Longer Ground Contact Time Is Related to a Superior Running Economy in Highly Trained Distance Runners.

ABSTRACT: Tanji, F, Ohnuma, H, Ando, R, Yamanaka, R, Ikeda, T, and Suzuki, Y. Longer ground contact time is related to a superior running economy in highly trained distance runners. J Strength Cond Res 38(5): 985-990, 2024-Running economy is a key component of distance running performance and is associated with gait parameters. However, there is no consensus of the link between the running economy (RE), ground contact time, and footstrike patterns. Thus, this study aimed to clarify the relationship between RE, ground contact time, and thigh muscle cross-sectional area (CSA) in highly trained distance runners and to compare these parameters between 2 habitual footstrike patterns (midfoot vs. rearfoot). Seventeen male distance runners ran on a treadmill to measure RE and gait parameters. We collected the CSAs of the right thigh muscle using a magnetic resonance imaging scanner. The RE had a significant negative relationship with distance running performance ( r = -0.50) and ground contact time ( r = -0.51). The ground contact time had a significant negative relationship with the normalized CSAs of the vastus lateralis muscle ( r = -0.60) and hamstrings ( r = -0.54). No significant differences were found in RE, ground contact time, or normalized CSAs of muscles between midfoot ( n = 10) and rearfoot ( n = 7) strikers. These results suggest that large CSAs of knee extensor muscles results in short ground contact time and worse RE. The effects of the footstrike pattern on the RE appear insignificant, and the preferred footstrike pattern can be recommended for running in highly trained runners.

Quantitative sonographic assessment of quadriceps muscle thickness for fall injury prediction in patients undergoing maintenance hemodialysis: an observational cohort study.

BACKGROUND: Accidental fall risk is high in patients undergoing maintenance hemodialysis. Falls are associated with fatal injury, comorbidities, and mortality. Risk assessment should be a primary component of fall prevention. This study investigated whether quadriceps muscle thickness measured using ultrasonography can predict fall injury among dialysis patients. METHODS: Using an observational cohort study design, 180 ambulatory hemodialysis patients were recruited from 2015 to 2016 from four dialysis clinics. The sum of the maximum quadriceps muscle thickness on both sides and the average of the maximum thigh circumference and handgrip strength after hemodialysis were calculated. Patients were stratified according to tertiles of quadriceps muscle thickness. Fall injury was surveyed according to the patient's self-report during the one-year period. RESULTS: Among the 180 hemodialysis patients, 44 (24.4%) had fall injuries during the 12-month follow-up period. When the quadriceps muscle thickness levels were stratified into sex-specific tertiles, patients in the lowest tertile were more likely to have a higher incidence of fall injury than those in the higher two tertiles (0.52 vs. 0.19 and 0.17 fall injuries/person-year). After adjusting for covariates, lower quadriceps muscle thickness was found to be an independent predictor of fall injury (hazard ratio [95% confidence interval], 2.33 [1.22-4.52], P < 0.05). Receiver operating characteristic curves were constructed to determine the optimal cutoffs of quadriceps muscle thickness, thigh circumference, and handgrip strength that best predicted fall injury (quadriceps muscle thickness, 3.37 cm and 3.54 cm in men and women; thigh circumference, 44.6 cm and 37.2 cm in men and women; and handgrip strength, 23.3 kg and 16.5 kg in men and women). Using these cutoff values, the areas under the curve were 0.662 (95% CI, 0.576-0.738), 0.625 (95% CI, 0.545-0.699), and 0.701 (95% CI, 0.617-0.774), for quadriceps muscle thickness, thigh circumference, and handgrip strength, respectively. Quadriceps muscle thickness was a more precise predictor of fall injury than thigh circumference and had similar diagnostic performance as handgrip strength tests in dialysis patients. CONCLUSIONS: Quadriceps muscle thickness can be measured easily at the bedside using ultrasonography and is a precise predictor of fall injury in patients undergoing maintenance hemodialysis.

Assessment of peripheral muscle thickness and architecture in healthy volunteers using hand-held ultrasound devices; a comparison study with standard ultrasound.

