Robert Michnik

• Associate Professor
• Professor (Associate) at Silesian University of Technology

Due to the complexity of the medical issues connected with cerebral palsy (CP), the classification of gait pathologies seems rather difficult. The aim of this study was to asses the usefulness of the Gait Kinematics Index (GKI) from a clinical point of view in the population of patients with CP. The assessment of the possibilities of using the GKI...

The increasing prevalence of adult obesity is a major global health problem. Causes include sedentary lifestyles and physical inactivity, as well as the place and style of work. This work aimed to assess the impact of an increase in BMI, resulting from a sedentary lifestyle, on the functioning of the human musculoskeletal system during daily activi...

One of the important elements of musical education is correct body posture and the ability to properlay use the motor organ to play. This work presented the possibility of applying biomechanical tests to support and enhance the education of playing instruments. The results showed that it is possible to perform such an assessment based on measuremen...

The aim of the study was to design and develop a comfortable, sturdy and lightweight canine wheelchair prototype. The wheelchair was created for small dogs with paresis or hind limbs paralysis. The final product is adjustable to allow comfortable and customized use and therefore is suitable for more than one patient. Wheelchair implementation in th...

Physical fitness is an important indicator that reports on physical fitness as well as health. In March 2020, as a result of the increasing incidence of COVID, many countries introduced significant restrictions that resulted in an increase in sedentary lifestyles. The aim of this study was to investigate the effect of isolation on the physical fitn...

OBJECTIVE: The study aimed to identify the effects of ground reaction forces (GRF) recorded during landing in typical elements of three dance styles, including classical, modern, and folk dance, on injuries` topography. METHODS: The research involved a survey and measurements of GRF generated during landing after the jump. The survey involved a gro...

Studies investigating the relationship between balance ability and body size, build and proportions tend to concentrate on body mass and height rather than breadth parameters or size of individual body segments. The purpose of this study was to determine a relationship between the ability to keep balance and the size, build and proportions, based o...

Pain in the lower part of the back is one of the most common chronic illnesses globally. This work aimed to determine the impact of the reinforcement of particular groups of abdominal and dorsal muscles on the loads exerted on the lumbar section of the spine in 30 mothers of children with motor disabilities. An optical Ariel Performance Analysis Sy...

BACKGROUND: Correct body weight is one of the factors that allows you to maintain a properly functioning body. Abnormal body weight can cause muscle tissue remodelling, affecting activity and muscle fatigue. Changes in the muscular system can cause occurrence of functional limitations. OBJECTIVE: To determine the effect of weight change on fatigue...

Abstract Background Balance disorders in patients diagnosed with Parkinson’s disease (PD) are associated with a change in balance-keeping strategy and reflex disorders which regulate the maintenance of vertical body posture. Center of foot pressure (COP) displacement signals were analyzed during quiet standing experiments to define such changes. Th...

Due to the increasing number of people requiring rehabilitation and an aging society, the need to streamline, improve, and, above all, increase the availability of rehabilitation has been identified. In the present study, research was conducted to evaluate the feasibility of adapting an industrial robot to assist in the rehabilitation process. The...

This work aimed to determine the impact of the restrictions imposed during the SARS-CoV-2 coronavirus pandemic on the physical activity of young people who were staying in the territory of Poland. The investigations included 11 subjects at the age of 20–25. The measurements consisted in the monitoring of a daily number of steps using a mobile devic...

The aim of the study was the biomechanical assessment of selected motor and cognitive exercises carried out with the use of the Neuroforma rehabilitation system. The selected parameters of the kinematics of the upper limbs’ movements during exercises with the Neuroforma system were compared with the kinematics of the movement of selected activities...

The work aimed to compare the body posture taken during 3 different sitting positions: I) slumped position, II) preferred position, and III) upright position, to obtain a reference point, posture measurements were also made while standing. The Zebris ultrasound system was used to assess the body posture of the analyzed activities. In the experiment...

The aim of the study was to assess the electromechanical response times of muscles and to assess the effect of repeatability of the performed task on the indicated times: TRT (total reaction time), PMT (premotor time), and EMD (electromechanical delay). The test consisted in squeezing the dynamometer with maximum force in the shortest possible time...

Purpose: This work aimed to develop a novel indicator of upper limb manipulative movements. A principal component analysis (PCA) algorithm was applied to kinematic measurements of movements of the upper limbs performed during an everyday activity. Methods: Kinematics of the upper limb while drinking from a mug were investigated using the commercial...

