scholarly journals KINETIC AND KINEMATIC ANALYSIS OF STANCE WITH AND WITHOUT ARM SUPPORT IN INCOMPLETE SPINAL CORD INJURED SUBJECTS

2010 ◽  
Vol 22 (06) ◽  
pp. 465-474
Author(s):  
Elin Allen Yu ◽  
Pei-Pei Hsu ◽  
Tung-Wu Lu ◽  
Wen-Ling Yeh ◽  
Kwan-Hwa Lin

There is a lack of studies concerning standing stability in subjects with incomplete spinal cord injury (SCI). The aims of this study were to analyze the changes of center of pressure (COP), joint moment, joint angle, and muscle activities in patients with incomplete SCI during quiet stance with and without arm support. Ten cervical–thoracic cord incompletely injured patients (mean age: 47.8 ± 13.4 years old) participated in this study. They performed quiet standing with each leg on separate force plate (AMTI, USA) for 5 s with and without holding the walker to obtain the kinetic data. The kinematic data of joint angles were recorded by Motion Analysis System (Vicon 250, Oxford, UK). The electromyographic activities of trunk muscles and quadriceps were recorded by surface electrodes. The results indicated that the COP sway area and the normalized COP sway area significantly (P < 0.01) increased from 94.9 ± 61.3 mm2 to 254.6 ± 91.8 mm2 and from 0.0013 ± 0.0007 to 0.0037 ± 0.0012, respectively, in patients with incomplete SCI, while standing with arms released from walker. The ankle and knee moments also increased significantly (P < 0.05) during stance without support. However, the joint angles and recorded muscle activities were not significantly different between those with and without support. The conclusion was that the proprioceptive feedback of postural sway, and the motor control strategies of knee–ankle muscles would be important for patients with incomplete SCI during stance without arm support.

Author(s):  
Jae W Lee ◽  
Katherine Chan ◽  
Janelle Unger ◽  
Jaeeun Yoo ◽  
Kristin E Musselman ◽  
...  

Individuals with motor incomplete spinal cord injuries (iSCI) often have impaired abilities to maintain upright balance. For able-bodied (AB) individuals, the ankle and hip joint accelerations are in anti-phase to minimize the postural sway during quiet standing. Here we investigated how inter-joint coordination between the ankle and hip joints was affected in individuals with iSCI leading to their larger postural sway during quiet standing. Data from sixteen individuals with iSCI, fourteen age- and sex-matched AB individuals and thirteen young AB individuals were analyzed. The participants performed quiet standing during which kinematic and kinetic data were recorded. Postural sway was quantified using center-of-pressure velocity and center-of-mass acceleration. Individual ankle and hip joint kinematics were quantified, and the inter-joint coordination was assessed using the cancellation index (CI), goal-equivalent variance (GEV), non-goal-equivalent variance (NGEV) and uncontrolled manifold (UCM) ratio. Individuals with iSCI displayed greater postural sway compared to AB individuals. The contribution of ankle angular acceleration towards one's sway was significantly greater for those with iSCI compared to AB groups. CI and the UCM ratio were not statistically different between the groups, while GEV and NGEV were significantly greater for the iSCI group compared to the AB groups. We demonstrated that individuals with iSCI show larger postural sway compared to the AB individuals during quiet standing, primarily due to larger ankle joint acceleration. We also demonstrated that the inter-joint coordination between ankle and hip joint is not affected in individuals with iSCI, which is not successfully able to reduce the large COM acceleration.


