Evaluation of Differences Between Joint Localizations Determined by Physical Examination and Ultrasound-Confirmed Joint Positions of the Knee, Elbow, Ankle and Wrist

This study is designed as a prospective, cross-sectional, observational comparison of clinical joint localization and ultrasound-confirmed joint positioning. The study will be conducted at Bursa City Hospital and will include volunteer physicians working as residents or specialists in Physical Medicine and Rehabilitation or Orthopedics and Traumatology.

Participants will be asked to localize the joint space of the knee (tibiofemoral), elbow (humeroulnar), ankle (tibiotalar), and wrist (radiocarpal) based on physical examination in standardized positions. Clinically determined joint locations will be marked on the skin using a removable marker.

Following clinical marking, musculoskeletal ultrasound examinations will be performed by an experienced investigator using a high-frequency linear transducer. Ultrasound-confirmed joint positions will be identified according to standardized scanning protocols. The investigator performing the ultrasound assessment will be blinded to the participant's specialty and level of experience.

The primary outcome measure will be the distance, measured in millimeters, between the clinically marked joint location and the ultrasound-confirmed joint position. Secondary analyses will evaluate differences in localization accuracy among different joints and between physicians with different levels of clinical experience.

The study involves no therapeutic or diagnostic intervention and poses minimal risk to participants. All data will be collected anonymously and analyzed at the group level. The results are expected to contribute to a better understanding of the limitations of physical examination-based joint localization and to inform educational strategies incorporating ultrasound in clinical anatomy training.