Effects of Different Stimuli on Muscle Activation, Hand Grip Strength, Reaction Time, and Hand Function

Effects of Different Stimuli Applied to the Forearm Flexor Muscles on Muscle Activation, Hand Grip Strength, Reaction Time, and Hand Function

The study will include three separate intervention groups: an ice application group, a vibration application group, and a control group. Accordingly, three groups were randomly generated using the Research Randomizer software.

To determine the group allocation of the participants, individuals will be asked to draw a number from a bag containing numbers, each written only once. The intervention corresponding to the drawn number will be applied to the participant.

All interventions will be administered by the researcher Demet Öztürk, while the outcome measurements will be evaluated by the researchers Seda Baktır Doğan and Mustafa Sarı. The interventions and assessment procedures will be conducted in separate rooms in order to ensure assessor blinding.

Participants included in the study will first complete a Demographic Data Form. This form will record demographic information including age, sex, body weight, height, dominant side, alcohol consumption status, medical history, and family history.

Following the relevant tactile stimulus application, participants' hand grip strength, muscle activation, hand function, and upper extremity reaction time will be assessed.

Cold Application (Ice Therapy):

Ice application will be administered to the forearm flexor muscle group. The application will be performed using a gel pack available in the Physiotherapy and Rehabilitation Laboratory. The gel pack will be kept in a refrigerator for at least 20 minutes prior to application. The pack will be placed between wet towels and applied continuously to the target area for 3 minutes (reference).

Vibration Application:

Vibration therapy will be applied using the Compex Fixx 1.0 device. The device has three different vibration speed levels. In the present study, vibration will be applied to the forearm flexor muscle groups for 3 minutes at the first speed level (1500 RPMs; Power: W / Voltage: 12.0 V / Current: 0.28 A / Sound level: 57-60 dB).

Control Group:

The control group will be planned as a passive control group, and no intervention will be applied. After the initial measurements, participants will rest in the intervention room for 3 minutes (equal to the duration of the other interventions), followed by post-intervention assessments conducted in the assessment room.

Inclusion Criteria:

• Healthy adult individuals aged between 18 and 35 years
• Voluntary participants who have read and signed the informed consent form will be included in the study

Exclusion Criteria:

• Individuals with any systemic, inflammatory, neurological, or degenerative disease affecting the upper extremity
• Individuals with acute inflammation or inflammatory disorders, acute thrombosis, cardiovascular/circulatory diseases, migraine, or epilepsy
• Individuals with a history of trauma or surgery involving the upper extremity within the past year
• Individuals who have started using medications within the last 6 months that may affect the nervous or musculoskeletal systems
• Individuals with implanted metallic foreign bodies in the upper extremity
• Individuals with a pacemaker
• Individuals with circulatory disorders in the upper extremity
• Individuals with any diagnosed sensory impairment
• Individuals with any health condition (e.g., visual or cognitive impairment) that may prevent the proper completion of the assessments