Work-Related Dermatoses of the Feet in Professional Dancers: A Pilot Study.

OBJECTIVE: The feet of professional dancers are exposed to high work-related stresses. To date, data from the professional dance sector concerning this matter are lacking. The aim of this exploratory project was to analyze and evaluate skin health in the foot area with regard to the prevalence of dermatoses, their locations, as well as gender-specific and load-specific differences. METHODS: Professional classical and neo-classical ballet dancers were examined at two time points: in a phase with increased stress (T0: daily training sessions, rehearsals, and high performance frequency) (n=51, 35 females, 16 males) and after a 24-day rest phase (T1: n=35, 28 females, 7 males). In addition, gender-specific and load-specific (T0 and T1) differences were evaluated. RESULTS: All professional dancers were affected by skin lesions of the feet at T0. Hyperkeratosis (96.1%), onychomycosis (27.5%), and subungual hematoma (11.8%) were the most frequent dermatoses of the feet of professional dancers. Onychomycosis affected the nails of the big toes in particular (right 15.7%; left 13.7%), and subungual hematomas were found exclusively on the nails of the first toe (right 7.8%; left 7.8%). Women tended to be more frequently affected by hyperkeratosis, men more frequently by onychomycosis. There were no load-specific differences between the stress and rest phases. CONCLUSION: The prevalence of work-related dermatoses is equally high among female and male dancers. The results can be used for further research and serve as a basis for specific measures of behavioral and environmental prevention in dance.

Influence of design of dentist's chairs on body posture for dentists with different working experience.

BACKGROUND: Musculoskeletal disorders (MSD) are a common health problem among dentists. Dental treatment is mainly performed in a sitting position. The aim of the study was to quantify the effect of different ergonomic chairs on the sitting position. In addition, it was tested if the sitting position of experienced workers is different from a non-dental group. METHODS: A total of 59 (28 m/31f) subjects, divided into two dentist groups according to their work experience (students and dentists (9 m/11f) < 10 years, dentists (9 m/10f) ≥ 10 years) and a control group (10 m/10f) were measured. A three-dimensional back scanner captured the bare back of all subjects sitting on six dentist's chairs of different design. Initially, inter-group comparisons per chair, firstly in the habitual and secondly in the working postures, were carried out. Furthermore, inter-chair comparison was conducted for the habitual as well as for the working postures of all subjects and for each group. Finally, a comparison between the habitual sitting posture and the working posture for each respective chair (intra-chair comparison) was conducted (for all subjects and for each group). In addition, a subjective assessment of each chair was made. For the statistical analysis, non-parametric tests were conducted and the level of significance was set at 5%. RESULTS: When comparing the three subject groups, all chairs caused a more pronounced spinal kyphosis in experienced dentists. In both conditions (habitual and working postures), a symmetrical sitting position was assumed on each chair. The inter-chair comparisons showed no differences regarding the ergonomic design of the chairs. The significances found in the inter-chair comparisons were all within the measurementerror and could, therefore, be classified as clinically irrelevant. The intra-chair comparison (habitual sitting position vs. working sitting position) illustrated position-related changes in the sagittal, but not in the transverse, plane. These changes were only position-related (forward leaned working posture) and were not influenced by the ergonomic sitting design of the respective chair. There are no differences between the groups in the subjective assessment of each chair. CONCLUSIONS: Regardless of the group or the dental experience, the ergonomic design of the dentist's chair had only a marginal influence on the upper body posture in both the habitual and working sitting postures. Consequently, the focus of the dentist's chair, in order to minimize MSD, should concentrate on adopting a symmetrical sitting posture rather than on its ergonomic design.

Systematic changes of the static upper body posture with a symmetric occlusion condition.

