Although respiratory dysfunction has been recognized as a cause of morbidity and mortality in patients with Parkinson's disease (PD), most of the patients were not aware of their respiratory problems due to restriction in their activities.~Respiratory dysfunction in patients with PD has not been well characterized. However, there are many studies showing restrictive or obstructive type respiratory disorders and decreased respiratory muscle strength in the literature. Ineffective cough due to decreased respiratory muscle strength may cause to secretion retention and secondary infections in PD patients who have severe symptoms. Therefore, the assessment and rehabilitation of these respiratory problems is important in PD patients treatment. There are studies in the literature showing that respiratory muscle training is effective in PD.~Walking difficulty is seen as a common problem in PD. Typically, walking is slow despite adequate Levodopa therapy. It is known that exercise capacity may be affected by respiratory impairment, walking difficulties and personal exercise habits in patients with PD. Respiratory and walking problems lead to limitation of physical activity in PD, which leads to a decrease in exercise capacity. In a recently published article reported that walking is a good example of exercise.~Although walking training is important for PD patients, there is no studies what happens to pulmonary function and functional exercise capacity when walking training is combined with respiratory muscle training in patients with Parkinson's disease. Therefore, this study planned to investigate the effects of walking and respiratory muscle training on pulmonary function and functional exercise capacity in PD.
The purpose of this randomised and controlled study is to investigate the effects of walking training combined with respiratory muscle training on pulmonary function, respiratory muscle strength, and functional exercise capacity.