Predicting in vivo soft tissue masses of the lower extremity using segment anthropometric measures and DXA

The purpose of this study was to derive and validate regression equations for the prediction of fat mass (FM), lean mass (LM), wobbling mass (WM), and bone mineral content (BMC) of the thigh, leg, and leg + foot segments of living people from easily measured segmental anthropometric measures. The segment masses of 68 university-age participants (26 M, 42 F) were obtained from full-body dual photon x-ray absorptiometry (DXA) scans, and were used as the criterion values against which predicted masses were compared. Comprehensive anthropometric measures (6 lengths, 6 circumferences, 8 breadths, 4 skinfolds) were taken bilaterally for the thigh and leg for each person. Stepwise multiple linear regression was used to derive a prediction equation for each mass type and segment. Prediction equations exhibited high adjusted R2 values in general (0.673 to 0.925), with higher correlations evident for the LM and WM equations than for FM and BMC. Predicted (equations) and measured (DXA) segment LM and WM were also found to be highly correlated (R2 = 0.85 to 0.96), and FM and BMC to a lesser extent (R2 = 0.49 to 0.78). Relative errors between predicted and measured masses ranged between 0.7% and -11.3% for all those in the validation sample (n = 16). These results on university-age men and women are encouraging and suggest that in vivo estimates of the soft tissue masses of the lower extremity can be made fairly accurately from simple segmental anthropometric measures.     

Manual segmentation of DXA scan images results in reliable upper and lower extremity soft and rigid tissue mass estimates

Quantification of segment soft and rigid tissue masses in living people is important for a variety of clinical and biomechanical research applications including wobbling mass modeling. Although Dual-energy X-ray Absorptiometry (DXA) is widely accepted as a valid method for this purpose, the reliability of manual segmentation from DXA scans using custom regions of interest (ROIs) has not been evaluated to date. Upper and lower extremity images of 100 healthy adults who underwent a full body DXA scan in the supine position were manually segmented by 3 measurers independently using custom ROIs. Actual tissue masses (fat mass, lean mass, bone mineral content) of the arm, arm with shoulder, forearm, forearm and hand, thigh, leg, and leg and foot segments were quantified bilaterally from the ROIs. There were significant differences between-measurers, however, percentage errors were relatively small overall (<1–5.98%). Intraclass correlation coefficients (ICCs) were very high between and within-measurers, ranging from 0.990 to 0.999 and 0.990 to 1.00 for the upper and lower extremities, respectively, suggesting excellent reliability. Between and within-measurer errors were comparable in general, and differences between the tissue types were small on average (maximum of 42 and 53 g for upper and lower extremities, respectively). These results suggest that manual segmentation of DXA images using ROIs is a reliable method of estimating soft and rigid tissues in living people.     

Upper extremity soft and rigid tissue mass prediction using segment anthropometric measures and DXA

Regression equations for predicting bone mineral content (BMC), fat mass (FM), lean mass (LM), and wobbling mass (WM) of living people from simple anthropometric measures (segment lengths, circumferences, breadths, and skin folds) have been reported in the literature for the lower extremities, but are lacking for the upper extremities. Multiple linear stepwise regression was used to generate such equations for the arm, forearm, and forearm and hand segments of healthy university aged people (38 males, 38 females). Actual tissue masses were obtained from full body Dual-energy X-ray Absorptiometry (DXA) scans and were used to validate the developed equations with an independent sample of 24 participants (12 male, 12 female). Prediction equations exhibited very high adjusted R² values (range from 0.854 to 0.968), with more explained variance for LM and WM than for BMC and FM. Scatter plots of actual versus predicted tissue masses revealed a close relationship (R² range from 0.681 to 0.951). Relative errors between the predicted and actual tissue masses for the validation group ranged from ?2.2% to 15.5%, and the root-mean-squared error (RMS_error) ranged from 7.92 to 180.26 g, for BMC of the forearm and LM of the arm, respectively. These results suggest that accurate estimates of in-vivo tissue masses for the upper extremities can be predicted from simple anthropometric measurements in young adults. Access to tissue masses such as these will enable the development of more accurate models for predicting dynamic in-vivo response of the body to activities involving impact.     

