Validity and Reliability of the Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2) in Adolescents With Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine that emerges during growth and often requires prolonged conservative management. Physiotherapeutic scoliosis-specific exercises (PSSE) are recommended in international guidelines and have demonstrated effectiveness in controlling curve progression and improving functional outcomes. However, adherence to exercise programs remains a major challenge, particularly during adolescence, where motivation plays a critical role in sustaining health-related behaviors.

Exercise motivation is commonly conceptualized within the framework of Self-Determination Theory as a continuum ranging from amotivation to intrinsic motivation. The Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2) is a theory-based, multidimensional instrument designed to assess motivational regulation underlying exercise behavior. While the BREQ-2 has demonstrated strong psychometric properties across different populations, its validity and reliability have not been established in adolescents with idiopathic scoliosis.

This study is designed as a methodological, cross-sectional validation study aiming to evaluate the validity, reliability, and applicability of the Turkish version of the BREQ-2 in adolescents with idiopathic scoliosis. Participants aged 10-19 years who have been receiving scoliosis-specific therapeutic exercise treatment for at least two months will be recruited. Data will be collected using online questionnaires, including the BREQ-2, the motivation subscale of the Questionnaire on Physiotherapeutic Scoliosis-Specific Exercises (QPSSE), and the Exercise Motivations Inventory-2 (EMI-2).

Internal consistency of the BREQ-2 will be assessed using Cronbach's alpha coefficients. Test-retest reliability will be evaluated using the intraclass correlation coefficient (ICC) with a two-week interval between administrations. Criterion-related validity will be examined by analyzing correlations between BREQ-2 scores and scores obtained from the QPSSE motivation subscale and the EMI-2. Statistical analyses will be performed using appropriate correlation methods based on data distribution.

The findings of this study are expected to provide evidence regarding the psychometric adequacy of the BREQ-2 for assessing exercise motivation in adolescents with idiopathic scoliosis. Establishing a valid and reliable motivation assessment tool may contribute to improved evaluation of treatment adherence and support the development of individualized motivational approaches in scoliosis rehabilitation.

Inclusion criteria

• Aged between 10 and 19 years
• Diagnosed with adolescent idiopathic scoliosis
• Receiving scoliosis-specific therapeutic exercise treatment for at least 2 months
• Able to read and write in Turkish
• Volunteered to participate in the study and provided informed consent

Exclusion criteria

• Presence of congenital or neuromuscular scoliosis
• Presence of systemic disease
• Presence of syndromic conditions such as Marfan syndrome or Ehlers-Danlos syndrome