Front Thigh Research Articles

ISAK-Based Anthropometric Standards for Elite Male and Female Soccer Players.

This study aimed to provide reference values for anthropometric characteristics of elite male and female soccer players, considering a group of individuals from the general population as controls. The anthropometric profiles of 357 elite soccer players [184 males (age 24.3 ± 4.3 y) and 173 females (age 25.2 ± 5.1 y)] participating in the first Italian league (Serie A) and 363 subjects from the general population [188 males (age 24.2 ± 4.8 y) and 175 females (age 25.0 ± 5.1 y)] were measured according to the guidelines of the International Society for the Advancement of Kinanthropometry (ISAK). Reference percentiles for stature, body mass, circumferences, eight skinfolds (biceps, triceps, subscapular, suprailiac, supraspinal, abdominal, front thigh, and calf), breadths, and somatotype were calculated and stratified by player position and sex. No difference (p > 0.05) was found in age between the two groups. Soccer players showed lower values for the sum of the eight ISAK skinfolds than individuals from the general population of the same sex. This suggests lower adipose tissue, as indicated by a lower endomorphic component. The somatotype was endomorphic mesomorph and mesomorphic endomorph for the male and female individuals from the general population, respectively. The male soccer players were ectomorphic mesomorphs, while the females were balanced mesomorphs, defining a sport-specific morphology. This study provides sex- and role-specific anthropometric standards for elite soccer players. Raw anthropometric reference values may be useful for evaluating body composition without using any predictive equations or assumptions.

Comparisons and associations among anthropometric indices of first and second division and assistant soccer referees.

Body composition is an important predictor of performance and a key component of health and physical fitness. Therefore, the purposes of this study were to compare soccer referees of the first and second divisions and field assistant referees from Iran and to analyze associations of a body shape index (ABSI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), conicity index (ConI), and body mass index (BMI) with body fat percentage (%BF). A total of 270 male soccer referees from the first (n = 124) and second (n = 72) divisions and assistant referees (n = 74) participated in this study. Skinfold thickness (measured at the chest, biceps, triceps, subscapular, abdominal, iliac crest, and front thigh), height, weight, hip circumference, and waist circumference were assessed to evaluate waist-to-height ratio (WHtR), %BF, and also ABSI, BRI, BAI, ConI, and AVI according to the ISAK protocol. The main results indicated differences in WHR, WHtR, ABSI, BRI, AVI, ConI, and BF% with the assistant referees presenting higher values (p < 0.05). When considering the backward selection model, there were some associations with %BF in each group, specifically BMI, BAI, and ABSI in the first division; BMI, WHR, and ABSI in the second division; and BMI in the assistant referee group (all p < 0.05). The present study did not confirm the hypothesis that the first-division referees presented better body composition-related variables than the second division or assistant referees. Instead, it showed that the assistant referees that participated in both divisions showed a tendency to higher values which suggests that the level of division is not a major factor when analyzing body composition.

Cutaneous warmth and hotness thresholds to radiation heat exposure at a distance of 10 cm from 17 body regions

The purpose of the present study was to evaluate body regional differences in cutaneous warmth and hotness thresholds in relation to radiant heat exposure. Fourteen male subjects participated in this study (age: 25 ± 5 y, height: 176.6 ± 5.5 cm, body weight: 70 ± 5.8 kg). Cutaneous warmth and hotness thresholds were measured on the forehead, neck, chest, abdomen, upper back, lower back, upper arm, forearm, palm, back of hand, front thigh, shin, top of foot, buttock, back thigh, calf, and sole. The forehead (34.8 ± 0.2 °C), lower back (34.1 ± 1.2 °C) and palm (34.3 ± 0.7 °C) had the highest warmth thresholds, whereas the foot (29.8 ± 1.9 °C) and sole (28.0 ± 2.1 °C) had the lowest values among the 17 regions (P<0.001). Higher warmth thresholds were related to higher initial skin temperatures (Tsk) (r=0.972, P<0.001). Increases in Tsk for detecting warmth sensation were smaller for the lower back with a rise of 0.2 ± 0.4 °C and the abdomen (0.3 ± 0.3 °C) than for the buttock (0.9 ± 0.8 °C) and sole (0.8 ± 0.6 °C) (P<0.05). Increases in Tsk for detecting hotness sensation ranged from 0.5 to 1.5 °C. Warmth and hotness thresholds on the abdomen or sole had significant relationships with body mass index, indicating that the overweight are less sensitive to detecting radiant heat on the abdomen or sole. Thermal thresholds from radiant heat exposure of 100 cm2 were lower than the values from conductive heat exposure of 6.25 cm2, which might be explained by the effect of spatial summation.

