Row-a-boat phenomenon - Respiratory compensation in advanced Duchenne muscular dystrophy

Background: "Row-a-boat" phenomenon (RBP) is a spontaneous upper-body movement in patients with advanced Duchenne muscular dystrophy (DMD), when sitting upright supported by a belt around the body in a wheelchair. However, the role of REP has not been clarified. Objectives: To support the hypothesis that REP is an abnormal pattern of respiration to compensate for the atrophied respiratory muscles in advanced DMD. Patients and methods: Age, degree of ventilator dependency, and blood gas and spirometry values of 12 patients with spontaneous REP were compared to those of 8 patients without REP. Ah patients were men, and all exhibited a comparable level of motor function (unable to ambulate). Spirometry was undertaken with an ambulatory pneumotachograph in six patients with REP in two conditions: sitting with REP and sitting without REP. In the latter condition, because a patient's shoulders, neck, and head were manually restricted, REP was prevented. Results: We found that the patients with REP were older (mean, 25.98 years vs 19.84 years), more dependent on mechanical ventilation (13.96 h/d vs 4.31 h/d), and had lower FVC and percentage of FVC (511.3 mt vs 762.5 mt and 13.37% vs 20.11%, respectively) than those without REP. We also found that the frequency of REP was identical with tidal breathing, and FVC was increased by 50.8% by simply allowing REP. Conclusion: We conclude that RBP is a respiratory movement to compensate for the atrophied respiratory muscles in advanced DMD.