Mediolateral Trunk Sway Research Articles

Digital Motor Biomarkers of Cerebellar Ataxia Using an RGB-Depth Camera-Based Motion Analysis System.

This study aimed to identify quantitative biomarkers of motor function for cerebellar ataxia by evaluating gait and postural control using an RGB-depth camera-based motion analysis system. In 28 patients with degenerative cerebellar ataxia and 33 age- and sex-matched healthy controls, motor tasks (short-distance walk, closed feet stance, and stepping in place) were selected from a previously reported protocol, and scanned using Kinect V2 and customized software. The Clinical Assessment Scale for the Assessment and Rating of Ataxia (SARA) was also evaluated. Compared with the normal control group, the cerebellar ataxia group had slower gait speed and shorter step lengths, increased step width, and mediolateral trunk sway in the walk test (all P < 0.001). Lateral sway increased in the stance test in the ataxia group (P < 0.001). When stepping in place, the ataxia group showed higher arrhythmicity of stepping and increased stance time (P < 0.001). In the correlation analyses, the ataxia group showed a positive correlation between the total SARA score and arrhythmicity of stepping in place (r = 0.587, P = 0.001). SARA total score (r = 0.561, P = 0.002) and gait subscore (ρ = 0.556, P = 0.002) correlated with mediolateral truncal sway during walking. These results suggest that the RGB-depth camera-based motion analyses on mediolateral truncal sway during walking and arrhythmicity of stepping in place are useful digital motor biomarkers for the assessment of cerebellar ataxia, and could be utilized in future clinical trials.

Postural Stability and Academic Achievements among Fifth Graders: An Experimental Field Study

Postural stability was previously associated with academic achievements among primary school children, but only little is known on how cognitive-motor processes underlie academic achievements. This research was primarily aimed at investigating cognitive-motor performance (e.g., single vs. dual-task gait) and it correlates with achievements in math and language-arts. Fifth-graders (N = 86) performed several motor tasks while their mediolateral trunk sway was assessed using a Kinect 3D sensor. Achievements in math and language-arts were assess one's comply with motor task demands using standardized tests.

A Matter of (Inner) Balance: The Association Between Facets of Mindfulness, Attention Deficit, and Postural Stability

Mindfulness and motor performance are theoretically related through attention and awareness, yet little research has been conducted to date. The present study was aimed at exploring the role of facets of mindfulness in static and dynamic balance tasks. Specifically, 103 college students and staff completed the five facets of mindfulness questionnaire (which assesses awareness, non-reacting, non-judging, observing, and describe) and participated in eight motor tasks (e.g. standing on 1 ft, tandem walk, etc.). Motor performance was assessed by measuring participants’ mediolateral trunk sway. Hierarchical regression analyses revealed that the facet of observing was associated with more stable performance in the absence of visual information. Furthermore, predisposed awareness was associated with less stable performance when attention was divided and in the absence of visual information. Moreover, awareness interacted with attention deficit disorder, such that as compared to non-ADD/ADHDs, participants diagnosed with ADD/ADHD performed worse in static balance tasks if their awareness was low but performed better if their awareness was high. However, an opposite pattern was found for dual-task gait performance, thus indicating on stereotype threat effect. These findings are discussed from the perspectives of recent mindful movement and the fringe consciousness frameworks.

Effect of gait retraining for reducing ambulatory knee load on trunk biomechanics and trunk muscle activity

The purpose of this study was to test the hypothesis that walking with increased medio-lateral trunk sway is associated with lower external knee adduction moment and lower extremity muscle activation, and higher external ipsilateral trunk moment and trunk muscle activity than walking with normal trunk sway in healthy participants. Fifteen participants performed walking trials with normal and increased medio-lateral trunk sway. Maximum trunk sway, first maximum knee adduction moment, lateral trunk bending moment, and bilateral vastus medialis, vastus lateralis, gluteus medius, rectus abdominis, external oblique and erector spinae muscle activity were computed. Walking with increased trunk sway was associated with lower maximum knee adduction moment (95% confidence interval (CI): 0.50–0.62Nm/kg vs. 0.62–0.76Nm/kg; P<.001) and ipsilateral gluteus medius (−17%; P=.014) and erector spinae muscle activity (−24%; P=.004) and greater maximum lateral trunk bending moment (+34%; P<.001) and contralateral external oblique muscle activity (+60%; P=.009). In all participants, maximum knee adduction moment was negatively correlated and maximum trunk moment was positively correlated with maximum trunk sway. The results of this study suggest that walking with increased trunk sway not only reduces the external knee adduction moment but also alters and possibly increases the load on the trunk. Hence, load-altering biomechanical interventions should always be evaluated not only regarding their effects on the index joint but on other load-bearing joints such as the spine.

Effects of support surface stability on feedback control of trunk posture.

This study aimed to examine the interactions of visual, vestibular, proprioceptive, and tactile sensory manipulations and sitting on either a stable or an unstable surface on mediolateral (ML) trunk sway. Fifteen individuals were measured. In each trial, subjects sat as quiet as possible, on a stable or unstable surface, with or without each of four sensory manipulations: visual (eyes open/closed), vestibular (left and right galvanic vestibular stimulation alternating at 0.25 Hz), proprioceptive (left and right paraspinal muscle vibration alternating at 0.25 Hz), and tactile (minimal finger contact with object moving in the frontal plane at 0.25 Hz). The root mean square (RMS) and the power at 0.25 Hz (P25) of the ML trunk acceleration were the dependent variables. The latter was analyzed only for the rhythmic sensory manipulations and the reference condition. RMS was always significantly larger on the unstable than the stable surface. Closing the eyes caused a significant increase in RMS, more so on the unstable surface. Vestibular stimulation significantly increased RMS and P25 and more so on the unstable surface. Main effects of the proprioceptive manipulation were significant, but the interactions with surface condition were not. Finally, also tactile manipulation increased RMS and P25, but did not interact with surface condition. Sensory information in feedback control of trunk posture appears to be reweighted depending on stability of the environment. The absolute effects of visual and vestibular manipulations increase on an unstable surface, suggesting a relative decrease in the weights of proprioceptive and tactile information.

Trunk sway during walking among older adults: Norms and correlation with gait velocity

The aim of this study was to establish quantitative norms for trunk sway during walking for older male and female ambulatory adults at different age groups (65–70, 71–75, 76–80, ≥81). We also assessed the relationship between dynamic trunk sway and gait velocity in older individuals with clinically normal or abnormal gaits. Trunk sway in medio-lateral (roll) and antero-posterior (pitch) planes was measured using a body-mounted gyroscope (SwayStar) during walking on a 4.5m long instrumented walkway. Of the 284 older adults (mean age 76.8, 54.6% women) in this sample, the mean±SD value of roll and pitch angles were 6.0±2.0° and 6.7±2.2° respectively. Older women showed significantly greater trunk sway in both roll and pitch angles than older men (p<0.01). In both men and women, there was no significant association of roll angle with age although gait velocity decreased with increasing age. The relationship between roll angle and gait velocity was U-shaped for the overall sample. Among the subgroup with clinically normal gait, increased roll angle was associated with increased gait velocity (p<0.001). However, there was no significant relationship between roll angle and gait velocity among the subgroup with abnormal gait. Therefore, the relationship between medio-lateral trunk sway and gait velocity differs depending on whether gait is clinically normal.We conclude that trunk sway during walking should be interpreted with consideration of both gait velocity and presence of gait abnormality in older adults.

The effectiveness of voluntary modifications of gait pattern to reduce the knee adduction moment

It has been suggested to use gait modifications in the retraining of patients with knee osteoarthritis (OA), in order to reduce the external knee adduction moment (KAdM). This study focused on the effect of walking speed, foot position and trunk sway, and on the 3D knee moments. Gait analyses of fourteen healthy volunteers were performed in a gait laboratory. Subjects walked at three different speeds in their normal gait pattern, as well as with toe-in and toe-out gait and with medio-lateral trunk sway at a self-selected speed.Fast walking speed increased the KAdM (17–30%) and flexion moment (32%). A slower walking speed did not decrease the KAdM. Toe-in mainly decreased the KAdM (45%) and the transverse moment (38%) during early stance. Toe-out decreased the KAdM during late stance (56%), but increased the KAdM during early stance and midstance (21–24%), due to decreased endorotation of the hip with knee flexion. Trunk sway decreased the KAdM during early stance and midstance (31–33%). Gait modifications mainly affected the KAdM, but changes in sagittal and transverse knee moments and kinematics were also observed. This indicates that, when estimating knee load, taking only the frontal plane kinetics into consideration may lead to erroneous simplifications. No conclusive beneficial effects were found in any of the gait modifications throughout the entire stance phase.