BACKGROUND: Temporary occlusal changes and their influence on the upper body statics are still controversially discussed. Furthermore, concrete statements on whether age- or gender-specific differences in neurophysiological reactions exist are missing. Therefore, it is the aim of this study to evaluate the immediate effects of a symmetrical occlusion blocking on the upper body posture. These effects shall be investigated for both genders and for a larger age range. METHODS: In this study, 800 (407f/393 m) subjects volunteered aged from 21 to 60 years. Both genders were divided into four age groups according to decades. The three-dimensional upper body posture was measured by using the rasterstereography (ABW-Bodymapper). The habitual static posture was measured in two dental occlusion conditions (a) in rest position and (b) symmetrical blocking in the bicuspid region by cotton rolls. RESULTS: A significant reduction of the trunk length (0.72 mm; p <  0.001), an increase of the lumbar (0.30°; p <  0.001) and the thoracic bending angle (0.14°; p = 0.001), a reduction of the spinal forward decline (0.16°; p <  0.001) and a reduction of the scapular distance (0.36 mm; p = 0.001) was found. Gender-specific reactions can only be recorded in scapular distance, in that regard men reduce this distance while over all age groups women did not show a significant change. DISCUSSION: Slight gender- and age-independent reactions due to a symmetric occlusion blockade are shown: A gender independent reaction of the spinal related variables in the sagittal plane (thoracic and lumbar flexion angle, trunk length, spinal forward decline). In addition, a gender specific change of the shoulder blade distance could be observed, where men reduced the distance while female did not show a change. However, since these reactions are of a minimum amount, it can be concluded that neurophysiological compensation mechanisms work equally well regardless of age and sex, and the upper body posture of healthy people changes only very slightly due to a temporarily symmetrical altered bite position.

[Effects of knee pain on postural control excluding the musculature of the craniomandibular system]. / Auswirkungen von Kniebeschwerden auf die posturale Kontrolle unter Ausschluss der Muskulatur des kraniomandibulären Systems.

BACKGROUND: Knee pain can influence postural control in addition to changes in the anatomical structure of the knee joints. OBJECTIVE: Because the influence of imbalances in the craniomandibular system has been proven multiple times, it is the aim of the present work to investigate the influence of various knee diagnoses on postural control excluding occlusal information by means of symmetrical packing using cotton rolls. MATERIALS AND METHODS: One hundred and fifteen patients (74 male/41 female) aged 18-75 years with an average BMI of 25.13 ± 3.66 kg/m2 took part in the study, among them 34 patients (26 male/8 female) with cruciate ligament injury, 26 (16 male/10 female) with meniscal lesions, 24 (13 male/11 female) with arthrosis, 21 (11 male/10 female) with patellar pain, and 10 (8 male/2 female) with other painful knee complaints. Postural control was increased using a force platform, the degree of severity of the disorder was recorded using the "Knee Injury and Osteoarthritis Outcome" questionnaire, and the occlusion packed on both sides with cotton rolls in the premolar area. RESULTS: With increasing age, patients with knee arthrosis are more likely to stand on the hindfoot. In those with patellar disorder, increased weight-bearing on the forefoot correlates with increasing BMI. An increase in weight-bearing on the forefoot on the side of the uninjured knee in people with patellar disorder results not only in a reduction in quality of life but also level of daily activity. DISCUSSION: The percentage weight-bearing on the zones of the feet differs in unilateral knee injuries (in particular, comparison of the side with the knee injury and the uninjured side). Age, BMI or gender are influencing factors. Because various correlations and/or effects in the subgroups of knee injuries are generated, an injury-specific analysis should be carried out. These effects are also identifiable in the subjective assessment of quality of life.

[Evaluation of the Global Research Architecture Regarding Diabetic Retinopathy]. / Eine szientometrische Analyse der globalen Forschungslandschaft zum Thema diabetische Retinopathie.

Aims and Scope: Diabetic retinopathy (DR) is of major scientific and socioeconomic interest in most of the industrialized countries due to increasing prevalence. This interest is reflected by a marked increase in the number of publications since the 1990 s. It is therefore difficult for a single author to obtain an overview of the topic. Material and Methods: The total number of published items on DR was determined in the Web of Science database. All bibliometric data were collected for the period 1900 to 2008 (search term:"diabet* retinopath*" and "diabet* macul*"). A number of different scientometric methods were applied in accordance with the NewQIS protocol, e.g. state of the art visualisation techniques such as density equalising maps and network diagrams. Results: A total of 15,624 publications were identified. The U. S. A. leads in the overall number of publications (4,689). The most productive and the most prolific institutions, authors and publications are all in the U. S. A. The University of Wisconsin (i.e. Ronald Klein and his wife Barbara Eden Kobrin Klein) have established an international network with a large number of institutions publishing important work. Nevertheless, many other important institutions can be identified, e.g. the Joslin Diabetes Center, which has published many articles on VEGF. Conclusion: The results reveal that the scientific interest on the topic DR is continuously increasing. International collaboration is of growing importance in this field.