Evaluation of fatigue in young female adults due to repeated exposure to heat in summer and cold in winter.

The magnitude of fatigue (MF) from psychological and physiological responses during repeated exposure to heat in summer and during repeated exposure to cold in winter was evaluated to test two hypotheses on fatigue models. The first hypothesis is that exposure time (ET, min) would be a factor determining the MF and the second hypothesis is that the same fatigue models as a function of the number of exposure repetitions (NR) could be applied to both repeated exposure to heat in summer and cold in winter. In summer, eight young adult female subjects with clothing insulation (Icl, clo) of 0.3 clo first stayed in the control room at 26 ℃ for 15min, moved to the main testing room at 30 ℃ for 25min, 33°C for 15min, or 36 ℃ for 10min, and then returned to the control room. The product of air temperature difference (ΔTa, ℃) and ET was designed to be almost equal among these latter three conditions. The exposure was repeated five times. In winter, the same female subjects with Icl of 0.84 clo first stayed in the control room at 24 ℃ for 15min, moved to the main testing room at 18 ℃ for 30min, 15 ℃ for 20min, or 12 ℃ for 15min, and then returned to the control room. Again, the product of ΔTa and ET was designed to be equal among these latter three conditions. The exposure was repeated four times. The scores of subjective fatigue feeling (SFF) and salivary amylase value (SAV) were recorded when the subjects returned to the control room. Tympanic temperature, skin temperatures and local sweat rates (Sw, mg/cm2/min) at chest, forearm, front thigh, and front shin, and ECG were continuously monitored, except for Sw in the winter experiment. In the summer experiment, the SFF showed a threshold value at ΔTa = 4 ℃ but continuously increased with NR at ΔTa = 7 ℃ and 10 ℃. It was not correlated with ECG variables, but was positively correlated with SAV (R2 = 0.50) and the mean Sw (R2 = 0.76) at ΔTa = 7 ℃ and 10 ℃. In the winter experiment, the SFF showed a threshold value at ΔTa = - 6 ℃ but continuously increased with NR at ΔTa = - 9 ℃ and - 12 ℃. It was correlated with SAV at ΔTa = - 9 ℃ (R2 = 0.77) and score of LF: HF ratio at ΔTa = - 6 ℃ and - 9 ℃ (R2 = 0.49). It was confirmed that ET may be related to the MF and that different fatigue models may be applied dependent on ΔTa during repeated exposure to heat in summer and during repeated exposure to cold in winter. Thus, the two hypotheses were verified.

Sensitivity and preference of local airflows beneath garments with personalised temperatures and velocities

Microclimate ventilation under garment is one of the effective means to relieve heat stress of human body, while the sensitivity and preference of airflow at different body parts are not thoroughly studied. This study investigates the local airflow sensitivity of five body segments by a psychophysical method, whereby twelve subjects were stimulated by three temperatures of ventilation under garment (Tsk - 5 °C, Tsk, or Tsk + 5 °C, Tsk is the initial local skin temperature); at the front chest, upper back, lower back, front thigh, and back thigh areas. Airflow sensitivity was tested to enhance when the airflow became warmer or cooler than the Tsk, showing that human skin can recognise variations in airflow velocity with a difference threshold of 0.23 ± 0.06 m/s. The front chest was the least sensitive of all three airflow temperatures, while the back thigh was the most sensitive to cool airflow. Twelve subjects then underwent controllable local ventilation at 35 °C, RH 40%. The airflow preference, psychological and physiological responses, and energy consumption were analysed. The preferred airflow temperature was approximately 26 °C (25.7 ± 1.8–25.9 ± 1.4 °C), while the preferred airflow velocity had a large individual variation. The lower back should be primarily ventilated, obtaining comfort enhancement with an energy saving of 30–40% compared to others; the front chest or the upper back should be added for higher cooling demand. This study helps us to understand the characteristics of airflow sensitivity on localised skin and optimises the design of individual ventilation.

