Musculoskeletal Ultrasound Imaging: Protocol for Lower Extremities (Knee, Ankle & Foot) DVD was designed for Physicians and sonographers who are involved with the evaluation of lower extremity musculoskeletal pathology. Physician participants may include (but are not limited to) those involved with specialties in: radiology, orthopedics, sports medicine, physical therapy, chiropractics, rheumatology, and emergency medicine.