The Stride4 is the latest addition to the Stride Family of interchangeable stance control knee joints. It contains many additional features to enhance patient function and like the FullStride and SafetyStride, the Stride4 is a mechanical stance control orthotic knee joint that utilizes a low-profile cabling system to automatically unlock at the end of stance phase. At the end of swing phase, when the orthotic knee joint reaches full extension, the locking mechanism reengages to provide knee stability for stance phase. Cable adjustment clevises allow the practitioner to easily adjust the cable length to match the patient’s stride length. The joint body of the Stride4 is comprised of a four bar linkage mechanism; the upper and lower aspects of the joint do not purely rotate about one fixed center of rotation. Instead, the joint motion involves some translation, in addition to rotation, to more closely mimic anatomical knee motion. In the stance control mode of operation, the four bar linkage mechanism provides stability when the orthotic knee joint is fully extended. An integral extension assist spring housed within the midsection assists with knee extension, while an adjustable extension stop allows the practitioner to adjust and fine tune the point at which the joint enters into its stable/locked state. If desired, the extension stop can be fully adjusted to eliminate the stability feature to facilitate free motion. A button on the Stride4 allows the patient to switch between locked and stance control modes of operation. This feature provides the patient with the option of locking the joint should they desire. When the lock option is selected and engaged by the patient, the joint will allow approximately 3° of flexion to provide some shock absorption to the user.