This pilot study evaluates whether passive static stretching can improve hip movement in three groups: people who have had hip replacement surgery, individuals with long-term hip pain, and healthy volunteers. Participants will follow a 4-week stretching program, doing exercises three times per week under the supervision of a trained clinician. Hip range of motion will be measured before and after the program using accurate electronic sensors. The goal is to determine if passive static stretching is a safe and effective way to increase hip flexibility and support daily activities. The study involves no new medications or invasive procedures and is considered low risk.