Background: The course of Parkinson's disease is characterized by gait disturbance and falls, which affect patients' quality of life and engender high healthcare costs. These factors are not greatly improved by levodopa therapy or deep brain stimulation of the subthalamic nuclei. Indeed, the symptoms may even worsen with these treatment. Physiotherapy may be the most appropriate treatment to reduce the incidence of falls in these cases; how ever,itsbenefitsaremodest. Objective: To assess the effectiveness of trunk muscle strengthening in 10 patients with Parkinson's disease being treated with deep brain stimulation of the subthalamic nuclei who are affected by gait disturbances and falls. Method: A standardized physiotherapy programme centred on trunk muscle strengthening was conducted. Its effectiveness was assessed using a clinical approach combined with video-based motion analysis. Results: After 4 weeks of trunk muscle strengthening , the gait item on the Unified Parkinson's Disease Rating Scale (UPDRS, part 3) together with several gait kinematic parameters (step length, walkingcycledurationvariability,gaitspeed)were significantlyimprovedandthenumberoffallsde-creased. Conclusion:Thesepreliminaryfindingssuggestthat physiotherapy centred on rachis mobility improves the quality of gait and reduces the number of falls in patients with Parkinson's disease who are being treated with deep brain stimulation of the subtha-lamic nuclei. This is a potentially useful supplement to the traditional physiotherapy approach, in addition to the pharmacological and surgical treatment of Parkinson's disease.