Upper Extremity Skills, Trunk Control, and Body Awareness in Parkinson's Disease

Primary outcomes

1. Manual Dexterity Measured by Purdue Pegboard Test

   Time frame: Baseline

   The Purdue Pegboard Test is used to measure gross movements of the hands, fingers and arms, as well as fingertip dexterity. The assessment includes four subtests: preferred hand, non-preferred hand, both hands, and assembly. For the first three subtests, the score is the number of pins placed within a 30 second time limit (higher numbers indicate better dexterity). For the assembly subtest, the score is the number of parts assembled in 60 seconds (higher numbers indicate better dexterity).

2. Hand Grip Strength Measured by Hand Dynamometer

   Time frame: Baseline

   Hand grip strength of both dominant and non-dominant hands is measured using a standart digital hand dynamometer. Participants perform maximum isometric contractions in a seated position. Measurement is recorded in kilograms (kg). The average value of three trials is used. Higher scores indicate greater hand grip strength.

3. Pinch Strength Measured by Pinch Gauge

   Time frame: Baseline

   Pinch strength is evaluated using a standard mechanical or digital pinch gauge (pinchmeter) to assess lateral (key) pinch strength and palmar (tip-to-tip) pinch strength for both dominant and non-dominant hands. Participants perform maximum isometric contractions. Measurement is recorded in kilograms (kg) or pounds (lbs). Higher scores indicate greater pinch strength.

4. Reaction Time Measured by Light Trainer System

   Time frame: Baseline

   Visual and auditory reaction times are assessed using an electronic light trainer system. The system measures the latency between the presentation of a light stimulus and the participant's physical response (hitting or pressing the light target)while tracking the total number of successfully touched targets. The time score is recorded in milliseconds (ms). Lower time scores and higher hit counts indicate faster reaction time and better overall performance.

5. Reaction Time Measured by Ruler Drop Test

   Time frame: Baseline

   The ruler drop test is used to evaluate clinical reaction time based on free-fall distance. A standard metric ruler is suspended and dropped without warning, and the participant catches it as quickly as possible. The distance fallen is measured in centimeters (cm) using a standard formula. Lower distances indicate faster reaction time.

6. Motor Speed and Coordination Measured by Finger Tapping Test

   Time frame: Baseline

   The Finger Tapping Test is used to assess motor speed, coordination, and bradykinesia in the upper extremities. Participants are asked to tap their index finger against their thumb as rapidly and fully as possible within a specified time frame (typically 60 seconds) or for a set number of repetitions. The score is recorded as the total number of correct taps achieved within the time limit. Higher numbers of taps indicate faster motor speed and better neurological function.

7. Trunk Control Measured by Trunk Impairment Scale

   Time frame: Baseline

   The TIS evaluates motor impairment of the trunk through three subscales: static sitting balance, dynamic sitting balance, and coordination. Total scores range from 0 to 23. Higher scores indicate better trunk control and balance.

8. Body Awareness Measured by Body Awareness Questionnaire (BAQ)

   Time frame: Baseline

   The BAQ is a self-report scale designed to assess non-clinically invert-focused body awareness, such as sensitivity to normal bodily processes and changes. It consists of 18 items scored on a 7-point Likert scale (1 = not at all true of me, 7 = very true of me). Total scores range from 18 to 126. Higher scores indicate a higher level of subjective body awareness.

9. Upper Extremity Disability Measured by Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire

   Time frame: Baseline

   The DASH questionnaire is a 30-item self-report questionnaire designed to measure physical function and symptoms in patients with musculoskeletal disorders of the upper limb. Items are scored on a 5-point Likert scale. The responses are used to calculate a scale score ranging from 0 (no disability) to 100 (most severe disability). Lower scores indicate better upper extremity function and less disability.