scholarly journals STUDY OF NORMAL VALUES OF PROPRIOCEPTION BASED ON AGE

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0023
Author(s):  
Marie-Lyne Nault ◽  
Olivier Chémaly ◽  
Guy Grimard ◽  
Mélanie Sarda ◽  
Marie-Pier Trottier ◽  
...  
Keyword(s):  
Postural Control ◽  
Lower Limb ◽  
Normal Values ◽  
Pediatric Population ◽  
Stability Index ◽  
Primary Objective ◽  
Return To Sports ◽  
The Mean ◽  
Stability Indexes ◽  
The Stability

Background: Proprioception is an important function which allows the brain to perceive the body’s position. It is a safety mechanism aiding the generation of movements to correct and maintain balance. During a return to sports for adults, it is essential to have a good postural control. However, this requirement is applied subjectively in a pediatric setting. The Biodex Stability System (BSS) is a validated instrument capable of evaluating proprioception by producing stability indexes. Unfortunately, the stability indexes for a healthy pediatric population and the associated characteristics have not yet been determined. Purpose: The primary objective was to establish normal pediatric values of proprioception using the BSS. The secondary objectives were to find correlations between various subgroups (sex, physical activity participation and joint laxity, etc) and the stability indexes. Methods: An observational cohort study was done. Patients from July 2018 to September 2018 were included from the facture clinic. Inclusion/exclusion criteria were: (1) a consolidated upper limb fracture, (2) no previous history of lower limb injury, (3) no congenital anomalies of the lower limb or neuromuscular disease. Included subjects underwent 3 test trials of 20 seconds each of single-leg shoeless postural control with eyes open and at a stability level of 4. The overall stability index (OSI), anteroposterior stability index (APSI) and mediolateral stability index (MLSI) were noted. The protocol was conducted on both legs. Kolmogorov-Smirnov test will be used for the primary objective and, Pearson correlation for secondary objective. Results: Seventy-one participants (29 girls and 42 boys) with a mean age of 12.75±2.2 years old and a mean Beighton laxity score of 2.5±2.5 were recruited. The mean left OSI is 4.4±3.1 and the mean right OSI is 4.5±3.3. When comparing the subgroups, we were able to find correlations between the body mass index (BMI) and the OSI for both legs (left: r= 0.312, p = 0.008; right: r= 0.437, p = 0.001). We did not find any other correlations for any other groups (sex, age and Beighton score). Conclusion: A larger sample size will be needed to establish normal values based on sex and skeletal maturity but a mean value for OSI for a normal pediatric population was established. This study illustrates that, in our pediatric population, an increase in BMI is associated with an increase in OSI. Therefore, children with a higher BMI could potentially benefit from a proprioception training program in order to prevent the occurrence of injuries.

scholarly journals EVALUATION OF THE UTILITY OF THE ANTERIOR CRUCIATE LIGAMENT RETURN TO SPORT AFTER INJURY (ACL-RSI) SCALE WITHIN PEDIATRIC ATHLETES

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0003
Author(s):  
Elliot Greenberg ◽  
Miranda Dabbous ◽  
Anne Leung ◽  
Gabriella Marinaccio ◽  
Benjamin Ruley ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Pediatric Population ◽  
Cruciate Ligament ◽  
Return To Sport ◽  
The United States ◽  
Return To Play ◽  
Return To Sports ◽  
Youth Athletes ◽  
The Mean ◽  
Anterior Cruciate