BACKGROUND: Pocket-sized ultrasound devices are increasingly used in a variety of clinical situations, and perform well against standard ultrasound machines. We sought to investigate if a pocket-sized ultrasound device can assess muscle thickness and architecture in healthy volunteers. METHODS: Healthy male volunteers (n = 21) across a range of ages were recruited to the study. Laying supine, ultrasound images were taken from the right anterior and lateral thigh. Thickness of the rectus femoris (RFMT), vastus intermedius (VIMT), and the two combined (anterior thigh, AMT) were measured, along with thickness of vastus lateralis (VLMT), pennation angle (VLPA) and derived fascicle length (VLFL). These scans were performed initially using a pocket-sized ultrasound (VScan) and then using a standard device (Telemed Echoblaster 128). RESULTS: In all six variables, there was no significant difference between the two sets of measurements. Intra-class correlation co-efficients (ICC) for VLMT, VLPA, and AMT were all excellent (0.93, 0.89, 0.90 respectively) with the derived value of VLFL having an ICC of 0.84. All ICC values were statistically significant. Regression analysis demonstrated no evidence of proportional bias in any of the measured or derived variables. CONCLUSION: A pocket-sized ultrasound device gives similar measurements of lower limb muscle thickness and architecture as a standard device in healthy volunteers.

The Ideal Thigh: A Crowdsourcing-Based Assessment of Ideal Thigh Aesthetic and Implications for Gluteal Fat Grafting.

BACKGROUND: As the popularity of aesthetic gluteoplasty continues to grow, there is renewed focus on defining the ideal buttocks. However, the literature lacks studies characterizing an ideal thigh, despite the impact of thigh contour on overall gluteal aesthetic. OBJECTIVES: The authors performed the first population analysis of the characteristics of perception of attractive thighs, to identify a role for fat grafting of the thigh in gluteoplasty. METHODS: Survey images were digitally modified to create thighs of varying widths and angles relative to fixed buttocks. Thigh-to-buttock ratios and the buttock-thigh junction were studied. Data were stratified and analyzed according to age, gender, and ethnicity of the respondents. Amazon Mechanical Turk was used as a novel crowdsourcing platform for surveying aesthetic preferences. RESULTS: A total of 1034 responses were included of whom 54.4% were male, and 45.6% were female. All age groups and ethnicities were represented. Overall, 43.8% of respondents preferred the widest buttock-thick junction angle on posterior view. There was no clear preference between larger or smaller thigh-to-hip ratios on lateral view. CONCLUSIONS: Characteristics of the ideal thigh include wider thighs with greater horizontal projection, creating a more natural contour from the augmented buttock. These findings represent a paradigm shift from the traditionally assumed preference for slender thighs. Plastic surgeons should carefully consider thigh anatomy in their gluteal augmentation patients, as simultaneous thigh augmentation may lead to a more aesthetically pleasing outcome. Further research is needed into best practices and techniques to attain ideal thigh proportions.

A two-center, assessor-blinded, prospective trial evaluating the efficacy of a novel hypertonic draining cream for cellulite reduction: A Clinical and instrumental (Antera 3D CS) assessment.

INTRODUCTION: Gynoid lipodystrophy, also known as cellulite, is a very common skin alteration representing mainly a cosmetic problem rather than a real disease. An effective treatment of cellulite has not been well established. The initial phase of cellulite is characterized by subdermal tissue edema with interstitial fluids retention. A new hypertonic topical product with draining action (HTC) containing NaCl 13%, escine, caffeine, and beta-sitosterol has been recently developed. A 28-day double-blind placebo-controlled study has shown that this cream is able to reduce thigh circumference and the thickness of adipose tissue. No data so far are available regarding an objective evaluation of skin appearance for a longer application period. STUDY AIM: To evaluate the clinical efficacy of 2-month HCT treatment with clinical and instrumental assessments. SUBJECTS AND METHODS: In a prospective, 2-center, assessor-blinded trial 20 women (mean age 34 years) with cellulite of Grade I-III in severity were enrolled after their informed consent. HTC was applied once daily for 60 days. Primary outcomes of the trial were the evolution of thigh circumference measurements (assessed at baseline, after 1 and 2 months) and the computer-analysis of skin profilometry (ie, skin volumes) of a prespecified target area evaluated by means of Antera 3D CS digitalized images (assessed at baseline and at the end of the trial). Secondary outcome was the orange peel severity score (from 0 to 5) before and after pitch test. RESULTS: All subjects concluded the study period. Thigh circumference was reduced by -0.88 (right)/-1.2 cm (left) and by -1.8(right)/-2.1 (left) cm, after 30 and 60 days of treatment, respectively (P = .001, Wilcoxon test vs baseline). Antera 3D profilometry of the target zone showed a significant reduction in skin depression expressed in mm3 of -56% (from 59.7 to 26.73 mm3 ) after HTC application. Orange peel (no pitch test) mean (SD) score was 2.3 (1) at baseline, 2.0 (1) and 1.8 (0.8) after 1 and 2 months (P = .0031), respectively. After-pitch orange peel score was significantly reduced after treatment (from 3.3 to 2.2). CONCLUSION: Once daily application of HTC for 2 months has confirmed its efficacy in the improvement of objective and subjective assessments of cellulite parameters.(Trial Number registration: ISRCTN15111614).