Reference Values for Body Composition and Anthropometric Measurements in Athletes

Background

Despite the importance of body composition in athletes, reference sex- and sport-specific body composition data are lacking. We aim to develop reference values for body composition and anthropometric measurements in athletes.

Methods

Body weight and height were measured in 898 athletes (264 female, 634 male), anthropometric variables were assessed in 798 athletes (240 female and 558 male), and in 481 athletes (142 female and 339 male) with dual-energy X-ray absorptiometry (DXA). A total of 21 different sports were represented. Reference percentiles (5^th, 25^th, 50^th, 75^th, and 95^th) were calculated for each measured value, stratified by sex and sport. Because sample sizes within a sport were often very low for some outcomes, the percentiles were estimated using a parametric, empirical Bayesian framework that allowed sharing information across sports.

Results

We derived sex- and sport-specific reference percentiles for the following DXA outcomes: total (whole body scan) and regional (subtotal, trunk, and appendicular) bone mineral content, bone mineral density, absolute and percentage fat mass, fat-free mass, and lean soft tissue. Additionally, we derived reference percentiles for height-normalized indexes by dividing fat mass, fat-free mass, and appendicular lean soft tissue by height squared. We also derived sex- and sport-specific reference percentiles for the following anthropometry outcomes: weight, height, body mass index, sum of skinfold thicknesses (7 skinfolds, appendicular skinfolds, trunk skinfolds, arm skinfolds, and leg skinfolds), circumferences (hip, arm, midthigh, calf, and abdominal circumferences), and muscle circumferences (arm, thigh, and calf muscle circumferences).

Conclusions

These reference percentiles will be a helpful tool for sports professionals, in both clinical and field settings, for body composition assessment in athletes.     

Component inertia modeling of segmental wobbling and rigid masses

A modification to an existing mathematical model is described, which permits the determination of subject-specific inertia parameters for wobbling and rigid masses of female body segments. The model comprises segment-specific soft tissue, bone, and lung components. A total of 59 geometric solids (40 soft tissue, 17 bone, 2 lung) were used to represent the body components. Ninety-five anthropometric measurements were collected from 7 female participants and were used to develop and evaluate the model. The success of the model is evaluated using predicted mass and mass distribution. The overall absolute accuracy in predicted whole body mass was better than 3.0%, with a maximum error of 4.9%. The appropriateness of the cadaver-based density values used in the model is addressed and the accuracy of the component inertia model in relation to uniform density models is discussed. The model offers a novel approach for determining component inertia parameters, which have been used successfully in a wobbling mass model to produce realistic kinetic analyses of drop-landings.     

Estimation of body composition from bioelectrical impedance of body segments

This study provides values of anthropometric measurements and specific impedance, for a sample of 104 adults. The hypothesis that the body composition can be estimated more accurately from measurements of lengths and impedance values of the body segments than from the whole body was tested. The impedance of upper and lower extremities (arm and leg) and trunk were used to compute estimates of body composition parameters (FFM, FM, %F, TBW, ECW). The results were compared with those estimated by the impedance of the whole body. These comparisons demonstrated that significative differences resulted from body composition obtained by segmental impedance and by the whole body.     

Mean muscle activation comparison between fastballs and curveballs with respect to the upper and lower extremity

Baseball research on muscle activity (upper and lower extremity) during the throwing motion is important to understanding pitching mechanics for the future. Therefore, it is the purpose of this research study to compare the lower extremity muscle and upper extremity muscle activation patterns associated with the curveball pitch and the fastball pitch from the stretch position. Twelve skilled (NCAA collegiate level) pitchers volunteered to be in this study, with a mean age of 22.3 ± 4.53 years, mean height of 1.74 ± 0.13 m, and mean mass of 89.0 k ± 10.97 kg. The pitchers were fitted with six surface electromyography (EMG) bipolar electrodes on the stride leg biceps femoris, medial gastrocnemius, ipsilateral side lower trapezius, upper trapezius, triceps brachii and biceps brachii. Each pitcher underwent maximum voluntary isometric contraction (MVIC) testing and then performed the fastball & curveball pitching sequence. All EMG variables of interest were normalized using MVIC data and compared between pitching type. A repeated measures ANOVA was conducted for all muscle activity as well. If significance was found a pairwise analysis (Bonferroni) was performed between pitch type, using SPSS (p 0.05). Significant differences in the mean muscle activity for the fastball and curveball pitched from the stretch were observed. A higher level of muscle activity was found for the stretch fastball when compared to the stretch curveball. This study was able to provide a baseline measurement of muscle activity; however, kinematics and kinetics should be measured in future studies.     