Author(s):  
Elżbieta Piątek ◽  
Michał Kuczyński ◽  
Bożena Ostrowska

Due to balance deficits that accompany adolescent idiopathic scoliosis (AIS), the potential interaction between activities of daily living and active self-correction movements (ASC) on postural control deserves particular attention. Our purpose was to assess the effects of ASC movements with or without a secondary mental task on postural control in twenty-five girls with AIS. It is a quasi-experimental within-subject design with repeated measures ANOVA. They were measured in four 20-s quiet standing trials on a force plate: no task, ASC, Stroop test, and both. Based on the center-of-pressure (COP) recordings, the COP parameters were computed. The ASC alone had no effect on any of the postural sway measures. Stroop test alone decreased COP speed and increased COP entropy. Performing the ASC movements and Stroop test together increased the COP speed and decreased COP entropy as compared to the baseline data. In conclusion, our results indicate that AIS did not interfere with postural control. The effects of the Stroop test accounted for good capacity of subjects with AIS to take advantage of distracting attentional resources from the posture. However, performing both tasks together exhibited some deficits in postural control, which may suggest the need for therapeutic consultation while engaging in more demanding activities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Lon Fok ◽  
Jae W. Lee ◽  
Janelle Unger ◽  
Katherine Chan ◽  
Kristin E. Musselman ◽  
...  

AbstractPrevious findings indicate that co-contractions of plantarflexors and dorsiflexors during quiet standing increase the ankle mechanical joint stiffness, resulting in increased postural sway. Balance impairments in individuals with incomplete spinal cord injury (iSCI) may be due to co-contractions like in other individuals with reduced balance ability. Here we investigated the effect of co-contraction between plantar- and dorsiflexors on postural balance in individuals with iSCI (iSCI-group) and able-bodied individuals (AB-group). Thirteen able-bodied individuals and 13 individuals with iSCI were asked to perform quiet standing with their eyes open (EO) and eyes closed (EC). Kinetics and electromyograms from the tibialis anterior (TA), soleus and medial gastrocnemius were collected bilaterally. The iSCI-group exhibited more co-contractions than the AB-group (EO: 0.208% vs. 75.163%, p = 0.004; EC: 1.767% vs. 92.373%, p = 0.016). Furthermore, postural sway was larger during co-contractions than during no co-contraction in the iSCI-group (EO: 1.405 cm/s2 vs. 0.867 cm/s2, p = 0.023; EC: 1.831 cm/s2 vs. 1.179 cm/s2, p = 0.030), but no differences were found for the AB-group (EO: 0.393 cm/s2 vs. 0.499 cm/s2, p = 1.00; EC: 0.686 cm/s2 vs. 0.654 cm/s2, p = 1.00). To investigate the mechanism, we performed a computational simulation study using an inverted pendulum model and linear controllers. An increase of mechanical stiffness in the simulated iSCI-group resulted in increased postural sway (EO: 2.520 cm/s2 vs. 1.174 cm/s2, p < 0.001; EC: 4.226 cm/s2 vs. 1.836 cm/s2, p < 0.001), but not for the simulated AB-group (EO: 0.658 cm/s2 vs. 0.658 cm/s2, p = 1.00; EC: 0.943 cm/s2 vs. 0.926 cm/s2, p = 0.190). Thus, we demonstrated that co-contractions may be a compensatory strategy for individuals with iSCI to accommodate for decreased motor function, but co-contractions may result in increased ankle mechanical joint stiffness and consequently postural sway.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Omid Rasouli ◽  
Egil A. Fors ◽  
Ottar Vasseljen ◽  
Ann-Katrin Stensdotter

Background and Objectives. Cognitive complaints are common in fibromyalgia (FM) and chronic fatigue syndrome (CFS). Fatigue as well as pain may require greater effort to perform cognitive tasks, thereby increasing the load on processing in the central nervous system and interfering with motor control.Methods. The effect of a concurrent arithmetic cognitive task on postural control during quiet standing was investigated in 75 women (aged 19–49 years) and compared between FM, CFS, and matched controls (n=25/group). Quiet standing on a force plate was performed for 60 s/condition, with and without a concurrent cognitive task. The center of pressure data was decomposed into a slow component and a fast component representing postural sway and adjusting ankle torque.Results. Compared to controls, CFS and FM displayed lower frequency in the slow component (p<0.001), and CFS displayed greater amplitude in the slow (p=0.038andp=0.018) and fast (p=0.045) components. There were no interactions indicating different responses to the added cognitive task between any of the three groups.Conclusion. Patients displayed insufficient postural control across both conditions, while the concurrent cognitive task did not perturb quiet standing. Fatigue but not pain correlated with postural control variables.


