Which sampling technique would be most appropriate to use when conducting a research study to investigate the effectiveness of a new pain management intervention for patients with lumbar radiculopathy like mrs. pasig ?

A 45-year-old female patient named Mrs. Pasig presents with complaints of persistent lower back pain that radiates down her left leg. She describes the pain as sharp and shooting, worsening with movement and prolonged sitting. Mrs. Pasig works as a nurse and mentions that her symptoms have been affecting her ability to perform her duties effectively.