Final answer:
The sciatic nerve is the most likely nerve to be affected during a buttocks injection, potentially causing sciatica if the injection is improperly administered.
Step-by-step explanation:
The nerve most apt to be affected during an injection in the buttocks is the sciatic nerve. The sciatic nerve is a systemic nerve originating from the sacral plexus, encompassing both the tibial and fibular nerves. It extends across the hip joint, through the gluteal region, and into the upper posterior leg. This nerve is responsible for sensation and movement in the anterior leg, and importantly, it is a branch nerve from the larger sciatic nerve structure. An improperly placed intramuscular injection in the buttocks can lead to a painful condition known as sciatica, characterized by inflammation or compression of the sciatic nerve, resulting in pain, numbness, or weakness in the lower back, buttock, and leg.