2020 ◽  
Vol 29 (2) ◽  
pp. 174-178
Author(s):  
Kelly M. Meiners ◽  
Janice K. Loudon

Purpose/Background: Various methods are available for assessment of static and dynamic postural stability. The primary purpose of this study was to investigate the relationship between dynamic postural stability as measured by the Star Excursion Balance Test (SEBT) and static postural sway assessment as measured by the TechnoBody™ Pro-Kin in female soccer players. A secondary purpose was to determine side-to-side symmetry in this cohort. Methods: A total of 18 female soccer players completed testing on the SEBT and Technobody™ Pro-Kin balance device. Outcome measures were anterior, posterior medial, and posterior lateral reaches from the SEBT and center of pressure in the x- and y-axes as well as SD of movement in the forward/backward and medial/lateral directions from the force plate on left and right legs. Bivariate correlations were determined between the 8 measures. In addition, paired Wilcoxon signed-rank tests were performed to determine similarity between limb scores. Results: All measures on both the SEBT and postural sway assessment were significantly correlated when comparing dominant with nondominant lower-extremities with the exception of SD of movement in both x- and y-axes. When correlating results of the SEBT with postural sway assessment, a significant correlation was found between the SEBT right lower-extremity posterior lateral reach (r = .567, P < .05) and summed SEBT (r = .486, P < .05) and the center of pressure in the y-axis. A significant correlation was also found on the left lower-extremity, with SD of forward/backward movement and SEBT posterior medial reach (r = −.511, P < .05). Conclusions: Dynamic postural tests and static postural tests provide different information to the overall assessment of balance in female soccer players. Relationship between variables differed based on the subject’s lower-extremity dominance.


1997 ◽  
Vol 21 (3) ◽  
pp. 210-221 ◽  
Author(s):  
G. Baardman ◽  
M. J. Ijzerman ◽  
H. J. Hermen ◽  
P. H. Veltink ◽  
H. B. K. Boom ◽  
...  

The effect of reciprocally linking the hip hinges of a hip-knee-ankle-foot orthosis on standing performance was studied in a comparative trial of the Advanced Reciprocating Gait Orthosis (ARGO) and an ARGO in which the Bowden cable was removed (A_GO). Six male subjects with spinal cord injury (SCI) at T4 to T12 level participated in the study, which was conducted using a single case experimental design. Standing balance, the ability to handle balance disturbances (standing stability), and the performance of a functional hand task during standing were assessed in both orthosis configurations in the order A_GO-ARGO-A_GO-ARGO. No significant differences with respect to standing performance were found for the two orthosis configurations. However, the results indicate that the crutch force needed for maintaining balance during various tasks, especially for quiet standing with two crutches, may be much higher in the orthosis without Bowden cable. Therefore, it is very likely that the reciprocal hip joint link in the ARGO provides a substantial and clinically relevant reduction of upper body effort required for standing under functional conditions.


2020 ◽  
pp. 003151252094509
Author(s):  
Mark Walsh ◽  
Caroline Church ◽  
Audrey Hoffmeister ◽  
Dean Smith ◽  
Joshua Haworth

Measurements of postural sway are used to assess physiological changes due to therapy or sport training, or to describe group differences based on activity history or disease status. Portable force plates have been widely adopted for this purpose, leading us in this study to validate with linear and nonlinear metrics the posturographic data derived from both a portable plate (Natus) when compared to an in-ground plate (Bertec). Twenty participants stood on each plate for two trials each, with and without a foam perturbation and with and without eyes open on each surface. We calculated measures of path length, range, root mean squares, sample entropy, and correlation dimensions from center of pressure traces on each plate. An intraclass correlation coefficient across trials from each plate in each condition indicated satisfactory overall reliability (ICC consistency), supporting the use of either plate for postural sway research and interventions. Additionally, our results generally supported common validity (ICC absolute agreement), though, the specific degree of similarity differed for each of the tested metrics of postural sway, especially when considering whether or not data was filtered. For situations in which participants cannot visit a laboratory (e.g. performing athletes, community dwelling clinical patients, and virus risk concerns) an in-home portable force plate is a trusted and valuable data collection tool.


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