Background: Music, rhythm, symmetry, and body awareness are important aspects of dancing training. Flamenco dancers not only mark and accentuate the rhythm, but they produce the rhythm through the footwork (zapateado). The main purpose of this study was to determine whether the rhythm tapped by the flamenco dancer's feet occurs with the symmetry in...

Many diseases and conditions can alter an ability to maintain body balance. The aim of the present study was to investigate whether thoracic surgery may elicit diaphragm dysfunction thereby impairing postural stability. 40 patients qualified to video-assisted thoracoscopy (VATS) lobectomy or lobectomy via thoracotomy due to pulmonary carcinoma were...

Pregnancy induces numerous modifications in the musculoskeletal system of the female body. Since one of the essential roles of the lumbopelvic structure is to support mechanical loads in the upright position, this study was designed to simulate the response of this complex to the growing foetus in pregnant women. The authors hypothesized that postu...

Purpose: The aim of this study was to develop a method to implement muscle forces to a numerical model of a dummy and to evaluate the effect of muscle activation on driver behavior during a frontal collision. The authors focused on the forces acting at the knee, hip, and elbow joints. Methods: The authors carried out torque measurements in joint...

Purpose We investigated whether an increase in muscular tone induced by the information about imminent posture destabilisation brings a positive result and prevents such destabilisation. Methods We measured forward and backwards movements of 38 participates (27 females and 11 males, aged 23 (SD 2.6)) on the treadmill (forward and backward movements...

Purpose: This paper presents an assessment of the influence of isometric rotation of the lower limb in a standing position on the functioning of the muscles stabilizing the knee joint in the frontal plane with the use of modeling the loads on the musculoskeletal system. Methods: The research was carried out in the AnyBody Modeling System softwar...

Purpose: The proper shape of the foot determines its proper functioning and efficiency, which is significant as far as dancers are concerned. The aim of the study was to identify the arch of feet based on the Arch Index (AI), ability to maintain balance on the basis of stabilometric parameters and the distribution of loads acting on the feet of pr...

Footwork is one of the basic features of flamenco dancing and is performed in traditional high-heeled shoes. The purpose of this study was to analyse the mechanical profile of flamenco dancing in terms of vertical ground reaction force, and knee joint kinematics of the supporting limb in footwork technique in order to understand causes which predis...

Purpose: In clinical practice, motor development in infants is assessed subjectively. Many researchers propose objective methods, which have numerous limitations, by attaching markers or sensors to the child's limbs. The purpose of this study is to attempt to develop objectified numerical indices to describe the limb movements of infants without i...

Purpose: The aim of the study was to assess the possible use of biofeedback (information on the course and values of ground reaction forces (GRF) during landing following the performance of a dance evolution) for training minimising impact loads after a jump in modern dance. Methods: The tests involved the analysis of a total of 60 expressive el...

Simple Summary The purpose of this research was to assess footprint parameters in a group of ballet dancers and the correlation between these parameters with lateralisation, stabilometric parameters, pedo-barographic parameters and work environment. The research was carried out on a group of 44 elite professional ballet dancers—the reference group...

The main purpose of this study was to identify a dancer’s body alignment while performing flamenco footwork to provide a detailed description that could be used by flamenco practitioners: teachers, instructors and students of different levels of advancement. The zapateado technique performed by a professional flamenco dancer was analyzed. The biome...

The aim of the study was to define the effect of different short-term metro-rhythmic stimulations on the time and spatial parameters of gait. The secondary goal was to test whether prior instructions on how to respond to stimulations played a significant role in the stimulation by sound stimuli. Experimental tests of gait were conducted on a group...

Assessment of human balance is one of the most common diagnostic tests, both in medical applications and during sports training. Many new methods of measuring are introduced in these studies; however, the analysis of results is still carried out mainly based on the values determined in the time domain – the average COP speed or the ellipse field of...

The research discussed in the article involved the assessment of the effect of various types of metro-rhythmic stimulations and the manner of their application on the variability of gait frequency in a group of persons without locomotor function disorders. Tests of gait were attended by 22 adults in two equal groups: group 1—persons, who were not i...

The aim of the study was to perform a comparative analysis of the transverse abdominal muscles in patients before and after resection of the lung parenchyma. As part of the work, study was carried out on a group of 32 healthy people and a 41-person study group. Zebris FDM-S platform was used for measuring the pressure of the feet on the substrate a...

