Effect of Thoracic Mobilization in People With Central Obesity

The Challenge: Central Obesity and Respiratory Dysfunction

Central obesity is a growing global health concern that affects not only metabolic and cardiovascular health but also respiratory function. Excess accumulation of abdominal and visceral fat mechanically restricts chest wall movement, limits diaphragmatic excursion, and reduces lung volumes, leading to impaired ventilatory function and decreased chest wall expansion. These respiratory limitations can contribute to dyspnea, reduced exercise tolerance, and poorer quality of life. Although weight loss through dietary modification and aerobic exercise remains the cornerstone of obesity management, these approaches do not directly address the mechanical restrictions imposed on the thoracic cage. Therefore, additional physiotherapy interventions targeting thoracic mobility may provide further improvements in respiratory function.

The Goal of the Study

This study aims to determine whether adding Mulligan thoracic mobilization in extension to a standardized low-carbohydrate diet and aerobic exercise program provides greater improvements in ventilatory functions and chest wall expansion than diet and exercise alone in adults with central obesity. The study will also investigate whether this intervention improves functional exercise capacity and health-related quality of life.

How the Study Works

The study will involve 60 adult males with central obesity who meet the study eligibility criteria. Participants will be randomly assigned into two equal groups:

The Mulligan Thoracic Mobilization Group: Participants will receive Mulligan thoracic mobilization in extension performed by a trained physiotherapist three times per week for eight weeks. The mobilization will be applied to the mid-thoracic spine (T6-T8) using the Mobilization with Movement (MWM) concept while participants perform thoracic extension combined with deep inspiration. In addition, participants will follow an individualized low-carbohydrate diet and participate in a supervised aerobic exercise program.

The Control Group: Participants will receive the same individualized low-carbohydrate diet and supervised aerobic exercise program without Mulligan thoracic mobilization.

Both groups will participate in the intervention program for 8 weeks, with regular monitoring to ensure adherence and participant safety.

What Is Being Measured?

To determine the effectiveness of the intervention, the study will evaluate several important clinical outcomes:

Ventilatory Functions: Pulmonary function will be assessed using spirometry by measuring Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV₁), the FEV₁/FVC ratio, and Maximum Voluntary Ventilation (MVV).

Chest Wall Expansion: Chest wall mobility will be measured using a non-elastic tape measure at the fourth intercostal space and at the xiphoid process during maximal inspiration and expiration.

Functional Capacity: The Six-Minute Walk Test (6MWT) will be used to assess participants' functional exercise capacity.

Health-Related Quality of Life: Participants will complete the 36-Item Short Form Health Survey (SF-36) to evaluate physical and mental aspects of quality of life.

Why This Matters

Respiratory impairment associated with central obesity is largely driven by mechanical restriction of the thorax, yet current obesity management strategies rarely address this component directly. By investigating the effects of Mulligan thoracic mobilization in extension, this study aims to identify a safe, non-invasive, and clinically practical physiotherapy intervention that can complement conventional weight management. If effective, this approach may improve respiratory mechanics, enhance chest wall mobility, increase functional capacity, and improve quality of life for adults with central obesity while expanding the evidence base for manual therapy in cardiopulmonary rehabilitation.