Concurrent agreement between an anthropometric model to predict thigh volume and dual-energy X-Ray absorptiometry assessment in female volleyball players aged 14-18 years.

BACKGROUND: A variety of performance outputs are strongly determined by lower limbs volume and composition in children and adolescents. The current study aimed to examine the validity of thigh volume (TV) estimated by anthropometry in late adolescent female volleyball players. Dual-energy X-ray absorptiometry (DXA) measures were used as the reference method. METHODS: Total and regional body composition was assessed with a Lunar DPX NT/Pro/MD+/Duo/Bravo scanner in a cross-sectional sample of 42 Portuguese female volleyball players aged 14-18 years (165.2 ± 0.9 cm; 61.1 ± 1.4 kg). TV was estimated with the reference method (TV-DXA) and with the anthropometric method (TV-ANTH). Agreement between procedures was assessed with Deming regression. The analysis also considered a calibration of the anthropometric approach. RESULTS: The equation that best predicted TV-DXA was: -0.899 + 0.876 × log10 (body mass) + 0.113 × log10 (TV-ANTH). This new model (NM) was validated using the predicted residual sum of squares (PRESS) method (R2PRESS = 0.838). Correlation between the reference method and the NM was 0.934 (95%CI: 0.880-0.964, Sy∙x = 0.325 L). CONCLUSIONS: A new and accurate anthropometric method to estimate TV in adolescent female volleyball players was obtained from the equation of Jones and Pearson alongside with adjustments for body mass.

Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass.

Assessment of body fat composition disturbances by bioimpedance analysis in HIV-infected adults.

HIV-lipodystrophy syndrome is characterized by different patterns of body fat distribution (BFD) which are identified by clinical and body composition (BC) assessment, including bioimpedance analysis (BIA). Our aim was to compare BC in HIV-infected patients on combination antiretroviral therapy (cART) according to 4 distinct phenotypes of BFD (G1-no lipodystrophy, G2-isolated central fat accumulation, G3-lipoatrophy, G4-mixed forms of lipodystrophy) and assessed factors associated with them. Anthropometry and BIA were performed in 344 HIV-1 patients. G2 and G4 phenotype patients had significantly higher fat mass (FM) but no differences were observed in fat-free mass (FFM) and total body water among the 4 phenotypes. Significant negative associations were found between the presence of lipoatrophy and female gender, body mass index (BMI), waist (WC), hip (HC) and thigh circumferences, and total body FM estimated by BIA. After adjustment for gender, cART duration and BMI, G3 had significant lower WC [odds ratio (OR)=0.84; 0.78- 0.90] and HC (OR=0.88; 0.81-0.96) mean. Independently of gender, cART duration and BMI, G2 remained significantly associated with higher WC (OR=1.11; 1.05-1.18) and HC (OR=1.15; 1.07-1.23) mean, and with FM estimated by BIA [FM as %, OR=1.17 (1.09-1.26); and FM as kg, OR=1.15 (1.06- 1.25)]. There was a significant positive association between G4 and female gender (OR=1.66; 1.01-2.75), BMI (OR=1.10; 1.04-1.17) and WC (OR=1.15; 1.09-1.21). The similar FFM along the BFD spectrum describes the actual BC of these patients without sarcopenia. In a clinical setting, BIA is an easy and useful tool to evaluate fat mass and FFM and gives us a picture of BC that was not possible with anthropometry.

