Postural motor learning in Parkinson's disease: The effect of practice on continuous compensatory postural regulation.

Only eleven participants with Parkinson's disease were tested, and they had mild to moderate disease. Only ten Parkinson's participants were included in the retention correlation analysis. The healthy control data had been reported previously and included more training, though only the first six blocks were analysed. The study tested learning over one day of practice and a 24-hour retention test, not a longer-term training programme over weeks and months. All participants with Parkinson's disease took anti-Parkinson medication within two hours before testing. Some trials were omitted because participants stepped: 17/693 trials from the Parkinson's group and 21/1001 trials from controls. Transfer trials changed amplitude but kept the same frequency, so improvement may reflect using a constant frequency cue. The authors state that a short protocol may not reveal altered learning over later stages.

One author has an equity interest in APDM, a company that may have a commercial interest in the results; this was reviewed and managed by OHSU and the Portland VA Medical Center. The other authors reported no conflicts.

Do not read this as proof that a clinical balance training programme will improve Parkinson's disease. It tested eleven people with Parkinson's disease after taking medication within two hours, in a laboratory, over one day with a 24-hour retention test, and only two of eleven reached the less than 2° timing target that seven of eleven controls reached.