Strumpel Phenomena

Strumpel Phenomena. There are 3 phenomena described by Strumpel. 1. The tibial phenomenon, consisting of involuntary dorsal flexion and supination of the foot during active flexion of the leg against resistance in the hip and knee joints; caused by tension of the m. tibialis ant., examined with the patient lying on their back; the patient is made to flex the leg at the hip and knee, while simultaneously preventing this movement by pressing the patient's thigh against the bed. In pronounced cases, this phenomenon occurs already during free active flexion of the leg. 2. The pronation (pronator) phenomenon, consisting of increased pronation of the hand when flexing the forearm, as a result of which the hand approaches the shoulder with its dorsal side during flexion. 3. The radial, or radial phenomenon, consisting of involuntary extension of the hand while simultaneously clenching the fingers into a fist. All three symptoms are observed in lesions of the pyramidal system and represent pathologically enhanced synergistic movements (synkinesias). Like all other synergistic movements that occur in lesions of the pyramidal system, they are particularly pronounced in hemiplegia. Strumpel phenomena represent phenomena of disinhibition of lower subcortical motor apparatuses, caused by the loss of inhibitory influence of higher cortical centers due to interruption of the pyramidal pathways conducting this influence (see Hemiplegia, Pyramidal System).