Our walking patterns must be adjusted continuously in everyday living, whether for maneuvering on slippery surfaces or stepping over cracks on the street. Walking becomes more challenging as it requires more energy to lift and accelerate the body due to additional loads on the body as we move through space. This dissertation investigates gait, stability, and adaptation in adults with range of adiposity. First, we studied how people with obesity adapt to spatial (obstacle crossing) and temporal (metronome walking) task constraints during walking over-ground. Results indicated that people prioritized a spatial over temporal constraint when attempting to meet both constraints at the same time. Second, we tested how massive weight loss affects gait and stability. We measured how bariatric surgery patients walked and crossed obstacles before and one year after surgery. Findings indicated that massive weight loss improved not only gait but also postural stability during gait. Third, we quantified whole-body rotational characteristics in adults with obesity through changes in angular momentum quantities during steady-state walking. I found that angular momentum (1) was greater in adults with higher BMI, (2) was highly regulated by foot placement, and (3) did not change with walking speed. Taken together these results suggest that gait and stability can be adapted. These findings may help to develop interventions to target specific walking deficits in patients with mobility limitations such as obesity.

Introduction: There is proven therapeutic benefit in bariatric surgery for obese patients. Consequently the National Institute of Clinical Excellence UK has provided referral guidelines for bariatric surgery. Successful bariatric surgery will result in massive weight loss and ptotic skin, which can cause significant functional and psychological problems. As the number of cases of bariatric surgery increases, a corresponding number of massive weight loss patients will require plastic surgery. In this novel field of post massive weight loss surgery there is a lack of understanding of the demographics, physical symptoms and psychological health of this new group of patients. The tools to assess them are few and not validated, the patient pathway is disjointed and there is no consensus on standardised provision. Method: A prospective multicentre, observational study of outcomes in 100 patients undergoing bariatric and post massive weight loss plastic surgery at 2 clinical sites was performed. Each patient followed a standard operating protocol. This included undergoing a semi structured interview, completing five patient-report outcome measures, having anthropometric measurements and clinical photographs taken. Conclusion: This observational study identified key psychosocial themes prevalent in massive weight loss patients, during their weight loss journey. It identified there are no validated patient reported outcome measures available specific to this cohort of patients. This work led to the development of a new validated tool for massive weight loss body contouring.