Influence of central and extremity circumferences on all-cause mortality in men and women

For a given level of adiposity, greater lower body circumferences appear to exert a protective effect on several disease outcomes including cardiovascular disease and diabetes; however, the independent associations between extremity circumferences and mortality have not been widely investigated. The purpose of this study was to determine the independent and shared influences of upper- and lower-body circumferences on the risk of mortality in a population-based sample of adults. The sample included 10,638 adults 20-69 years of age (5,012 men; 5,626 women) from the nationally representative 1981 Canada Fitness Survey (CFS), who were monitored for over 12 years for mortality. BMI was calculated from measured height and weight. Waist, hip, thigh, calf, and upper arm circumferences were measured using a flexible, nonelastic anthropometric tape. Sex-specific proportional hazards regression models were used to evaluate the relationship between standardized values (Z-scores) of extremity circumference measures, waist circumference (WC) and mortality. Age, smoking status, alcohol consumption, and leisure-time physical activity were collected by questionnaire and were included as covariates. During 131,563 person-years of follow-up, there were 340 deaths in men and 231 in women. After mutual adjustment, WC was positively associated with mortality whereas arm, thigh, and calf circumferences were significantly protective in men, and arm and thigh circumferences were protective in women. In conclusion, waist and extremity circumferences appear to have opposite, independent effects on mortality in this sample of Canadians. Independent of BMI and WC, men and women with larger extremity circumferences had a lower risk of mortality.     

Mass, center of mass, and moment of inertia estimates for infant limb segments.

To quantify limb dynamics, accurate estimates are needed of anthropometric inertia parameters (mass, center-of-mass location, and moments of inertia). These estimates, however, are not available for human infants; therefore, the movement dynamics of infants have not been studied extensively. Here, regression equations for the masses, center-of-mass locations, and transverse moments of inertia of upper and lower limb segments (upper arm, forearm, and hand; thigh, leg, and foot) of 0.04 to 1.50 yr old infants are provided. A mathematical model of the human body was used to determine the anthropometric inertia parameters for upper limbs in 44 infants and for lower limbs in 70 infants. Stepwise linear regressions were used to fit the distributions of the anthropometric inertia parameters. The regression equations accounted for significant amounts of the variance (64-98%), and the R2-values compared favorably when our equations were cross-validated. Consequently, these regression equations can provide, for infants of similar ages, reasonable estimates of upper and lower limb anthropometric inertia parameters, suitable for equations of motion in the analysis of limb dynamics in human infants.     

Inertial characteristics of adolescent male body segments

In response to the presently limited information on body segment inertial characteristics of children and adolescents this investigation estimated the mass, centre of mass and principal moments of inertia of adolescent male body segments. Significant prediction equations based on anthropometric measurements were then sought. Thirteen subjects were measured at 6-monthly intervals for 2.5 yr to provide inertial characteristics for the leg, thigh, lower trunk and upper trunk segments. These characteristics were derived using an elliptical zone modelling technique. Following a correlation analysis, significant prediction equations of segment inertial parameters were derived from five, or fewer, anthropometric measurements. For all cases, more than 84% of the variance in the dependent variable was accounted for with a maximum R2 value of 94% being recorded for the prediction of thigh segment mass. The use of these prediction equations offered accurate and convenient estimates of body segment inertial characteristics within the limitations applicable to all modelling approaches. In contrast to recent studies, these equations accommodated the current morphological status of the subject.     

