A 40-year-old woman is evaluated for neck pain that has gradually worsened over the past several months. The patient reports a pulling sensation in her neck that causes difficulty in keeping her head straight. She has had no trauma and has no other medical conditions. Physical examination shows a spastic and thickened sternocleidomastoid muscle causing head tilt. The patient is diagnosed with idiopathic torticollis. She is treated with injections of a bacterial product into the affected muscle, with significant relief of her symptoms.