Conservative Gait Termination Strategy Following Concussion

Balance is key to controlling body posture. Balance is typically assessed by measures of the body's vertical orientation, obtained by balancing out the forces acting on different body segments. The ability to maintain balance is assessed by evaluating centre of pressure (CoP) displacement; such assessments are typically used to evaluate responses to a treatment process. This study evaluated the efficiency of compensatory reactions in children according to the extent of thoracic kyphosis and lumbar lordosis. The study enrolled 312 children aged 8‒12 years, including 211 patients with postural disorders: thoracic kyphosis outside the 47‒50-degree range and lordosis outside the 38‒42-degree range (study group). A control group was also recruited and comprised 101 children without postural disorders. The DIERS formetric 4D system was used to assess posture and CoP displacement. Children in the study group showed a significantly greater range of CoP displacement than children in the control group. The kyphosis angle correlated with the maximum CoP displacement in the coronal plane and the maximum CoP displacement in the sagittal plane during gait. The kyphosis angle also correlated with the maximum CoP displacement back in the static test. The size of the lordosis angle correlated with the maximum displacement of CoP in the coronary plane during gait, and with the maximum displacement of CoP toward the left, forward, and backward in the static test. The correlation coefficient of the lordosis angle with displacement of the CoP in the sagittal plane was 0.999. We found an association between kyphosis and lordosis and the amplitude of CoP displacement, which may reflect the postural control system's response to biomechanical destabilisation caused by changes in kyphosis and lordosis.The lordosis angle correlation strength for displacement of CoP in sagittal plane is 0.999 and adopts a linear value.

IntroductionPostural control is essential for humans to maintain balance under both static and dynamic conditions. A variety of unstable support surfaces are used to evaluate postural control. Balance foam pads are relatively expensive, whereas natural rubber pads use a natural material with equivalent viscoelastic properties that are inexpensive and widely available. No postural sway and reliable data existed to support the practice of using a natural rubber pad. The purposes of the study were to determine the test-retest reliability of postural sway by using a natural rubber pad and to compare postural sway in healthy adults while using a foam pad, a natural rubber pad and a firm surface.MethodsNineteen healthy participants were measured for centre of pressure (COP) velocity and displacement during a quiet stance, with their eyes closed, on a balance foam pad (blue foam – Airex®), a natural rubber pad and a firm surface on a force platform. Two repeated sessions were conducted three days apart. Intraclass correlation coefficients were used to determine the test-retest reliability. A one-way repeated measures ANOVA was used to compare the three surface conditions.ResultsThe natural rubber pad demonstrated moderate to good reliability for COP velocity and COP displacement. Also, there were no significant differences in anteroposterior (AP) and mediolateral (ML) COP velocity and displacement between the balance foam pad and the natural rubber pad.ConclusionsOur findings indicate that a natural rubber pad could be employed as a low-cost alternative to the balance foam pad for evaluating the balance of healthy adults.

Postural stability control performance assessment is necessary in providing important information for individuals who are at risk of falling or who have balance impairment. Instrumented assessment is suggested as a valid and reliable test, but the cost and the difficulty of setup are significant limitations. The aim of this cross-sectional (test-retest reliability) study was to develop and determine the reliability of a low-cost posturography for assessing postural stability control performance during standing. The low-cost posturography was developed with four load cells and an acrylic platform. The center of pressure (COP) displacement and velocity were analyzed using written software. Test-retest reliability was performed with six different standing postural stability tests in twenty healthy volunteers on two different days. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), coefficient of variation (CV), and Bland–Altman plot and limits of agreements (LOA) were used for analyses. The low-cost posturography was accurate (ICC = 0.99, p < 0.001; SEM = 0.003 cm) when compared to the true with calculated X and Y coordinates, with a moderate to excellent test-retest reliability for both COP displacement (ICCs ranged 0.62–0.91, p < 0.05; SEMs ranged 17.92–25.77%) and COP velocity (ICCs ranged 0.62–0.91, p < 0.05; SEMs ranged 18.09–27.69%) in all standing postural stability tests. Bland–Altman plots and LOAs suggested good agreement of tested parameters from the developed low-cost posturography between different days. In conclusion, the developed low-cost posturography had adequate reliability for assessing COP displacement and velocity during standing postural control stability performance tests.