Background: The incidence of anterior cruciate ligament (ACL) injury and surgical reconstruction in youth athletes is increasing. In the United States, most athletes elect to undergo ACL reconstruction (ACLR), with the goal of returning to their previous level of athletic performance. Although surgery and rehabilitation address the underlying impairments in knee stability and function, recent literature indicates psychological or emotional factors, such as fear or confidence, may be contributing factors limiting successful return to play. The Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) is a 12-item scale designed to assess an athlete’s psychological readiness to return to sports across three separate domains (emotions, confidence in performance and risk appraisal). In adults, the ACL-RSI is reliable and valid, and several studies have documented that athletes with higher scores are more likely to successfully return to their pre-injury level of sports participation. The predictive abilities of this scale, have led many experts to advocate for the ACL-RSI to be used as part of rehabilitation guidelines, in order to identify those athletes that may benefit from a modified course of post-operative rehabilitation or additional emotional or psychological support. Although the information from the ACL-RSI is valuable in adults, the utility of this scale has never been explored within the pediatric population. Thus, the purpose of this study is to evaluate the utility of the ACL-RSI within the pediatric population and establish normative values among healthy children. Hypothesis: As all of these subjects were currently healthy, we hypothesized that mean scores should demonstrate a positive skew towards higher levels of confidence (ceiling effect) with values of 80-100 on each question. Methods: A group of 84 healthy, youth athletes between the ages of 8-14, completed the ACL-RSI. All subjects were currently involved in competitive sports at the time of participation. The athletes were instructed to complete the 12-item ACL-RSI questionnaire and were able to seek assistance from parents as necessary. Each item is scored on a scale ranging from 0-100 and a total score is calculated from summing all responses and expressing them a percentage of 100%. Higher scores indicate a greater degree of athletic confidence or more positive psychological response to injury. Mean and variability measures for each question and total score were calculated and compared to existing literature. Results: A total of 83 subjects (mean age 11.1 ± 1.2) completed the questionnaire in full. There were slightly more females (n=46, 54.8%) than males. The majority of participants were White (70%), African American (13%) or more than one race (10%). The most frequent primary sport was soccer (38%), followed by baseball (27%) and basketball (26%). The mean ACL-RSI score for the entire sample was 79.9 (SD 14.1). Individual question analysis revealed lower than expected mean scores (<80%) with large standard deviations for 7 out of 12 questions. (Table 1) With the exception of only question #1 and #12, responses demonstrated such large variability that both the maximum and minimum (0-100) scores were selected, indicating both ceiling and floor effects. (Table 1) Conclusions/Significance: The mean ACL-RSI score (79.9) within this group of uninjured pediatric athletes was similar to previous values for post-ACLR adults that successfully return to sports. However, it was surprising that the mean score wasn’t higher, as this was a healthy population of un-injured youth athletes, and we hypothesized that our data would demonstrate a positive skew towards the upper range of this scale. Response ranges including 0 (indicating either high fear or severe lack of confidence) within nearly all questions was unexpected. Additionally, there were particularly low mean scores and high variability within 7 of the 12 questions. All of these factors raise the suspicion that children may not fully comprehend the material or have difficulty interpreting the response system of the ACL-RSI and thus calls into question the validity of this scale in youth athletes. Similar to other research efforts that have modified adult outcome scales to be utilized within the pediatric population, our results support further exploration of the utility of the ACL-RSI within pediatric athletes and may possibly suggest that a pediatric specific version should be created. [Table: see text]

Appraisement and Analysis of Dynamical Stability of Under-Constrained Cable-Driven Lower-Limb Rehabilitation Training Robot

Robotica ◽  
2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yan-Lin Wang ◽  
Ke-Yi Wang ◽  
Wan-Li Wang ◽  
Zhuang Han ◽  
Zi-Xing Zhang
Keyword(s):  
Lower Limb ◽  
Stability Index ◽  
Dynamical Stability ◽  
Eigenvalue Decomposition ◽  
Constrained System ◽  
Rehabilitation Training ◽  
Distribution Laws ◽  
The Stability ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

SUMMARY The dynamical stability of the cable-driven lower-limb rehabilitation training robot (CLLRTR) is a crucial question. Based on the established dynamics model of CLLRTR, the solution to the wrench closure of the under-constrained system is presented. Secondly, the stability index of CLLRTR is proposed by the Krasovski method. Finally, in order to analyze the stability distribution of CLLRTR in the workspace, the stability evaluation index in the workspace is calculated using the eigenvalue decomposition method. The stability distribution laws of CLLRTR are further verified by the experimental study. The results provide references for studying trajectory planning and anti-pendulum control of CLLRTR.