[Sarcoidosis: A Descriptive Approach to the Global Research Network and Recent Scientific Developments]. / Eine deskriptive Betrachtung der globalen Forschungslandschaft und der aktuellen Forschungsentwicklungen zum Thema Sarkoidose.

AIMS AND SCOPE: Sarcoidosis continues to be an underestimated disease that can cause severe morbidity and mortality in individuals. There has, however, been an increasing awareness of this disease as shown by the increasing number of publications since the 1990  s. The large number of available publications makes it challenging for a single scientist to provide an overview of the topic. To quantify the global research activity in this field, a scientometric investigation was conducted. MATERIAL AND METHODS: The total number of publications on sarcoidosis was determined in the Web of Science to obtain their bibliometric data for the period 1900-2008. According to the NewQIS-protocol, different visualisation techniques and scientometric methods were applied. RESULTS: A total of 14,190 published items were evaluated. The U.S. takes a leading position in terms of the overall number of publications and collaborations. Prolific institutions and authors are of U.S. origin. Only a relatively small number of international co-operations were identified. The most intensive network is between the "University of Colorado" and the "National Jewish Medical Research Center". "Semenzato, G" has the highest citation rate of all authors. The most productive co-operative author is "du Bois, RM". CONCLUSION: The scientific interest in the topic sarcoidosis is growing steadily. The influence of international co-operation on scientific progress in this area is of increasing importance.

[Density equalizing mapping of obesity: analysis of a global epidemic]. / Density Equalizing Mapping der Adipositas: Analyse einer globalen Epidemie.

Obesity is a chronic disease whose origin is determined by genetic factors as well as environmental influences. The prevalence has rapidly increased worldwide in the recent decades. This paper evaluated the research on obesity in the period of 1900 - 2009 in the ISI "Web of Science" by Thomson Reuters. For this purpose scientometric methods were used and the results were graphically illustrated by "Density Equalizing Map Projections". From 1900 till 2009 94.987 published items are the basis for the present qualitative and quantitative data analysis. The publication rates show an exponential growth indicating a pronounced research activity. Concerning the country comparison the United States has the highest number of publications and citations, the highest modified h-index and most academic institutions. This manuscript shows the first comprehensive scientometric data on obesity. In this research area, the United States is a leader and is located at the center of global collaborations.

[Magnetic resonance imaging. Density equalizing mapping analysis of global research architecture]. / Magnetresonanztomographie. Eine Density-equalizing-mapping-Analyse der globalen Forschungsarchitektur.

BACKGROUND: Despite the great medical importance, there is still no comprehensive scientometric analysis regarding the results of magnetic resonance imaging (MRI) and the development of the importance for the healthcare system. AIMS: This paper evaluated and analyzed the entire research publication results on the topic of MRI for the period 1981-2007 based on scientometric methods and parameters. MATERIAL AND METHODS: A scientometric analysis (database: ISI Web of Science 1981-2007, search terms MRI and magnetic resonance imaging) was performed. The following parameters were analyzed: number of publications, countries of publication, number of citations, citation rate and collaborations, using various analytical and display techniques, including density equalizing map projections. RESULTS: Most of the 49,122 publications on MRI could be attributed to the USA (32.5 %), which also has the most cooperative collaborations. Within Europe, Germany (10.3 %) is the country with the highest number of publications followed by the UK (9.3 %). The western industrialized nations dominate over the rest of the world in terms of scientific developments of MRI. The thematic focus of the publications lies in the fields of radiology and neuroscience. In addition to the journal Neurology most scientific articles were published in Magnetic Resonance in Medicine and Circulation. DISCUSSION: The results show that the current trend is continuing and the scientific interest in MRI is continuously increasing.

[Arthrosis: a scientometric analysis]. / Arthrose : Eine szientometrische Analyse.

BACKGROUND: In industrialized nations, arthrosis is one of the most frequent causes of physical disability and impaired quality of life in older people. OBJECTIVES: There are still no direct and curative therapies. In addition, the causative mechanisms of this disease have not been sufficiently deciphered and investigated so far. MATERIALS AND METHODS: For the present article, publications from 1900-2013 in the ISI Web of Science were reviewed. Quantitative and qualitative aspects are taken into account and are examined based on scientometric analysis methods. The illustrations demonstrate the global structure of the research and citation activity by Density Equalizing Map Projection. In addition, the radar charts illustrate the bi- and multilateral research and institutional cooperation. RESULTS: On the basis of the search criteria, a total of 46,212 publications were identified. Approximately 95 % of the publications date back to the last 25 years. In addition to the number of publications, the number of citations has increased continuously. The analysis of the country collaborations as well as the number of institutions indicates a predominance of the United States. Most articles about arthrosis concern the subject areas of rheumatology, orthopedics, and surgery. CONCLUSION: This study provides the first comprehensive, scientometric findings and illustrates corresponding representations of research activities, geographical contexts as well as research cooperation. It shows a great scientific interest, especially by North American and European scientists. The steady growth of research is explained by the high prevalence of arthrosis.

