Introduction: Human foot make up the functional whole, thus changes in one of them may contribute to activating individual compensating mechanisms leading to disorders in the shape of the remaining segments and dysfunctions and consequently to complications in other elements of the motor system. Aim of the research: Analyze correlations between characteristics of feet structure in women and men over 60. Material and methods: The research conducted by podoscopic method involved seniors from the Podkarpackie and the Małopolskie voivodeships, including 116 females and 82 males. Tested persons were divided into three age groups (60-69 years, 70-79 years, 80-90 years). The following indices were analyzed: the Clarke's angle, Wejsflog's index (W wp), heel angle (γ), hallux valgus angle (α), and the V toe varus deformity angle (β). In order to evaluate the correlations between characteristics of feet structure the Spearman's rank correlation was employed. Results: We observed a statistically significant correlations of the hallux valgus angle and Clarke's angle as well as between the V toe varus deformity angle with the Wejsflog's index and the heel angle in the absence of statistically significant associations between V toe varus deformity angle and Clarke's angle. Conclusions: Changes in different parts of the foot that result from involution processes increasingly interact with one another in the elderly age. Prevention of foot deformities and dysfunctions should focus primarily on maintaining or restoring the capacity of foot muscles, improving proprioception and proper selection of footwear, which should not distort the shape and function of the frontal foot segments. Streszczenie Wprowadzenie: Stopa ludzka stanowi funkcjonalną całość, dlatego zmiany w jednym z segmentów mogą stanowić przyczynę uruchomienia zmiennych osobniczo mechanizmów kompensacyjnych, prowadząc do zaburzeń w ukształtowaniu pozostałych segmentów i dysfunkcji, a w konsekwencji również powikłań w obrębie innych elementów narządu ruchu. Cel pracy: Analiza związków pomiędzy cechami stóp u kobiet i mężczyzn po 60. roku życia. Materiał i metody: Badaniami metodą podoskopową objęto seniorów z województwa podkarpackiego i małopolskiego, w tym 116 kobiet i 82 mężczyzn. Badanych kwalifikowano do 3 przedziałów wieku: 60-69 lat, 70-79 lat, 80-90 lat. W analizach uwzględniono następujące wskaźniki: kąt Clarke'a, wskaźnik W wp Wejsfloga, kąt piętowy (γ), kąt koślawości palucha (α), kąt szpotawości V palca (β). Do oceny związków między cechami budowy stóp zastosowano korelację rang Spearmana. Wyniki: Stwierdzono statystycznie istotne związki między kątem koślawości palucha (α) a kątem Clarke'a oraz między kątem szpotawości V palca a wskaźnikiem Wwp Wejsfloga i kątem piętowym wobec braku statystycznie istotnych związków kąta szpotawości V palca z kątem Clarke'a. Wnioski: W wieku podeszłym na skutek procesów inwolucyjnych zmiany w poszczególnych częściach stopy coraz silniej na siebie oddziałują. W działaniach zapobiegających zniekształceniom i dysfunkcjom stóp ...

Introduction and Aim Down syndrome (DS) is associated with numerous developmental abnormalities, some of which cause dysfunctions of the posture and the locomotor system. The analysis of selected features of the foot structure in boys with DS versus their peers without developmental disorders is done. Materials and Methods The podoscopic examination was performed on 30 boys with DS aged 14-15 years. A control group consisted of 30 age- and gender-matched peers without DS. Results The feet of boys with DS are flatter compared to their healthy peers. The hallux valgus angle is not the most important feature differentiating the shape of the foot in the boys with DS and their healthy peers. In terms of the V toe setting, healthy boys had poorer results. Conclusions Specialized therapeutic treatment in individuals with DS should involve exercises to increase the muscle strength around the foot joints, enhancing the stabilization in the joints and proprioception. Introducing orthotics and proper footwear is also important. It is also necessary to monitor the state of the foot in order to modify undertaken therapies.

Purpose. The aim of the study was to distinguish the kinematic indicators influencing the average horizontal velocity of swimming (v cOM ) with underwater dolphin kicks (UDK). Methods. The study involved 15 boys and 20 girls (mean age, 11.5 ± 1.00 years; height, 1.57 ± 0.09 m; training experience, 2.5 ± 1.00 years) practicing swimming 7 times a week. We determined the body height (H), the length of the body with the arms lifted (L b ), and the best result in the 50-m freestyle (pbt); characteristic anthropological points were marked on the body. The subjects performed UDK after a water-start for a distance of ca. 8 m (without a push-off from the wall). Movements were recorded with an underwater camera. The recordings were kinematically analysed with the SkillSpector program. On this basis, we calculated v cOM , frequency of movement (f), amplitude of movement (A), horizontal displacement in one cycle (D pk ), maximum flexion in the knee joints (KF max ), the product of f and A (I Af ), the Strouhal number (St), and relative amplitude of toe movement (A rEL ).Results. The movements of the subjects were characterized as follows: v cOM = 1.08 ± 0.13 m/s, f = 2.00 ± 0.

SummaryAim of the study. To determine the level of technical efficiency of gymnasts from the youngest sports category in elementary floor exercises.Material and methods. Study participants comprised 12 boys who trained in gymnastics in four gymnastic clubs in the Małopolskie Voivodeship. The participants were 7 and 8 years old. The study assessed their performance in floor exercises using a test developed and implemented by trainers from the aforementioned gymnastic clubs. All exercises were registered with a camera. The obtained video footage was subjected to further analysis. The performed exercises were evaluated by experts in gymnastics, who ascribed numerical values to observed errors. Each exercise was divided into movement phases, which were subjected to separate analysis by the experts.Results. The results of this study are presented in tables together with points ascribed by the experts. The technique of performing each exercise (according to all the constituent phases) was presented on the basis of elementary parameters of descriptive statistics. A synthetic indicator of technical efficiency was created by summing up the values of errors in each phase (Me = 30.00 pts).Conclusions. Study participants vary significantly in terms of technical efficiency. The greatest values of technical errors in all floor exercises performed by youngest-category gymnasts were noted in the forward roll onto arms and in the left leg cartwheel. Analysis of video footage of individual exercise phases allowed the experts to reliably spot technical errors. The analysis will enable trainers to select appropriate training methods in order to eliminate these errors.