scholarly journals Impact of Treatment Regimen with Moroctocog Alfa (AF-CC) on Bleeding Frequency in Pediatric Aged Subjects with Moderately Severe to Severe Hemophilia A

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1205-1205
Author(s):  
Mark P. Smith ◽  
Jeremy Rupon ◽  
Yasser Wali ◽  
Hala Remawi ◽  
Joan Korth-Bradley ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Hemophilia A ◽  
Pediatric Population ◽  
Low Frequency ◽  
Primary Objective ◽  
Severe Hemophilia ◽  
On Demand ◽  
Routine Prophylaxis ◽  
The Mean ◽  
Safety Signals

Abstract Moroctocog alfa (AF-CC) is a B-domain deleted recombinant factor VIII product for the treatment of patients with hemophilia A. It has previously been studied in pediatric aged hemophilia patients, however direct comparisons between treatment regimens have not been evaluated. Importantly, as prophylaxis has been shown to be superior to on-demand treatment, comparisons between different prophylaxis regimens are needed. Reducing the frequency of infusions without sacrificing efficacy may reduce the burden of hemophilia management. This study was an open label, multicenter, randomized crossover study of two routine prophylaxis (RP) regimens of moroctocog alfa (AF-CC) compared to on-demand (OD) therapy in 2 cohorts of children with hemophilia A. The primary objective was to demonstrate that prophylaxis reduces ABR relative to OD therapy. A secondary objective was to compare the efficacy of two different RP regimens. Additional objectives focused on FVIII recovery and safety. Study Design: The study was open to previously treated patients (≥20 exposure days (ED) to any FVIII replacement product) with moderately severe to severe hemophilia A (<2% FVIII) aged 6 months to <16 years. The study enrolled 2 cohorts of subjects who were treated in two segments. The first cohort started with OD treatment for 6 months (segment 1) followed by 1 year of RP of 25 international units (IU)/kg every other day (segment 2). Subjects in the second cohort were randomized to one of 2 RP regimens for 1 year (segment 1) and then crossed over to a second RP regimen for an additional year (segment 2). The RP regimens were high frequency (HF) (25 IU/kg every other day) and low frequency (LF) (45 IU/kg twice weekly). Recovery assessment after administration of 50 IU/kg of moroctocog alfa (AF-CC) was optional. Results: A total of 51 subjects were enrolled in the study: 9 subjects (age 2.4-5.9 yr; median 4.9 yr) in the OD group, 18 subjects (age 1.1-12.7 yr; median 4.7 yr) received LF followed by HF, and 24 subjects (age 1.2 to 9.6 yr; median 4.6 yr) received HF followed by LF. The mean (standard deviation [SD]) ABR for the first cohort (n=9) during the OD segment was 47.0(32.2) and during the RP segment (HF) was 1.5(2.2). In those subjects from cohort 2 that completed both segments (n=38), the mean (standard deviation) ABR for HF was 2.2(4.1) and for LF was 3.3(5.3). Based on a prospectively defined equivalence limit of (-3, 3) bleeds per year, equivalence between these two regimens was demonstrated as the 90% CI for the difference, (0.03, 2.22) fell within this range. The mean (SD) recovery in 6 children aged 3.7 to 5.8 yrs was 1.44(0.61) IU/dL/IU/kg. Three subjects tested positive for FVIII inhibitors, however 2 were considered to be false positives for an overall rate of 2%. There were no new safety signals that emerged during this study. Conclusion: This study met its primary objective of demonstrating that RP reduces the ABR compared to OD. Notably, LF prophylaxis with moroctocog alfa (AF-CC) is as efficacious as a HF prophylaxis regimen. This has important implications as less frequent infusions can improve adherence and the quality of life for patients with hemophilia. Additionally, recovery was as expected in this pediatric population and no new safety signals emerged. Moroctocog alfa (AF-CC) is safe and efficacious for routine prophylaxis in pediatric patients with hemophilia A and a low frequency (twice weekly) prophylaxis regimen is as efficacious as every other day prophylaxis. Disclosures Rupon: Pfizer: Employment. Korth-Bradley:Pfizer Inc.: Employment. Smith:Pfizer: Employment. Rendo:Pfizer: Employment.

