Nerve entrapment syndrome, also known as strangulation syndrome, strangulation neuropathy or compression nerve injury, is caused by a segment of peripheral nerve in the anatomical pathway, or a point or points with narrow, tough wall structures, and these structures not only restrict the movement of the segment of peripheral nerve perpendicular to its long axis, but also make the force in this direction to produce mechanical compression of the nerve, thus A specific type of peripheral nerve injury disease is caused. The site of nerve compression in the peripheral nerve anatomical channel is called the anatomical strangulation point or inlay point. Predisposing factors: 1. Long-term labor, such as repeated flexion and extension of the wrist joint, repeated rotation of the forearm, causing the inlay pressure point and the surrounding tissue to proliferate. 2. The number of nerve bundles and the content of adipose tissue within the nerve have a certain relationship with nerve compression. (Sciatic nerve, common peroneal nerve > tibial nerve) 3, injury to the impingement point and adjacent tissues (hemorrhage, edema, tissue fibrosis, ligament thickening, osteophytes, fracture fragment displacement) 4, pathological factors such as metabolic neuritis. 5. superimposed effect of multiple sources of nerve impingement. Pathological changes: 1. early – ischemic edema phase (outer membrane – slow blood – hypoxia – slow nerve impulses = functional paralysis) 2. middle – demyelination phase (continue – myelin edema – thinning – tearing – laminar lysis – vacuole formation) 3. late – Waller degeneration phase (axonal, myelin disintegration – Schwann cell proliferation) 4. common clinical upper limb entrapment syndrome: thoracic outlet syndrome radial canal syndrome radial nerve sensory Interosseous dorsal nerve impingement elbow canal syndrome carpal tunnel syndrome carpal ulnar canal syndrome interosseous palmar nerve impingement