scholarly journals Ambulatory Assessment of the Dynamic Margin of Stability Using an Inertial Sensor Network

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4117 ◽  
Author(s):  
Michelangelo Guaitolini ◽  
Federica Aprigliano ◽  
Andrea Mannini ◽  
Silvestro Micera ◽  
Vito Monaco ◽  
...  
Keyword(s):  
Balance Control ◽  
Inertial Sensor ◽  
Center Of Mass ◽  
The Body ◽  
Lower Limbs ◽  
Measurement Unit ◽  
Margin Of Stability ◽  
Walking Velocity ◽  
Body Center ◽  
Base Of Support

Loss of stability is a precursor to falling and therefore represents a leading cause of injury, especially in fragile people. Thus, dynamic stability during activities of daily living (ADLs) needs to be considered to assess balance control and fall risk. The dynamic margin of stability (MOS) is often used as an indicator of how the body center of mass is located and moves relative to the base of support. In this work, we propose a magneto-inertial measurement unit (MIMU)-based method to assess the MOS of a gait. Six young healthy subjects were asked to walk on a treadmill at different velocities while wearing MIMUs on their lower limbs and pelvis. We then assessed the MOS by computing the lower body displacement with respect to the leading inverse kinematics approach. The results were compared with those obtained using a camera-based system in terms of root mean square deviation (RMSD) and correlation coefficient (ρ). We obtained a RMSD of ≤1.80 cm and ρ ≥ 0.85 for each walking velocity. The findings revealed that our method is comparable to camera-based systems in terms of accuracy, suggesting that it may represent a strategy to assess stability during ADLs in unstructured environments.

scholarly journals Estimation of 3D Body Center of Mass Acceleration and Instantaneous Velocity from a Wearable Inertial Sensor Network in Transfemoral Amputee Gait: A Case Study

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3129
Author(s):  
Emeline Simonetti ◽  
Elena Bergamini ◽  
Giuseppe Vannozzi ◽  
Joseph Bascou ◽  
Hélène Pillet
Keyword(s):  
Sensor Network ◽  
Inertial Sensor ◽  
Center Of Mass ◽  
Vertical Component ◽  
The Body ◽  
Estimation Accuracy ◽  
Measurement Unit ◽  
Transfemoral Amputee ◽  
Body Center ◽  
The Impact

The analysis of the body center of mass (BCoM) 3D kinematics provides insights on crucial aspects of locomotion, especially in populations with gait impairment such as people with amputation. In this paper, a wearable framework based on the use of different magneto-inertial measurement unit (MIMU) networks is proposed to obtain both BCoM acceleration and velocity. The proposed framework was validated as a proof of concept in one transfemoral amputee against data from force plates (acceleration) and an optoelectronic system (acceleration and velocity). The impact in terms of estimation accuracy when using a sensor network rather than a single MIMU at trunk level was also investigated. The estimated velocity and acceleration reached a strong agreement (ρ > 0.89) and good accuracy compared to reference data (normalized root mean square error (NRMSE) < 13.7%) in the anteroposterior and vertical directions when using three MIMUs on the trunk and both shanks and in all three directions when adding MIMUs on both thighs (ρ > 0.89, NRMSE ≤ 14.0% in the mediolateral direction). Conversely, only the vertical component of the BCoM kinematics was accurately captured when considering a single MIMU. These results suggest that inertial sensor networks may represent a valid alternative to laboratory-based instruments for 3D BCoM kinematics quantification in lower-limb amputees.

scholarly journals A Feasibility Study of Kinematic Characteristics on the Upper Body According to the Shooting of Elite Disabled Archery Athletes

2021 ◽  
Vol 18 (6) ◽  
pp. 2962
Author(s):  
Tae-Whan Kim ◽  
Jae-Won Lee ◽  
Seoung-Ki Kang ◽  
Kyu-Yeon Chae ◽  
Sang-Hyup Choi ◽  
...  
Keyword(s):  
The Body ◽  
Lower Limbs ◽  
Upper Body ◽  
Movement Trajectory ◽  
Phase 2 ◽  
Kinematic Characteristics ◽  
Significant Difference ◽  
Athletes With Disabilities ◽  
Body Center ◽  
Time Required