Comparison of human lung tissue mass measurements from Ex Vivo lungs and high resolution CT software analysis

ABSTRACT: BACKGROUND: Quantification of lung tissue via analysis of computed tomography (CT) scans is increasingly common for monitoring disease progression and for planning of therapeutic interventions. The current study evaluates the quantification of human lung tissue mass by software analysis of a CT to physical tissue mass measurements. METHODS: Twenty-two ex vivo lungs were scanned by CT and analyzed by commercially available software. The lungs were then dissected into lobes and sublobar segments and weighed. Because sublobar boundaries are not visually apparent, a novel technique of defining sublobar segments in ex vivo tissue was developed. The tissue masses were then compared to measurements by the software analysis. RESULTS: Both emphysematous (n = 14) and non-emphysematous (n = 8) bilateral lungs were evaluated. Masses (Mean +/- SD) as measured by dissection were 651 +/- 171 g for en bloc lungs, 126 +/- 60 g for lobar segments, and 46 +/- 23 g for sublobar segments. Masses as measured by software analysis were 598 +/- 159 g for en bloc lungs, 120 +/- 58 g for lobar segments, and 45 +/- 23 g for sublobar segments. Correlations between measurement methods was above 0.9 for each segmentation level. The Bland-Altman analysis found limits of agreement at the lung, lobe and sublobar levels to be 13.11% to 4.22%, -13.59% to 4.24%, and -45.85% to 44.56%. CONCLUSION: The degree of concordance between the software mass quantification to physical mass measurements provides substantial evidence that the software method represents an appropriate non-invasive means to determine lung tissue mass.     

An anthropometric assessment of Huntington's disease patients and families

An anthropometric investigation was designed to evaluate patterns of physical deterioration in Huntington's disease (HD). In this study a comprehensive set of measurements was taken including height, weight, body circumferences, skinfold thickness, and craniofacial, linear, and breadth components of the body, on 44 normal, 26 affected, and 70 at-risk individuals between 14 and 88 years of age. The anthropometric data were converted to z-scores using standards to adjust for age and sex differences. These scores were then adjusted for inter-family variation. There were significant differences among normal and affected individuals for all dimensions of body mass, as well as for several craniofacial and linear components of the body. Several significant differences were also found between normals and particular age cohorts of at-risk persons. HD gene carrier status was further assessed by factor analysis of the adjusted scores.     

Body build classification for ordinary schoolgirls (aged 7-18 years) and volleyball girls (aged 13-16 years)

The article describes two Estonian anthropometric cross-sectional studies of 1549 ordinary schoolgirls (aged 7-18) and 46 girls, who regularly practised volleyball (aged 13-16). Data are presented on 22 basic anthropometric measurements and 6 body composition characteristics (body mass index, mean skinfold, body density, relative mass of fat by Siri, absolute mass and relative mass of subcutaneous adipose tissue). All anthropometric variables were classified into five height-weight SD classes. Schoolgirls were divided into six age groups (7-8, 9-10, 11-12, 13-14, 15-16, 17-18). Volleyballers were observed as one group as their age in SD classes did not differ significantly. The classification consisted of five categories: three height-weight concordant categories: I--small (small height, small weight), II--medium (medium height, medium weight), III large--(big height, big weight) and two height/weight discordant categories: IV--so-called pyknomorphs, V--so-called leptomorphs. To assess the differences between classes the Scheffé-test was used (alpha = 0.05). It proved likewise possible to comparatively systematize length, breadth and depth measurements, circumferences and body composition characteristics in all six age groups (7-18 years) of ordinary schoolgirls and in 13-16-year-old volleyballers as in their case the average age did not differ significantly between the classes.     

No correlation of anthropometry and race performance in ultra-endurance swimmers at a 12-hours-swim

BACKGROUND: In swimmers, the effects of the anthropometric factors, upper extremity length, hand length and body height, on performance over 100 m have been shown, but no data exist about the influence of anthropometric factors on performance in ultra-endurance swimmers. SUBJECTS AND METHODS: Twelve male Caucasian ultra-swimmers participated in our study at the 9th edition in 2007 of the 12-hours-swim in Zurich, Switzerland. We determined body mass, length of arms and legs, body height, circumferences of extremities, skeletal muscle mass and fat mass in order to correlate with the covered distance and to find an effect on race performance. RESULTS: The 12 swimmers achieved an average distance of 29.4 +/- 5.1 km, varying from 22.8 km to 39.1 km during these 12 hours. There was no correlation between body mass, length of arms and legs, body height, circumferences of extremities, skeletal muscle mass and fat mass to race performance. CONCLUSION: In these 12 male ultra-endurance swimmers no effect of the anthropometric parameters body mass, body height, BMI, circumferences of extremities, length of arms and legs, skeletal muscle mass and fat mass, on performance in a 12-hours-swim has been found.     

