Piotr Wodarski

The influence of frequency of visual disorders on stabilographic parameters.

PURPOSE Defining the influence of parameters of visual disorders on ability of balancing turns out to be an important process in effective diagnostics. Current diagnostic methods relating mainly to determination of the coefficient of BRUTM (Balance Rehabilitation Unit Trade Mark) depend on lots of tests carried out in a disturbed environment created by Virtual Reality Technology. The aim of this study is to determine the effect of the frequency of visual disturbances on stabilographic values in the virtual reality environment. METHODS The study was carried out involving one research group in Virtual Cave. There were induced visual disturbances with different frequencies and with the change of frequency during measuring the position of the center of pressure (COP) in the test. Before each test the reference test was performed. All tests were performed with disorders in two different sceneries: closed and open scenery. All measurements were carried out on an immobile Zebris platform which enables determination of feet pressure distribution. From the measured values of the position of the COP Short Time Fourier Transform (STFT) was calculated. RESULTS The results of calculation are shown in graphs. Their analysis showed that changing the parameters of disorder frequency in world created using Virtual Reality Technology affects stabilographic parameters. The intensity of these changes is also affected by applied research scenery. CONCLUSIONS Conditions have been set out to carry out similar studies in order to obtain reliable results. The study is the first step in a project to develop a system for diagnosis and rehabilitation of human movement using Virtual Reality Technology.

The Upper Limb Motion Deviation Index: A new comprehensive index of upper limb motion pathology

PURPOSE The aim of the research was to formulate a new index enabling assessment of the overall pathology of the upper limb movement. It defines the difference between the pathological movement and a normal movement pattern. METHODS Methodology of determining the index is based on a mathematical algorithm for calculating the Gait Deviation Index which is based on advanced methods of image comparison. To calculate the ULMDI index, one must divide the analyzed movement into cycles appropriate to the nature of the movement (similarly in gait it is the gait cycle) and then determine kinematic quantities (courses of joint angles). RESULTS A group of 23 healthy people (10 women: k1-k10 and 13 men: m1-m13) as the reference group and a group of 3 persons with mobility impairments (p1-p3) took part in the research. Time values of the angles of the joints on both upper limbs were registered and then ULMDI indexes were calculated. CONCLUSIONS It has been shown that the developed ULMDI index allows to detect the deviations from the accepted norm in the performance of movements. The results showed that both the description of the motor dysfunction of examined person based on the diagnosis of the physician, a detailed analysis of kinematic waveforms received during the tests and the calculated values provide a coherent picture of the state of a human movement. The index analysis is less time-consuming for the doctor, and the comparison of the results at various stages of therapy gives an objective picture of the rehabilitation progress.

Determination of Loads in the Joints of the Upper Limb During Activities of Daily Living

The elaborated methodology applied in the research integrates experimental measurements of kinematic parameters, which are then used in numerical computation. Measurements of kinematics of the upper limb motion were carried out during experimental studies using a MVN Biomech System. A mathematical model of movement of the upper limbs allowing the determination of force reaction in joints in a non-invasive way while performing selected routine activities is an important element of the applied research methodology. In the study the resultant reaction forces in the shoulder, elbow and wrist joints were determined and analyzed for the group of 8 healthy people as well as patterns of joint reaction force of the individual joints were developed.

Three-Dimensional Children Gait Pattern – Reference Data for Healthy Children Aged Between 7 and 17

The research aimed to determine the standards of kinematic quantities and indices of regularity, namely the Gillette Gait Index and the Gait Deviation Index related to children aged between 7 and 17 as well as the identification of differences concerning the above-named quantities according to age and height. The study group consisted of 56 healthy children aged 7 to 17. The tests were performed using the BTS Smart system. The original applications developed in the Matlab environment for all of the children subjected to the tests enabled the identification of the Gillette Gait Index (GGI) and the Gait Deviation Index (GDI). Detailed analysis involved a set of sixteen variables describing gait kinematics; the above-named variables are used when creating the GGI. The children were divided into five groups in relation to age and six groups in relation to height. Time values of the angles of the joints were registered and then the GGI and the GDI were calculated. Sixteen parameters composing the GGI were determined for all of the children constituting the test group. The confirmation or the exclusion of differences between age-related and height-related groups was based on statistical analysis. The identified courses of the kinematic time series can be used as normative in relation to patients aged 7–17.

Analysis of the Course of Displacements of the Center of Mass While Using a Chair with a Spherical Base

BACKGROUND: An increase in the occurrence of spine problems has resulted in the necessity to analyze the activities which have the highest impact on the condition of the motor organ. One of such activities is sitting, which takes up approximately 44% of our day. OBJECTIVE: The aim of the study is to determine course of displacements of the BCoM (center of body mass), the HCoM (center of head mass) and the PCoM (center of pelvis mass) while using a chair with a spherical base and normal chair. METHODS: A group of 8 men participated in the tests. Each of the people declared that they had not suffered from any conditions related to the motion system nor from any balance disorders. RESULTS: On the basis of body kinematics tests with the use of a motion capture system, the following parameters have been determined: the course of BCoM, the course of displacements of the HCoM, and the course of displacement of the PCoM. CONCLUSIONS: The results depict an increase in the displacements of the HCoM in relation to the PCoM while using chairs of spherical base. There is also an increase of displacements in the BCoM.

Research on the stability of the users of chair with a spherical base

One of the way to get rid of the spine issues is using chairs with a movable seat. The essence of chairs with a movable seat is to increase the range of motion of pelvis movement. Natural ability to maintain the upright position of the body can cause the increasing of pelvis movement. That requires the involvement of the spine stabilizing muscles. The construction of chairs with a spherical base should provide stability and prevent from slipping away from the chair. At the same time chairs with spherical base should provide mobility to force pelvis movements. We made an ergonomic analysis of chair with spherical base. Studies have determined the stability of the seat and the range of pelvis movements. These measurements used the whole body kinematics. The ergonomic assessment of the spherical seat required investigation to determine the following parameters: center mass displacement, lean of spherical chair and kinematics of the human body.

Determination of the number and frequency of the steps for gait with elbow crutches based on a crutch acceleration

Gait is one of the basic and most important forms of human locomotion. Gait can be described by parameters such as: speed, step length, stepping rate, ground reaction force values. One way to determine these parameters is analysis of acceleration of selected body segments. There are not many algorithms in the literature that could be used to analyze gait with the elbow crutches. Accordingly, an algorithm should be developed to determine, for example, the frequency and number of steps based on the crutch acceleration. In the following study, signal from IMU sensor located on elbow crutch was used to determine the parameters. The algorithm based on double filtration of recorded acceleration and peak detections from obtained signal. Results were compared and correlated with MVN Biomech motion capture system (high accuracy system). The discussion chapter considers uncertainty of the measuring methodology and the possibilities of using the designed system.

Interactive System of Enginering Support of Upper Limb Diagnosis

System of engineering support of upper limb diagnosis was developed and verified as a part of the research. Virtual Cave 3D, System VRTouchDevice and inertial motion analysis system MVNBiomech were used to build this system. In cooperation with the physiotherapist 2 applications were developed to motivate to do exercises during which kinematic parameters of the examined people were registered. The prepared system was positively verified by correlating waveforms angles in joints for a physiotherapist with the waveforms of people who exercise in the developed system.