Introduction. The aim of this study was to measure the duration of biopotentials in selected muscles of the lower limbs, evaluate the time of elevated bioelectrical activity in these muscles, and identify similarities and differences in electrical phenomena that occur in the muscles for various external settings of a cycle ergometer. Material and methods. The study examined 10 healthy people (5 women and 5 men) aged from 20 to 30 years. A cycle ergometer and EMG apparatus were used in the experiment. The bioelectrical activity of six muscles of the lower limbs (rectus femoris, vastus medialis, tibialis anterior, biceps femoris, gastrocnemius caput mediale, and gastrocnemius caput laterale) was recorded for four different settings of the cycle ergometer (variable saddle height and method of foot attachment to pedals). The EMG records were presented with reference to the bicycle crankset rotation cycle. Conclusions. The study found that changing the height of the saddle of the cycle ergometer and the use of toe clips in the pedals caused changes in bioelectrical activity in the muscles. The adjustment of saddle height affected the duration of potentials more noticeably than the use of toe clips. Furthermore, only one period of elevated electrical activity in the muscles of the lower limbs was found in the pedalling cycle. The longest time of the presence of action potentials was recorded for the m. gastrocnemius caput laterale, whereas the shortest time was observed in the m. vastus medialis.

Introduction. The aim of this case study was to compare selected kinematic parameters that characterise the back handspring technique performed by advanced artistic gymnasts. Material and methods. Three elite gymnasts with varied training experience were examined in the study. The athletes performed back handsprings video-recorded at a frequency of 120 Hz. The values of selected kinematic parameters were determined using SkillSpector v.1.3.2 computer software. Results. The most substantial differences between athletes were found in the values of the horizontal velocity of the centre of mass (CoM) at the end of the back handspring. The athlete with the longest training experience achieved values which were three times higher (1.04 m/s) than those obtained by the other two athletes with shorter experience (Gymnast 2: 0.36 m/s; Gymnast 3: 0.37 m/s). The horizontal CoM velocity at the end of the back handspring declined for all the gymnasts, with the smallest decrease observed for the athlete with the longest training experience (two-fold decrease from 1.95 to 1.04 m/s) and the biggest one found for the athlete with the shortest training experience (six-fold decrease from 2.18 to 0.37 m/s). The vertical CoM velocity increased in all the athletes in the consecutive phases of the back handspring; this increase was the biggest for the athlete with the longest training experience (five-fold increase from 0.71 to 3.42 m/s) and the lowest for the athlete with the shortest training experience (three-fold increase from 1.08 to 3.24 m/s). Conclusions. The results obtained in this study demonstrated both similarities and substantial differences in the technique of performing the back handspring in artistic gymnasts with many years of training experience. In most cases, the directions of linear CoM velocities and angular velocities were similar in the joints analysed. Very similar values of angular positions were also obtained. Furthermore, the values which turned out to be the most varied were those recorded for angular velocity.

The objective of this paper is to identify the parameters of a new plane biodynamic model of a man jumping down on a hard base. In the modelling of this kind of dynamic phenomena, with dominant directions of human body motion and reactions, many simple and complex models have already been applied. Some of them were lumped parameter and unidirectional [Książek, 1999], [Fritz, 2001] or plane [Pandy, 1990], [Farley, 1998]. There are also spatial models, applied in the sport and medical investigations of the kinematics and dynamics of the human body [Morecki, 1990], [A. Nagano and col., 2005]. The presented approach has been founded on the results of experiments described in [Nosiadek, 2006] where body motions of 40 men volunteers were registered during drop jumping and landing from several assumed heights. By means of video cameras in 3D space and a dynamic platform linear and angular displacements of participants’ bodies and three mutually perpendicular components of the dynamical reactions between the feet and platform were measured. The numerical results of the displacements were numerically remodelled by the authors of the present paper and used for synthesis of models of muscles of a man during drop landing. Similar investigations can be found in [Pain and Challis, 2006].

Open Access License:This is an open access article distributed under the terms of the Creative Commons Attribution-Non-commercial 4.0 International (http://creativecommons.org/licenses/by-nc/4.0/), which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non-commercial and is otherwise in compliance with the license. abstract BackgroundThe aim of the study was to determine the changes that occur during a back handspring performed by artistic gymnastics competitors on the basis of selected biomechanical quantities. Material/MethodsThe case study included five masterclass artistic gymnastics competitors. The activities were recorded at the frequency of 120 [Hz]. Using the SkillSpector computer software, selected biomechanical variables of the back handspring technique were analyzed. The coefficient of variation was used to evaluate the variability of movement, which, in turn, was used to describe the repeatability of the back handspring technique. ResultsKinematic analysis of the back handspring carried out with the recorded video material enables the qualitative evaluation of the repeatability of the sports technique. The position of the center of mass on the vertical axis determined at borderline points of phases in the back handspring technique was the quantity of highest repeatability. The lowest repeatability was observed in the absolute and relative (movement rhythm) durations of particular phases. ConclusionsIt is possible to master the back handspring while maintaining full repeatability of some biomechanical quantities characterizing the movement technique. The assessment of movement repeatability in gymnastics requires further research, with the simultaneous analysis of various biomechanical quantities and a determination of the best methods of comparison.