Final answer:
Proper positioning of the fingers is crucial for evaluating the interphalangeal joints in oblique and lateral projections with interossei muscles assisting in movement at both the metacarpophalangeal and interphalangeal joints.
Step-by-step explanation:
To evaluate the interphalangeal joints in the oblique and lateral projections, the fingers must be positioned properly. The palmar interossei muscles play a role in this process, as they abduct and flex each finger at the metacarpophalangeal joints and extend each finger at the interphalangeal joints.
Meanwhile, the metacarpophalangeal joint is the articulation between the distal end of a metacarpal bone of the hand and a proximal phalanx bone of the finger which is a type of condyloid joint. When examining these joints radiographically careful attention must be given to ensure that each finger is correctly abducted or adducted and flexed or extended to provide a clear view of the joint spaces and bone structures in the desired projection.