Anthropometric Profile and Body Composition of the Mexican Olympic Beach Volleyball Team

The present research corresponds to a cross-sectional descriptive study in the anthropometric field, which allows coaches to develop standards to identify talent and optimize training in the discipline of beach volleyball. Its objective was to define the anthropometric profile and body composition of the Mexican Olympic beach volleyball teams in both sexes. The participants were couples one and two of Mexico in both sexes (defined by FIVB ranking), 4 women and 4 men with average age of 30.25±6.85 and 27.25±7.36 years. The technique used was Heath-Carter´s somatotype method and the anthropometric profile restricted ISAK protocol. Among the findings resulting from the research, unification can be observed in the male morphological characteristics (triceps skinfold, front thigh skinfold, calf skinfold, circumference of relaxed and contracted arm, waist, hip, femur diameter and BMI), as for the somatotype, both sexes of Mexican couples are positioned in mesomorphs-balanced. In relation to other studies consulted, balance in somatotype and muscular development is observed with high performance teams. Weight and height, as well as age, are important variables for the selection of talent and future optimal performance in world and professional volleyball.

Acute Effects of Varied Back Squat Activation Protocols on Muscle-Tendon Stiffness and Jumping Performance.

Krzysztofik, M, Wilk, M, Pisz, A, Kolinger, D, Tsoukos, A, Zając, A, Stastny, P, and Bogdanis, GC. Acute effects of varied back squat activation protocols on muscle-tendon stiffness and jumping performance. J Strength Cond Res 37(7): 1419-1427, 2023-Intensity, movement velocity, and volume are the principal factors to successfully use postactivation performance enhancement. Therefore, 15 resistance-trained volleyball players completed 3 different back squat configurations as a conditioning activity (CA) in randomized order: (a) 3 sets of 3 repetitions at 85% 1RM (HL); (b) a single set of back squats at 60% 1RM until 10% mean velocity loss (VB); (c) and 2 sets of back squats at 60% 1RM until 10% mean velocity loss (2VB) on subsequent countermovement jump performance, Achilles tendon, and vastus lateralis stiffness with concomitant front thigh skin surface temperature assessment. The measurements were performed 5 minutes before the CA and at 2, 4, 6, 8, and 10 minutes. The jump height was significantly increased in the second minute and at peak, post-CA compared with baseline for all conditions ( p = 0.049; ES = 0.23 and p < 0.001; ES = 0.37). Skin surface temperature was significantly increased for all post-CA time points compared with baseline in the 2VB condition ( p from <0.001-0.023; ES = 0.39-1.04) and in the fourth minute and at peak post-CA in HL condition ( p = 0.023; ES = 0.69 and p = 0.04; ES = 0.46), whereas for the VB condition, a significant decrease in peak post-CA was found ( p = 0.004; ES = -0.54). Achilles tendon stiffness was significantly decreased for second, fourth, eighth, 10th, and peak post-CA in comparison to baseline for all conditions ( p from p = 0.004-0.038; ES = -0.47 to -0.69). Vastus lateralis stiffness was significantly decreased for peak post-CA compared with baseline for all conditions ( p = 0.017; ES = -0.42). We recommend using a single set of barbell squats with a 10% velocity loss as a mechanism of fatigue control to acutely improve jump height performance and avoid unnecessary increases in training volume.

