Inclusion Criteria:  Patients in the age range of 18 years to 85 years (both inclusive) Patients who have a BMI less than 35 Patients who do not have previous surgery on the implanted knee that might restrict their movement Patient who are at least 6 months post-operative Patients who do not experience any pain or other post-operative complications Patients who have a stable TKA and can perform a deep knee bend activity Patients who are willing to participate in this study and are willing to sign appropriate HIPAA and informed consent forms Subjects will have a Journey II knee system  Exclusion Criteria:  Pregnant, potentially pregnant, or lactating females. To satisfy radiation protocol, each female subject will be asked if she is pregnant, or possibly could be pregnant. A pregnant person will not be allowed to participate in the study. Patients who have currently enrolled in a fluoroscopic study within the past year. Patients currently involved in any personal injury litigation, medical/legal or workman's compensation claims. Patients with known drug or alcohol abuse histories or psychological disorders that could affect ability to complete all aspects of the study. Patients with neurological or musculoskeletal disorders that might adversely affect weight-bearing motion ability Subjects who are unable to perform a deep knee bend. Subjects who are unwilling to sign Informed Consent/ HIPAA documents. Subjects without the required type of knee implant.