Effectiveness of exercise-based rehabilitation for the treatment of axial rigidity in people with Parkinson's disease: A Scoping Review

Background: Axial rigidity is a common symptom in people with Parkinson's disease (PD) and is believed to contribute towards mobility problems and leads to an increased risk of falling. To date, effective treatment interventions to improve axial rigidity in PD have yet to be confirmed. Therefore, the aim of this scoping review was to identify and summarize the findings of exercise-based rehabilitation that have been successfully used to reduce axial rigidity in people with PD. Methods and analysis: Fourteen studies from the following databases were identified systematically: Cochrane Library, PEDro, Scopus, Web of Science and PubMed. Articles comparing the effects of exercise-based treatment as an experimental intervention with a non-physiotherapy intervention as the control were described using the synthesis method. Results: Four out of fourteen studies eligible for inclusion focussed explicitly on exercise-based treatment for axial rigidity in people with PD. Two studies suggested beneficial results of exercise in improving axial rigidity as evidenced by: improvement in the Unified Parkinson's Disease Rating Scale (UPDRS), axial rotation range, spinal flexibility and motion of the neck and trunk. Three further studies provided evidence for improvement of functional problems related to axial rigidity. Conclusion: The information about exercise-based rehabilitation for axial rigidity in people with PD is very limited. This review suggests that interventions aimed at reducing axial rigidity yield positive outcomes on functional performance i.e. improve trunk mobility, turning, balance and gait patterns, as well as reducing the risk of falls in people with PD. However, the association between axial rigidity and performance following specific exercise treatments has not been explored. Furthermore, there is still a lack of evidence for the effectiveness of specific home-based exercise programmes on alleviating axial rigidity in people with PD. Therefore, there is a need for well-designed large-scale studies to elucidate these questions.