Katarzyna Kaczmarczyk

Associations between gait patterns, brain lesion factors and functional recovery in stroke patients

Brain CT scans and neurological condition were evaluated in 74 stroke patients. Firstly, we found that using a classification-tree technique based on CT scan parameters (an innovative method, analyzing four parameters simultaneously) coincided with our previously proposed kinematic artificial neural network (ANN) classification technique for 71.3% of patients. Lesion size and location were found to be the most significant CT scan predictors of gait classification. Secondly, we sought to gauge post-rehabilitation functional recovery in patients within the same three groups of gait pattern. We found significant differences in scores between the three gait pattern groups, before and after rehabilitation (Kruskal-Wallis test, p<0.001), while significant improvement was observed in each group (Wilcoxon text; p<0.01). We conclude that patient classification into pathological gait groups on the basis of gait or CT scan parameters may serve as an early predictor of future functional outcome.

Artificial Neural Networks (ANN) Applied for Gait Classification and Physiotherapy Monitoring in Post Stroke Patients

1.1 Overview of the problem Humans have an innate predisposition for ambulation (walking). The motor neuron stimulation involved in ambulation is generated by a natural neural network located in the spinal cord, known as the central pattern generator for locomotion. This network is strongly influenced both by super-spinal structures situated mainly in the hypothalamus and brainstem, and by signals coming from various types of peripheral receptors (Carter & Page 2009). To facilitate research and analysis, free gait in humans is traditionally divided into phases and cycles. Each full gait cycle comprises two individual steps; a single step consists of a stance phase and a swing phase. The gait cycle includes a stage of single limb stance (when the body rests on a single lower extremity) and a double limb stance (on both lower extremities). Kinematic gait analysis assumes a simplified, 15-segment model of the human body (feet, shins, thighs, forearms, upper arms, hands, head, torso, and pelvis) (Blaszczyk 2004). There are two kinds of basic parameters adopted for gait modelling and routine testing of ambulation in healthy and disabled individuals: spatial values of motion (including step length, velocity of the body mass centre, progressions of changes in joint angles, body mass oscillations) and dynamic values of gait mechanics (most often including ground reaction forces in 3 planes and the distribution of foot forces on the ground). These physical values are measured in parallel with bioelectric muscle activity (EMC), registered by surface electrodes as a subject walks (Perry & Burnfield, 2010). Correct ambulation requires the precise integration of practically all the systems of the human body. When one of the elements, especially a motor organ, is damaged as a consequence of injury, degeneration, or deformation, this immediately finds reflection in divergences of the above parameters from normative values, which is in practice described as pathological gait (Perry & Burnfield, 2010). The field of clinical biomechanics therefore

The Impact of a Vestibular-Stimulating Exercise Regime on Postural Stability in People with Visual Impairment

The aim of the study was to assess the impact of a vestibular-stimulating exercise regime on postural stability in individuals with visual impairment. The study group consisted of 70 people, including 28 persons (15 female and 13 male) with visual impairment and 42 (21 female and 21 male) without visual impairment. Each individual in the group with visual impairment was medically qualified for a 3-month training program. The research methodology included medical examination, anthropometric tests, and stabilometry tests on a Biodex Balance System SD (BBS). The tests were conducted twice: once before the start of training and again after 3 months of rehabilitation. The group with visual impairment showed significantly worse postural stability results than the control group for most of the stability parameters evaluated (OSI, APSI, and MLSI). Differences were noted between the groups with and without visual impairment for dynamic tests in women and for static tests in men. After training, the two groups showed roughly similar results for the stabilometry test with eyes closed. We conclude that exercises stimulating the vestibular system with head and body movements should be recommended for individuals with visual impairments to achieve better balance retention.

