This study is a prospective, single-blind, randomized controlled trial designed to investigate the effects of whole-body vibration (WBV) exercise on balance, mobility, fall risk, and proprioception in patients with Parkinson's disease.

A total of 68 patients diagnosed with Parkinson's disease, aged between 50 and 75 years, will be recruited from the outpatient clinic of the Department of Physical Medicine and Rehabilitation at Istanbul University, Istanbul Faculty of Medicine. Eligible participants will be clinically stable (no medication changes within the last 3 months), classified as Hoehn and Yahr stage 1-3, and MDS-UPDRS stage 2-3. Written informed consent will be obtained from all participants before enrollment.

Participants will be randomly assigned in a 1:1 ratio to either the intervention group (n=34) or the control group (n=34). Randomization will be performed using a computer-generated random allocation sequence. Outcome assessments will be conducted by a blinded assessor.

The intervention group will receive whole-body vibration (WBV) training in addition to a standardized home exercise program. WBV sessions will be performed using the Power Plate pro5 vibration platform (Performance Health Systems, LLC, Northbrook, IL, USA). Training will be conducted three times per week for 8 weeks (24 sessions total). Each session will include 5 sets of vibration exposure, consisting of 1 minute of vibration followed by 1 minute of rest. Exercises will be performed in semi-squat and lunge positions. Vibration parameters will be set at 6 Hz frequency with 2-4 mm amplitude. Sessions will be scheduled during the "on" phase of dopaminergic medication. Each session will include a 10-minute warm-up and a 5-minute cool-down period.

The control group will perform only the standardized home exercise program. Both groups will receive initial in-clinic instruction for the home exercise program, which includes posture exercises, breathing and relaxation exercises, lower extremity active range-of-motion exercises, stretching, quadriceps strengthening, terminal knee extension exercises, rhythmic gait training, and balance/coordination/proprioceptive exercises. Home exercises will be performed three times per week for 8 weeks, lasting 30-45 minutes per session. Participants will be contacted weekly to monitor adherence.

Outcome assessments will be conducted at baseline, at 8 weeks (post-intervention), and at 16 weeks (follow-up).

The primary outcome measure is the Berg Balance Scale (BBS).

Secondary outcome measures include:

• Timed Up and Go (TUG) test
• Six-Minute Walk Test (6MWT)
• Fall Risk Index measured by computerized static posturography (TETRAX®)
• Knee joint position sense measured using an isokinetic dynamometer (Biodex System 3 Pro), calculated as absolute angular error

The primary analysis will evaluate changes in BBS scores between groups across time points using repeated measures analysis of variance. Secondary outcomes will be analyzed using similar statistical methods. Statistical significance will be set at p < 0.05.

The study aims to determine whether WBV combined with a home exercise program provides superior improvements in balance, mobility, fall risk, and proprioception compared with a home exercise program alone in individuals with Parkinson's disease.

Inclusion Criteria:

• • Age between 50 and 75 years

  • Clinical diagnosis of Parkinson's disease
  • Hoehn and Yahr stage 1-3
  • MDS-UPDRS stage 2-3
  • Clinically stable (no change in antiparkinsonian medication or treatment plan within the last 3 months)
  • Ability to stand independently and participate in exercise sessions
  • Provided written informed consent

Exclusion Criteria:

• • Participation in an inpatient or outpatient rehabilitation program within the last 3 months

  • Diagnosis of dementia or significant cognitive/communication impairment
  • Contraindications to whole-body vibration (e.g., severe peripheral neuropathy affecting vibration perception, epilepsy, pregnancy, metal implants or joint prostheses in the lower extremities, cardiac or brain pacemaker, uncontrolled hypertension, history of acute thrombosis)
  • Presence of additional neurological disorders affecting balance or neuromuscular performance
  • Functional Ambulation Classification (FAC) level 0-2
  • Musculoskeletal conditions preventing safe standing on the vibration platform (e.g., fracture, ulcer, acute injury)