Abstract
Introduction Full range of motion and powerful shoulder abduction can be performed without any
deltoid muscle function by the supplemental action of the supraspinatus and biceps
brachii muscles. For evaluation of deltoid muscle function, we need to negate these
actions, which can be done with the “akimbo test,” in which patients place their hands
on the iliac crest with abduction in the coronal plane and internal rotation of the
shoulder joint while simultaneously flexing the elbow joint and pronating the forearm.
Methods We examined the akimbo test in five patients with incomplete upper-type brachial
plexus injury, five patients with suprascapular nerve palsy, and six patients with
axillary nerve palsy. Presence of some abduction is a prerequisite to perform this
test.
Results No patient with incomplete upper-type brachial plexus injury could demonstrate this
sign when the deltoid did not show a certain level of the power to abduct the shoulder
joint. All patients with suprascapular nerve could demonstrate this sign as the deltoid
was normal. No patient with axillary nerve paralysis could demonstrate this sign.
Conclusion The akimbo test is a simple clinical test to determine deltoid muscle paralysis or
dysfunction, especially when patients can demonstrate shoulder abduction due to supplementary
action of other muscles.
Keywords
axillary nerve paralysis - akimbo test - diagnosis