The article deals with measurements of ability to maintain the balance conducted for soldiers who were wounded during combat missions. Measurements were carried out both in real and virtual environment. Tests in the real environments were performed with open and closed eyes. Tests in the virtual environment were performed with the use of spatial sc...

Purpose: The work aimed to assess the functioning of the musculoskeletal system within the lumbar spine in relation to everyday postures of sitting and standing. Methods: The comparative analysis was based both on experimental tests and computer simulations performed in the AnyBody Modeling System environment. Input data used to prepare models w...

Purpose: This work aimed to define the impact of the introduction of power and speed dry-land training in female swimmers aged 15-16 on the rise of time results at a distance of 200 m and on the increase of the strength level of the muscle groups in the elbow joint. Method: The investigations were conducted on a group of 28 junior female swimmer...

As a result of the constantly growing number of people in the World, disabilities became one of the most important aspects related to human health. According to the World Health Organization, a disabled person is "anyone who affects a reduction in performance or fitness in the construction or functioning of the body in terms of psychological, physi...

Mikula, BarbaraWolny, SabinaNowakowska, KatarzynaGuzik-Kopyto, AgataChuchnowska, IwonaMichnik, RobertThe aim of this work was to assess the hand grip strength and the suppleness of pole dancers with different training experiences. The tests involved a group of 35 females representing various levels of skills. The hand grip strength was measured usi...

Jochymczyk-Woźniak, KatarzynaNowakowska, KatarzynaZakałużna-Żerebecka, AnnaMichnik, RobertThis study presents the analysis of the gait of a patient with infantile cerebral palsy provided with orthoses and various types of footwear with an individually adjusted sole. The research work involved the use of state-of-the-art methods of gait kinematics m...

Purpose: The objective of the work was to define a new comprehensive method of evaluating gait pathology (Gait Kinematics Index, Global Symmetry Index and Gait Deviations Profile). Methods: The article presents in detail a mathematical algorithm of a new comprehensive method of evaluating gait pathology. Input data for the algorithm are the kine...

This work aimed to determine the influence of strengthening or weakening of the transversus abdominis (TrA) muscle on loads in the lumbar spine using musculoskeletal modelling methods. The input kinematic data of two positions (a standing position and a position during a sitting-down task) were angles in the elbow joint (0°;4°), shoulder joint (0°;...

Background: The assessment of spontaneous activity of infants is of fundamental importance to the diagnosis and prediction of abnormal psychomotor development in children. Comprehensive and early diagnosis allows for quick and effective treatment and therapy. Subjective methods are based on the knowledge and experience of the diagnostician. The lac...

Purpose: Analysis of human gait as well as diagnosis of human locomotion organ should always be conducted with velocity of gait equal to Preferred Walking Speed (PWS). The literature review shows that the PWS value is not the same in real and virtual environment. The aim of this study was to determine PWS values in both environments and to specify...

Purpose: The research work aimed to perform the mathematical modelling-based assessment concerning the effect of the position of the pelvis in the sagittal plane on loads present in the musculoskeletal system in the standing position. Methods: The analysis of the effect of various positions of the pelvis was performed using the Free Posture Mode...

Purpose: The objective of the work was to determine biomechanical parameters influencing loads affecting the musculoskeletal system and shock absorption during the landing phase in Grand Jeté, Entrelacé and Ballonné. Methods: Motion kinematics measurements of the landing phase in GrandJeté, Entrelacé and Ballonné were carried out using the optical...

Purpose: The objective of the work was to determine biomechanical parameters influencing loads affecting the musculoskeletal system and shock absorption during the landing phase in Grand Jeté, Entrelacé and Ballonné. Methods: Motion kinematics measurements of the landing phase in GrandJeté, Entrelacé and Ballonné were carried out using the optic...

Purpose: The objective of the work was to determine biomechanical parameters influencing loads affecting the musculoskeletal system and shock absorption during the landing phase in Grand Jeté, Entrelacé and Ballonné. Methods: Motion kinematics measurements of the landing phase in GrandJeté, Entrelacé and Ballonné were carried out using the optical...

The article presents statistical research aiming at the formulation of functions of the child’s head growth in the first year of age. The research group consisted of 129 infants, from 0 to 12 months of age, whose heads were subjected to computer tomography tests within a regular diagnosis of neurological and oncological diseases and other condition...

