Presence of an ape hand deformity when the hand is at rest, due to an hyperextension of index finger and thumb, and an adducted thumb
Presence of benediction sign when attempting to form a fist, due to loss of flexion of radial half of digits
Sensory deficit: Loss of sensation in lateral 3+1⁄2 digits including their nail beds, and the thenar areaAt the elbow

Entrapment at the level of the elbow or the proximal forearm could be due to the pronator teres syndrome.Within the proximal forearm: Anterior interosseous syndrome

Injury to the anterior interosseous branch in the forearm causes the anterior interosseous syndrome
Common mechanisms: Tight cast, forearm bone fracture
Motor deficit: Loss of pronation of forearm, loss of flexion of radial half of digits and thumb
Sensory deficit: NoneAt the wrist

Common mechanism: Wrist laceration
Motor deficit:
Weakness in flexion of radial half of digits and thumb, loss of abduction and opposition of thumb
Presence of an ape hand deformity when the hand is at rest may be likely, due to an hyperextension of index finger and thumb, and an adducted thumb. Nevertheless, an ape hand deformity is not a requirement for a carpal tunnel syndrome diagnosis.
A cervical rib in humans is an extra rib which arises from the seventh cervical vertebra. Their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.2% to 0.5% (1 in 200 to 500) of the population. People may have a cervical rib on the right, left or both sides.Most cases of cervical ribs are not clinically relevant and do not have symptoms; cervical ribs are generally discovered incidentally, most often during x-rays and CT scans. However, they vary widely in size and shape, and in rare cases, they may cause problems such as contributing to thoracic outlet syndrome, because of pressure on the nerves that may be caused by the presence of the rib.A cervical rib represents a persistent ossification of the C7 lateral costal element. During early development, this ossified costal element typically becomes re-absorbed. Failure of this process results in a variably elongated transverse process or complete rib that can be anteriorly fused with the T1 first rib below. Diagnosis
On imaging, cervical ribs can be distinguished because their transverse processes are directed inferolaterally, whereas those of the adjacent thoracic spine are directed anterolaterally. Associated conditions
The presence of a cervical rib can cause a form of thoracic outlet syndrome due to compression of the lower trunk of the brachial plexus or subclavian artery. These structures become encroached upon by the cervical rib and scalene muscles.