The present study assessed the influence of visual feedback on stance stability and soleus H-reflex excitability. The centre of pressure (COP) displacement was measured in upright stance on a rigid surface (stable surface) and on a spinning top (unstable surface) while subjects either received "normal" visual feedback (without laser pointer = WLP) or pointed with a laser pointer on a target on the wall (LP). In order to verify that laser pointing influenced visual feedback, two additional experiments were conducted: (1) Subjects performed a finger reaction task which was thought to increase attention and cognitive demands without alteration of the visual feedback. (2) The effect of laser pointing on the wall was compared with pointing at a board, which was attached to the subjects themselves. In this case, the laser point could not serve as a reference for sway because the board moved in synchrony with the body. On stable and unstable surface, COP displacement was reduced in the LP compared to the WLP task (-17 cm +/- 6, P < 0.05; -14 cm +/- 6, P < 0.05). Conversely, H-reflexes were greater in the LP condition (stable: +20 microV +/- 30, not significant; unstable +115 microV +/- 40, P < 0.05). Stance stability and H-reflex modulation were negatively correlated (R(2) = -0.5; P < 0.001). The finger reaction task did neither influence COP displacement nor H-reflexes. Pointing at the body-fixed target did not alter COP displacement. These findings suggest that postural sway can be reduced by a handheld laser pointer targeting on an external reference point. It is argued that altered visual input was responsible for modulating the H-reflex.

The effects of postural training on postural stability and vestibulospinal reflexes (VSRs) were investigated in normal subjects. A period (23 minutes) of repeated episodes (n = 10, 50 seconds) of unipedal stance elicited a progressive reduction of the area covered by centre of pressure (CoP) displacement, of average CoP displacement along the X and Y axes and of CoP velocity observed in this challenging postural task. All these changes were correlated to each other with the only exception of those in X and Y CoP displacement. Moreover, they were larger in the subjects showing higher initial instability in unipedal stance, suggesting that they were triggered by the modulation of sensory afferents signalling body sway. No changes in bipedal stance occurred soon and 1 hour after this period of postural training, while a reduction of CoP displacement was apparent after 24 hours, possibly due to a beneficial effect of overnight sleep on postural learning. The same period of postural training also reduced the CoP displacement elicited by electrical vestibular stimulation (EVS) along the X axis up to 24 hours following the training end. No significant changes in postural parameters of bipedal stance and VSRs could be observed in control experiments where subjects were tested at identical time points without performing the postural training. Therefore, postural training led to a stricter control of CoP displacement, possibly acting through the cerebellum by enhancing feedforward mechanisms of postural stability and by depressing the VSR, the most important reflex mechanism involved in balance maintenance under challenging conditions.

Flat foot in children is a common deformity in which the medial longitudinal arch is reduced or eliminated. The objective of this article was to compare flat foot and healthy children on the displacement of the center of pressure and walking parameters in children with two common orthoses (functional foot orthosis and medical shoe). Comparative study. This study included 30 children with flat foot and 20 healthy children as a control group. The step length and width, walking velocity, symmetry, and center of pressure (CoP) displacements were recorded and compared for three conditions: functional foot orthosis and regular shoe, a medical shoe and barefoot. The results from the CoP displacements showed that the regular shoe with functional foot orthosis caused a significant decrease in the level of displacement of the CoP in flat foot children. The findings indicated a significant improvement in symmetry of steps and walking speed with the functional foot orthosis in comparison to the medical shoe in flat foot children. The CoP displacement was decreased and the percentage of gait symmetry and walking speed were increased by the use of regular shoes with a functional foot orthosis in comparison to the medical shoes. An orthopaedic shoe can be expensive, and in particular heavy with most children reluctant to wear it. This study focussed on the CoP displacement and selected gait parameters with an orthopaedic shoe and functional foot orthosis, and showed that a combined prescription of a functional foot orthosis and with regular shoes may be a useful alternative for children with moderate flat foot.