First signs of elderly gait for women

BACKGROUND The aims of this study have been twofold: to attempt to reduce the number of spatiotemporal parameters used for describing gait through the factor analysis and component analysis; and to explore the critical age of decline for other gait parameters for healthy women. MATERIAL AND METHODS A total of 106 women (aged ≥ 40 years old (N = 76) and ≤ 31 years old (N = 30)) were evaluated using a pressure-sensitive mat (Zebris Medical System, Tübingen, Germany) for collecting spatiotemporal gait parameters. RESULTS The factor analysis identified 2 factors - labelled Time and Rhythm - that accounted for 72% of the variation in significant free-gait parameters; the principal component analysis identified 4 of these parameters that permit full clinical evaluation of gait quality. No difference was found between the groups in terms of the values of parameters reflecting the temporal nature of gait (Rhythm), namely step time, stride time and cadence, whereas significant differences were found for total double support phase (p < 0.001). Next, seeking evidence of a critical decline in gait, we selected 3 parameters: total double support, stride time and velocity. We concluded that the women taking part in the experiment manifested significant signs of senile gait after the age of 60 years old, with the first symptoms thereof already manifesting themselves after 50 years of age. CONCLUSIONS We show that among 26 spatiotemporal parameters that may be used for characterizing gait, at least a half of them may be omitted in the assessment of gait correctness; a finding that may be useful in clinical practice. The finding that the onset of senile gait occurs in the case of women after the age of 60 years old, in turn, may be useful in evaluating the ability for performing types of physical work that mainly require ambulation. Med Pr 2017;68(4):441-448.

Effect of Drop Foot on Spatiotemporal, Kinematic, and Kinetic Parameters during Gait

Background. The complexity of the structure and function of a living body can be affected by disorders and can cause various dysfunctions. Objective. The aim of this study was to determine compensatory mechanisms in subjects with drop foot during gait. Methods. The study evaluated 10 subjects with drop foot (DF) whose results were compared to a group of 10 healthy controls (C). Spatiotemporal, kinematic, and kinetic parameters during the gait cycle were collected using Vicon system synchronized with Kistler platforms. Results. Spatiotemporal, kinematic, and kinetic parameters were significantly different between the analysed groups. In the DF group, the subjects walked almost 47% slower and performed 60% less steps per minute compared to the C group. The main problem in the DF group was insufficient ankle dorsiflexion in the 0–10% of the gait cycle. Mean values in the groups during the first 10% of the gait cycle were as follows: DF (−10.42 ± 5.7°) and C (−2.37 ± 1.47°), which affected the substantial differences in the values of muscle torque: DF (0.2 ± 0.1 Nm/kg) and C (−0.26 ± 0.06 Nm/kg). Conclusions. Comparative analysis for joint angles and torques demonstrated that the mechanism of compensation is the most noticeable in the knee joint and less in the hip joint.

Lower limb loading during knee up in step aerobics: a pilot study

Summary Study aim: Step aerobics is a form of aerobic power distinguished from other types of aerobic exercise by its use of an elevated platform. The purpose of this study was to examine how the aerobic exercise “knee up” affects kinematic and kinetic parameters and, above all, the length of the muscle contractions. Material and methods: The study analysed ten female fitness instructors with at least six years of experience. The task consisted in the knee up move performed using a 15 cm step and music with the beat frequency of 148 BPM. Kinematic and kinetic parameters were recorded using the Vicon system synchronized with two Kistler force plates. OpenSim software was used for calculation of the length of involved muscles. Results: Ranges in angles and torques suggest that the location that is the most prone to injuries and overtraining is the knee joint, followed by the hip and ankle joints. Greater values of the vertical component of ground reaction forces were observed during stepping down, which suggests greater load to the joints. The greatest work in the move analysed in this study was performed by the sartorius muscle and the tensor fasciae latae muscle. Conclusions: Despite the benefits that have been demonstrated when step classes are structured correctly and adapted to the participants, further research is needed concerning biomechanical load, exercise prescription, and injury prevention.

Types of falls and strategies for maintaining stability on an unstable surface

BACKGROUND Falls constitute an important health issue. They cause significant morbidity, mortality and have marked psychological effects on the individual, too. The aim of this study has been to determine parameters describing human movement strategies for balance and the reaction if balance is lost as a result of an unstable ground, and to attempt to describe the types of falls. MATERIAL AND METHODS The study group comprised 20 volunteers. Kinematic parameters of falling and dynamic stability were measured using the Vicon Motion System and the Biodex Balance System SD. During the test, subjects stood for 20 s on the tilting platform. The analysis was conducted based on the first recordings, when the participants were not prepared for the event and their reactions were natural. A cluster analysis tool was applied to divide the behavior of people during the test. RESULTS Based on motion range for kinematic parameters, the cluster analysis revealed 2 types of human behavior: falling (stepping) and restoring balance. Two types of falls were also observed: side and back falls. Moreover, on the basis of angular values for tilting plate, 4 zones were determined. The frequency of access to these zones by each joint revealed 3 strategies to maintain balance: ankle, knee and hip strategy. CONCLUSIONS A set of initial conditions that may be used for future numerical simulations was also determined. Furthermore, the results presented in this study are likely to support the analysis of the effects and the falling patterns. Med Pr 2018;69(3):245-252.

