Swelling and hardening of the neck muscles is a clinical condition caused by myositis ossificans disease. Myositis ossificans is a disease of muscle sclerosis, toe and bunion deformities caused by the deposition of progressive bony structures in the muscles and connective tissue. The etiology is unclear. It is partly autosomal dominant. It is common in children or young adults. It presents with a deformed congenital oblique neck, torsion, and swelling and stiffening of the neck muscles, but most are not associated with pain. The whole body muscles can be involved. Strenuous exercise or trauma can cause muscle rupture, hemorrhage and hematoma formation, which in most patients is resorbed, but can be followed by muscle stiffness and ossification, eventually leading to stiffness and disability of the corresponding joint of the affected muscle. Etiology of swelling and stiffening of neck muscles: Swelling and stiffening of neck muscles is a disease of muscle sclerosis, toe and bunion deformity caused by the deposition of progressive bony structures in the muscles and connective tissues. The etiology is unclear. A part of it is autosomal dominant. It has been reported that there are four factors that produce ossification: 1. Irritation factors: often contusions account for 60% to 70% and can lead to hematomas. This injury can be very mild, only a small amount of skeletal muscle or myogenic fibers are damaged. 2, injury signal: injury tissue or cells secrete a signal protein. 3, the presence of mesenchymal cells with defective gene expression: these cells can generate bone-like or cartilage-like cells after receiving the appropriate signal. 4, the existence of continuous occurrence of ossified tissue environment: where the signaling gene is the most critical, Urist named the gene as BMP.