Coordinative patterns require experience and learning to be acquired, producing movements that offer efficient solutions to various situations and involving certain degree of variability. This coordination variability implies functionality in movement, but it can be impacted by the type of sport practice from early years. The purpose of this work is to analyze the coordination variability and coordination patterns in a specific action such as single-leg landing in children practicing gymnastics, volleyball and non-sporting children. Thirty children (15 girls) performed 10 successful trials of single-leg landing from a height of 25 cm. A motion capture system (9 cameras) was used to capture 3D thigh and shank kinematics. To identify the significant effect of children's groups on coordination and coordination variability during single-leg landing, one-dimensional Statistical Parametric Mapping (SPM) was used. Regarding the coordination patterns, in the frontal plane, during the attenuation phase of single-leg landing, the control group exhibited a higher frequency of Anti-Phase with proximal dominancy compared to the sport groups (i.e., gymnastics, and volleyball). In addition, in the sagittal plane during the second peak phase, volleyball players exhibited a higher coordination variability than the gymnastics. The children in the control group showed a greater frequency of antiphasic movements, which indicates the influence of training at an early age, being a determining factor in the increase or not of variability.

• MeSH
• Leg physiology   MeSH
• Biomechanical Phenomena MeSH
• Child MeSH
• Gymnastics * MeSH
• Humans MeSH
• Motor Skills physiology   MeSH
• Movement MeSH
• Psychomotor Performance physiology   MeSH
• Volleyball * MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

• MeSH
• Adult MeSH
• Fourier Analysis MeSH
• Humans MeSH
• Parasympathetic Nervous System MeSH
• Stress, Psychological physiopathology   MeSH
• Psychomotor Performance MeSH
• Spectrum Analysis methods   utilization   MeSH
• Heart Rate MeSH
• Sympathetic Nervous System MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH

Tradičně se lidská ruka studuje prostřednictvím měření a srovnávání jednotlivých segmentů (prstů, článků prstů, záprstních kostí) bez zohlednění jejich vzájemných prostorových souvislostí. Cílem této studie je výzkum vnitro-populační variability formy lidské ruky jako celku v oblasti tříčlánkových prstů se zvláštním zaměřením na sexuální dimorfismus a vztah mezi velikostí a tvarem ruky. Pravé ruce 99 žen a 70 mužů, převážně vysokoškolských studentů, byly ve standardizované poloze z palmární strany zaznamenány běžným stolním skenerem. Na každém dvourozměrném snímku bylo umístěno 16 význačných bodů a byla studována variabilita mezi těmito konfiguracemi prostřednictvím metod geometrické morfometrie. Pro lepší pochopení vnitřních vzorců variability tvaru byl tvarový prostor rozložen na afinní a neafinní podprostor, které byly dále analyzovány samostatně. Převážná část celkové variability byla spojena s afinními tvarovými rozdíly, které jsou identické v celé studované oblasti ruky. Jejich větší část představovala střižnou změnu v proximodistálním směru, menší část pak napínání odpovídající změnám v šířce ruky. Toto napínání také silně korelovalo s velikostí ruky. Mezipohlavní rozdíly představovala afinní změna, ve které byla proximodistální střižná změna neoddělitelně spojena se změnami v relativní šířce ruky. Lokální neafinní pohlavní rozdíly byly zaznamenány v určitých článcích prstů a mohou souviset s rozdíly v poměrech délek prstů. Domníváme se, že oddělení globálních a lokálních sexuálně dimorfních znaků ruky může pomoci blíže ozřejmit původ/počátek jejich dimorfismu v rané ontogenezi – čím lokálnější znak, tím později se v ontogenezi zakládá. Dimorfní znaky lokální a globální by proto mohly být ovlivněny odlišnými ontogenetickými faktory.

Traditionally, the human hand has been analyzed by measuring and comparing individual segments (fingers, phalanges, metacarpals) without considering their mutual spatial relationships. The present study aimed to analyze intra-population variability of the human hand form in the region of fingers as whole with special focus given to sexual dimorphism and the association between shape and size. Right hands of 99 females and 70 males, mostly college students, were scanned with a document scanner in standardized position from the palmar side. For each image 2-D coordinates of 16 landmarks were recorded and variability between configurations of landmarks were studied using geometric morphometrics. To understand patterns of variability, shape spaces were decomposed into affine and non-affine subspaces and further studied separately. The prevalence of the total variability was associated with affine shape change identical for the whole studied region of the hand. Its major portion was represented by shearing in proximodistal direction and to a lesser extent by straining in the relative hand width. The strain also strongly correlated with size of the hand. Intersexual differences were represented by affine change in which the proximodistal shearing was inextricably tied with the differences in relative hand width. Local non-affine sex differences were found in specific phalanges and might be associated with differences in finger length ratios. We presume that separating global and local sexually dimorphic features of the hand might shed light on the origin/onset of the dimorphism during early ontogeny – the more local the feature, the later differentiated, and thus influenced by different ontogenetic factors than global features.

