The Journal of NeuroEngineering and Rehabilitation published a study on Monday, Sep. 26, 2011 that demonstrates that the combination of obesity and lower back pain affects gait pattern more than obesity alone.
Since obesity is frequently associated with lower back pain, Italian scientists decided to look at the combined effect of obesity and lower back pain on gait. They wished to quantify gait patterns of obese people, both those who do and donâ€™t suffer from lower back pain by using Gait Analysis to examine the cumulative effects.
Previous studies have confirmed the relationship between obesity and a variety of musculoskeletal disorders, including lower back pain, functional impairment of the spine, low spinal flexibility and increased dorsal stiffness. Evidence also exists that obesity affects standing up, walking and running. Because excess mass imposes abnormal mechanics on body movements, the jointsâ€™ physiological range of motion is decreased, while the risk of musculoskeletal overload is increased. Although previous research has show that the gait pattern in obese adults is similar to that of lean adults, there has been a dearth of research looking at the relationship between gait patterns, obesity and lower back pain.
Included in the study were 8 obese females (BMI â‰¥ 35kg/m2) with chronic lower back pain (lumbar pain with no evidence of specific origin lasting more than 3 months), and two control groups: one with obese women with no reported lower back pain and another with normal-mass women who had experienced no lower back pain within the previous six months.
The obese group with lower back pain showed a longer stance duration and shorter step length when compared to the two control groups. They also had a low range of motion in the pelvis and hip in the frontal plane, and low knee flexion during the swing phase as compared to the control groups. The maximum ankle power during the impact on the ground was also lower in the study group. In functional terms, this means that the obese with lower back pain group had to generate much of its walking power from the hips rather than from ankle plantar flexion.
Based on the results of this study, the researchers suggest tailoring specific treatment to recover a normal gait pattern. They recommend exercises for spine flexibility and strength, range of motion exercises at the knee, and strengthening of the distal (ankle dorsiflexor) and proximal (knee flexor) muscles. Crucial to any exercise program, of course, is the additional need for a parallel weight loss program.
Although the study sample was small, the researchers have made a significant first step in looking at the correlation between gait, obesity and lower back pain!