A 32-year-old female marathon runner presents to an outpatient clinic complaining of progressive numbness and tingling along the medial aspect of her right forearm and hand, affecting her ring and little fingers. She reports worsening symptoms during long training runs and while sleeping, often waking with her hand "asleep." She recently began incorporating more strenuous upper body workouts into her routine. She denies any acute trauma or neck pain. On examination, she exhibits diminished sensation in the volar and dorsal aspects of the 4th and 5th digits of her right hand. Motor testing reveals 4/5 grip strength on the right, with mild weakness in finger abduction and adduction compared to the left. Phalen's and Tinel's signs are negative at the wrist, but a Tinel's sign at the elbow in the cubital tunnel region elicits tingling in her ring and little fingers. There is no evidence of muscle atrophy or clawing. What is the most likely diagnosis and the appropriate initial non-surgical management strategy?

A 45-year-old woman presents to an outpatient orthopedic clinic for a follow-up visit, three weeks after being discharged from the hospital following a motor vehicle collision. She sustained a mid-shaft humeral fracture and a non-displaced olecranon fracture of her left arm. She reports that while her initial pain has largely subsided, she has recently developed an intermittent "pins and needles" sensation that started about a week ago, primarily affecting her left ring and little fingers. She also notes a subtle difficulty with fine motor tasks, such as buttoning clothes. Her past medical history is unremarkable, and she takes no regular medications. On physical examination, her vital signs are stable: temperature 36.80C, blood pressure 128/78 mmHg, pulse 75/min, and respirations 14/min. Examination of the left upper extremity reveals mild tenderness over the medial epicondyle. There is diminished sensation in the ulnar nerve distribution of the hand, specifically the palmar and dorsal aspects of the little finger and the ulnar half of the ring finger. Subtle atrophy of the first dorsal interosseous muscle is noted, and she demonstrates mild weakness in finger abduction/adduction against resistance. Tinel's sign over the cubital tunnel is positive. Given the patient's delayed neurological findings, what is the most likely diagnosis and the appropriate initial management strategy?