The aim of this study is to investigate whether spinal alignment and spinal mobility have an effect on upper extremity functions in Parkinson's patients. In the light of the data obtained as a result, we think that our study will also contribute to determining the factors that may cause upper limb dysfunctions seen in Parkinson's patients and will guide new treatment-oriented studies to be carried out in the future.

Parkinson's disease is a neurodegenerative disease that occurs due to the influence of dopaminergic pathways, causing progressive deficits, especially in motor functions. The four main motor symptoms of Parkinson's are tremor, muscular rigidity, bradykinesia (slowing down of movements) and postural instability.

One of the inadequacies of these symptoms on patients is the disruption of the functions of the upper extremities. Since the formation of isometric force at parkinson disease is delayed, the reaction time is disrupted. In addition, patients exhibit sensory deficits, such as a decrease in the spatial and temporal tactile discrimination thresholds of the fingertips. Since patients tend to have difficulty initiating movement to a goal (akinesia), there are disorders of reaching and grasping it. There is also a lack of coordination between the timing of the movement components. In particular, tremor and rigidity can cause serious deficiencies during targeted activities in which the patient uses their upper limbs in their daily life. Incidence studies conducted to date have shown that Parkinson disease, causes various degrees of impairment in the manual skills of about 90% of individuals. In this context, the fine manipulative skills of the hand and the identification of components affecting the functions of the upper extremities in this group of diseases are important in the detection and management of the problem.

In Parkinson's disease, forward oblique posture, forward tilting of the head and neck, and scoliosis are common spinal deformities. The studies conducted have revealed that these deformities are directly proportional to the severity of the disease. In addition, the rigidity of the global trunk muscles may reduce the spinal mobility of the patients and may affect the independence measures in trunk-dependent activities. In this regard, it is important to analyze the spine sequence and mobility when monitoring patients in this group of diseases. At the same time, postural correction and balance reactions are also reduced due to postural changes, such as the development of flexion posture and reduced body rotation in Parkinson's disease. This condition causes Parkinson's patients to have difficulty maintaining their current posture and an increased risk of falling.

In a study conducted with healthy adults, upper extremity function was evaluated using the 'Jebsen Taylor Hand Function Test' in three different trunk postures (flexion, lateral flexion, neutral posture), and the best upper limb performance was obtained in neutral trunk posture. In another study, it was found that Pisa Syndrome (lateral flexion deformity of the trunk) was associated with both upper extremity functions and the level of independence in activities of daily living in Parkinson's disease. To the best of our group's knowledge, extremity dysfunctions, spinal posture and mobility involvement in Parkinson's disease have been well defined in the studies we have conducted in the literature, but we have not found any study investigating the effects of spinal alignment and spinal mobility on upper extremity functions and quality of life.

The aim of this study, which was planned accordingly, was to investigate: (A) spinal postural changes in Parkinson's disease, (B) changes in upper extremity functions in Parkinson's disease, (C) effects of spinal alignment and spinal mobility on upper extremity functions and quality of life in Parkinson's disease.

Inclusion Criteria:

For Parkinson's Patients;

• Being 18 years or older
• Receiving a diagnosis of Parkinson's made by a specialist neurologist
• Being able to walk independently
• Being between stages 1-4 on the Hoehn & Yahr scale

For the Control Group;

• Being 18 years or older

Exclusion Criteria:

For Parkinson's Patients;

• Having any neurological disease other than Parkinson's
• Presence of cardiovascular, vestibular and musculoskeletal disease
• Having a score of <24 on the Standardized Mini Mental Test

For the Control Group;

• Having any disease that may affect balance, gait, posture and respiratory functions
• Using sedative - antidepressant medication that will impair physical well-being
• Having a score of <24 on the Standardized Mini Mental Test

Healthy individuals with similar age and body mass index values for Parkinson's patients who were diagnosed with Parkinson's disease according to the UK Parkinson's Disease Association Brain Bank criteria, followed in the Health Sciences University Gülhane Training and Research Hospital Neurology Department Parkinson's Polyclinic, and the control group will be included in the study.