• Keywords
• geometrická morfometrie,
• MeSH
• Anatomic Landmarks MeSH
• Phenotype MeSH
• Humans MeSH
• Sex Characteristics * MeSH
• Hand * anatomy & histology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

The purpose of this study was to examine the effects of rowing stroke rates on lower extremity intra-joint coordination variability in professional rowers. Fifteen experienced young rowers volunteered to participate in this study. Kinematic data were recorded at different rowing speeds with seven Vicon cameras. The continuous relative phase (CRP) and CRP variability (CRPV) were used to calculate joint coordination and coordination variability, respectively, for the hip, knee, and ankle in the sagittal and horizontal planes, and a comparison was made among different rowing stroke rates. A vector analysis repeated measure ANOVA using statistical parametric mapping revealed that there were statistically significant differences in the hip-ankle, hip-knee, and knee-ankle CRPs for rowing at different stroke rates. Moreover, there was higher CRPV in the mid-drive and mid-recovery phases and less variability in the transition from the drive phase to the recovery phase. The results demonstrate the importance of knee joint in rowing tasks in experienced rowers during submaximal rowing stroke rate and the shift of movement to the hip at higher rowing stroke rate. Moreover, there was a smaller variability during drive-to-recovery transition, which may suggests an increased risk for overuse injuries.

• MeSH
• Biomechanical Phenomena MeSH
• Lower Extremity MeSH
• Knee MeSH
• Ankle MeSH
• Humans MeSH
• Sports * MeSH
• Water Sports * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

The initial stance position (ISP) has been observed as a factor affecting the execution technique during taekwondo kicks. In the present study, authors aimed to analyse a roundhouse kick to the chest by measuring movement coordination and the variability of coordination and comparing this across the different ISP (0°, 45° and 90°). Eight experienced taekwondo athletes performed consecutive kicking trials in random order from every of the three relative positions. The execution was divided into three phases (stance, first swing and second swing phase). A motion capture system was used to measure athletes' angular displacement of pelvis and thigh. A modified vector coding technique was used to quantify the coordination of the segments which contributed to the overall movement. The variability of this coordination (CV) for each ISP was also calculated. Comparative analysis showed that during the stance phase in the transverse plane, athletes coordinated movement of the trunk and thigh with a higher frequency of in-phase and lower frequency of exclusive thigh rotation in the 0° stance than the 90° stance position (P < 0.05). CV was also influenced by the different ISP. During the first swing and the majority of the second swing phase, predominant in-phase coordination of the pelvis and thigh was observed. Including exercises that require in-phase movement could not only help athletes to acquire coordination stability but also efficiency. The existence of a constraint such as ISP implies an increase of the variability when the athletes have to kick from ISP they are not used to adopt (i.e., 0° and 90° ISP) as an evidence of adaptability in the athletes' execution technique.

• MeSH
• Biomechanical Phenomena MeSH
• Martial Arts * MeSH
• Lower Extremity MeSH
• Adult MeSH
• Humans MeSH
• Motor Skills * MeSH
• Pelvis MeSH
• Task Performance and Analysis * MeSH
• Movement * MeSH
• Posture * MeSH
• Rotation MeSH
• Athletic Performance * MeSH
• Thigh * MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Recently, the use of treadmills for walking and running has increased due to lifestyle changes. However, biomechanical differences in coordination between running on a treadmill or overground have not been adequately addressed. RESEARCH QUESTION: The purpose of this study was to compare coordination and its variability in lower limb segments during treadmill and overground running at different speeds. METHODS: Twenty physically active university undergraduate students participated in this study. Each participant ran trials for both overground and treadmill running at slow and fast speeds. Three-dimensional kinematic data of the lower limb segments were captured. The continuous relative phase (CRP) was used to compute coordination and its variability (VCRP) for foot, shank, and thigh segments of the dominant side of the participants. RESULTS: A vector analysis using statistical parametric mapping (SPM) revealed that there were statistically significant differences in the calculated CRPs for treadmill and overground running in the stance phase of running and for different running speeds in the late stance and swing phases. However, the VCRPs calculated for the two locations and speeds did not exhibit any statistically significant differences. CONCLUSION: The findings of this study suggest differences in segment coupling between treadmill and overground running may affect lower extremity biomechanics. In addition, changes in the coupling patterns for different running speeds suggest that segment coordination is not stable in the range of training speeds used by runners. Finally, the lack of differences in the variability of segment couplings during treadmill and overground conditions at different speeds potentially demonstrates similar dynamic neuromuscular control and degrees of freedom at these different running locations and speeds.

