We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.
Brachial Plexus/*anatomy & histology ; Cervical Plexus/anatomy & histology ; Female ; Humans ; Male ; Thoracic Nerves/*anatomy & histology

We experienced a rare case of winged scapula that was caused by the rupture of the rhomboideus major and the lower trapezius muscles without any nerve injury in a 12 yr old female after she had carried a heavy backpack. Electrodiagnostic study revealed that the onset latencies, amplitudes and conduction velocities were normal in the long thoracic nerve, the spinal accessory nerve and the dorsal scapular nerve. The needle EMG findings were normal as well. An explorative operation was performed and the rupture of the rhomboideus major and lower trapezius muscles was detected. Direct surgical repair of the ruptured muscle was carried out and the deformity was corrected. The anatomical and functional restoration was satisfactorily accomplished.
Weight Lifting/injuries ; Thoracic Nerves/*injuries ; Scapula/anatomy & histology/*physiopathology ; Rupture ; Neurons/metabolism ; Muscle, Skeletal/*injuries/innervation/*pathology ; Humans ; Female ; Electromyography/*methods ; Child