Human Postural Control

Two experiments examined postural responses of 3-to 6-year-old children to visual informarion for oscillation. In Experiment 1, children saw oscillations of the surround, with these movements ranging in frequency between 0.2 and 0.8 Hz. Analyses of anterior-posterior postural sway revealed that, similar to previous developmental investigations, the frequency of sway matched the frequency of oscillations. Analyses of sway amplitude and timing, however, revealed patterns of results more in keeping with research on adults. Experiment 2 extended these findings, presenting oscillations in which the frequency changed during the trial. Analyses of anterior--posterior sway revealed that sway frequency matched both speeds of movement. In contrast, amplitude and timing measures were again in line with adult data. These results suggest that the postural sway of children contains both adultlike and nonadultlike parameters of balance control.

Balance is an important element of almost all sports activities and activity daily living (ADL). Balance can be measured based on individual postural control which consisted of static, semi-dynamic and dynamic. These aspects were controlled by neuromuscular and reduction in the neuromuscular ability due to injury such as patellofemoral pain syndrome (PFPS) may alter the postural control ability. The aim of this study was to investigate the effects of neuromuscular control training on athletes with PFPS. In this study, there were 27 athletes with PFPS (male = 22, female = 5; mean age = 14.59 ± 1.28 years, height = 161.96 ± 7.85 cm, weight = 54.93 ± 11.42 kg and Body Mass Index (BMI = 20.65 ± 2.20) voluntarily took part in 8-week of computerized neuromuscular control training (CNCT) program. The Y-Balance Test was used for assessment of athlete’s dynamic postural control (DPC). A doubly multivariate analysis of variance was performed on two measures of the test (pre and post-test) over three (3) dynamic postural control (DPC) characteristics between groups. This analysis was performed in order to identify the interaction and main effects of the intervention (CNCT) to participant’s dynamic postural control (DPC). An 8-week of computerized neuromuscular control training (CNCT) program resulted significant changes in all aspects of dynamic postural control (DPC). It showed that CNCT program significantly enhanced athlete with PFPS’s DPC ability in terms of anterior (F(1,25) = 14.037, p = .001, ή = .260), posteriolateral direction (F(1,25) = 13.774, p =.001, ή =.355) and posteriomedial direction (F(1,25) = 11.318, p =.002, ή =.312). This study suggested the physician and coaches should emphasize more on neuromuscular training for athlete’s with PFPS since the PFPS may reduce the athlete’s performance especially in sports that require dynamic postural control.

When balance is exposed to perturbations, hand contacts are often used to assist postural control. We investigated the immediate and the transitionary effects of supportive hand contacts during continuous anteroposterior perturbations of stance by automated waist-pulls. Ten young adults were perturbed for 5 min and required to maintain balance by holding to a stationary, shoulder-high handle and following its removal. Center of pressure (COP) displacement, hip, knee and ankle angles, leg and trunk muscle activity and handle contact forces were acquired. The analysis of results show that COP excursions are significantly smaller when the subjects utilize supportive hand contact and that the displacement of COP is strongly correlated to the perturbation force and significantly larger in the anterior than posterior direction. Regression analysis of hand forces revealed that subjects utilized the hand support significantly more during the posterior than anterior perturbations. Moreover, kinematical analysis showed that utilization of supportive hand contacts alter posture of the whole body and that postural readjustments after the release of the handle, occur at different time scales in the hip, knee and ankle joints. Overall, our findings show that supportive hand contacts are efficiently used for balance control during continuous postural perturbations and that utilization of a handle has significant immediate and transitionary effects on whole body posture.

We investigated the effects of modified preprogrammed training mode Chase Trainer from Balance Trainer (BT3, HurLab, Tampere, Finland) on athlete who experienced unilateral Patellofemoral Pain Syndrome (PFPS). Twenty-seven athletes with mean age= 14.23 ±1.31 years, height = 164.89 ± 7.85 cm, weight = 56.94 ± 9.28 kg were randomly assigned to two groups: experiment (EG; n = 14) and injured (IG; n = 13). EG performed a series of Chase Trainer program which required them to shift their body weight at different directions, speeds and angle of leaning twice a week for duration of 8 weeks. The static postural control and perceived pain level measures were taken at baseline, after 6 weeks and 8 weeks of training. There was no significant difference in any of tested variables between EG and IG before and after 6-week the intervention period. However, after 8-week of training, the postural control (eyes open) and perceived pain level of EG improved compared to IG (p<0.05). The postural control with eyes closed of EG improved (p<0.05) but the values were not significantly different compared to IG after training. The results suggest that using Chase Trainer exercise program it is possible to improve individual postural control and decreased perceived pain level in athlete with unilateral Patellofemoral Pain Syndrome (PFPS).