Morphologic assessment of the tendon graft donor sites: palmaris longus, plantaris, tensor fascia lata.

The purpose of this study is to compare and measure the tendon graft donor sites and to predict the sizes of these tendons preoperatively. Seventeen cadavers were included in the study. The morphologic evaluation of the palmaris longus (n = 29), plantaris (n = 32), and tensor fascia lata (n = 34) tendons were done. The length of the forearm, leg, and thigh and the width of the wrist, ankle, and knee joints were noted. The length, width, and the thickness of the tendons were measured. Degree of association between measurements was calculated by Pearson's correlation coefficient. We found statistically significant correlation between the length of the extremities and the length of the muscle tendons, and we formulated these correlations. The correlation between the length or width of the extremity and the tendon to be harvested could be designated as the ratios presented, and this could ease the preoperative planning at the craniofacial and other areas of surgery.

Pre-operative assessment of K-nail length in fracture shaft of femur.

INTRODUCTION: Internal fixation of diaphyseal fracture of shaft of femur in an adult by Kuntscher nail is the most common operative method of treatment in Nepal where operative facilities for the same exist. Since the complete range of K-nail sizes and length are not available in most operation theatres in Nepal, most orthopaedic surgeons assess the size and length of the K-nail pre-operatively by various methods and keep one size above and below the assessed length for the planned surgery. MATERIALS AND METHODS: The following measurements were taken in five hundred people involved in the study: Measurement No. 1: Tip of the greater trochanter to lateral knee joint line minus 2 cm. Measurement No. 2: Tip of the olecranon process to the tip of little finger, and Measurement No. 3: Tip of the greater trochanter to the upper pole of patella. An average of all three lengths were analysed to see if there were any differences in their mean lengths. RESULTS: Analysis showed that there were significant differences between the mean lengths measured by the three different methods. The average length of measurement no: 2 was 3 cm longer than the average length of measurement no: 1, which is the reference pre-operative length of K.nail. CONCLUSION: However, in practice since measurement no:2 is more convenient to perform and can also be used when the patient has sustained bilateral fractures of femur, an accurate pre-operative K-nail length assessment can be done by subtracting 3 cm from measurement no:2, i.e. the tip of the olecranon process to the tip of the little finger.

Three-dimensional ultrasound in the assessment of normal fetal thigh volume.

Accurate assessment of the fetal organ volumes is very important in the evaluation of fetal well-being and maturation. Previous investigators have pointed out that fetal thigh volume (ThiV) may be a useful predictive factor of intrauterine growth retardation. Yet, 2-D ultrasound (US) is limited in assessing fetal ThiV accurately. With the recent advance of 3-D US, the limitation in assessing fetal ThiV by 2-D US can be overcome. To establish a normal reference chart of fetal ThiV for clinical use, a prospective and cross-sectional study using 3-D US was undertaken to assess the fetal ThiV in normal pregnancy. In total, 204 singleton fetuses ranging between 20 and 40 weeks of gestation and fitting the criteria of normal pregnancies were enrolled in this study. Our results showed that fetal ThiV is highly correlated with the gestational age (GA). Furthermore, using GA as the independent variable and ThiV as the dependent variable, the best-fit regression equation was ThiV (mL) = 35.494 - 4.985 x GA + 0.183 x GA(2) (r = 0.91, n = 204, p < 0.0001). For further clinical use, a chart of normal growth centiles of fetal ThiV was then calculated based on this equation. Furthermore, common indexes of fetal biometry, such as biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW), were all highly correlated with ThiV (all p < 0.0001). In conclusion, our data of fetal ThiV assessed by 3-D US can serve as a useful reference in evaluating fetal growth and nutrition status during normal gestation.

Effect of exercise training on energy expenditure, muscle volume, and maximal oxygen uptake in female adolescents.