Estimativa da massa gorda em adolescentes do sexo feminino do sul do Brasil: desenvolvimento e validação de modelos matemáticos

abstract This study aimed to develop and validate the first mathematical models, based on anthropometric properties, to estimate fat mass (FM) in a heterogeneous sample of female adolescents. A cross-sectional and quantitative study conducted with 196 individuals aged 12 to 17 years from the metropolitan region of Curitiba, Paraná, Brazil. The participants were randomly divided into two groups: regression sample (n = 169) and validation sample (n = 27). Dual-energy X-ray absorptiometry (DXA) was used as the reference method to determine body fat in relative and absolute values. Stature, body mass, waist girth and triceps, subscapular, biceps, iliac crest, abdominal, front thigh and medial calf skinfold thickness were defined as independent variables and measured according to an international technical protocol. Statistical analyzes used the Ordinary Least Square (OLS) regression model, paired t test and Pearson correlation. Four multivariate mathematical models with high determination coefficients (R2 ≥90%) and low estimated standard errors (SEE = ≤2.02 kg) were developed. Model 4 stands out for its low number of independent variables and significant statistical performance (R2 = 90%; SEE = 1.92 kg). It is concluded that the four mathematical models developed are valid for estimating FM in female adolescents in southern Brazil.

Analiza laserskog i ručnog stvaranja efekata brkova i procesa struganja u pogledu industrijskog inženjerstva i održivosti za industriju pranja denima

Whisker and scrapping is a well-known dry process in the denim washing industry. Whisker is the worn-out lines and impression patterns generated by natural wearing on hips and front thigh area. On the other hand, to create a distressed look hand scrapping is applied on the front thigh, upper back knee, upper pocket side, or overall area of a denim garment. Nowadays those are common dry processes for denim wash. Those are used to increase the fashionable look of a denim garment. Whisker and scraping are the first process of the denim dry process. There are many types of whisker and scrapping process for denim garments. In the manual version generally, it is done by pattern, chalk, and emery paper. Another popular and well-established way is laser burning. Both process is well qualified to meet consumer demand. The final outlook and outcome are also the same for both processes. But here the main issue is SMV, per-hour output, Manpower, and Sustainability. For manual processes, SMV is more and Per hour output is less as a result the production is less, and extra manpower is required. For manual scrapping PP spray process is required to increase the distress look. That's why this process is not sustainable for the application of potassium permanganate (PP Spray). For laser burning, the machine output is much higher for machine operation less manpower is required. And here the laser effect enhancing chemical is applied instead of PP spray which is a sustainable process. As a result, production must be higher for a washing plant by implementing a laser burning process instead of a manual process.

Development and Validation of an Anthropometric Equation to Predict Fat Mass Percentage in Professional and Semi-Professional Male Futsal Players.

This study aimed to (i) characterise the body composition of professional and semi-professional male futsal players, (ii) assess the validity of commonly used equations to estimate FM%, (iii) develop and cross-validate a futsal-specific FM% prediction equation. In a cross-sectional design, 78 adult male futsal players were assessed for body mass, stature, skinfolds, and girths as per the International Society for the Advancement of Kinanthropometry protocol and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. Using paired-sample t-tests, the FM% from the DXA and nine published equations were compared. New sport-specific models were developed by stepwise multiple regression. Existing equations were cross-validated using the least squares regression, concordance correlation coefficient, and the Bland-Altman analyses. New equations were further cross-validated using the PRESS approach. None of the existing equations accurately predicted the DXA-derived FM% (p &lt; 0.001; R2 ≤ 0.76, SEE ≥ 1.59; CCC ≤ 0.83; bias = -8.2% to -1.3%, limited agreement, and varying trends). The novel Bettery® equation: -0.620 + (0.159 ∗ Σ4SKF [triceps, abdominal, iliac crest, and front thigh (mm)]) + (0.120 ∗ waist girth (cm)), demonstrated a high accuracy (R2 = 0.85, SEE = 1.32%), a moderate strength of agreement (CCC = 0.92), no bias (0.2%), good agreement (±2.5%), and no trend (r = -0.157; p = 0.170) against the DXA. The Bettery® equation is the first to allow for a valid and sport-specific assessment of FM% in male futsal players.

