In the Median nerve injury at elbow FDS is gone for all finger means flexion of PIP is gone for all finger but while making fist how little and ring finger flexed but index finger not flexed at pip ?
Fds don’t cause flexion at pip. Its caused by flexor digitorum profundus. In median nerve palsy, fdp of middle finger and index finger are lost so no flexion of pip
Fdp is inserted at base of distal phalynx (flexion at dip)
Fds inserted into base of middle phalynx (flexion at pip)
And nerve supply of fds as a whole is by median nerve
But fdp has dual supply…lat half by median nerve and medial half by ulnar nerve…
So median nerve injury at elbow effects lat 2nd 3rd finger causing pointing index finger.