The significance of lower jaw position in relation to postural stability. Comparison of a premanufactured occlusal splint with the Dental Power Splint.

AIM: The purpose of this study was to investigate the effects on postural stability of two different lower jaw positions held in place by splints with eyes open and eyes closed. METHODS: The postural stability in 21 healthy adult volunteers was investigated using two different sets of occlusal conditions with the lower jaw being at rest either with the eyes opened or closed. Two occlusal splints (standard splint and DPS splint) were used in order to maintain this lower jaw position. The balance behaviour was recorded using a balance platform. RESULTS: In a comparison of the habitual occlusion with the two occlusal splints, the balance posturographic values with the eyes opened fell between 7-9% and those for weight distribution with the eyes closed between 22-26% (with greater improvement being achieved with DPS) with the result that the variability in the range of fluctuations was reduced. The level of positioning accuracy deteriorated with the wearing of a splint between 13% with the DPS splint and 30% with the standard splint. Gender-specific differences of minor importance in relation to the positioning accuracy were recorded, with there being significant differences in the female participants (P≤0.00). CONCLUSION: An occlusal change in the stomatognathic system impacts on postural stability. Balance deficits seem to correlate with deteriorated body sway, which, according to the results, can be improved by a myocentric bite position using a DPS splint. This is more the case with the eyes closed than with the eyes opened.

Standard values of the upper body posture in healthy adults with special regard to age, sex and BMI.

In order to classify and analyze the parameters of upper body posture in clinical or physiotherapeutic settings, a baseline in the form of standard values with special regard to age, sex and BMI is required. Thus, subjectively healthy men and women aged 21-60 years were measured in this project. The postural parameters of 800 symptom-free male (n = 397) and female (n = 407) volunteers aged 21-60 years (Ø♀: 39.7 ± 11.6, Ø â™‚: 40.7 ± 11.5 y) were studied. The mean height of the men was 1.8 ± 0.07 m, with a mean body weight of 84.8 ± 13.1 kg and an average BMI of 26.0 ± 3.534 kg/m2. In contrast, the mean height of the women was 1.67 ± 0.06 m, with a mean body weight of 66.5 ± 12.7 kg and an average BMI of 23.9 ± 4.6 kg/m2. By means of video rasterstereography, a 3-dimensional scan of the upper back surface was measured when in a habitual standing position. The means or medians, confidence intervals, tolerance ranges, the minimum, 2.5, 25, 50, 75, 97.5 percentiles and the maximum, plus the kurtosis and skewness of the distribution, were calculated for all parameters. Additionally, ANOVA and a factor analyses (sex, BMI, age) were conducted. In both sexes across all age groups, balanced, symmetrical upper body statics were evident. Most strikingly, the females showed greater thoracic kyphosis and lumbar lordosis angles (kyphosis: Ø â™€ 56°, Ø♂ 51°; lordosis: Ø â™€ 49°, Ø♂ 32°) and lumbar bending angles (Ø â™€ 14°, Ø♂ 11°) than the males. The distance between the scapulae was more pronounced in men. These parameters also show an increase with age and BMI, respectively. Pelvic parameters were independent of age and sex. The upper body postures of women and men between the ages of 21 and 60 years were found to be almost symmetrical and axis-conforming with a positive correlation for BMI or age. Consequently, the present body posture parameters allow for comparisons with other studies, as well as for the evaluation of clinical (interim) diagnostics and applications.

The movement profile of trunk and neck during habitual vacuuming.

