Which sensor test can indicate injury to the axillary nerve?

The test that indicates injury to the axillary nerve is the assessment of sensation over the deltoid area. The axillary nerve is primarily responsible for providing motor innervation to the deltoid muscle, which is crucial for arm abduction. Additionally, it supplies sensory innervation to the skin overlying the deltoid muscle.

When assessing a potential axillary nerve injury, checking for sensory loss in the area of the deltoid provides direct evidence of an affected nerve. If the sensation in this region is diminished or absent, it strongly suggests axillary nerve involvement, which can occur in situations like shoulder dislocations or surgical trauma.

In contrast, testing temperature sensation, vibratory sensation, and proprioception are not specific to the axillary nerve. These tests evaluate sensory pathways that can involve other nerves and systems in the body. Therefore, while they are important in a comprehensive neurological examination, they do not pinpoint axillary nerve injury like the sensation over the deltoid does.