scholarly journals Neuromuscular adaptations and sensorimotor integration following a unilateral transfemoral amputation

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Claudia Ramos Claret ◽  
Georg W. Herget ◽  
Lukas Kouba ◽  
Daniel Wiest ◽  
Jochen Adler ◽  
...  
Keyword(s):  
Postural Control ◽  
Lower Limb ◽  
Sensory Feedback ◽  
Sensorimotor Integration ◽  
Center Of Pressure ◽  
Temporal Structure ◽  
Weight Bearing ◽  
Transfemoral Amputation ◽  
Neuromuscular Adaptations ◽  
The Mean

Abstract Background Following an amputation, the human postural control system develops neuromuscular adaptations to regain an effective postural control. We investigated the compensatory mechanisms behind these adaptations and how sensorimotor integration is affected after a lower-limb transfemoral amputation. Methods Center of pressure (CoP) data of 12 unilateral transfemoral amputees and 12 age-matched able-bodied subjects were recorded during quiet standing with eyes open (EO) and closed (EC). CoP adjustments under each leg were recorded to study their contribution to posture control. The spatial structure of the CoP displacements was characterized by measuring the mean distance, the mean velocity of the CoP adjustments, and the sway area. The Entropic Half-Life (EnHL) quantifies the temporal structure of the CoP adjustments and was used to infer disrupted sensory feedback loops in amputees. We expanded the analysis with measures of weight-bearing imbalance and asymmetry, and with two standardized balance assessments, the Berg Balance Scale (BBS) and Timed Up-and-Go (TUG). Results There was no difference in the EnHL values of amputees and controls when combining the contributions of both limbs (p = 0.754). However, amputees presented significant differences between the EnHL values of the intact and prosthetic limb (p <  0.001). Suppressing vision reduced the EnHL values of the intact (p = 0.001) and both legs (p = 0.028), but not in controls. Vision feedback in amputees also had a significant effect (increase) on the mean CoP distance (p <  0.001), CoP velocity (p <  0.001) and sway area (p = 0.007). Amputees presented an asymmetrical stance. The EnHL values of the intact limb in amputees were positively correlated to the BBS scores (EO: ρ = 0.43, EC: ρ = 0.44) and negatively correlated to the TUG times (EO: ρ = − 0.59, EC: ρ = − 0.69). Conclusion These results suggest that besides the asymmetry in load distribution, there exist neuromuscular adaptations after an amputation, possibly related to the loss of sensory feedback and an altered sensorimotor integration. The EnHL values suggest that the somatosensory system predominates in the control of the intact leg. Further, suppressing the visual system caused instability in amputees, but had a minimal impact on the CoP dynamics of controls. These findings points toward the importance of providing somatosensory feedback in lower-limb prosthesis to reestablish a normal postural control. Trial registration DRKS00015254, registered on September 20th, 2018.

