy, repeatability and reproducibility. The result showed that the femoral clamp did not change the walking speed and the natural knee kinematics pattern of the subjects. The clamp-measured kinematics had smaller knee translation in the transverse plane and were closer to data from the literature obtained by dual fluoroscopic imaging. The clamp had improved repeatability and reproducibility compared to the rigid cluster technique, suggesting that this technology is suitable for accurate measurement of gait.