Abstract Proximal Hamstring Tendinopathy (PHT) provides a challenging diagnosis for clinicians due to limited evidence-based research. Presenting as chronic pain originating at the ischial tuberosity, PHT can progress to entrap the sciatic nerve, resulting in proximal hamstring tendinopathy-related sciatic nerve entrapment (PHTrSNE). This case expands the understanding of PHT by describing the osteopathic assessment and treatment of a runner with PHTrSNE. A 24-year-old female marathoner presented to the neurology clinic with a unique running gait: a left leg circumduction, or “leg whip,” that presented only when running. She also reported constantly dull hamstring pain, which occasionally elicited a sharp, shooting pain from her lower gluteal muscles to mid-hamstrings. Activities such as prolonged sitting and intense running exacerbated the sharp pain. On examination, the patient displayed ischial tuberosity tenderness and positive tests for hamstring tendinopathy. Evaluation with EMG/NCS showed mild chronic denervation of the left tibialis anterior muscle. A treatment plan for the patient’s PHTrSNE was created based on the principles of the neurological model of osteopathic medicine. Patients presenting with chronic hamstring discomfort accompanied by sharp, shooting pain may benefit from the diagnostic and therapeutic approach outlined in this study.