Musculoskeletal disorders of the trunk and neck are common among cleaners. Vacuum cleaning is a demanding activity. The aim of this study was to present the movement profile of the trunk and neck during habitual vacuuming. The data were collected from 31 subjects (21f./10 m) using a 3D motion analysis system (Xsens). 10 cycles were analysed in vacuuming PVC and carpet floors with 8 vacuum cleaners. The joint angles and velocities were represented statistically descriptive. When vacuuming, the trunk is held in a forwardly inclined position by a flexion in the hip and rotated from this position. In the joint angles and velocities of the spine, the rotation proved to be dominant. A relatively large amount of movement took place in the cervical spine and also in the lumbar spine. The shown movement profile is rather a comfort area of vacuuming which may serve as a reference for ergonomics in vacuuming.

Influence of dental occlusion conditions on plantar pressure distribution during standing and walking - A gender perspective.

The aim of this study was to investigate gender-specific influences of different symmetric and asymmetric occlusion conditions on postural control during standing and walking. The study involved 59 healthy adult volunteers (41 f/19 m) aged between 22 and 53 years (30.2 ± 6.3 years). Postural control measurements were carried out using a pressure plate by measuring plantar pressure distribution during standing and walking test conditions. Seven different occlusion conditions were tested. Prior to a MANOVA model analysis, the relationship between the two test conditions were checked using a factor analysis with a varying number of factors (between 2 and 10). The plantar pressure distributions during walking and standing are independent test conditions. The coefficient of variance across all variables between the conditions and genders was not significant: t(46) = 1.51 (p = 0.13). No statement can be made whether, or not, the influence of gender is greater than the influence of the conditions. Healthy male and female test subjects did not show any difference between seven occlusion conditions on the plantar pressure distribution while standing or walking. No differences between the genders were found for any of the investigated variables. In contrast to custom-made occlusion splints, simple cotton rolls appear not to influence the neuromuscular system in a systematic manner.

A device-based stretch training for office workers resulted in increased range of motion especially at limited baseline flexibility.

BACKGROUND: It is unclear whether and under which conditions stretch training programs lead to gains in flexibility when applied in work health promotion for office workers in order to reduce musculoskeletal disorders (MSD). OBJECTIVE: The aim of this study was to analyze whether the stretch training "five-Business" leads to gains in range of motion (ROM). Furthermore, the influence of baseline flexibility and socio-demographic factors (sex, age, weight, height and body mass index (BMI)) on trainability was assessed. METHODS: 161 office workers (n = 45 female; n = 116 male) without major MSD were recruited. Over three months, a standardized static stretch training ("five-Business") was executed on a device, supervised twice per week for 10 min. ROM was assessed using a digital inclinometer (shoulder, hip and trunk extension) and a tape measure (fingertip-to-floor and lateral inclination). RESULTS: ROM gains (p≤0.001) were present in all tests, except for the hip extension. ROM changes correlated moderately (0.24-0.62) with the baseline flexibility (p≤0.001). Subjects with limited flexibility reached the largest gains (1.41-25.33%). Regarding the socio-demographic factors only one low correlation occurred (weight - retroflexion; -0.177). CONCLUSION: The "five-Business" stretch training effectively increases ROM in office workers, especially when baseline flexibility is limited.

Symmetrical dental occlusion blocking - changes of body sway and weight distribution in healthy subjects across 4 age decades.

OBJECTIVES: Symmetrical dental occlusion blocking is used in dentistry as a quick diagnostic tool to test for potential influences of the craniomandibular system on body sway and weight distribution. This study presents the changes of body sway and pressure distribution in healthy subjects, free of a temporomandibular dysfunction (TMD). Immediate effects between occlusal blocking and rest position on body sway and body weight distribution in general, as well as for both genders and for four age decades will be evaluated. MATERIALS AND METHODS: 725 (396f/329 m) subjects (neither subjective signs of TMD nor acute/chronic complaints in the musculoskeletal system) volunteered (21 to 60 years) while both genders were divided into four age groups according to decades. A pressure measuring platform was used. Body sway and weight distribution were recorded in two dental occlusion conditions (a) in rest position and (b) symmetrical blocking (bicuspid region) by cotton rolls. RESULTS: Both, the frontal sway and the sagittal sway reduced by 0.67 mm (t(724) = - 3.9 (p <  0.001)) and by 0.33 mm (t(724) = - 3.4 (p <  0.001)). The relative pressure under the left forefoot increased by 0.33% (t(724) = 2.88 (p <  0.001)) and the relative pressure overall under the forefoot increased by 0.67% (t(724) = - 3.4 (p <  0.001)). Gender-specific, age-specific and BMI-specific reactions could not be identified. CONCLUSIONS: Subjects, free of any TMD and with no complaints of the musculoskeletal system, show small changes of the body sway and weight distribution when biting symmetrically on a cotton roll. These changes are independent of age, gender or body mass index (BMI). Due to the relative large sample size, the presented results can also be seen as norm values when body sway is used as an additional assessment of a TMD.

