A patient is trying to make a fist, but can only paially flex Index and Middle finger. Which nerve is damaged most probably:

Median nerve injury leads to 'Benediction hand deformity', as observed in this patient. Hand of benediction occurs as a result of prolonged compression or injury of the median nerve at the forearm or elbow. Note: The answer can't be Anterior Interosseous Nerve, because in that case, Flexor digitorum superficialis (intact median nerve supply) will be functional and patient can do flexion at the proximal interphalangeal joint.