Postural Habits, Body Awareness, and Functional Performance Across BMI Categories in Women

Obesity is a growing global public health concern that affects not only metabolic and cardiovascular systems but also musculoskeletal health, postural control, and proprioceptive mechanisms. Increased body mass and altered fat distribution, particularly abdominal adiposity, may lead to biomechanical changes such as anterior shift of the center of mass, altered load distribution, and increased stress on the lower extremities. These changes may negatively influence functional performance and postural organization.

Body awareness is a multidimensional construct involving the perception, interpretation, and regulation of internal bodily sensations, while postural habits reflect behavioral patterns related to body alignment in daily activities. Although previous studies have examined body awareness and functional performance in individuals with obesity, findings regarding their interrelationships remain inconsistent. Additionally, the combined evaluation of postural habits, body awareness, and functional performance across BMI categories is limited in the literature.

This study is designed as a cross-sectional, comparative investigation including women aged 18-65 years. Participants will be classified into four BMI categories according to World Health Organization criteria. Postural habits and awareness will be assessed using the Posture Habits and Awareness Scale (PHAS), and body awareness will be evaluated using the Body Awareness Questionnaire (BAQ). Functional performance will be measured using the Timed Up and Go (TUG) test and the Five Times Sit-to-Stand (5×STS) test. A composite functional performance index will be created using standardized scores of these tests.

Anthropometric measurements including BMI and waist circumference will be obtained to assess general and central obesity. Additional variables such as physical activity level and psychological status (anxiety and depression) will also be evaluated.

The primary objective is to examine whether postural habits and body awareness differ across BMI categories and how these variables are associated with functional performance. Furthermore, the study aims to determine whether central adiposity contributes independently to these relationships when controlling for functional performance and psychological factors.

It is hypothesized that higher BMI levels will be associated with altered postural habits and body awareness, and that decreased functional performance will play a mediating role in these relationships. Additionally, waist circumference is expected to have an independent effect on postural and perceptual parameters.

Inclusion criteria

• Female individuals aged 18-65 years
• Classified into BMI categories (normal weight, overweight, obesity class I, obesity class II-III)
• No obesity-related medical or surgical treatment in the last 6 months
• Able to understand instructions and complete questionnaires

Exclusion criteria

• Neurological disorders affecting mobility (e.g., stroke, Parkinson's disease, multiple sclerosis, peripheral neuropathy)
• Rheumatologic or inflammatory diseases (e.g., rheumatoid arthritis, ankylosing spondylitis)
• Severe orthopedic conditions limiting mobility (e.g., advanced osteoarthritis)
• Major surgery within the last 12 months affecting mobility or physical performance
• Pregnancy
• Acute musculoskeletal injury within the last 4 weeks