While Unloading the Trunk of Her Car, Amy Pulls a Muscle

Essay

While unloading the trunk of her car, Amy pulls a muscle. As a result, she has difficulty moving her arm. The attending physician in the emergency room tells her that she injured her latissimus dorsi muscle. Knowing that the latissimus dorsi was a back muscle, Amy doesn't understand what the muscle has to do with her injured arm. Explain the involvement of the muscle in Amy's injury.