A 42-year-old male was presented with complains of a constant dull ache located in the left shoulder girdle and the post

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A 42-year-old male was presented with complains of a constant
dull ache located in the left shoulder girdle and the
postero-lateral side of the neck, associated with sudden difficulty
during overhead activities and heavy lifting. A month ago, he had a
diagnostic lymph node biopsy procedure in the posterior triangle of
the neck. Physical examination revealed winging of his left scapula
and severe atrophy of the left trapezius muscle. He also had an
asymmetrical neckline, drooping of the shoulder girdle and weakness
of his left arm/shoulder elevation.
1. Based on this presentation and history, what nerve you
suspect is most likely being damaged? Justify your answer.
2. What other muscle may be damaged as well? How you can test
its integrity?
3. What other nerves could be damaged in the posterior neck
triangle? How you can test this?