The scalene muscles are a group of three pairs of muscles located in the neck, known as the anterior, middle, and posterior scalene muscles. They play a crucial role in breathing by elevating the first and second ribs, which helps expand the chest cavity. Additionally, these muscles assist in neck movement, allowing for lateral flexion and rotation. These muscles are innervated by the cervical spinal nerves and are important for maintaining posture and stability in the neck. Tightness or strain in the scalene muscles can lead to discomfort and may contribute to conditions like thoracic outlet syndrome, where nerves or blood vessels are compressed.