Background and objectives: Virtual reality (VR) is increasingly often finding applications in physiotherapy and health promotion. Recent years have seen the use of advanced technologies in the promotion of physical activity (PA) in society. New simulators, e.g., treadmills, enable the performance of PA (e.g., locomotive movements) in VR (artificial...

The research work aimed to identify and analyse reactions in the joints of the lower limb as well as in the intervertebral joints of the lumbar spine when lifting weights and making a squat. The determination of loads of the skeletal-muscular system involved the performance of simulations in the AnyBody software programme. Input data used in the re...

Gait is the most important form of human locomotion and can be decribed by kinematics quantities and stabilographics paramaters. It is possible to determie those parameters from the distribution of forces on the ground. The purpose of this study is determining of repeatability of gait on treadmill in virtual reality. Thirty-two healthy adults have...

An essential aspect of rehabilitation is the maintenance of balance both when standing and in gait. Clinical practice sees equipment enabling the dynamic evaluation of posture stability involving the use of virtual reality. The use of virtual reality in rehabilitation supporting processes and, particularly, with respect to the improvement of motor...

The research aimed to identify the standards of gait-related kinematic quantities and normalcy indices of the Gillette Gait Index related to adults aged between 20 and 24. In addition, it was decided to compare the standard obtained for adults with the gait standard of children. The study group consisted of 32 healthy adults aged 20 to 24. The test...

PURPOSE: The aim of the study was to assess and compare kinematic and dynamic aspects of ‘grand pas de chat’ dancing element performed by ballet dancers: a female and a male. METHOD: Tests were carried out with the use of the motion analysis system and the force plate. RESULTS: The research enabled kinematic and dynamic analysis of elements perform...

According to the World Health Organization, a disabled person is anyone whose performance, or fitness is affected by reduced functioning of the body – psychologically, physically or anatomically. On a world scale, one of the main causes of acquired motor disability is ischemic stroke and the most common complication is symmetry disturbances in the...

Unstable gait is also a frequent problem in patients with neurological dysfunctions. It proves to be essential to develop methods of objective diagnostics of human mobility and early detection of defects which are often a result of more serious conditions. The aim of this research is to develop methods of evaluation of gait instability with open an...

This work aimed to determine loads exerted on the muscular and skeletal system in the segment of the lumbar spine during the execution of everyday activities, such as sitting down and getting up from a chair as well as lifting a 10 kg object off the table of various heights – 50 and 72 cm. Simulations were made by means of a dynamic mathematical mo...

For the proper functioning of the lower limb, it is necessary that each of the anatomical structures function in the correct way. The reduced ability to generate the torque of the lower limb in the hip joint can lead to abnormal functioning of the lower limb. The aim of the study is evaluation of muscle activity of the lower limb during isometric r...

The use of VR Technology is a trend aiming at the improvement of the efficacy of the exercises performed. There is worldwide research on the influence of 3D graphics on human senses. There has not been any research done concerning the influence of VR using HMD systems on the change of gait parameters on the treadmill. The objective of the research...

Heart rate variability (HRV) indicates that the body is under internal or external stressors. Higher HRV parameters usually means that the body has a ability to cope with those stressors. The paper presents the results of the heart rate variability analysis obtained for a group of healthy adults. 70 adults had been examined. Photoplethysmogram sign...

Aims: To compare the differences in bone mineral density (BMD) at loaded and non-loaded skeletal sites in professional ballet dancers. We hypothesized that in both male and female elite ballet dancers, a significant difference in BMD will be observed between impact and non-impact sites. Methods: 44 elite ballet dancers, 22 men (age 26.4±5.9 yrs)...

Background In pursuit of improvement in cardiopulmonary resuscitation (CPR), new technologies for the measurement and assessment of CPR quality are implemented. In our study, we assessed the kinematics of the rescuer during continuous chest compression (CCC–CPR). The proper performance of the procedure is a survival predictor for patients with card...

The aim of the work was to assess locomotion functions and posture stability of patients who had undergone prenatal or postnatal surgery for myelomeningocele. The gait tests were conducted with BTS System and the stabilographic tests with the dynamographic platform by Zebris. Eight patients operated for myelomeningocele, 4 prenatally and 4 postnata...

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...

