Camptocormia, or "bent spine syndrome", was first described as a psychiatric phenomenon in men facing armed conflict (a "war neurosis"). It has subsequently been realized that reducible lumbar kyphosis may also result from neurological disorders, including muscle disease (paravertebral myopathy, nemaline myopathy), Parkinson’s disease, dystonia, motor neurone disease, and, possibly, as a paraneoplastic phenomenon. Cases with associated lenticular (putaminal) lesions have also been described. Camptocormia may be related in some instances to dropped head syndrome.
Djaldetti R, Mosberg-Galili R, Sroka H, Merims D, Melamed E. Camptocormia (bent spine) in patients with Parkinson’s disease: characterization and possible pathogenesis of an unusual phenomenon. Movement Disorders 1999; 14: 443-447
Oerlemans WGH, de Visser M. Dropped head syndrome and bent spine syndrome: two separate entities or different manifestations of axial myopathy? Journal of Neurology, Neurosurgery and Psychiatry1998; 65: 258-259