The aim of this study is to develop a scale to assess the manual therapy application behaviors of physiotherapists in Türkiye, based on the Theory of Planned Behavior (Ajzen, 1991). A literature-based item pool will be created, and expert opinion (Delphi method) will be obtained to ensure content validity. The final scale will be administered online to physiotherapists, and construct validity and reliability analyses will be conducted. The study aims to contribute scientifically to the determination of manual therapy application behaviors in physiotherapy practices, the understanding of clinical decision-making processes, and the measurement of behavioral intention. No risks were anticipated for the participants, and data collection was voluntary.

Manual therapy is an evidence-based intervention method based on manual techniques widely used by physiotherapists in the treatment of musculoskeletal disorders. However, clinicians' decisions to implement manual therapy are influenced by multidimensional factors such as personal attitudes, professional beliefs, institutional policies, educational experiences, and the culture of clinical practice. The use of behavior-based theoretical models is recommended to evaluate these factors together.

The Theory of Planned Behavior (Ajzen, 1991) is a powerful approach that explains individuals' intentions to perform a specific behavior through variables such as attitude, subjective norm, perceived behavioral control, and intention. Although this theory is frequently used to understand the clinical decision-making processes of healthcare professionals, there is no valid and reliable measurement tool in Turkey for measuring behavior toward manual therapy practices.

This study will develop a new scale adapted to Turkish culture to assess physiotherapists' manual therapy practices in a theoretically based manner. The research will consist of three phases:

Item Development Phase:

The item pool generated through the literature review will be presented to expert physiotherapists.

Expert Panel/Delphi Phase:

Experts will evaluate the items based on content validity, and items will be revised or removed based on consensus. In this phase, the Content Validity Index (CVI) and Content Validity Ratio (CVR) will be evaluated.

Statistical Analysis Phase:

The final scale will be administered online to physical therapists.

Inclusion Criteria:

• Be actively working as a physiotherapist in Turkey (public/private hospital, university hospital, private clinic, etc.)
• Have received basic training in manual therapy or have clinical practice experience
• Be a healthy adult aged 22 or over
• Be able to read and understand Turkish (the survey language is Turkish)
• Agree to participate in the study voluntarily and provide individual informed consent

Exclusion Criteria:

• Professionals working in healthcare fields other than physiotherapy
• Physiotherapists without manual therapy experience
• Participants who complete the survey form incompletely, incorrectly, inconsistently, or provide duplicate entries
• Individuals who refuse to provide informed consent
• Individuals who withdraw their voluntary consent during the research process

The study population for this study consists of healthy adult physiotherapists actively working in public or private healthcare institutions or university hospitals in Turkey. Participants are expected to have basic training in manual therapy or clinical practice experience. Data collection will be conducted online, and participation is entirely voluntary. No medical interventions will be administered; data will be collected solely through a self-report questionnaire.

Because data is collected entirely on a voluntary basis, protecting participant privacy is a priority. Therefore, there are no plans to share Individual Participant Data (IPD) with third parties.