Does visual feedback during walking result in similar improvements in trunk control for young and older healthy adults?

Abstract

BackgroundMost current applications of visual feedback to improve postural control are limited to a fixed base of support and produce mixed results regarding improved postural control and transfer to functional tasks. Currently there are few options available to provide visual feedback regarding trunk motion while walking. We have developed a low cost platform to provide visual feedback of trunk motion during walking. Here we investigated whether augmented visual position feedback would reduce trunk movement variability in both young and older healthy adults.MethodsThe subjects who participated were 10 young and 10 older adults. Subjects walked on a treadmill under conditions of visual position feedback and no feedback. The visual feedback consisted of anterior-posterior (AP) and medial-lateral (ML) position of the subject’s trunk during treadmill walking. Fourier transforms of the AP and ML trunk kinematics were used to calculate power spectral densities which were integrated as frequency bins “below the gait cycle” and “gait cycle and above” for analysis purposes.ResultsVisual feedback reduced movement power at very low frequencies for lumbar and neck translation but not trunk angle in both age groups. At very low frequencies of body movement, older adults had equivalent levels of movement variability with feedback as young adults without feedback. Lower variability was specific to translational (not angular) trunk movement. Visual feedback did not affect any of the measured lower extremity gait pattern characteristics of either group, suggesting that changes were not invoked by a different gait pattern.ConclusionsReduced translational variability while walking on the treadmill reflects more precise control maintaining a central position on the treadmill. Such feedback may provide an important technique to augment rehabilitation to minimize body translation while walking. Individuals with poor balance during walking may benefit from this type of training to enhance path consistency during over-ground locomotion.

Trunk motion visual feedback during walking improves dynamic balance in older adults: Assessor blinded randomized controlled trial

“…Subjects walked on a treadmill a approximately 24 inches in front of a 27” TV b , as shown in Figure 2. The VFB device has been described in detail and is briefly presented here [32]. Each of the 10 rings of the bull’s-eye was one inch wide and corresponded to one inch of physical space on the treadmill (translation) or 1 degree from vertical (orientation).…”

“…VFB training involving trunk orientation and trunk translation would allow the individual to more flexibly solve the stability problem (trunk on legs, stepping, or both) by taking advantage of their many degrees of freedom [30]. Considering the benefits of improved trunk motion for balance [31], providing concurrent VFB of trunk motion during walking may be a beneficial training strategy to improve balance [32].…”

“…This study builds on responses to concurrent trunk motion VFB during treadmill walking [32,33] to investigate carry over and transfer to over-ground dynamic balance for older adults at risk of falling. The primary aim of this study was to determine whether training with trunk motion VFB for 4 weeks would result in improved balance for older adults with self-reported balance problems.…”

Using visual stimuli to enhance gait control

“…Individuals with vestibular dysfunction have been shown to have increased trunk motion profiles [5,97], so using visual feedback to reduce trunk motion could be a useful modality to learn a new motor pattern. Anson and colleagues explored this postulate with younger and older adults and found that trunk translation variability was reduced in while walking on the treadmill, but without any appreciable changes in the variability of trunk orientation [6]. The ability to exert translational control in the medial-lateral plane would be useful for vestibular patients because it would improve directional consistency of locomotion, which has been reported to be impaired in this population [11,24].…”

Visual control of trunk translation and orientation during locomotion

“…Neck position was defined as the AP or ML displacement of the marker on the cervical vertebrae. Trunk angle was defined as the AP or ML difference in position of the cervical and lumbar markers (Logan et al 2010; Anson et al 2013). The difference between cervical and lumbar translations in the AP or ML direction approximates the trunk angle relative to vertical in the sagittal or frontal plane, respectively, when this angle is small.…”