This project aims to investigate the effects of different hyperextension braces (Jewett and Spinomed) on spinal mobility and posture. Hyperextension braces are commonly prescribed to limit spinal flexion and regulate load distribution, especially in cases of spinal injuries and postural disorders. However, their objective impact on spinal biomechanics remains unclear.

Purpose and Scope The study will be conducted on 30 healthy participants aged 18-35.

Spinal mobility, posture, and movement analysis will be assessed using a dual inclinometer and the PostureScreen mobile application.

Evaluations will be performed under three conditions:

• Without a brace
• With a Jewett brace
• With a Spinomed brace (applied in randomized order)

Assessments will include four-direction spinal mobility and postural analysis during daily life activities such as standing, squatting, and single-leg stance.

Hypotheses H0: Hyperextension braces do not restrict spinal mobility. H1: Hyperextension braces restrict spinal mobility. H2: Hyperextension braces do not alter body alignment during movements. H3: Hyperextension braces alter body alignment during movements.

Methodology

The study is designed as a cross-sectional trial.

Each measurement will be repeated three times. Data will be analyzed statistically using ANOVA or Kruskal-Wallis tests depending on distribution.

Ethical approval has been obtained (Yalova University, Protocol No: 2024/4).

Expected Contributions Academic: Results are expected to be presented at the Congress of the International Society of Biomechanics (2025) and published in a high-impact Q1 journal such as Spine.

Clinical: Findings will provide objective data on the effectiveness of hyperextension braces, guiding clinicians and physiotherapists in brace selection.

Educational: The project will also contribute to the training of young researchers, offering hands-on experience in research design and execution

Inclusion Criteria:

• Healthy young adults aged 18-35.
• Body mass index (BMI) between 18.5 and 24.9 kg/m2

Exclusion Criteria:

• Having experienced pain, discomfort, or discomfort in the upper back, waist, or lower extremities in the last 4 weeks on the Nordic Musculoskeletal System Questionnaire.
• A score above 20 on the Oswestry Disability Questionnaire.
• Having a condition related to spinal malalignment identified by a specialist physician (such as scoliosis, hyperkyphosis, hypokyphosis, Schuerman's kyphosis).
• Having a history of congenital hip dislocation.
• Having had surgery on the lower extremities or spine.
• Having a neurological disease or medication use that could cause balance loss.
• Having engaged in regular exercise in the last 6 months.
• Having a history of regular brace use in the last 6 months.
• Having a rheumatic disease affecting the axial skeleton.
• Having a diagnosis of a disease related to the axial skeleton, such as spondylosis, spondylolisthesis, spinal stenosis, or disc herniation.