Superantigen binding to a T cell receptor beta chain of known three-dimensional structure.

The three-dimensional structure of an unglycosylated T cell antigen receptor (TCR) beta chain has recently been determined to 1.7 A resolution. To investigate whether this soluble beta chain (murine V beta 8.2J beta 2.1C beta 1) retains superantigen (SAG)-binding activity, we measured its affinity for various bacterial SAGs in the absence of MHC class II molecules. Dissociation constants (KDs) were determined using two independent techniques: surface plasmon resonance detection and sedimentation equilibrium. Specific binding was demonstrated to staphylococcal enterotoxins (SEs) B, C1, C2, and C3 and to streptococcal pyrogenic exotoxin A (SPEA), consistent with the known proliferative effects of these SAGs on T cells expressing V beta 8.2. In contrast, SEA, which does not stimulate V beta 8.2-bearing cells, does not bind the recombinant beta chain. Binding of the beta chain to SAGs was characterized by extremely fast dissociation rates (> 0.1 s-1), similar to those reported for certain leukocyte adhesion molecules. Whereas the beta chain bound SEC1, 2, and 3 with KDs of 0.9-2.5 microM, the corresponding value for SEB was approximately 140 microM. The much weaker binding to SEB than to SEC1, 2, or 3 was surprising, especially since SEB was found to actually be 3- to 10-fold more effective, on a molar basis, than the other toxins in stimulating the parental T cell hybridoma. We interpret these results in terms of the ability of SEC to activate T cells independently of MHC, in contrast to SEB. We have also measured SE binding to the glycosylated form of the beta chain and found that carbohydrate apparently does not contribute to recognition, even though the N-linked glycosylation sites at V beta 8.2 residues Asn24 and Asn74 are at or near the putative SAG-binding site. This result, along with the structural basis for the V beta specificity of SEs, are discussed in relation to the crystal structure of the unglycosylated beta chain.

Standard reference values of weight and maximum pressure distribution in healthy adults aged 18-65 years in Germany.

BACKGROUND: The aim of this study was to collect standard reference values of the weight and the maximum pressure distribution in healthy adults aged 18-65 years and to investigate the influence of constitutional parameters on it. METHODS: A total of 416 healthy subjects (208 male / 208 female) aged between 18 and 65 years (Ø 38.3 ± 14.1 years) participated in this study, conducted 2015-2019 in Heidelberg. The age-specific evaluation is based on 4 age groups (G1, 18-30 years; G2, 31-40 years; G3, 41-50 years; G4, 51-65 years). A pressure measuring plate FDM-S (Zebris/Isny/Germany) was used to collect body weight distribution and maximum pressure distribution of the right and left foot and left and right forefoot/rearfoot, respectively. RESULTS: Body weight distribution of the left (50.07%) and right (50.12%) foot was balanced. There was higher load on the rearfoot (left 54.14%; right 55.09%) than on the forefoot (left 45.49%; right 44.26%). The pressure in the rearfoot was higher than in the forefoot (rearfoot left 9.60 N/cm2, rearfoot right 9.51 N/cm2/forefoot left 8.23 N/cm2, forefoot right 8.59 N/cm2). With increasing age, the load in the left foot shifted from the rearfoot to the forefoot as well as the maximum pressure (p ≤ 0.02 and 0.03; poor effect size). With increasing BMI, the body weight shifted to the left and right rearfoot (p ≤ 0.001, poor effect size). As BMI increased, so did the maximum pressure in all areas (p ≤ 0.001 and 0.03, weak to moderate effect size). There were significant differences in weight and maximum pressure distribution in the forefoot and rearfoot in the different age groups, especially between younger (18-40 years) and older (41-65 years) subjects. DISCUSSION: Healthy individuals aged from 18 to 65 years were found to have a balanced weight distribution in an aspect ratio, with a 20% greater load of the rearfoot. Age and BMI were found to be influencing factors of the weight and maximum pressure distribution, especially between younger and elder subjects. The collected standard reference values allow comparisons with other studies and can serve as a guideline in clinical practice and scientific studies.