The aim of this paper is to present a spectrum of virtual reality and biomechanical technologies that can be potentially used in supporting the rehabilitation of people after stroke, in both clinical and home conditions. The methodology was based on a systematic review of up-to-date, published research works available in Elsevier Science Direct dat...

The aim of this study was to determine the effect of the distance between load and the ankle joint on musculoskeletal system loading. The Any-Body software with the verified model was used for calculations of loads of muscoskeletal system during the initial phase of lifting. A total of 3,485 static musculoskeletal models in different positions were...

Fencing is a combat sport in which fencers compete in three weapons: foil, saber and epee. They differ from each other in blade type, valid target and scoring technique. Although the fundamental role of speed, coordination and sensory-motor skills in fencing is indisputable, merely rapid and correct accomplishment of a movement does not ensure succ...

Interactive devices supporting the rehabilitation of upper limbs are becoming more and more popular among physicians and physiotherapists. It has been observed that the motivation increases in patients while doing exercises aided by computer systems. A controller developed in this research supports the process of diagnosis and therapy. It has been...

Purpose: The quality of body posture and its balance depends on the efficiency of the receptors, the good work of the central nervous system integrating and coordinating the postural system and the effective musculoskeletal system. Physical activity of people with intellectual disability can stimulate the processes of improving the posture and its...

The diaphragm is well known for its role as the principal muscle of respiration. However, according to previous studies, its role is multifactorial, from breathing through pain perception, regulation of emotional sphere, collaborating in gastroesophageal functions, facilitating the venous and lymphatic return, to an essential role in the maintenanc...

The aim of this study was to assess locomotor functions of patients with cerebral palsy and qualified for various treatment procedures on the basis of indicative methods and parameters constituting the Gillette Gait Index. The studied group consisted of 57 healthy children and 60 children with different types CP and different degrees of disability:...

Background: Assessment of the foot arch is an important element of posture examination. In clinical practice, different methods are used. Reliability and repeatability of the techniques raises many doubts. Objective: Development and verification of our own, automated diagnostic algorithm for evaluation of the longitudinal arch of the foot with t...

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....

More frequently fall of older people can be caused by increasing of the degeneration of a human motor system and a human maintaining balance system. The aim of study was to determine the association of balance and risk of falling of older people lived at a social welfare home. The authors examined the dependence between the ability to maintain bala...

Purpose: The current study aimed to quantify the main influences and the interactions (joint effects) of gender, leg and type of target on the biomechanics of front kick quality. Through the quantification, we tried to identify the relevant factors related to the kick accuracy and maximum velocity for coaching practice. Methods: A ten-camera NIR...

The aim of this study was to analyze locomotor function of children with cerebral palsy based on changes in muscle length and to evaluate if the muscle length changes may be used as a diagnostic indicator. The study group consisted of 23 people with normal gait and 3 patients with cerebral palsy. Locomotor function tests were performed using the BT...

The paper presents an analysis of the loads acting on lumbar spine during movement of sitting down and getting up from a chair. The study was conducted on a group of 30 people (parents of disabled children) complaining about chronic low back pain. Basing on kinematics, obtained during experiment from APAS system, simulations were performed in the A...

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 para...

Background and Aim: People older than 60 years, with dysfunctions of musculoskeletal or motor system, impaired vision or hearing etc. are in a group of higher risk of collisions with objects in motion, which suddenly are heading towards their body (cyclists, runners, thrown an object, intentional punch or kick etc.). This study aims to verify compe...

Wstęp Celem pracy była prospektywna ocena jakości kompresji klatki piersiowej podczas symulacji ciągłego masażu serca na manekinie w czasie rzeczywistym, wykonywanego przez czynnych zawodowo ratowników medycznych, z uwzględnieniem ich BMI. Materiał i metody Badanie przeprowadzono w grupie 17 ratowników medycznych oraz 21 studentów kierunku ratowni...

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 Ind...

Purpose: The aim of the study was to examine the influence of different types of virtual sceneries and frequencies of movement of visual disturbances on stabilometric values as well as whether individual sceneries and changing frequency can minimize effect of adaptation of tested person to applied disturbances. Methods: There were 23 healthy par...

Introduction. To our knowledge, no studies have checked the effect of the abdominal drawing-in maneuver (ADIM) on gait and stabilometric parameters in lower back pain (LBP) and pain-free subjects Aim. To assess the effect of sustained ADIM on a) gait pattern and b) stabilometric parameters with opened eyes and closed eyes in an adult population. Ma...