The purpose of this study is to compare and analyze the kinematic characteristics of the upper limb segments during the archery shooting of Paralympic Wheelchair Class archers (ARW2—second wheelchair class—paraplegia or comparable disability) and Paralympic Standing Class archers (ARST—standing archery class—loss of 25 points in the upper limbs or lower limbs), where archers are classified according to their disability grade among elite disabled archers. The participants of this study were selected as seven elite athletes with disabilities by the ARW2 (n = 4) and ARST (n = 3). The analysis variables were (1) the time required for each phase, (2) the angle of inclination of the body center, (3) the change of trajectory of body center, and (4) the change of the movement trajectory of the bow center by phase when performing six shots in total. The ARW2 group (drawing phase; M = 2.228 s, p < 0.05, holding phase; M = 4.414 s, p < 0.05) showed a longer time than the ARST group (drawing phase; M = 0.985 s, holding phase; M = 3.042 s), and the angle of the body did not show a significant difference between the two groups. Additionally, in the direction of the anteroposterior axis in the drawing phase, the change in the movement trajectory of the body center showed a more significant amount of change in the ARW2 group than in the ARST group, and the change in the movement trajectory of the bow center did not show a significant difference between the two groups.

scholarly journals Effect of foot–floor friction on the external moment about the body center of mass during shuffling gait: a pilot study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Kei Shibata ◽  
Hiromi Wada ◽  
Hiroshi Kakehi ◽  
Kazuo Hokkirigawa
Keyword(s):  
Friction Surface ◽  
Center Of Mass ◽  
Young Male ◽  
The Body ◽  
Low Friction ◽  
Surface Conditions ◽  
Normal Gait ◽  
External Moment ◽  
Body Center ◽  
Floor Condition

AbstractHerein, we investigated the effect of friction between foot sole and floor on the external forward moment about the body center of mass (COM) in normal and shuffling gaits. Five young male adults walked with normal and shuffling gaits, under low- and high-friction surface conditions. The maximum external forward moment about the COM (MEFM-COM) in a normal gait appeared approximately at initial foot contact and was unaffected by floor condition. However, MEFM-COM in a shuffling gait under high-friction conditions exceeded that under low-friction conditions (p < 0.001). Therein, MEFM-COM increased with an increasing utilized coefficient of friction at initial foot contact; this effect was weaker during a normal gait. These findings indicate that increased friction between foot sole and floor might increase tripping risk during a shuffling gait, even in the absence of discrete physical obstacles.

scholarly journals RELATIONSHIP OF PELVIC ALIGNMENT WITH BALANCE AND GAIT IN PATIENTS WITH STROKE: A SYSTEMATIC REVIEW

2021 ◽  
pp. 1-9
Author(s):  
Ashwini Mishra ◽  
Dr. Suvarna Ganvir
Keyword(s):  
Observational Studies ◽  
Pelvic Tilt ◽  
Balance Control ◽  
Lateral Displacement ◽  
Weight Bearing ◽  
Lower Limbs ◽  
Pelvic Inclination ◽  
Base Of Support ◽  
Relationship Of ◽  
Pelvic Instability

Background- Pelvis is the key structure that connects the spine and the lower limbs. Altered Pelvic Alignment and asymmetrical weight bearing on affected lower limbs is a common problem leading to pelvic instability which may have an effect on balance and gait in patients with stroke. Hence, it was aimed to investigate the interdependence of these three components in patients with stroke. Methods- Four databases (PubMed, Google Scholar, Cochrane, Science Direct) were searched to identify eligible studies using the keywords Pelvic Alignment, Gait, Balance, Stroke. Only observational studies published in last 10 years (2010-2020) were included in this review. Results- Thirteen studies were included in the review conducted on sub-acute and chronic stage. All studies investigated the affection of pelvic mal-alignment, balance and gait in combination of two variables except 3 studies which investigated the combined effect of pelvic inclination on both balance and gait. The abnormal pelvic tilt results in lateral displacement of the pelvis on affected side, altered Base of Support, reduced balance control, asymmetry in weight bearing leading to altered gait. Conclusion- Pelvic tilt, anterior and lateral has a significant impact on static balance, gait variables, weight bearing symmetry.