• MeSH
• Running physiology   MeSH
• Biomechanical Phenomena MeSH
• Lower Extremity physiology   MeSH
• Humans MeSH
• Young Adult MeSH
• Students MeSH
• Universities MeSH
• Exercise Test MeSH
• Check Tag
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

This study was aimed to compare the variability of inter-joint coordination in the lower-extremities during gait between active individuals with transtibial amputation (TTAs) and healthy individuals (HIs). Fifteen active male TTAs (age: 40.6 ± 16.24 years, height: 1.74 ± 0.09 m, and mass: 71.2 ± 8.87 kg) and HIs (age: 37.25 ± 13.11 years, height: 1.75 ± 0.06 m, and mass: 74 ± 8.75 kg) without gait disabilities voluntarily participated in the study. Participants walked along a level walkway covered with Vicon motion capture system, and their lower-extremity kinematics data were recorded during gait. The spatiotemporal gait parameters, lower-extremity joint range of motion (ROM), and their coordination and variability were calculated and averaged to report a single value for each parameter based on biomechanical symmetry assumption in the lower limbs of HIs. Additionally, these parameters were separately calculated and reported for the intact limb (IL) and the prosthesis limb (PL) in TTAs individuals. Finally, a comparison was made between the averaged values in HIs and those in the IL and PL of TTAs subjects. The results showed that the IL had a significantly lower stride length than that of the PL and averaged value in HIs, and the IL had a significantly lower knee ROM and greater stance-phase duration than that of HIs. Moreover, TTAs showed different coordination patterns in pelvis-to-hip, hip-to-knee, and hip-to-ankle couplings in some parts of the gait cycle. It concludes that the active TTAs with PLs walked with more flexion of the knee and hip, which may indicate a progressive walking strategy and the differences in coordination patterns suggest active TTA individuals used different neuromuscular control strategies to adapt to their amputation. Researchers can extend this work by investigating variations in these parameters across diverse patient populations, including different amputation etiologies and prosthetic designs. Moreover, Clinicians can use the findings to tailor rehabilitation programs for TTAs, emphasizing joint flexibility and coordination.

• MeSH
• Amputation, Surgical * MeSH
• Amputees MeSH
• Biomechanical Phenomena MeSH
• Gait * physiology   MeSH
• Walking physiology   MeSH
• Lower Extremity MeSH
• Adult MeSH
• Ankle Joint physiopathology   MeSH
• Knee Joint physiopathology   surgery   MeSH
• Hip Joint surgery   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Range of Motion, Articular * MeSH
• Tibia surgery   physiopathology   MeSH
• Artificial Limbs * MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Publication type
• Journal Article MeSH

Understanding the intricacies of human movement coordination and variability during running is crucial to unraveling the dynamics of locomotion, identifying potential injury mechanisms and understanding skill development. Identification of minimum number of cycles for calculation of reliable coordination and its variability could help with better test organization and efficient assessment time. By adopting a cross-sectional study design, this study investigated the minimum required cycles for calculating hip-knee, hip-ankle and knee-ankle coordination and their variability using a continuous relative phase (CRP) method. Twenty-nine healthy adults ran on a treadmill at speeds of 9, 12.5, and 16 km.h-1 while 3D kinematic data of their lower limbs were recorded using 6 optoelectronic cameras. Using Intraclass Correlation Coefficient (ICC) analysis, reliability between CRP and its variability (CRPv) in different gait cycles (3, 5, 10, 20, 30) was assessed for each speed. A minimum of 10 cycles was required for CRP calculation across all speeds, whereas CRPv necessitated a minimum of 30 cycles for moderate to good reliability. While increasing the number of cycles improved ICC values for inter-joint CRP, the same trend was not consistently observed for CRPv, emphasizing the importance of separately assessing CRP and its variability metrics.

• MeSH
• Running * physiology   MeSH
• Biomechanical Phenomena MeSH
• Gait * physiology   MeSH
• Adult MeSH
• Ankle Joint * physiology   MeSH
• Knee Joint * physiology   MeSH
• Hip Joint physiology   MeSH
• Humans MeSH
• Young Adult MeSH
• Cross-Sectional Studies MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H4do2p, 1,4-H2do2pOEt, and 1,4-H2Bn2do2pH, were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H4do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H4do2p is ~1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H4do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H2do2pOEt and Gd(III)-H2Bn2do2pH complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H4do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H4do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H4do2p complexes.