Amplitude and Phasing of Trunk Motion is Critical for the Efficacy of Gait Training Aimed at Reducing Ambulatory Loads at the Knee

The purpose of this study was to determine the contribution of changes in amplitude and phasing of medio-lateral trunk sway to a change in the knee adduction moment when walking with increased medio-lateral trunk sway. Kinematic and kinetic data of walking trials with normal and with increased trunk sway were collected for 19 healthy volunteers using a standard motion analysis system. The relationship between the change in first peak knee adduction moment (ΔKAM) and change in trunk sway amplitude (ΔSA; difference between maximum contralateral trunk lean and maximum ipsilateral trunk lean) and phasing (SP; time of heel-strike relative to time of maximum contralateral and time of maximum ipsilateral trunk lean) was determined using nonlinear regression analysis. On average, subjects increased their SA by 9.7 ± 3.6 deg (P < 0.001) with an average SP of 98.8 ± 88.8 ms resulting in an average reduction in the first peak knee adduction moment of -55.2 ± 30.3% (P < 0.001). 64.3% of variability in change in peak knee adduction moment with the increased trunk sway condition was explained by both differences in SA and SP, and the relationship among these parameters was described by the regression equation ΔKAM = 27.220-4.128 [middle dot] ΔSA-64.785 [middle dot] cos(SP). Hence, not only the amplitude but also the phasing of trunk motion is critical. Not only lower limb movement but also lumbar and thoracic lateral flexion should be considered in the decision making process for an optimal intervention aimed at reducing the load on the medial compartment of the knee during walking. However, these promising findings originated from studies on healthy subjects and their relevance for gait training interventions in patients with presumably painful knee osteoarthritis remains to be determined.

Executive Functions Are Associated With Gait and Balance in Community-Living Elderly People

Cognition influences gait and balance in elderly people. Executive functions seem to play a key role in this mechanism. Previous studies used only a single test to probe executive functions, and outcome measures were restricted to gait variables. We extend this prior work by examining the association between two different executive functions and measures of both gait and balance, with and without two different cognitive dual tasks. This is a cross-sectional study with randomly selected community-living elderly people. Executive functions were tested with the Trail Making Test Parts A and B and the Stroop Color Word Test; memory with Cambridge Neuropsychological Test Automated Battery (CANTAB) subtests. Patients walked without and with two dual tasks (subtracting serial sevens and animal naming). Main outcomes focused on gait (velocity, stride length, and stride time variability), measured on an electronic walkway, and balance, measured as trunk movements during walking. Associations were assessed with multiple regression models. One hundred elderly people, with a mean age 80.6 years (range 75-93 years) participated. Both dual tasks decreased gait velocity and increased variability and trunk sway. Executive functions were associated with only stride length variability and mediolateral trunk sway during performance of animal naming as the dual task. Memory was not associated with the gait and balance variables. In community-living elderly people, executive functions are associated with gait and balance impairment during a challenging dual-task condition that also depends on executive integrity. Next steps will be to explore the value of executive functions in defining fall-risk profiles and in fall-prevention interventions for frail patients.

Implications of increased medio-lateral trunk sway for ambulatory mechanics

The purposes of this study was to test a mechanism to reduce the knee adduction moment by testing the hypothesis that increased medio-lateral trunk sway can reduce the knee adduction moment during ambulation in healthy subjects, and to examine the possibility that increasing medio-lateral trunk sway can produce similar potentially adverse secondary gait changes previously associated with reduced knee adduction moments in patients with knee osteoarthritis. Nineteen healthy adults performed walking trials with normal and increased medio-lateral trunk sway at a self-selected normal walking speed. Standard gait analysis was used to calculate three-dimensional lower extremity joint kinematics and kinetics. Knee and hip adduction moments were lower (−65.0% and −57.1%, respectively) for the increased medio-lateral trunk sway trials than for the normal trunk sway trials. Knee flexion angle at heel-strike was 3° higher for the increased than for the normal trunk sway trials. Knee and hip abduction moments were higher for the increased medio-lateral trunk sway trials, and none of the other variables differed between the two conditions. Walking with increased medio-lateral trunk sway substantially reduces the knee adduction moment during walking in healthy subjects without some of the adverse secondary effects such as increased axial loading rates at the major joints of the lower extremity. This result supports the potential of using gait retraining for walking with increased medio-lateral trunk sway as treatment for patients with degenerative joint disease such as medial compartment knee osteoarthritis.