Among the most striking and interesting characteristics of patients with parkinsonism of any origin are the postural abnormalities. The most typical disorder is a combination of masklike facies, forward flexion of the head and trunk, flexion at the hips and knees, adduction of the arms and flexion of the elbows and fingers. In addition, flexion of the wrist may be present. This posture was named "dissolution of erectness" by one of us in 1924.1 This idea was further developed in 1927,2 and at the same time Brock and Wechsler3 put forward the thesis that this posture occurred because of disease of the paths underlying the righting reflex which enables erectness to be maintained under normal circumstances.
However, this classic dissolution of erectness does not always occur in all details; the exceptions may be divided as follows: (1) fragments of the complete picture of dissolution of erectness
KRAUS WM, SILVERMAN NE. AN ANALYSIS OF ABNORMAL POSTURE OF THE HEAD IN PARKINSONISM OF VARIOUS ORIGINS. Arch NeurPsych. 1928;19(2):301-310. doi:10.1001/archneurpsyc.1928.02210080103006