Freezing of gait (FoG) in Parkinson’s disease (PD) is an incapacitating transient phenomenon, followed by continuous postural disorders. Spinal cord stimulation (SCS) is a promising intervention for FoG in patients with PD, however, its effects on distinct domains of postural control is not well known. The aim of this study is to assess the effects of SCS on FoG and distinct domains of postural control. Four patients with FoG were implanted with SCS systems in the upper thoracic spine. Anticipatory postural adjustment (APA), reactive postural responses, gait and FoG were biomechanically assessed. In general, the results showed that SCS improved FoG and APA. However, SCS failed to improve reactive postural responses. SCS seems to influence cortical motor circuits, involving the supplementary motor area. On the other hand, reactive posture control to external perturbation that mainly relies on neuronal circuitries involving the brainstem and spinal cord, is less influenced by SCS.

The influence of bilateral practice on the modification of well-established lateral asymmetries of performance was investigated in overlearned motor skills related to soccer in 12- to 14-year-old adolescent players. The participants had extensive practice before entering the experiment and were trained 2 hours per day, five times per week, during a period of 4 months. In the training, the participants were assigned to one of two groups: practice with emphasis on the preferred leg (PL), or practice with emphasis on the nonpreferred leg (NpL). Lateral asymmetries of performance were assessed before and after training on three motor tasks: kicking for force, kicking for accuracy, and speed of dribbling. The analysis of the results indicated a consistent asymmetry of performance throughout the tests, favouring the preferred leg. The asymmetry of performance was maintained at a constant level across the tests for the kicking tasks in both experimental groups. For speed of dribbling, however, the index of lateral asymmetry was reduced from the pre- to the post-test in the NpL group only, which was due to a higher rate of improvement with the nonpreferred leg after the experimental training. These results are indicative of the role played by bilateral practice in modifying lateral asymmetries of performance established as a consequence of previous unilateral training.