Constraint-induced movement therapy.

Kunkel and colleagues 1 recently published an article on constraint-induced (CI) movement therapy for motor recovery in chronic stroke patients. They presented the results of an uncontrolled series of 5 stroke patients undergoing CI therapy. The authors also presented a review of five studies, including their own, concerning the effectiveness of CI therapy based on a calculation of effect sizes. We have several concerns with this paper. In our opinion, research in physical medicine and rehabilitation has progressed to a point at which patient series no longer make any substantial contribution to the accumulation of knowledge. Controlled studies, preferably randomized, are needed to determine the effectiveness of treatment modalities. Uncontrolled studies can be misleading and will almost always report grossly overestimated treatment effects.2 The importance of a control group, when evaluating CI therapy, is emphasized by the interim conclusions of a controlled study carried out by Wittenberg and colleagues, 3 who found that patients who received standard therapy also showed improvement, possibly due to expectation bias. The results of a randomized clinical trial conducted at our hospital, which will be published shortly, confirm this. 4 In their literature review, Kunkel and colleagues claim to have identified two controlled studies. However, the publication on one of these studies mentions a control group of 15 patients, but provides no data concerning improvement in either the experimental or the control group) Therefore, we were puzzled by the fact that Kunkel presented data on the experimental group of 20 patients in this study, but no data on the control group. Finally, we strongly disagree with the interpretation of effect sizes based on trends over time in uncontrolled series as important evidence in favor of CI movement therapy. In fact, when using within-group time trends to calculate effect sizes, all the methodologic advantages of having a control group are ignored. We conclude that Kunkel failed to demonstrate that CI therapy is efficacious for chronic stroke patients.