[Mental practice has influence on limitation of motion and muscle atrophy following immobilisation of the radiocarpal joint - a prospective randomised experimental study].

Purpose: Distal radial fracture is the most common bony injury in man. Still there are unsatisfying treatment results, such as limited joint movement, muscle atrophy and pain, resulting from immobilisation while the fracture is healing. During this period, also joint movement seems to be "forgotten". This study experimentally examined if the method of mental practice, meaning the systematic repetition of a consciously imagined movement or action without simultaneous practical execution, can positively influence these findings.

Materials And Methods: 21 right-handed males had application of a circular forearm plaster for immobilisation of their left radiocarpal joint, simulating a distal radial fracture for three weeks. Following randomisation, half of the study participants learned mental practice for "virtual movement" of their radiocarpal joint and had to perform it, the others were not treated at all. At beginning and end of the experiment, joint movement was measured, and an MRI examination of the forearm muscles was performed. The brain (cortex) areas, responsible for radiocarpal joint movement, were examined concerning their activity with functional MRI at the beginning and also at the end of the three weeks. The experiment was also performed on three "real" patients suffering from a distal radial fracture demanding plaster immobilisation, all of them were mentally treated.

Results: Mental practice significantly ameliorated dorsal extension and ulnar abduction after plaster removal in comparison to those not having been mentally trained. Muscle atrophy of forearm muscles, measured via MRI, was significantly less in those having mental training. The cortex areas responsible for radiocarpal joint movements (supplementary motor area, precentral gyrus, putamen, nucleus caudatus, prefrontal cortex, thalamus and cerebellum) showed significant signal changes at the end of the three weeks in those having been mentally trained. There were significant correlations between MRI and functional MRI findings. The findings in the three "real" patients were similiar.

Conclusions: The results of this experimental study show that mental practice can have a positive influence on the outcome of distal radial fractures demanding immobilisation. A study with a larger number of "real patients" should follow.