This study assessed whether the use of an "anchor system" benefited older adults who performed a tandem walking task. Additionally, we tested the effects of practice with the anchor system during walking on trunk stability, in the frontal plane, of older adults. Forty-four older adults were randomly assigned to three groups: control group, 0g anchor group, and 125g anchor group. Individuals in each group performed a tandem walking task on the GaitRite system with an accelerometer placed on the cervical region. The participants in the 125g anchor group held, in each hand, a flexible cable with a light mass attached at the end of the cable, which rested on the ground. While the participants walked, they pulled on the cables just enough to keep them taut as the masses slid over the ground. The 0g anchor group held an anchor tool without any mass attached to the end portion. The results of this study demonstrated that the use of the anchor system contributed to the reduction of trunk acceleration in the frontal plane. However, this effect did not persist after removal of the anchors, which suggests that the amount of practice with this tool was insufficient to generate any lasting effect, or that the task was not sufficiently challenging, or both.

This study assessed the contribution of the "anchor system's" haptic information to balance control during walking at two levels of difficulty. Seventeen young adults and seventeen older adults performed 20 randomized trials of tandem walking in a straight line, on level ground and on a slightly-raised balance beam, both with and without the use of the anchors. The anchor consists of two flexible cables, whose ends participants hold in each hand, to which weights (125 g) are attached at the opposing ends, and which rest on the ground. As the participants walk, they pull on the cables, dragging the anchors. Spatiotemporal gait variables (step speed and single- and double-support duration) were processed using retro-reflective markers on anatomical sites. An accelerometer positioned in the cervical region registered trunk acceleration. Walking on the balance beam increased single- and double-support duration and reduced step speed in older adults, which suggests that this condition was more difficult than walking on the level ground. The anchors reduced trunk acceleration in the frontal plane, but the level of difficulty of the walking task showed no effect. Thus, varying the difficulty of the task had no influence on the way in which participants used the anchor system while tandem walking. The older adults exhibited more difficulty in walking on the balance beam as compared to the younger adults; however, the effect of the anchor system was similar in both groups.

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BackgroundIn Duchenne muscular dystrophy, functional deficits seem to arise from body misalignment, deconditioning, and obesity secondary to weakness and immobility. The question remains about the effects of postural deviations on the functional balance of these children. ObjectivesTo identify and quantify postural deviations in children with DMD in comparison to non-affected children (eutrophic and overweight/obese), exploring relationships between posture and function.MethodThis case-control study evaluated 29 participants aged 6 to 11 years: 10 DMD (DG), 10 eutrophic (EG), and 9 overweight/obese (OG). Digital photogrammetry and SAPo program were used to measure postural alignment and the Pediatric Balance Scale (PBS) was used to measure balance. The Kruskall-Wallis and Dunn post-hoc tests were used for inter-group comparison of posture and balance. Spearman's coefficient tested the correlation between postural and balance variables. ResultsThe horizontal pelvic alignment data indicated that the anteversion of the DG was similar to that of the OG and twice that of the EG (p<0.05). Compared to the EG, the DG and OG showed an increased forward position of the center of mass (p<0.05). There was a moderate and weak correlation between the PBS score and horizontal pelvic alignment (0.58 and 0.47-left/right). The PBS showed a weak correlation with asymmetries in the sagittal plane (-0.39). The PBS scores for the OG and EG suggest that obesity did not have a deleterious effect on balance. ConclusionsThe balance deficit in children with DMD was accompanied by an increased forward position of the center of mass and significant pelvic anteversion that constitutes a compensatory strategy to guarantee similar performance to the children not affected by the disease.

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During locomotion, we respond to environmental and task changes by adjusting steps length and width. Different protocols involving stepping on targets and obstacle avoidance suggest the involvement of cortical and subcortical pathways in these online adjustments. The addition of a concomitant cognitive task (CT) can affect these online corrections depending on the neural pathway used. Thereby, we investigated the online adjustment using a target stepping task and a planar obstacle avoidance task in young adults and analyzed the effect of a CT on these adjustments. Twenty young adults executed two blocks of trials of walking performing the target task (TT) and obstacle avoidance task (OAT), with and without a concomitant CT. In the TT, participants stepped on a target projected on the ground, whereas in the OAT they avoided stepping on an obstacle projected on the ground. The target/obstacle could change its original position in four directions at contralateral foot contact on the ground. Overall, the CT did not affect the latency to start the adjustments due to target/obstacle change. The main changes were restricted to the frontal plane adjustments. The latency for the medial and lateral choices in the OAT was ~ 200 ms, whereas for the TT was ~ 150 ms. These results suggest the involvement of a slow cortical pathway in the OAT in the frontal plane modifications. In turn, the TT may be controlled by one of two fast adjustment neural pathways.

Background. Depending on the dimensions of a hole, the characteristics of the walking surface, and the position of the hole relative to normal walking, individuals may need to step into the hole with the dominant or non-dominant limb. Aim. We investigated the effect of the lower limb dominance in walking adaptations in the presence of a hole on the ground. Methods: Twenty young adults walked and stepped into a hole positioned in the middle of the pathway using the dominant and non-dominant lower limbs. Results. For the trailing limb, the impulses were not affected by the lower limb dominance, but for the leading limb, the non-dominant leg increased the braking and propulsive impulses compared to the dominant leg. On the other hand, toe-off velocity increased when the non-dominant leg was used as trailing and leading limbs. Stride speed increased when the non-dominant leg was the trailing limb. Interpretation. Our results were consistent with asymmetrical behavior between dominant and non-dominant legs. Although the differences between the dominant and non-dominant legs have not affected the success in the task, they can put the individual at higher risk of stumbling and consequently a fall when stepping with the non-dominant leg into the hole.