In general, athletes with Patellofemoral Pain Syndrome (PFPS) were assumed to have less postural control ability compared to healthy athletes. However, this assumption was not validated in static postural control (SPC). Therefore, the SPC profiles of athletes with PFPS and healthy athletes were compared using a 60-second Bilateral Romberg Protocol on Triangle Balance Platform, known as BT3 (Hurlabs, Tampere, Finland). This study was approved by Ethic Committee of Faculty Sports Science and Coaching, Universiti Pendidikan Sultan Idris, Tanjong Malim, Perak, Malaysia. All the participants in this study were Malaysian junior athletes from three types of sports (rugby, soccer and field hockey). There were 27 athletes with PFPS (age = 14.59 ± 1.28, height = 161.96 ± 9.54, mass = 54.92 ± 11.42, BMI = 20.65 ± 2.20) and 20 healthy athletes ( age = 13.3 ± 0.92, height = 168.05 ± 3.47, mass = ± 59.9 ± 7.33, BMI = 21.22 ± 2,79). The participants were asked to perform three trials of 60-second Bilateral Romberg Test with eyes-opened and eyes-closed conditions, along with 60-second rest intervals. Postural control data were collected using postural score (C90 area), which represented the amount of sways. The data was analyzed using ANOVA with eta squared calculations. The sway area in both groups showed no significant difference in eyes-opened condition [F (1,45) = 1.460, p= 0.233, ƞp2 = 0.031] and eyes closed condition [F (1,45) = 0.009, p = 0.924, ƞp2 = 0.000]. This demonstrated that PFPS athletes could compensate and limit the disturbance on their static postural control by adjusting other parts of bodies to control the postural sway. Future studies are advised to compare the biomechanical and musculoskeletal ability between athletes and normal population who experience PFPS within the framework of rehabilitation medicine.

Full text:  https://rdcu.be/cDPVb        The approaches to determining the horizontal coordinates of the center of mass (CoM) applicablefor force plate are compared. The force plate for which only vertical forces are the measurements takes into account. The first of these approaches uses the information not only about the initial position and rate of CoM, but also about its terminal state. The second is associated with the use of the assumption about the absence of unstable components in the movement and uses frequency filtering methods. Known algorithms were modified to solve the problem in conditions of sufficiently intense movements by a person. The considered modified algorithms were compared for recordings movement of the subjects who performed a “test with a stepwise visual disturbance” on a force plate. A system of video cameras was simultaneously used to determine the coordinates of a marker fixed approximately at the CoM height. The working capacity of all modified algorithms was demonstrated. It was noted that the error of the estimation method using a double filtration in forward and reverse time was lower than in other procedures.

The aim of this study was to investigate the effects of neuromuscular control training on athlete with Patellofemoral Pain Syndrome (PFPS). Thirty six athletes (36) with PFPS (Age = 14.75 ± 1.20 years, height = 163 ± 9.03 cm, weight = 55.31 ± 9.93 kg and Body Mass Index (BMI) = 20.58 ± 1.99) voluntarily took part in this study. They were randomly divided into two groups (intervention and control). The intervention group went through normal training routine from their coach and one hour of computerized neuromuscular control training program. This training program consists of two sets of nine level preprogrammed Chase Trainer (Balance Trainer, HurLab, Tamperer, Finland) and subject performed twice a week for duration of eight weeks. Meanwhile, the control group followed their normal training routine from their coach. The pre and post of standardized measurement protocol of Limit of Stability (LOS) test was proposed. It consist of four phases – 1st phase – the maximal forward leaning, 2nd phase – the maximal rearward leaning, 3rd phase- the maximal leftward leaning and the 4th phase – the maximal rightward leaning. Each of this phase required subject to performed in duration of eight seconds at individual self paced manner. The MANOVA (significance level p>0.05) was used to diagnose the difference between group during pre and post test. The results showed significant differences between group of LOS test with p=0.000, where the chosen parameters of rearward rightward and leftward shown a significance differences with p<0.05 while no significant differences for forward direction. The results of this study suggest that neuromuscular control training significantly enhanced the ability of athlete PFPS’s stability especially in direction of the injured limb.

Résumé Le présent article s&#x27; efforce de faire une synthèse des différents travaux liés au coût attentionnel du contrôle postural. Dans un contexte de double tâche, la mobilisation des ressources attentionnelles associées au contrôle de la posture dépend de plusieurs facteurs tels que (1) la focalisation attentionnelle volontaire ou automatique sur le contrôle postural,(2) les informations sensorielles disponibles,(3) la nature et la complexité de la tâche posturale,(4) l&#x27;âge, ou encore (5) le niveau d&#x27;expertise ou de handicap des sujets. ...

Background: The dentist often have a contort position of the body in order to be able perform oral treatments. The literature considers that musculoskeletal disorders are one of the important health and safety problems facing dentists' occupational diseases.

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