Optimization of the Bicycle Weave and Wobble Modes

2018 ◽  
Author(s):  
Sergio Roa ◽  
Alberto Doria ◽  
Luis Muñoz
Keyword(s):  
Stability Index ◽  
Stability Range ◽  
Systematic Analysis ◽  
Trade Off ◽  
Hands On ◽  
Modes Of Vibration ◽  
Road Racing ◽  
Stability Indexes ◽  
The Stability ◽  
Stability Area

Stability of bicycles has been studied by using models that assume both a rider with hands-off and hands-on the handlebars. Some authors have presented a general comparison between the behavior of the modes of vibration which affect stability in the two configurations; nonetheless, a systematic analysis of the influence of several parameters on each configuration has not been addressed. In addition, the concept of self-stability range has been used as a stability indicator especially when analyzing a rider’s hands-off situation. In contrast, in this paper, the stability area concept is used as a stability index given that it provides more information about the vibration modes in a broader speed range. Therefore, this paper has two major aims. First, the different influence on stability indexes of geometrical, compliance and tire parameters of road racing bicycles is analyzed using hands-off and hands-on models previously published in the literature. Numerical results show that some parameters have different effects on the stability of weave and wobble modes in hands-off and hands-on conditions. Second, a trade-off between the stability behavior of weave and wobble modes is found when using the hands-on model. Therefore, a multi-objective optimization problem for maximizing the stability of both modes is addressed. A Pareto front of the stability of weave and wobble modes is found that serves to analyze the stability trade-off.

The stability index of hypersurfaces with constant scalar curvature in spheres

2014 ◽  
Vol 144 (3) ◽  
pp. 447-453
Author(s):  
Qing-Ming Cheng ◽  
Haizhong Li ◽  
Guoxin Wei
Keyword(s):  
Scalar Curvature ◽  
Mean Curvature ◽  
Constant Scalar Curvature ◽  
Stability Index ◽  
Dimensional Sphere ◽  
Weak Stability ◽  
Totally Umbilical ◽  
Compact Hypersurface ◽  
The Mean ◽  
The Stability

The totally umbilical and non-totally geodesic hypersurfaces in the (n + 1)-dimensional spheres are characterized as the only hypersurfaces with weak stability index 0. In our 2010 paper we proved that the weak stability index of a compact hypersurface M with constant scalar curvature n(n − 1)r, r> 1, in an (n + 1)-dimensional sphere Sn + 1(1), which is not a totally umbilical hypersurface, is greater than or equal to n + 2 if the mean curvature H and H3 are constant. In this paper, we prove the same results, without the assumption that H3 is constant. In fact, we show that the weak stability index of a compact hypersurface M with constant scalar curvature n(n − 1)r, r> 1, in Sn + 1(1), which is not a totally umbilical hypersurface, is greater than or equal to n + 2 if the mean curvature H is constant.

scholarly journals 4 Saline-lock versus continuous infusion: maintaining peripheral intravenous catheter access in children

2020 ◽  
Vol 25 (Supplement_2) ◽  
pp. e2-e2
Author(s):  
Frances Yeung ◽  
Sepideh Taheri ◽  
Michael Miller ◽  
Rahul Ojha ◽  
Brianna McKelvie ◽  
...  
Keyword(s):  
Continuous Infusion ◽  
Pediatric Population ◽  
Invasive Procedure ◽  
Primary Objective ◽  
Complication Rates ◽  
Intravenous Catheter ◽  
Chi Square ◽  
Caregiver Satisfaction ◽  
Peripheral Intravenous Catheter ◽  
The Mean

