The Impact of Obesity and Weight Loss on Gait in Adults - The Mechanobiology of Obesity and Related Diseases - page 137

compressive forces between the high weight loss and no weight loss groups was
primarily due to lower hamstring forces [ 35 ].
Aaboe et al. [ 1 ] investigated the effect of intensive weight loss, induced by a
16-week dietary intervention, on gait kinematics and kinetics in obese knee OA
patients (The Influence of Weight Loss or Exercise on Cartilage in Obese Knee
OA Patients (The CAROT Trial)) [ 46 ]. The average weight loss corresponded to
13.5 % of the baseline body weight. They found that the self-selected walking
speed increased significantly (mean change 0.04 ± 0.13 m/s) after weight loss
intervention compared to baseline speed [ 1 ]. The weight loss resulted in a 7 %
reduction in peak knee compression force, a 13 % lower axial impulse, and a 12 %
reduction in the internal knee abduction moment. There were no clear effects on
sagittal plane knee moments or peak knee flexion angle. Linear regression analyses
adjusted for changes in walking speed showed that for every 1 kg in weight loss,
the peak knee load was reduced by 2.2 kg at a given walking speed.
Although both of these studies showed that weight loss significantly reduced
knee joint loads in knee OA subjects during walking [ 1 , 34 ], this did not cause
decelerated structural disease progression [ 17 , 35 ]. Messier et al. [ 35 ] reported that
there was no difference between the groups in knee joint space width or plain
radiographic severity scores. Henriksen et al. [ 17 ] demonstrated using magnetic
resonance imaging analysis that an increased knee joint loading for 1 year was not
associated with accelerated symptomatic or structural disease progression com-
pared to a similar weight loss group that had reduced ambulatory compressive
knee joint loads. It is possible that a greater walking speed following weight loss
significantly increases joint loads, and this may consequently counteract the
benefits of the reduction in joint loads [ 17 ].
5.2 Bariatric Surgery
Bariatric surgery has been shown to induce sustainable and substantial weight loss,
on average 40 kg weight loss or 14 kg/m 2 BMI decrease, in morbidly obese
individuals [ 8 ]. Recent studies have revealed that excess weight loss after the
Roux-en-Y gastric bypass operation resulted in increased mobility and improved
physical function, in addition to other improvements in health-related quality of
life [ 22 , 31 , 37 ]. However, only three studies have evaluated the effects of massive
weight loss on gait [ 5 , 19 , 53 , 57 ].
Vincent et al. [ 57 ] investigated the effects of bariatric surgery on gait charac-
teristics 3 months after surgery, comparing the results with nonsurgical controls.
The mean change in BMI for the bariatric surgery and control groups was—7.9
and 0.5 kg/m 2 , respectively. The self-selected walking speed increased by 15 % in
the bariatric group. The bariatric group had a 4.8 cm increase in step length, a
2.6 % increase in single support time, and a 2.5 cm reduction in the step width.
The stride length and the step frequency did not change significantly 3 months
after bariatric surgery. The severity of low back pain and knee pain decreased by
54 and 34 %, respectively, with no changes in the control group [ 57 ].