Introduction. Many studies have compared different backpack designs and their influence on the carrier; however, no data referring to school students aged 7-8 years are currently available. Therefore, the aim of the research was to assess the influence of backpack design on centre of pressure (COP) displacement and plantar force distribution in children during an upright stance. Material and methods. Nineteen school students (9 males and 10 females) volunteered for the study. Two Polish backpacks intended for school use were evaluated: backpack A, which had two main compartments, and backpack B, which had one main compartment. The backpack load was composed of books, binders, and regular school equipment. During the measurements, the subjects were asked to look ahead with the head straight and arms at the sides in a comfortable position and to stand barefoot on the F-Scan® sensors (Tekscan, F-Scan®) attached to the force platform (Kistler), carrying a load corresponding to 10% of their body mass. Results. The study found insignificant differences between the two backpack designs. Moreover, COP parameters increased significantly during an upright stance while carrying backpack B in comparison to the empty backpack condition. Additionally, we observed significantly higher values of plantar force distribution in the heel region for the condition without load and insignificantly higher ones for carrying backpack A. Conclusions. The results of the current study suggest that the differences between the two backpack designs are too marginal to be detected through COP displacement. Disturbances in plantar force distribution suggest a lack of posture control and a lower stability of the standing position with a backpack, but these disturbances were significant only when the backpack with one main compartment was used.

Balance maintenance as an acquired motor skill: Delayed gains and robust retention after a single session of training in a virtual environment

BackgroundA core component of older adult health care assessment includes identifying fall risk, which also includes identifying those with subtle balance deficits.ObjectiveTo compare body displacement of the Center of Pressure (CoP) and time held during the balance test. Also, to examine whether balance tests at baseline can predict falls after 6 months.MethodsA longitudinal study with 153 community-dwelling older adults, between 60–89 years old. Anteroposterior (AP) and mediolateral (ML) amplitude and velocity CoP displacements were assessed in four upright positions using a force platform: double-leg, semi-tandem, tandem, and single-leg stances, with a maximum duration of 30 s each. Adjusted repeated measures ANOVA were used to compare the differences among the balance positions. Comparisons between males and females were also conducted. Logistic regression adjusted for confounders was performed to verify whether upright balance tests can predict future falls.ResultsAs the base of support narrows, body sway increases. A decrease in stance time was observed across the balance stages, i.e., double-leg/semi-tandem versus tandem versus single-leg stances. The mean duration held in the single-leg stance was 14.8 s and for tandem was 22.2 s. Similar stance durations were observed for double-leg and semi-tandem stances. Males were able to maintain balance positions longer than females even with greater CoP displacement. ML amplitude of CoP displacement and the time held during tandem and single-leg positions were able to predict falls after 6 months (p < 0.05).ConclusionIn clinical practice in which only stance time is recorded, it is possible to interchangeably use the double-leg or semi-tandem stance. To identify early signs of imbalance, we suggest setting a time limit for the balance test equal to or greater than 23 s, as 10 s appear to be insufficient to detect subtle balance deficits. The time maintenance on tandem and single-leg positions was able to predict future falls.

Standing balance in individuals with Parkinson's disease during single and dual-task conditions

Altered postural control has been observed in chronic ankle instability (CAI). Kinesiophobia (fear of re-injury) has been identified as a factor influencing postural stability. Therefore, postural control was assessed during jump landing among CAI athletes with and without kinesiophobia, as well as healthy controls. A total of 60 participants were recruited, including 40 individuals with CAI and 20 healthy controls. The CAI group was subdivided into two cohorts: 20 subjects with kinesiophobia (Tampa Scale of Kinesiophobia score > 37) and 20 without kinesiophobia. All participants performed a single-leg jump landing task on a force plate. The following postural stability metrics were calculated: time to stabilization (TTS), and the mean and standard deviation of center of pressure (COP) displacement and velocity in the anterior-posterior (AP), medial-lateral (ML), and total directions. CAI subjects with kinesiophobia exhibited longer TTSs in the AP (p = 0.019), vertical, and total directions (p < 0.001, p = 0.015, p = 0.002) than healthy subjects. Additionally, CAI subjects with kinesiophobia demonstrated a significant increase in the velocity of COP displacement in the AP and ML directions (p < 0.001, p = 0.004). These individuals showed greater variability in the velocity of COP displacement in the AP direction and in COP displacement in the ML direction than healthy subjects (p < 0.001). Also, CAI with kinesiophobia group presented less variability in the velocity of COP displacement in the ML direction than other groups (p < 0.001, p = 0.026). CAI with kinesiophobia group needed more time and more velocity in the AP direction than without kinesiophobia group (p = 0.003). Individuals with a high fear of re-injury may perceive the jump landing task as threatening, requiring more time to land and regain stability. This fear can restrict the variability of velocity in the ML direction, resulting in decreased control over the AP direction due to limitations on managing degrees of freedom.