Long bone cross-sectional geometry

2020 ◽  
pp. 307-320
Author(s):  
Christopher B. Ruff ◽  
Ryan W. Higgins ◽  
Kristian J. Carlson
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Lateral Displacement ◽  
Center Of Mass ◽  
Gait Pattern ◽  
Locomotor Behavior ◽  
The Body ◽  
Long Bone ◽  
Cross Sectional ◽  
Body Center

Long bone diaphyseal cross-sectional geometries reflect the mechanical properties of the bones, and can be used to aid in inferences of locomotor behavior in extinct hominins. This chapter considers all available long bone diaphyseal and femoral neck cross-sections of specimens from Sterkfontein Member 4, and presents comparisons of these section properties and other cross-sectional dimensions with those of other early hominins as well as modern samples. The cross-sectional geometry of the Sterkfontein Member 4 long bone specimens suggests some similarities to, but also interesting differences in, mechanical loading of these elements relative to modern humans. The less asymmetric cortical bone distribution in the Sterkfontein femoral necks is consistent with other evidence above indicating an altered gait pattern involving lateral displacement of the body center of mass over the stance limb. The relatively very strong upper limb of StW 431 implies that arboreal behavior formed a significant component of its locomotor repertoire. Bipedal gait may have been less efficient and arboreal climbing more prevalent in the Sterkfontein hominins.

Time-To-Contact Analysis of Gait Stability in the Swing Phase of Walking in People With Multiple Sclerosis

Motor Control ◽  
2015 ◽  
Vol 19 (4) ◽  
pp. 289-311 ◽  
Author(s):  
Jebb G. Remelius ◽  
Richard E.A. van Emmerik
Keyword(s):  
Multiple Sclerosis ◽  
Center Of Mass ◽  
Swing Phase ◽  
The Body ◽  
Head Movements ◽  
Gait Stability ◽  
Time To Contact ◽  
Prospective Control ◽  
Body Center ◽  
All Speeds

This study investigated timing and coordination during the swing phase of swing leg, body center of mass (CoM) and head during walking people with multiple sclerosis (MS; n = 19) and controls (n = 19). The MS group showed differences in swing phase timing at all speeds. At imposed but not preferred speeds, the MS group had less time to prepare for entry into the unstable equilibrium, as the CoM entered this phase of swing earlier. Time-to-contact coupling, quantifying the coordination between the CoM and the swing foot, was not different between groups. The projection of head motion on the ground occurred earlier after toeoff and was positioned closer to the body in the MS group, illustrating increased reliance on visual exproprioception in which vision of the body in relation to the surface of support is established. Finally, prospective control, linking head movements to the swing foot time-to-contact and next step landing area, was impaired in the MS group at higher gait speeds.

scholarly journals Sensorimotor feedback based on task-relevant error robustly predicts temporal recruitment and multidirectional tuning of muscle synergies

2013 ◽  
Vol 109 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Seyed A. Safavynia ◽  
Lena H. Ting
Keyword(s):  
Sagittal Plane ◽  
Balance Control ◽  
Center Of Mass ◽  
The Body ◽  
Muscle Synergy ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Initial State ◽  
Sensorimotor Feedback ◽  
Task Level

