This study will be conducted between May and August 2026 at Aydın Adnan Menderes University, Faculty of Health Sciences, with male individuals aged 18-35. For the study, cases will first be divided into 3 groups by computer-assisted randomization.The first group will be the Flex-i bar group, the second group will be the Theraband Flex bar group, and the third group will be the Sham bar group. Group 1 will perform the exercises with the Flex-i bar, while Group 2 will perform them with the Theraband Flex bar. The control group will perform the exercises with a rolling pin.After group assignment of cases is completed, demographic information such as age, height and weight of the participants will be recorded. Then, pre-exercise assessments of the participants will be conducted. The assessment will include proprioception, reaction time, power and upper extremity performance. Following the initial assessment, each group will perform their exercises with their own exercise material. Measurements will be repeated after the exercises. Measurements will be taken three times during the assessments and the best result will be recorded.

This study will be conducted between May and August 2026 at Aydın Adnan Menderes University, Faculty of Health Sciences, with male individuals aged 18-35. For the study, cases will first be divided into 3 groups by computer-assisted randomization.The first group will be the Flex-i bar group, the second group will be the Theraband Flex bar group, and the third group will be the Sham bar group. Group 1 will perform the exercises with the Flex-i bar, while Group 2 will perform them with the Theraband Flex bar. The control group will perform the exercises with a rolling pin.After group assignment of cases is completed, demographic information such as age, height and weight of the participants will be recorded. Then, pre-exercise assessments of the participants will be conducted. The assessment will include proprioception, reaction time, power and upper extremity performance. Following the initial assessment, each group will perform their exercises with their own exercise material. Measurements will be repeated after the exercises. Measurements will be taken three times during the assessments and the best result will be recorded.

Proprioception Measurement (Joint Position Sense): Before starting the test, the content of the test will be explained in detail and a trial will be conducted. For the test, the participant will first be asked to sit in a chair with back support. Then their eyes will be covered with an eye mask. A digital inclinometer will be placed on their wrist with Velcro (Baseline 12-1057 digital inclinometer). The researcher will show the participant the desired degree of movement, and the participant will be asked to do this themselves. Then the test phase will begin, and the individual will be asked to actively reach the target angle. The amount of deviation of the angle reached by the individual will be recorded. This process will be repeated 3 times, and the best value will be used as the analysis value.

Measurement of Reaction Time: The time it takes for a person to give a motor response (e.g., pressing a button, reaching for a light) upon perceiving a visual stimulus will be measured in milliseconds (ms). Simple reaction time tests are performed using complex technical equipment such as infrared lasers, step panels, and motion-based approach models. Portable, wireless light devices such as Blazepod, FitLight Trainer, and Reflexlight are among the current equipment used for reaction time. In this study, the Blazepod reaction time meter will be used. The participant will touch the button on one of four illuminated devices placed on a table, according to the visual stimulus, and turn off the light. The duration of the person pressing the button will be automatically detected by the device and the duration will be recorded.

Upper Extremity Performance Measurement: The Upper Quarter Y Balance Test will be used for performance measurement.

The person assumes a plank position (hands on the ground, feet behind). The supporting arm remains stationary, and the arm being tested is extended in 3 different directions: Medial (inward), superolateral (opposite), and inferolateral (outer diagonal backward).

In each extension, the maximum distance that can be reached with the test arm is measured (cm). 3 repetitions are performed for each direction. The furthest distance (maximum reach) is recorded. The distance reached is normalized according to the upper extremity length.

Power Measurement: Seated Medicine Ball Throw (SMBT); is the most commonly used test. It is used to measure the explosive power of the upper body and arm muscles. The participant sits upright against a wall. They throw a 2-3 kg medicine ball forward from chest height with maximum force. The distance reached is measured (the point of initial contact with the ball). The furthest distance (cm) is recorded.

The Flexi bar is an exercise tool designed by German physiotherapists. It weighs 719 grams and is 1520 mm long. It has a rubber handle in the middle (17.9 cm) and consists of a flexible fiberglass pole with rubber weights at both ends. Due to its elastomer properties and rubber structure, the Flexi-bar is designed to resonate at a frequency of 5 Hz when moving forcefully within the range of motion that needs to be maintained while maintaining physical stability. The desired force to be created in the bar, pulling, and control changes that cause changes in the body or living beings. The working principle is to cause the rubber handle to vibrate at 5 Hz by swinging the bar, and then this vibration is transmitted to the whole body through the arm that is held. For the flex-i bar exercise, the participant will be in a standing position. The movements in different angles and positions will be shown to the participant. Then the flexibar will be given to the participant and they will be asked to hold the exercise bar and swing it correctly in accordance with the desired movements. In flexibar exercises, a 1-minute rest period will be given after each exercise to prevent possible fatigue.

Theraband-Flex Bar is a flexible, durable, and economical exercise equipment made of natural rubber, 30.5 cm long. Its textured surface makes it easy to perform movements and grip. It is available in four colors: Yellow, Red, Green, and Blue. The difficulty levels of the FlexBar vary according to their diameters and colors. It is preferred for increasing grip strength, strengthening the upper extremities, hands, and feet through bending or swinging movements, and effectively providing soft tissue movements. Blue will be preferred for the exercise, and a 1-minute rest period will be given after each exercise.

Rolling pin; a standard size (100cm) rolling pin will be preferred in the control group. 1-minute rest period will be given after each exercise.

Exercises Each exercise will be performed for 30 seconds, followed by a 1-minute rest period.

1. Swing from side to side with elbow straight
2. Swing forward and backward with elbow straight
3. Swing from side to side with elbow bent
4. Swing forward and backward with elbow bent
5. Swinging the arm outwards with the elbow straight to the right and left.
6. Swinging the arm outwards with the elbow straight to the forward and backward.
7. Swinging the shoulder externally to the right and left.
8. Swinging the shoulder externally to the forward and backward.

Inclusion Criteria:

• Aged between 18 and 35 years
• Healthy individuals
• No history of upper extremity injury
• No neurological disorders
• Voluntary participation

Exclusion Criteria:

• Presence of any neurological disease
• History of upper extremity surgery
• Current musculoskeletal pain or injury
• Any condition affecting proprioception or reaction time
• Inability to comply with study procedures

male and healthy person

Study results will be shared

From May 2026-August 2026