The objective of this study is to analyze subjects having a normal hip and compare the in vivo kinematics to subjects requiring a total hip arthroplasty (THA) due to having a diseased hip and then later post-operative to their implanted hip. Ten subjects will have a normal hip, ten hips will be diseased, requiring a THA and then those ten diseased hips will be re-analyzed at least six months post-operatively after implantation of a THA.

Inclusion Criteria for diseased/implanted subjects:

• Subjects will require a THA and will be implanted with either Summit/Pinnacle THA or Corail/Pinnacle THA.
• Patients must be at least six months post-operative with no other surgical procedures conducted within the past six months that will prohibit them from performing the study activities.
• Patients must be between 40-85 years of age.
• Potential subjects will have a body weight of less than 250 lbs.
• Participants must have Body Mass Index (BMI) of less than 38.
• Potential subjects' THAs should be judged clinically successful with a HHS >90.
• Subjects must have demonstrated no evidence of post-operative hip subluxation or dislocation.
• Subjects must not walk with a detectable limp and must be able to actively abduct their operated hip against gravity without difficulty.
• Participants must be able to walk on level ground, ascend and descend a ramp and rise from a chair without assistance.
• Patients from the physician's list who do not meet the study requirements will not be considered.
• Patients must be willing to sign the Informed Consent (IC)/HIPAA form to participate in the study.

Exclusion Criteria for diseased/implanted subjects:

• 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.
• Subjects without one of the two types of required hip implants.
• Subjects who have had surgery within the past 6 months that would prohibit them from performing level walking, ascend and descend a ramp and rise from a chair without aid or support of any kind.
• Subjects who are unable to perform level walking, ascend and descend a ramp and rise from a chair without aid or support.
• Subjects with pain, functional deficits, or generalized inflammatory.
• Subjects who walk with a detectable limp.
• Subjects who cannot actively abduct their operated hip against gravity without difficulty.
• Subjects who are unwilling to sign IC/HIPAA document.
• Subjects who have a HHS <90.

Inclusion Criteria for normal subjects:

• Patients must not have any kind of hip implant.
• Subjects must not have had any type of hip surgery or any pathological hip conditions, including osteoarthritis, or hip pain.
• Patients must be between the ages of 18 and 65.
• Potential subjects will have a body weight of less than 250 lbs.
• Participants must have BMI of less than 38.
• Pregnant or potentially pregnant females will be excluded from the study. 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.
• Participants must be able to walk on level ground, ascend and descend a ramp and rise from a chair without aid of any kind or have had any kind of surgical procedure within the past 6 months that would affect his/her ability to perform the study activities.
• Patients must be willing to sign the IC and HIPAA forms to participate in the study.
• Patients must be between 160cm (5'3) and 193cm (6'4) tall

Exclusion Criteria for normal subjects:

• 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
• Subjects with any kind of hip implant.
• Subjects who have had any past hip surgery, have pathological hip conditions and/or hip pain.
• Subjects who have had surgery within the past 6 months that would prohibit them from performing level walking, ascend and descend a ramp and rise from a chair without aid or support of any kind.
• Subjects who are unable to perform level walking, ascend and descend a ramp and rise from a chair without aid or support.
• Subjects who are unwilling to sign IC/HIPAA document.

Subjects with a diseased hip that requires THA. OR Subjects with a normal hip.

Researchers would like to retain this study data in our secure database so as to continue to add relevant, current data to our digital collection to help us work with manufacturers in the future to create better implants that last longer and will not require revision surgery. Participants will be asked if their study data may remain a part of the University of Tennessee's Center for Musculoskeletal Research data collection for use in future studies in the IC. Identifiers are automatically removed from the database upon entry into the secure server. Data shared with sponsors is de-identified.

approximately 2 years, 8 months