Abstract Background Peripheral intravenous catheter (PIVC) insertion is a painful and invasive procedure performed on most paediatric patients. In children, PIVCs are maintained by either a continuous infusion of fluid “to keep vein open” (TKVO) or a saline-lock (SL). There is little uniformity between pediatric centres as to which method is used, and evidence is required to decide which method, if any, best maintains PIVC access. Objectives The primary objective was to compare duration of functional PIVC patency between TKVO and SL in children. Secondary objectives included assessing PIVC-related complications and patient/caregiver satisfaction. Design/Methods This prospective, time-allocated trial enrolled eligible patients from newborn to 17 years of age admitted to our pediatric ward. Patients enrolled in the first 3 months were assigned to TKVO, and patients in the latter 3 months were assigned to SL. Time of PIVC insertion and removal, PIVC-related complications, and satisfaction surveys were collected. Independent t-tests and chi-square tests were used to compare differences between arms for continuous and categorical outcomes, respectively. Results Complete PIVC data was available on 172 (n=85 TKVO, n=87 SL) of 194 enrolled patients. The mean (SD) duration of PIVC patency was 41.68 (41.71) hours in the TKVO group, and 44.05 (41.46) hours in the SL group, which was not statistically significant (p=0.71). There were no significant differences in complication rates or overall patient/caregiver satisfaction between the two groups. One patient in the TKVO group had their PIVC removed due to risk of strangulation from tubing. Conclusion There were no significant differences between TKVO and SL in the duration of PIVC patency in our pediatric population. This is consistent with previous results in neonates. There were also no significant differences in complication rates and overall patient/caregiver satisfaction. Overall, SL is a safe and reasonable alternative to TKVO in maintaining PIVC patency in children.

scholarly journals Postural Control during Progressively Increased Balance-Task Difficulty in Athletes with Unilateral Transfemoral Amputation: Effect of Ocular Mobility and Visuomotor Processing

2020 ◽  
Vol 17 (17) ◽  
pp. 6242
Author(s):  
Michał Zwierko ◽  
Piotr Lesiakowski ◽  
Teresa Zwierko
Keyword(s):  
Postural Control ◽  
Task Difficulty ◽  
Reaction Times ◽  
Stability Index ◽  
Positive Influence ◽  
Soccer Players ◽  
Transfemoral Amputation ◽  
Visuomotor Processing ◽  
Balance Task ◽  
Stability Indexes

This study examined postural control during single leg stance test with progressively increased balance-task difficulty in soccer players with unilateral transfemoral amputation (n = 11) compared to able-bodied soccer players (n = 11). The overall stability index (OSI), the anterior/posterior stability index, and the medial/lateral stability index during three balance tasks with increasing surface instability were estimated. The oculomotor and visuomotor contribution to postural control in disabled athletes was analyzed. Oculomotor function, simple and choice reaction times, and peripheral perception were assessed in a series of visuomotor tests. The variation in OSI demonstrated significantly greater increases during postural tests with increased balance-task difficulty in the able-bodied soccer players compared to amputees (F(2,40) = 3.336, p < 0.05). Ocular mobility index correlated (p < 0.05) with OSI in conditions of increasing balance-task difficulty. Moreover, speed of eye-foot reaction has positive influence (p < 0.05) on stability indexes in tasks with an unstable surface. Amputee soccer players displayed comparable postural stability to able-bodied soccer players. Disabled athletes had better adaptability in restoring a state of balance in conditions of increased balance-task difficulty than the controls. The speed of visuomotor processing, characterized mainly by speed of eye-foot reaction, significantly contributed to these results.

Stability Control of Continuous Compaction Measurement in High-Speed Railway Subgrade

2013 ◽  
Vol 438-439 ◽  
pp. 1104-1107 ◽  
Author(s):  
Tan Jiao ◽  
Xiang Wang ◽  
Ya Bing Huang
Keyword(s):  
Exponential Function ◽  
High Speed ◽  
Stability Index ◽  
Stability Control ◽  
Variation Method ◽  
Test Field ◽  
High Speed Rail ◽  
The Mean ◽  
The Stability ◽  
Dense State

The compaction stability is of great significant for the quality control and assurance of the continuous compaction measurement in subgrade engineering. Based on the mean-variation method, the exponential function between the roller passes and the roller measurement value was modeled to calculate the compaction stability index Δμtmv. The stabilization process of the compacted soil from loose state to dense state could be well described by the modeled function. Through the results of the roller measurement values in three test field of Shanghai-kunming high-speed rail in Huaihua, Zhijiang and Loudi, different compaction stability index due to the varied construction situations was calculated using the mean-variation method and the exponential function. The result shows that the exponential function is well adaptive to different situations and this method could be developed in controlling the stability of continuous compaction measurement.

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