P05-15 Effects on heart rate, physical activity and ambulatory blood pressure from occupational physical activity with and without lifting among farmers in Denmark

BackgroundHigh levels of occupational physical activity associate to increased risk of cardiovascular disease. However, knowledge regarding the acute effects of different components of the occupational physical activity, such as lifting, on risk factors for cardiovascular disease remains uninvestigated during every day work. Thus, the aim was to investigate the acute effects from exposure to occupational physical activity with and without lifting on heart rate, physical activity and ambulatory blood pressure.MethodsA randomized cross-over study among 18 farming workers in Denmark, all working in the stables of pig- producing farms. Workday measurements of heart rate (Actiheart), physical activity (Axivity placed at front thigh and upper back) and ambulatory blood pressure (Spacelabs 90217, measuring every 20th minute) were collected at a workday with and a workday without occupational lifting. The wash out period between the measurements was 48 hours. Data were processed in the Acti4 software.ResultsDuring workdays with lifting compared to workdays without lifting we observed higher intensity of occupational physical activity (Δ 6.57% heart rate reserve, 95% CI -1.34 – 14.47), number of steps/workday (Δ 4,965 steps, 95% CI -0.01 – 0.01), standing/walking activities (Δ 83 min/workday, 95% CI 2.49 – 168.97), as well as higher heart rate (Δ 9.10 bpm, 95% CI -4.66 – 22.85) and higher ambulatory blood pressures, both systolic (Δ 3.77 mmHg, 95% CI -2.64 – 10.18) and diastolic (Δ 1.37 mmHg, 95% CI -2.52 – 5.26). The average burden of the occupational lifting were 2,425 kg/workday and amount of lifts/workday were 239 lifts.ConclusionsThis pilot project indicated that occupational lifting are adding strenuousness on top of the general occupational physical activity, and influence blood pressure and heart rate at clinically relevant magnitudes. Disentangling the potential relations between one component of occupational physical activity, such as lifting, and risk for cardiovascular disease is key in the development of initiatives for specific prevention, exposure recommendations and vocational rehabilitation.

Mechanical power flow from trunk and lower limb joint power to external horizontal power in the track and field block start

ABSTRACT Sprint start performance is measured as the horizontal external power, the time-average rate of horizontal kinetic energy generation. Although joint powers have been examined, not all segment rotations on which positive powers are exerted necessarily contribute to forward propulsion; details regarding horizontal power remain unclear. Here we show the contributions of segment rotations to the forward and upward propulsion. We calculated the joint power exerted on each segment and the contributions from segment rotations to the normalised average horizontal and vertical external powers ( and ) during the sprint start by 12 male sprinters. Over half (55 ± 6%) is due to the front thigh rotation (0.30 ± 0.04), on which the hip and knee exert positive power. Pelvic rotation does not contribute to (0.00 ± 0.01). This highlights the importance of the hip-extensors strength and the need for it accompanied by the lumbar-extensors strength cancelling out the hip-extensors action on the pelvis and promoting hip-extensor-induced thigh rotation. The front thigh rotation decreases (−0.08 ± 0.02). is primarily induced by rotations of the thorax (0.04 ± 0.01), lumbar region (0.06 ± 0.02), and pelvis (0.04 ± 0.01). Rotations of the lower-limb segments did not contribute to upward propulsion. Therefore, the front thigh induces downward movement, which is counterbalanced by the trunk segments. We bridge the gap in the current understanding from joint power to . We present a case involving segments on which positive joint powers are exerted similarly but play different roles: forward or upward propulsion, thereby providing insights into directional control mechanisms in explosive initiation of motion. HIGHLIGHTS We examined the contributions of segment rotations to the normalised average horizontal and vertical external powers (, ): the sprint start performance and the parameter to assess upward propulsion. Over half the total (55 ± 6%) is due to the front thigh rotation, while the front thigh rotation decreases , which was counterbalanced by rotations of the thorax, lumbar region, and pelvis. We bridge the gap in the current understanding from joint power to and further present a case involving segments on which positive joint powers are exerted but play different roles: forward or upward propulsion.