Harmonization Process and Reliability Assessment of Anthropometric Measurements in the Elderly EXERNET Multi-Centre Study

Background

The elderly EXERNET multi-centre study aims to collect normative anthropometric data for old functionally independent adults living in Spain.

Purpose

To describe the standardization process and reliability of the anthropometric measurements carried out in the pilot study and during the final workshop, examining both intra- and inter-rater errors for measurements.

Materials and Methods

A total of 98 elderly from five different regions participated in the intra-rater error assessment, and 10 different seniors living in the city of Toledo (Spain) participated in the inter-rater assessment. We examined both intra- and inter-rater errors for heights and circumferences.

Results

For height, intra-rater technical errors of measurement (TEMs) were smaller than 0.25 cm. For circumferences and knee height, TEMs were smaller than 1 cm, except for waist circumference in the city of Cáceres. Reliability for heights and circumferences was greater than 98% in all cases. Inter-rater TEMs were 0.61 cm for height, 0.75 cm for knee-height and ranged between 2.70 and 3.09 cm for the circumferences measured. Inter-rater reliabilities for anthropometric measurements were always higher than 90%.

Conclusion

The harmonization process, including the workshop and pilot study, guarantee the quality of the anthropometric measurements in the elderly EXERNET multi-centre study. High reliability and low TEM may be expected when assessing anthropometry in elderly population.     

Prediction of body composition of live and post-mortem red foxes

A series of measurements (lengths, circumferences, skinfolds, masses and resistance) was taken on 29 red foxes (Vulpes vulpes) of both sexes before and after their death during the autumns of 1994 and 1995. Body composition of each carcass was determined by chemical analysis of homogenized samples of viscera, carcass and skin. Eight multiple regression models were then developed to predict body water, fat, protein, and mineral mass using body measurements as independent variables taken on live or dead animals. All final models were highly significant (P < 0.0001) and included three or four explanatory variables. Adjusted coefficients of determination varied between 0.95 for water mass and 0.81 for mineral mass. The models cover a wide range of conditions as percent body fat in the 29 samples varied between 1.1 and 28.4%. Our models can serve for management or research purposes with live or dead red foxes as they are quick, inexpensive and nondestructive.     

Cytologic diagnosis of alveolar soft part sarcoma of the lower extremity by fine needle aspiration and correlation with core biopsy: a case report

BACKGROUND: Alveolar soft part sarcoma is a rare soft tissue tumor of uncertain origin that is generally slow growing but unmistakably malignant due to its propensity for metastasis to lung, bone and brain early in the course of disease. Fine needle aspiration biopsy (FNAB) of these tumors and recognition of the characteristic cytologic features precludes more invasive diagnostic measures and facilitates appropriate treatment. CASE: A 54-year-old African-American man presented to our institution with a 2-week history of left leg pain. Imaging studies revealed a left leg soft tissue mass just below the popliteal fossa and multiple bilateral lung lesions suggestive of metastatic neoplasm. FNAB of the left lower extremity mass yielded uniform clusters of cells and sigle cells with large nuclei and single prominent nucleoli. Histologically, the biopsy showed nests of large polygonal cells with abundant eosinophilic cytoplasm, round regular nuclei and prominent nucleoli. A periodic acid-Schiff (PAS) stain highlighted intracytoplasmic rhomboidal crystals, a feature diagnostic of alveolar soft part sarcoma. CONCLUSION: Alveolar soft part sarcoma may be diagnosed by its unique morphologic characteristics and should be considered in the differential diagnosis of all cytologically sampled soft tissue lesions.     