Influence of typical handball characteristics on upper body posture and postural control in male handball players.

BACKGROUND: Well defined constitutional parameters support the physical fatigue resistance in handball to maintain the performance level for the majority of actions. Ideal constitutional conditions are necessary to achieve these physiological advantages in handball. But limited knowledge exists about the upper body posture or the postural control in correlation to the Body Mass Index (BMI), playing years, playing position and throwing arm in professional male handball. METHODS: Ninety-one male handball players participate (24.1 ± 5.9 years; playing experience 16.6 ± 5.7 years). A three-dimensional back scanner and a pressure measuring plate were used. RESULTS: Correlations between BMI and upper body posture and postural control were not significant. Same counts for the comparison between the left and right throwing arm according to upper body posture and postural control (p ≥ 0.05). Correlations between the years of playing can be found at pelvis height (p ≤ 0.04) and for the length of the Center of Pressure (CoP) (p ≤ 0.01). Wing players are 6.5-8.5 cm smaller. The playing position is independently of BMI, age or upper body posture (p ≥ 0.05). Backcourt players have a higher load of the left and a lower load of the right foot compared to wing players (p ≤ 0.001). Left-right comparison (p ≤ 0.001/ 0.01) can be seen in pivot player (covered area), backcourt player (weight distribution left/right [rear] foot), wing player (weight and force distribution left/right foot, covered area). CONCLUSION: Goalkeeper, Backcourt and pivot players are taller and heavier than wing players. These physiological demands are not detectable in the upper body posture and slightly in postural control. Wing players have the most asymmetric load distribution and the longest length of CoP. Since goalkeepers do not differ from pivot or backcourt players, this can be lead back to the same training.

The acute effect in performing common range of motion tests in healthy young adults: a prospective study.

In the application of range of motion (ROM) tests there is little agreement on the number of repetitions to be measured and the number of preceding warm-up protocols. In stretch training a plateau in ROM gains can be seen after four to five repetitions. With increasing number of repetitions, the gain in ROM is reduced. This study examines the question of whether such an effect occurs in common ROM tests. Twenty-two healthy sport students (10 m/12 f.) with an average age of 25.3 ± 1.94 years (average height 174.1 ± 9.8 cm; weight 66.6 ± 11.3 kg and BMI 21.9 ± 2.0 kg/cm2) volunteered in this study. Each subject performed five ROM tests in a randomized order-measured either via a tape measure or a digital inclinometer: Tape measure was used to evaluate the Fingertip-to-Floor test (FtF) and the Lateral Inclination test (LI). Retroflexion of the trunk modified after Janda (RF), Thomas test (TT) and a Shoulder test modified after Janda (ST) were evaluated with a digital inclinometer. In order to show general acute effects within 20 repetitions we performed ANOVA/Friedman-test with multiple comparisons. A non-linear regression was then performed to identify a plateau formation. Significance level was set at 5%. In seven out of eight ROM tests (five tests in total with three tests measured both left and right sides) significant flexibility gains were observed (FtF: p < 0.001; LI-left/right: p < 0.001/0.001; RF: p = 0.009; ST-left/right: p < 0.001/p = 0.003; TT-left: p < 0.001). A non-linear regression with random effects was successfully applied on FtF, RF, LI-left/right, ST-left and TT-left and thus, indicate a gradual decline in the amount of gained ROM. An acute effect was observed in most ROM tests, which is characterized by a gradual decline of ROM gain. For those tests, we can state that the acute effect described in the stretching literature also applies to the performance of typical ROM tests. Since a non-linear behavior was shown, it is the decision of the practitioner to weigh up between measurement accuracy and expenditure. Researchers and practitioners should consider this when applying ROM assessments to healthy young adults.

Structural origins of high-affinity biotin binding to streptavidin.

The high affinity of the noncovalent interaction between biotin and streptavidin forms the basis for many diagnostic assays that require the formation of an irreversible and specific linkage between biological macromolecules. Comparison of the refined crystal structures of apo and a streptavidin:biotin complex shows that the high affinity results from several factors. These factors include the formation of multiple hydrogen bonds and van der Waals interactions between biotin and the protein, together with the ordering of surface polypeptide loops that bury the biotin in the protein interior. Structural alterations at the biotin binding site produce quaternary changes in the streptavidin tetramer. These changes apparently propagate through cooperative deformations in the twisted beta sheets that link tetramer subunits.