The 4 main motor symptoms seen in Parkinson's patients are tremor, rigidity, postural instability and bradykinesia. In addition to these, another common symptom investigators encounter is balance problems. Increasing balance problems can lead to falls and fractures over time, which will further reduce the independence of Parkinson's patients who are not already active enough and reduce their quality of life. For these reasons, it is very important that balance is achieved and sustainable. It has been found in previous studies that spinal posture and body position sensation are affected in Parkinson's patients. But to our knowledge, no study has been found in the literature to address the effect these have had on balance function. In our planned study, investigators aim to investigate the effects of spinal posture and body position sensation on balance function.

Resting tremor, muscular rigidity, bradykinesia (slowing of movements) and postural instability in Parkinson's patients constitute the 4 main motor symptoms of Parkinson's. In addition, he has been in various studies where posture is affected in Parkinson's disease and proprioceptive sensory loss is seen. These symptoms reduce the quality of life of patients and can also cause loss of balance. It is very important to maintain balance due to problems such as loss of balance in Parkinson's patients leading to falls and the resulting fractures. Determining the factors that may cause falls in Parkinson's patients is important because of its guidance in terms of preventive approaches and treatment options to be developed afterwards. In our research in literature, no study has been found in Parkinson's exploring the effects of spinal proprioceptive sensory loss and spinal posture on balance function. With this work planned accordingly:

(A) Loss of spinal proprioceptive sensation in Parkinson's, (B) Changes in spinal posture in Parkinson's and (C) It was intended to investigate the effects of spinal proprioceptive sensory loss and spinal postural changes on balance function in Parkinson's patients.

Inclusion Criteria For Parkinson's patients:

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

Inclusion Criteria For Healthy Volunteers :

-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

Exclusion Criteria For Healthy Volunteers :

• 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. After the participants are informed about the study, a signed informed consent form will be obtained.