Effects of wearing knee-guards on skin pressure and skin blood flow during dynamic motions

The purpose of the present study was to explore the effects of wearing knee guards on skin blood flow and skin pressure during dynamic soccer motions. Twenty-one male subjects participated in the following two experimental conditions: wearing knee guards (KG) and no knee guards (Control). Subjects performed several consecutive soccer motions along with a standing position between each motion. Skin blood flow and skin pressure on the thigh, knee, and calf were monitored. The results showed that skin pressure had the greatest value in a sitting position for both the KG condition and Control, but the smallest during instep kicking and switching directions (P < 0.001). The rear calf had the greatest skin pressure for the KG condition (P < 0.001), while the side knee showed the greatest for the Control (P < 0.001). Normalized skin blood flow based on values from their standing position was the greatest during the jump motion among the various soccer motions. Interestingly, skin blood flow decreased by wearing the knee guards on the front thigh and calf (r = − 0.859; r = − 0.835; P < 0.001), while the blood flow increased on the side knee (r = 0.295, P < 0.001). Subjects felt greater skin pressure sensation during the jump motion and switching directions than other soccer positions/motions (P < 0.001). These results indicate that the knee guards result in relatively lighter pressure for dynamic motions (e.g., kick, switching directions, or jump) than for static positions (e.g., sitting or standing), and the skin blood flows for the thigh, knee, and calf are redistributed by wearing the knee guards, especially during jumping.

Fat tissue on the march: secular trend of body circumferences and skinfold thicknesses in Slovenia over the 70 years period.

Introduction: The prevalence of overweight and obesity among young adults has increased dramatically in recent decades. The survey examined anthropometric indicators of fat tissue amount in the population of adult males and females from Slovenia from 1950 to 2019. Methods: From a large anthropometric database body height, body mass, seven circumferences (C: waist, hip, relaxed and flexed upper arm, forearm, middle thigh, medial calf) and seven skinfold thicknesses (SFT: triceps, biceps, subscapular, iliac crest, supraspinale, front thigh and medial calf) were obtained in different combinations for more than 3400 males and almost 4600 females of age 18 to 29 years, measured in the years between 1950 and 2019. To evaluate the secular trend, data were classified into 10-year periods and compared with ANOVA. Results: Body mass, waist-to-height ratio, waist-to-hip ratio, waist C, relaxed and flexed upper arm C, calf C, Triceps/subscapular ratio, biceps SFT, supraspinale SFT, front thigh SFT, and medial calf SFT increased (p < 0.001) over the last 70 years, however, thigh C decreased (p < 0.001) over the last 30 years. Body mass index and forearm C increased in males and decreased in females. Triceps and subscapular SFT`s increased till 2009 and then decreased in next decade in both sexes. Body fat % increased over the 70-years observed period from 12% to almost 15% in males and from 24% to more than 26% in females. Conclusion: From 1950 to 2009 or even to 2019, large amount of body fat clearly became more prevalent in young adults from Slovenia, which mostly is in line with secular trend in fat tissue in other parts of the world; however, in many measurements this trend slows down or even reverses after 2009 in Slovenia. Slovenian population appears to be leaner compared to other populations.

