Ulnar Nerve Palsy is paralysis caused by damage, compression or trapping
of the ulnar nerve as it makes its way down the length of the arm. This
occurs due to nerve compression at the elbow (cubital tunnel) or at the
wrist (Guyon's canal). Muscle weakness and atrophy predominate the clinical
The cubital tunnel is in this region commonly referred to as the 'funny
bone', the area where the ulnar nerve crosses the elbow joint. The wrist
is made up of a number of small bones. Two of these bones and their
associated ligaments form a canal that runs through the wrist (Guyon's
canal). As the ulnar nerve crosses the wrist, it passes through this canal
before it branches to supply some of the fingers in the hand.
Hence depending on the area of affection two clinical syndromes exist:
Cubital Tunnel Syndrome
Cubital Tunnel Syndrome occurs when this area becomes irritated.
Bending of the elbow causes the nerve to stretch several
millimetres. Frequent bending of the elbow in activities such as pulling
levers, reaching or lifting causes the nerve to become irritated and
When the nerve is stretched over the elbow the nerve
can sometimes move or actually snap over the medial epicondyle causing
Leaning on the elbow, resting it on an elbow rest
during a long distance drive or running machinery may cause repetitive
pressure and irritation on the nerve.
A direct hit on the cubital tunnel may damage the ulnar
The symptoms of Cubital Tunnel Syndrome primarily involve numbness
and tingling in the ring and little finger and the sides and back of the
hand. These complaints or symptoms worsen when the elbow is bent i.e when
holding a telephone, resting the head on the hand and crossing the arms
over the chest. The hand may become weaker resulting in trouble opening
bottles or jars. The hand may not perform as well as it did before and
there may be a tendency to drop things. Clawing may occur in the ring
and little fingers.
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