We hypothesized that motor outputs are hierarchically organized such that descending temporal commands based on desired task-level goals flexibly recruit muscle synergies that specify the spatial patterns of muscle coordination that allow the task to be achieved. According to this hypothesis, it should be possible to predict the patterns of muscle synergy recruitment based on task-level goals. We demonstrated that the temporal recruitment of muscle synergies during standing balance control was robustly predicted across multiple perturbation directions based on delayed sensorimotor feedback of center of mass (CoM) kinematics (displacement, velocity, and acceleration). The modulation of a muscle synergy's recruitment amplitude across perturbation directions was predicted by the projection of CoM kinematic variables along the preferred tuning direction(s), generating cosine tuning functions. Moreover, these findings were robust in biphasic perturbations that initially imposed a perturbation in the sagittal plane and then, before sagittal balance was recovered, perturbed the body in multiple directions. Therefore, biphasic perturbations caused the initial state of the CoM to differ from the desired state, and muscle synergy recruitment was predicted based on the error between the actual and desired upright state of the CoM. These results demonstrate that that temporal motor commands to muscle synergies reflect task-relevant error as opposed to sensory inflow. The proposed hierarchical framework may represent a common principle of motor control across motor tasks and levels of the nervous system, allowing motor intentions to be transformed into motor actions.

Adding Light Touch While Walking in Older Adults: Biomechanical and Neuromotor Effects

2020 ◽  
Vol 28 (5) ◽  
pp. 680-685
Author(s):  
Alison R. Oates ◽  
Aaron Awdhan ◽  
Catherine Arnold ◽  
Joyce Fung ◽  
Joel L. Lanovaz
Keyword(s):  
Older Adults ◽  
Muscle Activity ◽  
Balance Control ◽  
Center Of Mass ◽  
Gait Pattern ◽  
Light Touch ◽  
Margin Of Stability ◽  
Complex Picture ◽  
Falls In Older Adults ◽  
Haptic Input

Adding haptic input may improve balance control and help prevent falls in older adults. This study examined the effects of added haptic input via light touch on a railing while walking. Participants (N = 53, 75.9 ± 7.9 years) walked normally or in tandem (heel to toe) with and without haptic input. During normal walking, adding haptic input resulted in a more cautious and variable gait pattern, reduced variability of center of mass acceleration and margin of stability, and increased muscle activity. During tandem walking, haptic input had minimal effect on step parameters, decreased lower limb muscle activity, and increased cocontraction at the ankle closest to the railing. Age was correlated with step width variability, stride length variability, stride velocity, variability of medial-lateral center of mass acceleration, and margin of stability for tandem walking. This complex picture of sensorimotor integration in older adults warrants further exploration into added haptic input during walking.

scholarly journals Symmetry Analysis of Amputee Gait Based on Body Center of Mass Trajectory and Discrete Fourier Transform

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2392
Author(s):  
Claudia Ochoa-Diaz ◽  
Antônio Padilha L. Bó
Keyword(s):  
Center Of Mass ◽  
Sine Wave ◽  
The Body ◽  
Compensatory Mechanisms ◽  
Magnitude Spectrum ◽  
Functional Aspects ◽  
Gait Mechanics ◽  
Body Center ◽  
Main Components ◽  
Amputee Gait

The calculation of symmetry in amputee gait is a valuable tool to assess the functional aspects of lower limb prostheses and how it impacts the overall gait mechanics. This paper analyzes the vertical trajectory of the body center of mass (CoM) of a group formed by transfemoral amputees and non-amputees to quantitatively compare the symmetry level of this parameter for both cases. A decomposition of the vertical CoM into discrete Fourier series (DFS) components is performed for each subject’s CoM trajectory to identify the main components of each pattern. A DFS-based index is then calculated to quantify the CoM symmetry level. The obtained results show that the CoM displays different patterns along a gait cycle for each amputee, which differ from the sine-wave shape obtained in the non-amputee case. The CoM magnitude spectrum also reveals more coefficients for the amputee waveforms. The different CoM trajectories found in the studied subjects can be thought as the manifestation of developed compensatory mechanisms, which lead to gait asymmetries. The presence of odd components in the magnitude spectrum is related to the asymmetric behavior of the CoM trajectory, given the fact that this signal is an even function for a non-amputee gait. The DFS-based index reflects this fact due to the high value obtained for the non-amputee reference, in comparison to the low values for each amputee.

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