Anthropometric Profile Assessed by Bioimpedance and Anthropometry Measures of Male and Female Rugby Players Competing in the Spanish National League

Different rugby positions make different demands on players. It therefore follows that optimum body composition may vary according to the position played. Using anthropometry and bioimpedance analysis (BIA) to assess body composition, the present study aimed to compare the effect of sex and position on body composition variables using anthropometry and BIA methods. A total of 100 competitive rugby players (35 women and 65 men) competing in the First Spanish National League were recruited voluntarily and for convenience for this study. In the laboratory, body composition was assessed by anthropometry, following the recommendations established by the International Society for the Advancement of Kinanthropometry (ISAK), and by direct segmental multi-frequency BIA, following the guidelines established by the Spanish Group of Kinanthropometry (GREC) of the Spanish Federation of Sports Medicine (FEMEDE). We found sex-related differences in height, weight, body mass index and body fat (%) by anthropometry and in body lean mass (%) by DSM-BIA, in 4 of the 6 skinfolds assessed (p &lt; 0.05). We also observed position-related differences in all the variables assessed (p &lt; 0.05) except for lean body mass, as measured by both methods of determining body composition, and front thigh skinfold. Body composition and ∑6skinfolds differs according to sex and playing position, backs (16.6 ± 3.8% and 92.3 ± 33.9 mm,) vs. forwards (20.0 ± 6.7 and 115.3 ± 37.6 mm), and the muscle-adipose (meso-endomorphic somatotype) development predominated in both sexes. Thus, forwards of both sexes are taller, heavier and fatter, possibly due to the specific demands of this position. In addition, body composition measurements vary according to the method used (DSM-BIA vs. anthropometry), indicating that anthropometry is probably the best body composition assessment method.

The Relationship between Skinfold and Ultrasound Measures of Subcutaneous Fat in Untrained Healthy Males

Ultrasound measurement of adipose tissue offers an alternative measure of body composition with less technical skill requirement than skinfolds. However, the relationship between skinfold and ultrasound measurements of adipose tissue is uncertain. The aim of this study was to compare these measures in a healthy untrained male population. One hundred male participants (aged 18–40 years) of varying body compositions had skinfold measures taken at the biceps, triceps and front thigh sites. Ultrasound measures were also taken at the same sites using B-wave ultrasound with a linear probe in the transverse plane. Strong, significant (p &lt; 0.01), positive correlations were observed between skinfold and ultrasound measures at the biceps (r = 0.828), triceps (r = 0.813), and front thigh (r = 0.888) sites. However, there was significant (p &lt; 0.01) variance between the techniques at all measurement sites. Whilst skinfold and ultrasound measures of adipose tissue have good linear agreement, skinfolds are consistently higher at all sites indicating a difference in the nature of the tissue measured via each technique. The exact nature of the relationship should be established on a population-specific basis.

Training in spikes and number of training hours correlate to injury incidence in youth athletics (track and field): A prospective 52-week study

ObjectivesThe aim was to describe the annual incidence and types of musculoskeletal injuries, and to examine factors associated with injury risk. DesignA 52-week prospective study in Swedish youth athletics aged 12–15 years. MethodsData on exposure to training and injury were collected from parents/caregivers and youth athletes using a web-survey system. ResultsA total of 101 (86%) youth athletes participated. Fifty-four (53%) of the athletes reported one new injury. Girls were at higher risk of sustaining an injury than boys (p = 0.048). Ninety-one percent of the new injuries were non-traumatic and 85% occurred in the lower extremities. Injuries to the front thigh represented 20% of the injuries. Cox proportional hazard regression analyses showed a six-fold increased risk for a first injury for athletes reporting use of spikes and training <6 h every two weeks (hazard ratio, 6.1; 95% confidence interval, 1.2–31.3) compared to athletes training <6 h using no spikes. Athletes training 6 h or more reporting use or no use of spikes had an eight-fold increase injury risk (p < 0.01). ConclusionsAlmost half of the youth athletes experienced a new injury and girls had a higher risk compared to boys. Nine out of ten injuries were related to overuse. An interesting observation was the high incidence of injuries to the quadriceps muscle complex. The study identified a correlation with training hours and an interaction with track spikes and risk of injury that needs further attention.

Hill Runner's Physiology, Performance and Nutrition: A Descriptive Study.