Control of dynamic foot-ground interactions in male and female soccer athletes: Females exhibit reduced dexterity and higher limb stiffness during landing

Controlling dynamic interactions between the lower limb and ground is important for skilled locomotion and may influence injury risk in athletes. It is well known that female athletes sustain anterior cruciate ligament (ACL) tears at higher rates than male athletes, and exhibit lower extremity biomechanics thought to increase injury risk during sport maneuvers. The purpose of this study was to examine whether lower extremity dexterity (LED) – the ability to dynamically control endpoint force magnitude and direction as quantified by compressing an unstable spring with the lower limb at submaximal forces – is a potential contributing factor to the “at-risk” movement behavior exhibited by female athletes. We tested this hypothesis by comparing LED-test performance and single-limb drop jump biomechanics between 14 female and 14 male high school soccer players. We found that female athletes exhibited reduced LED-test performance (p=0.001) and higher limb stiffness during landing (p=0.008) calculated on average within 51 ms of foot contact. Females also exhibited higher coactivation at the ankle (p=0.001) and knee (p=0.02) before landing. No sex differences in sagittal plane joint angles and center of mass velocity at foot contact were observed. Collectively, our results raise the possibility that the higher leg stiffness observed in females during landing is an anticipatory behavior due in part to reduced lower extremity dexterity. The reduced lower extremity dexterity and compensatory stiffening strategy may contribute to the heightened risk of ACL injury in this population.     

Gender differences in regional body composition and somatotrophic influences of IGF-I and leptin.

This study evaluated the arm, trunk, and leg for fat mass, lean soft tissue mass, and bone mineral content (BMC) assessed via dual-energy X-ray absorptiometry in a group of age-matched (approximately 29 yr) men (n = 57) and women (n = 63) and determined their relationship to insulin-like growth factor I (IGF-I) and leptin. After analysis of covariance adjustment to control for differences in body mass between genders, the differences that persisted (P < or = 0.05) were for lean soft tissue mass of the arm (men: 7.1 kg vs. women: 6.4 kg) and fat mass of the leg (men: 5.3 kg vs. women: 6.8 kg). Men and women had similar (P > or = 0.05) values for fat mass of the arms and trunk and lean soft tissue mass of the legs and trunk. Serum IGF-I and insulin-like growth factor binding protein-3 correlated (P < or = 0.05) with all measures of BMC (r values ranged from 0.31 to 0.39) and some measures of lean soft tissue mass for women (r = 0.30) but not men. Leptin correlated (P < or = 0.05) similarly for measures of fat mass for both genders (r values ranging from 0.74 to 0.85) and for lean soft tissue mass of the trunk (r = 0.40) and total body (r = 0.32) for men and for the arms in women (r = 0.56). These data demonstrate that 1) the main phenotypic gender differences in body composition are that men have more of their muscle mass in their arms and women have more of their fat mass in their legs and 2) gender differences exist in the relationship between somatotrophic hormones and lean soft tissue mass.     

Five-class height-weight model for systematization of seventeen-year-old recruits' anthropometric data

An anthropometric study of 552 Tartu city and Tartu county recruits aged 17 years was carried out. Height and weight, 33 anthropometric measurements and 12 skinfolds were measured. Body fat percentage was assessed by Omron BF 300 hand-held segmental body fat analyzer. From anthropometric measurements bone mass was derived by the Drink-water et al. (1986) equation, and total skeletal muscle mass by the Lee et al. (2000) equation. The data were systematized into five height-weight SD-classes. There were 3 classes with harmony between height and weight class: 1--small (small height and small weight), 2--medium (medium height and medium weight), 3--large (large height and large weight), 4--weight class dominating (pyknomorphic) and 5--height class dominating (leptomorphic). It was revealed that in classes 1, 2 and 3 the height and weight increase corresponded to the increase in all heights, breadths and depths, circumferences, skinfolds, body fat, muscle and bone mass. In class 4 circumferences, skinfolds, body fat and muscle mass were bigger. In class 5 all heights and the relative bone mass were bigger. The present investigation confirms the hypothesis that the five height-weight class system is applicable to seventeen-year-old recruits.