• MeSH
• Europium chemistry   MeSH
• Gadolinium chemistry   MeSH
• Heterocyclic Compounds chemistry   MeSH
• Coordination Complexes chemical synthesis   chemistry   MeSH
• Contrast Media MeSH
• Crystallography, X-Ray MeSH
• Phosphinic Acids chemistry   MeSH
• Ligands MeSH
• Magnetic Resonance Spectroscopy MeSH
• Manganese chemistry   MeSH
• Organophosphonates chemistry   MeSH
• Potentiometry MeSH
• Spectrophotometry, Ultraviolet MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH

Cíl: Sémontův repoziční manévr se v praxi užívá k léčbě pacientů s benigním paroxyzmálním polohovým vertigem zadního polokruhového kanálku. Cílem studie bylo zhodnotit interindividuální a intraindividuální variabilitu při provádění tohoto manévru a definovat parametry, které jeho provedení nejvíce ovlivňují. Metody: Tři zkušení terapeuti provedli manévr oboustranně u 10 zdravých jedinců. Inerciální měřicí jednotka složená z akcelerometru a gyroskopu získávala informace o trajektorii pohybu hlavy v prostoru a její rychlosti. Úhlové změny byly zaznamenány v souřadnicovém referenčním systému. Z odchylek od uvažované roviny polokruhového kanálku byla vyhodnocena data o přesnosti provedení manévru. Výsledky: Parametry ovlivňujícími přesnost manévru jsou výška probanda (p = 0,0252), fáze pohybu (p < 0,0001) a dále terapeut a strana pohybu, přičemž tyto faktory vykazují vliv především ve své interakci. Byl hodnocen vztah fáze pohybu k výšce probandů (p = 0,0130), terapeuta k fázi pohybu (p = 0,0001), terapeuta k výšce probandů (p < 0,0252). Největší zaznamenaný rozsah odchylky od senzorické roviny byl v rozmezí –37,17° až 31° se standardní odchylkou 16,6°. Závěry: Získaná data poukazují na překvapivě vysokou variabilitu při provádění Sémontova manévru ať v porovnání mezi jednotlivými měřeními u jednoho terapeuta nebo v porovnání mezi terapeuty. Analýza vlivu těchto odchylek na úspěšnost terapie benigního polohového paroxyzmálního vertiga a bližší analýza ovlivňujících parametrů by měly být předmětem dalšího výzkumu.

Aim: Sémont liberatory manoeuvre is used in the treatment of posterior semicircular canal in patients with benign paroxysmal positional vertigo. The aim of the study was to determine the inter-individual and intra-individual variability in the processing of the manoeuvre and to define the parameters that affect it the most. Methods: Three experienced therapists applied the manoeuvre bilaterally in 10 healthy probands. Inertial measurement unit consisting of the accelerometer and gyroscope recorded the trajectory and speed. Angle changes were placed in the coordinate reference system. Accuracy of the manoeuvre was evaluated based on the deviations from the projected sensory plane. Results: Parameters affecting the accuracy of the manoeuvre included height of a proband (p = 0.0252), phase of the movement (p < 0.0001), therapist and the side of the movement. The effect of these factors is the most pronounced when combined. We assessed interactions of the phase of the movement and the height of the probands (p = 0.0130), the therapist and the phase of movement (p = 0.0001), the therapist and the height of the probands (p < 0.0252). The largest magnitude of deviation from the sensory plane was in the range of –37.17° to 31° with a standard deviation of 16.6°. Conclusions: The data highlight high variability in the implementation of the Sémont liberatory manoeuvre, whether measurements by a single therapist or inter-individually between the therapists are compared. Analysis of the impact of these deviations on therapeutic efficacy in patients with benign paroxysmal positional vertigo and detailed analysis of influencing parameters should be the subject of further research. Key words: benign positional paroxysmal vertigo – variability – Sémont liberatory manoeuvre The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manu­script met the ICMJE “uniform requirements” for biomedical papers.

• MeSH
• Benign Paroxysmal Positional Vertigo * diagnosis   therapy   MeSH
• Adult MeSH
• Humans MeSH
• Mathematics MeSH
• Young Adult MeSH
• Posture * MeSH
• Postural Balance MeSH
• Rotation * MeSH
• Software MeSH
• Statistics as Topic MeSH
• Body Weights and Measures MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH