3 dimensional gait analysis and functional tests in the obese before and after weight loss

Overweight and obesity have become a common problem in modern society. The
World Health Organization (WHO) estimates that in 2008, 1.5 billion adults were
overweight, about 500 million of which were obese. Among other health-related
problems, the added weight is associated with changes in gait and functional
limitations in daily life. The goals of obesity treatment are to achieve and
then to maintain clinically meaningful weight loss, with the ultimate goal of
reducing the risk for or severity of obesity-related diseases, impairments, and
functional limitations.
Several studies have evaluated gait patterns (e.g. spatio-temporal parameters)
and biomechanical loads in obese subjects, but their results were not
consistent. Most recently, Browning and Kram have evaluated biomechanical loads
on the lower limbs involved in walking between lean and obese subjects. Their
research has shown that ground reaction force, net muscle moments, joint load
(at the hip, knee and ankle) and step width during walking are greater for
obese compared to lean subjects.
However, very little research has been performed with regard to the analysis of
these biomechanical loads in obese subjects before and after weight loss. It is
suggested that the increase in these biomechanical loads might explain the
association of incidence osteoarthritis (OA) with increased adiposity.
Therefore, weight loss could reduce the incidence of OA in the obese.
Obesity also causes functional limitations. Due to their increased body
measures, obese persons can experience problems in getting up from a chair,
climbing stairs, tying bootlaces or picking things up from the ground. We
hypothesize that when the obese perform these activities, the biomechanical
loads on the lower limbs are increased compared to their lean counterparts and
that weight loss can reduce these loads and improve the limitations the obese
experience in daily activities.
This study aims to investigate the single components associated with gait
analysis and biomechanical loads in obese subjects before and after weight
loss. Additionally we will investigate the effect of weight loss on the
functional limitations in the obese.

Primary Objective:
To investigate the spatio-temporal gait parameters in obese and lean subjects
to evaluate if there is an effect on the gait pattern after weight loss.

Secondary Objectives:
- To investigate the effect of weight loss on joint load during walking and
functional tests in obese subjects.
- To investigate the differences in functional limitations between lean and
obese subjects and if weight loss affects these functional limitations.

This study is a 9-month longitudinal observational study. For the obese
population we will ask subjects that are entering the CO-EUR treatment
programme to participate in this study. Lean subjects will be recruited by
local newspaper ads. At intake and after 9 months of treatment, the subjects
will be exposed to a 3D videographic gait analysis, stair ascent/descent, 6
minute walk-test and sit-to-stand movement.

There are no risks involved in participating in this study. It is a
non-invasive study and the tests that are being performed are all normal daily
activities. There is no known benefit for participating in this study.
Up until now there has been very little research on the effect of obesity
treatment and / or weight loss / change in body composition on gait patterns
and the functional limitations that the obese experience in daily life. This
study will provide new insight on these aspects of obesity treatment.