The main goal of this study is to evaluate, via EMG (electromyography) system, the muscle activity in the lower limbs, to understand the contribution of the muscle activity to FOG (freezing of gait) in Parkinson's patients. The phenomenon of FOG appears in advanced cases of Parkinson's disease (PD) and can lead to an increased risk of falls. There are several approaches claiming that there is abnormal activity in the calf muscles and the freezing events in Parkinson's patients. In the clinic, monitoring FOG is done subjectively, usually through observations or through questionnaires. As a result, the information about the phenomenon may be biased and insensitive. With an electromyographic monitor (EMG), objective information about the muscular activity during normal walking and during unusual events can be obtained.

The subject will arrive independently at the Tel Aviv Medical Center. After explaining the course of the study and signing a consent form, the subject will be administered the MoCA questionnaire to assess the cognitive state.

During this session, the patient will undergo gait evaluation using motion sensors and an EMG device.

This meeting will last up to an hour, according to the following breakdown:

Explanation of the test (10 min) Preparing the skin (light disinfection with alcohol) for EMG adhesion (10 min.) Performing of the test (20 minutes) Summary and discharge (5 min).

Inclusion criteria for patients:

1. Men and women aged 40-89.
2. Patients with idiopathic Parkinson's disease according to the diagnosis of a neurologist, who are able to walk with or without a walking aid for at least 5 minutes.
3. 21 or above in MoCA test.
4. people who gave their written and oral consent to participate in the study.

Inclusion criteria for healthy people:

1. Men and women aged 40-89.
2. 24 or above in MoCA test.
3. Without a neurological, cardiovascular or orthopedic disorder, which could affect the normal walking pattern, and all within the researcher's decision.

Criteria for exclusion from the experiment:

1. The patient has serious side effects that are not suitable for continuing in the study.
2. The patient does not wish to continue his participation in the study.

Exclusion criteria for Parkinson's patients:

1. Neurological or other psychiatric disorder (such as MSA, PSP, after a stroke with neurological signs, dementia diseases, clinical depression) at the researcher's decision.
2. History of head injury - traumatic brain injury or cerebrovascular accident (CVA)
3. This study will not include pregnant women and children.