A Comparison Of Treadmill And Overground Walking In Obese Women

Abstract

Several reports that have compared the kinematic differences between treadmill (TM) and overground (OG) walking in healthy subjects. Studies on temporal aspects of gait in lean, healthy individuals typically report increased stride frequency and decreased stride length as the main difference between the two walking modalities. Findings are varied for differences in peak joint angles but trend towards minimal differences in peak values. Obese individuals display markedly different kinematics relative to lean individuals and are often not experienced TM walkers. The dimensions of standard laboratory TMs may also constrain limb excursions or elicit the need for increased stability. PURPOSE: To compare selected kinematic parameters of TM and OG walking in obese women. METHODS: 12 obese women (28.7 ± 9.1 years; 36.7 ± 6.4 kg·m-2; 45.6 ± 5.1% body fat) walked OG and on a TM at their preferred OG walking speed (1.37 ± 0.14 m·s-1). Kinematic measures on the TM were recorded after 6 minute of walking. Measured kinematic variables across 5 strides included stride length, stride frequency, stance time, and peak sagittal and frontal plane hip, knee, and ankle joint angles during the stance phase of the gait cycle. Paired T-tests were calculated to assess statistical significance (α = 0.05). RESULTS: Obese women had significantly greater stance time on the TM than during OG walking (p=0.01). Peak knee flexion during stance was greater on the TM (p<0.01) while ankle dorsiflexion during midstance (p=0.05) and ankle eversion range of motion (p<0.01) were significantly greater during OG walking. There were no significant differences between conditions for stride frequency, stride length, peak hip flexion, hip extension, hip range of motion, hip abduction, knee adduction, ankle plantar flexion during midstance, or peak ankle eversion during stance (p>0.05). CONCLUSIONS: Obese women display different kinematics on the TM relative to OG walking. In addition, the differences found in this study do not match reports from similar studies on lean individuals. The greater limb dimensions of the obese population potentially necessitate that different strategies be used for forward locomotion on a TM compared to OG. The results of this study indicate that several kinematic measures recorded on a TM do not replicate OG walking in obese adults.