Long-term effects of premature birth on somatic development in women through adolescence and adulthood

Objectives To evaluate the long-term consequences of preterm birth on anthropometric parameters in women in adolescence and into adulthood. Methods Seventy girls born preterm (age 12.22 ± 1.52 years) and 48 born at term participated in the first stage. Eighteen years later, 13 of the same women participated in a follow-up and were compared with a control group of 27 women. We compared anthropometric results across the two examinations, and in the second stage, also assessed body composition using bioelectrical impedance analysis. Results No significant differences were found in anthropometric parameters or the content of individual components of the body between the preterm-born and control groups. However, the preterm-born group showed a tendency for higher average fat mass and lower fat-free and soft lean mass compared with the control group, and had a significantly higher mean waist–hip ratio. Conclusions Preterm birth does not adversely affect somatic development in girls during adolescence, but shows a correlation with an elevated waist–hip ratio in adulthood.

Are preterm-born survivors at risk of long-term respiratory disease?

Background: To evaluate the long-term impact of preterm birth on respiratory function in female patients born preterm, we undertook spirometric examinations twice, as they reached the age of puberty, then follow-up examinations of part of the same cohort in adulthood. We sought evidence that preterm birth is correlated with poorer spirometric results into adulthood. Methods: A total of 70 girls (aged 12.2 ± 1.5 years in 1997) who had been born preterm (at 34.7 ± 1.86 weeks, none having experienced bronchopulmonary dysplasia) took part in spriometric examinations in 1997 and again in 1998. Of those, after a gap of 17 years, a group of 12 were successfully recontacted and participated in the 2015 examination as adults (then aged 27.6 ± 2.6 years, born at 34.5 ± 1.92 weeks). We compared spirometric results across the adolescent and adult examinations, and compared the adult results with an adult reference group. Results: The percentage values of FEV1 (forced expiratory volume in 1 s), FVC (forced vital capacity) and MVV (maximal voluntary ventilation) showed significant improvement between the two examinations in the early adolescent period. In adulthood, FEV1%pred (percentage predicted forced expiratory volume in 1 s) showed no statistically significant difference. The mean values of both FVC and FVC%pred (percentage predicted forced vital capacity) for the preterm-born group were lower than for the reference group, but this was not statistically significant. The preterm-born group showed lower values of such parameters as forced expiratory flow at 25–75% of FVC, MEF25 (maximal expiratory flow at 25% of forced vital capacity) and FEV1/FVC as compared with the reference group, but again without statistical significance. Conclusions: (1) A somewhat below-norm level of respiratory parameters among preterm-born girls entering pubescence may attest to continued negative impact on their respiratory system. (2) A significant improvement in their spirometric results 1 year later may indicate that pubescence helps compensate for the earlier negative effect of preterm birth. (3) No significant differences were seen in lung function in preterm-born adults as compared with a reference group of adults, although the preterm-born group did exhibit lower values of all parameters studied and more frequent obstructive disorders.

Assessing the asymmetry of free gait in healthy young subjects

PURPOSE The purpose of this study was to derive reference values for a four-level scale intended to evaluate variation in free gait asymmetry measurements in healthy subjects. METHODS This evaluation is based on kinetic values for the left and right lower limbs during gait, registered with advanced measurement systems and assessed using the symmetry index (SI) developed by Robinson. RESULTS For the majority of parameters, the SI does not follow normal distribution. As such, quartile values were used to create intervals for a four-step scale of assessing symmetry of free gait in healthy subjects for each gait parameter of interest. The SI rating intervals were from 0% (very good symmetry) to 21.2% (very poor symmetry) for kinetic parameters. The poorest symmetry was observed for horizontal force F3. CONCLUSIONS The four-step scale of assessing symmetry in free gait in healthy subjects can be used in diagnosing gait disorders, devising surgical treatment strategies, and monitoring the rehabilitation process. Reference values for intervals of symmetry indicators in healthy subjects can be used as criteria for comparing individuals with/without disabilities.