Objectives: The aim of this descriptive study was to characterise anthropometric variables, aerobic capacity, running performance and energy intake and expenditure of hill runners in free-living conditions, and to investigate the relationship between age, anthropometric variables, aerobic capacity and running performance.Methods: Twenty-eight hill runners participated in this study (17 males and 11 females; aged 18–65 years). Body fat percentage estimate, sum of eight skinfolds (triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh and medial calf) and maximal oxygen capacity (VO2max) were assessed in a laboratory setting. Participants also completed a timed hill run (Dumyat Hill, Scotland, ascent: 420 m, distance: 8 km) while wearing a portable gas analyzer to assess oxygen consumption (VO2). Energy intake and energy expenditure were assessed in free-living conditions over three consecutive days different from the testing days through self-reported food diaries and accelerometers.Results: VO2max assessed in the lab (51.2 ± 7.6 ml·min−1·kg−1) showed a weak negative relationship with age [rs(23) = −0.38, p = 0.08]. Neither body fat percentage (median 12.4; IQR 10.1–17.1) nor the sum of skinfolds (median 81.8; IQR 62.4–97.8 mm) correlated with age [rs(28) = 0.001, p = 0.10 and 26 rs(28) = −0.02, p = 0.94, respectively]. The observed intensity of the hill run was 89 ± 6% of the age predicted maximum heart rate and 87 ± 9% of the VO2max observed in the lab. Hill running performance correlated with VO2max [r(21) = 0.76, p < 0.001], age [rs(26) = −0.44, p = 0.02] and with estimated body fat percentage and sum of skinfolds [rs(26) = −0.66, p < 0.001 and rs(26) = −0.49, p = 0.01, respectively]. Energy intake negatively correlated with age [rs(26) = −0.43, p = 0.03], with the overall energy intake being significantly lower than the total energy expenditure (2273 ± 550 vs. 2879 ± 510 kcal·day−1; p < 0.001; d = 1.05).Conclusion: This study demonstrated that hill running performance is positively associated with greater aerobic capacity and negatively associated with increases in adiposity and age. Further, the study highlights that hill runners are at risk of negative energy balance.

Percentage of subcutaneous fatty tissue as an indicator of the physical status of volleyball players

Subcutaneous adipose tissue (skin folds) is a disruptive factor in many sports that overcome the force of gravity, including volleyball. In the field of volleyball, it is imperative to identify the anthropometric constitution, where the amount ofsubcutaneous adipose tissue plays a significant role. The study included 18 active players of the women's volleyball club Jahorina from Pale (BH=173±8.77cm;BW=66.04±9.09kg; BMI=22.03±2.19kg/m2, age=19.11±2.63), a member of thevolleyball Premier League of Bosnia and Herzegovina with the main goal to analyze and determine the percentage of adipose fat as an indicator of physical status. Yuhasz skinfold test (Biceps skinfold, Triceps skinfold, Subscapular skinfold, Suprailiac skinfold, Abdomen skinfold, Front thigh skinfold, Rear thigh skinfold) was applied to assess skin folds. Measurements were performed with a skin fat measuring instrument (Caliper GIMA-model Plicometro, Italy) in accordance with the ISAK protocol. Statistical data processing included central and dispersion parameters andPearson's correlation coefficients. Based on the obtained results, it can be concluded that 30% of significant ICC p&lt;,05;p&lt;0,01;p&lt;0,001 were achieved. The percentage of skin folds of Jahorina volleyball players in body weight is 16.16% (12 kg), and body fat mass is 54.04 kg. Based on the obtained results, the amount of adipose tissue can be concluded that our sample is within the allowed values recommended for this population, and that amount is lower compared to previous research. DOI: https://doi.org/10.24040/sjss.2021.7.1.64-74

P‐106: An Electromechanical Integration Design Method with Strain Analysis Correlation for Flexible Hybrid Electronics

By friction correlation of CLO 3D simulation with 3D DIC strain map, the simulation errors in two areas are reduced from 16.7% and 11.6% to 10% and 4.3%, respectively. Second, three low‐stress (~26% compared to original design, on the front thigh) bike pants have been designed and sampled.