BackgroundLow back pain is common among athletes and it has been shown that postural control is altered in the general population with nonspecific low back pain (NSLBP). Psychological factors may also predispose individuals to risk of altered postural control. Dynamic postural control is essential to the performance of athletes. This study aimed to compare the dynamic postural control between women athletes with and without NSLBP with high and low pain-related anxiety.MethodsForty-five female athletes (15 NSLBP with high pain-related anxiety, 15 NSLBP with low pain-related anxiety, and 15 healthy (control)) were included. Pain-related anxiety was assessed using the Pain Anxiety Symptom Scale-20 (PASS-20). Based on the cut-off score of 30 for the total score of PASS-20, NSLBP patients were classified into two groups of low and high pain-related anxiety. Participants performed double-leg vertical drop jump (DVJ) and single-leg vertical jump (SVJ) tests on a Kistler force plate (type 9260AA6, Kistler Instruments Inc, Switzerland). The total root mean square (RMS) of the center of pressure (COP), COP displacement in the anteroposterior (AP), and mediolateral (ML) directions, COP mean velocity, and time to stabilization (TTS) in vertical, AP, and total directions were extracted from COP and ground reaction force data using MATLAB software. One-way Analysis of variance (ANOVA) and Welch’s ANOVA were employed to compare the groups. In case of significant findings, post hoc tests were performed.ResultsThe results showed that during DJV, athletes with high pain-related anxiety had significantly greater TTS in all total, AP, and ML directions than other groups (P < 0.05). Also, the control group showed greater total RMS distance during DJV than either NSLBP group. However, no significant differences in TTS and COP parameters were found between the groups during SVJ (P > 0.05).ConclusionsThe findings suggest that pain-related anxiety may contribute to athletes’ postural control strategies. Therefore, it is important to consider the level of pain-related anxiety during planning postural control exercises for women athletes with NSLBP.

Anticipatory postural control following fatigue of postural and focal muscles

Background and Aims Ankle sprain is the most common lower limb musculoskeletal injury in athletes, which can be improved with low-cost and non-invasive rehabilitation programs. The present study aimed to determine the effect of eight weeks of slide board exercises on the center of pressure (COP) displacement, ankle proprioception, and ankle muscle strength of female basketball players with chronic ankle instability (CAI). Methods This is quasi-experimental with a pre-test/post-test design. Participants were 28 professional female basketball players with CAI, who were randomly divided into two groups: Exercise (age:14.00±0.78 years, height: 167.78±6.45 cm, weight: 59.57±7.18 kg) and control (age:14.07±0.82 years, height: 167.08±3.85 years, weight: 62.92±3.45 kg). Before and after the training period, the variables of COP displacement (using a foot scan device), ankle proprioception and ankle muscle strength (using Biodex system 3 pro) were measured. The exercise group performed the slide board exercises for 8 weeks, three sessions per week, each for 60 minutes under the supervision of the examiner. For statistical analysis, the analysis of covariance test was used. The significance level was set at 0.05. Results The results showed a significant difference in COP displacement (P≤0.001), ankle proprioception (P≤0.001), and ankle muscle strength (P≤0.001) after exercises between the two groups, and confirmed the higher effectiveness of the slide board exercises. Conclusion The slide board exercises for eight weeks can reduce the COP displacement and ankle proprioception and improve ankle muscle strength in professional female basketball players with CAI. Therefore, slide board exercises are recommended for the rehabilitation of female athletes with CAI.

Identifying the functional status of patients after total knee arthroplasty is important. This study aimed to examine the differences in sit-to-stand and static standing ability balance between patients who underwent total knee arthroplasty and healthy participants. Twenty patients (mean age 70.05 years) who underwent total knee arthroplasty and 20 healthy participants (mean age 69.20 years) participated in this study. To assess the participants' sit-to-stand, the Good Balance System (Metitur Ltd, Finland) was used to measure each participant's mediolateral center of pressure (COP) displacement and time required to complete the sit-to-stand movement. To assess the participants' static standing balance, the Good Balance System was used to measure each patient's mediolateral COP displacement, anteroposterior COP displacement, and velocity moment when standing with eyes open and with eyes closed. A significant difference was found in the mediolateral COP displacement and the time required to complete the sit-to-stand movement in the two groups (P< 0.05). A significant difference was also found in the mediolateral and anteroposterior COP displacement and the velocity moment when standing with eyes open and with eyes closed in the two groups (P< 0.05). Patients who had total knee arthroplasty showed decreased sit-to-stand and static standing balance ability compared with the control group in the initial period after surgery.