The current study is a randomized controlled trail comparing the effectiveness of IASTM and Myofascial Release for individuals with DOMS at cervicothoracic region. The trail aims to evaluate improvements in pain, ROM, and neck disability. Interventions will be delivered twice weekly for a specific duration. The primary outcomes is pain reduction, while the secondary outcomes include improved disability level and ROM. To conclude, IASTM demonstrated a significantly higher improvement compared to MFR in acute cervicothoracic DOMS in terms of pain, disability level, and ROM in all directions tested in adults.

Delayed onset muscle soreness (DOMS) is a physiological condition that develops in the course of time after strenuous unaccustomed physical exertion. In particular, DOMS occurs mostly in response to eccentric muscle actions, i.e., when muscle fibers lengthen while still performing work. Examples of eccentric actions may be, among others, lowering the load (weight training), downhill running, decelerating movements, and controlled return phase of resistance exercise (1). Unlike most types of physiological phenomena, DOMS usually develops after some period of time. Typically, it appears 12-24 hours after the workout and reaches its peak in 24-72 hours; afterwards, it will subside gradually over several days. DOMS is considered a normal adaptation reaction of the muscle. However, despite being physiologically beneficial and helping to adapt skeletal muscles to subsequent exercises through repeated bout phenomenon, DOMS may lead to considerable discomfort and even affect a person's quality of life. As the result of damage of muscle fibers and adjacent connective tissue in response to unaccustomed mechanical load, inflammatory reaction, swelling, and stimulation of pain receptors occurs. These processes are responsible for characteristic soreness associated with DOMS, which may impair individual's ability to perform certain activities and exercise.

The randomization process took place after participants were screened and underwent baseline assessment. Then, those who met the criteria were randomly allocated to Group A and Group B. Those patients in Group A were assigned to receive Instrument Assisted Soft Tissue Mobilization, whereas those participants who belonged to Group B were subjected to Myofascial Release. Random allocation was performed by a computer and carried out through opaque sealed envelopes opened by an independent individual.

Inclusion Criteria:

• Participants aged between 30 and 40 years.
• Individuals presenting with delayed onset muscle soreness (DOMS) in the cervicothoracic region.
• Willingness to participate in either the IASTM or myofascial release intervention protocols.
• Ability to understand and sign the informed consent form.

Exclusion Criteria:

• History of recent cervical or thoracic spine surgery, fractures, or severe trauma in the region.
• Presence of open wounds, active skin infections, or severe dermatological conditions in the cervicothoracic area where interventions will be applied.
• Diagnosed neurological deficits, cervical radiculopathy, or myelopathy.
• Known contraindications to soft tissue mobilization or manual therapy (e.g., severe osteoporosis, bleeding disorders, or anticoagulant use).
• Current use of muscle relaxants, heavy analgesics, or NSAIDs that could mask DOMS symptoms during the study period.

Only IPD used in the results publication will be shared

It will be available after the completion of study.

Through the corresponding author.

The study uses a single masking in which the outcome assessor is blinded to group allocation. Participants will be assigned to either the IASTM group or the Myofascial Release group by an independent researcher who is not involved in the assessment. The assessor responsible for recording baseline and post intervention outcomes ( VAS, NDI, Universal goniometer) will not be informed of the participants intervention group. To maintain blinding, participants will be instructed not to disclose their group assignment during assessments.