Investigation of Validity and Reliability of the Minnesota Manual Dexterity Test in Patients with Parkinson's Disease

Parkinson's Disease (PD) is a disease that affects upper extremity functional skills with clinical findings such as bradykinesia, rigidity, and hypokinesia, and causes limitations in patients' daily life activities. The impairment of upper extremity functional skills is related to the deficiency in planning both voluntary and complex movements, as well as the deficiency in multiple motor planning. In particular; fine manual dexterity, reaching, and grasping movements are affected, greatly affecting patients' daily activities. Therefore, upper extremity evaluations are an important issue to consider for training upper extremity motor skills in PD. There are minimal assessment tools for evaluating the upper extremity functions of individuals with PD. The Nine-Hole Peg Test and the Jebsen Hand Function Evaluation Test are the most commonly used scales in the evaluation of the upper extremity in PD, and their validity and reliability have been demonstrated. These scales roughly evaluate both extremities separately. However, these scales are not suitable assessment tools for testing activities in which both extremities are frequently used in daily life. Therefore, there is a need for valid and reliable scales that can evaluate upper extremity activities both in isolation and bilaterally. The Minnesota manual dexterity test (MMDT) allows both hands to be evaluated together. It also evaluates hand-eye coordination and gross motor skills in addition to manual dexterity. MMDT is used in individuals with PD, but there is no study in the literature examining the validity and reliability of the scale. Therefore, this study aims to evaluate the reliability and validity of MMDT in individuals with PD.