The scalenes are a group of three muscles located in the neck: the anterior scalene, middle scalene, and posterior scalene. They play a crucial role in the movement and stability of the neck, helping to flex and rotate the head. Additionally, these muscles assist in elevating the first and second ribs during breathing, contributing to respiratory function. These muscles are innervated by the cervical spinal nerves and are important for maintaining posture. Tightness or strain in the scalenes can lead to discomfort and may affect nearby structures, such as the brachial plexus and subclavian artery, potentially causing pain or numbness in the arms.