OBJECTIVES: American female adolescents are at high risk of a physically inactive lifestyle that likely leads to health problems later in life. We hypothesized that a brief program of endurance exercise training in female adolescents would result in increased energy expenditure and quantifiable structural and functional adaptations. STUDY DESIGN: Forty-four high school girls (aged 15 to 17 years, none were elite athletes) enrolled in a 5-day per week anatomy class for 5 weeks and were randomly assigned to control (n = 22) and training groups. All subjects participated in a 2-hour daily teaching program. During the remaining time (2 hours), the training group members underwent endurance-type training and control group subjects participated in a computer workshop. The intervention was assessed by (1) comparison of total energy expenditure between groups with the doubly labeled water technique, (2) determination of changes in thigh muscle volume by magnetic resonance imaging, and (3) determination of changes in maximal oxygen uptake by use of respiratory gas exchange responses. RESULTS: Total energy expenditure was significantly greater (15.3%) in the training group compared with the control subjects (p < 0.003). Five weeks of training led to a 4.3% +/- 1% increase in thigh muscle volume (p < 0.0002) and a 12.1% +/- 3.7% increase in maximal oxygen uptake (p < 0.004); there were no changes in the control group. The training effect was most pronounced in the least fit subjects. CONCLUSIONS: Exercise training programs for female adolescents can be successfully integrated into a high school summer curriculum. Quantifiable, substantial structural and functional responses occur with relatively short periods of training. Approximately 60% of the training response was related to factors independent of muscle size per se. These data may serve to better design physical activity programs for female adolescents.

Anthropometric and computed tomographic assessment of the thigh in young and old men.

Anthropometric (AP) and computed tomographic (CT) methods of determining limb and muscle-plus-bone cross-sectional area (CSA) and volume (Vol) were compared in 13 young (M = 24.5 yrs) and 11 old (M = 71.0 yrs) men. CSA of total thigh, muscle-plus-bone, quadriceps, and hamstring muscle compartments and muscle were measured from CT scans. Corresponding muscle Vol were estimated from anthropometric equations. Prediction equations for CT measures were developed from AP measures using multiple linear regression. AP and CT techniques produced different values for thigh component CSA and Vol, especially in the old men. AP overestimated muscle-plus-bone CSA and Vol (4-6%) and underestimated skin and subcutaneous tissue CSA and Vol (17-33%). Prediction equations for quadriceps CSA and Vol (R2 = 80-96%) were more accurate than equations for hamstrings (R2 = 42-65%). Specific thigh muscle CSA and Vol can be predicted from AP measures (SEE 5-15%). These findings may have clinical significance when normalizing strength per unit of muscle size.

Computed axial tomographic scanning of the thigh: an alternative method of nutritional assessment in pediatrics.

In this study we compared the findings of computed axial tomographic (CT) scanning of the thigh with the findings of arm anthropometry and urinary creatinine determinations to assess nutrition in children with inflammatory bowel disease receiving total parenteral nutrition. All 14 children received our standard solution for total parenteral nutrition as well as prednisone and sulfasalazine (Azulfidine) therapy. All patients were assessed by arm anthropometry, 24-hour urine collections for creatinine clearance, and CT scanning of the thigh during total parenteral nutrition. Arm muscle and fat area were estimated by anthropometry, and those in the thigh were estimated by CT scanning. Our results show the total muscle area from the CT scan can predict muscle mass calculated from the urinary creatinine excretion rates. In addition, there is a close correlation between the thigh muscle area as measured by CT scanning and the muscle area calculated from urinary creatinine excretion rates. In addition, the comparison of thigh muscle area and thigh fat area to the midarm muscle area and midarm fat area, respectively, showed that the thigh is a better predictor of muscle than fat in the midarm. We conclude that the total thigh muscle area is a better predictor of muscle mass as compared to the midarm muscle area. In addition, the CT scan cut at the level of the thigh in children and adolescents with inflammatory bowel disease can provide valuable information about the thigh compartment and analyses of different cross-sectional areas of the thigh.

Cross-sectional thigh components: computerized tomographic assessment.

The purpose of this study was to examine the efficacy of the Picker Synerview Fourth Generation CT Scanner in assessing cross-sectional areas of muscle, bone, and subcutaneous fat of the thigh. A secondary purpose was to resolve individual muscle bellies using the CT scanner and to determine the effects of body composition in isolating those muscles. Both limbs of one cadaver were used to compare actual cross-sectional areas with the CT images. Each limb was dissected and photographed. Accuracy of repeated measurements was assessed using human volunteers. Absolute and percent error between the CT measurements and the measurements of the cross-sectional areas differed most at the bone. No differences were found between repeat scans. CT images and photographic measurements of individual muscles were generally quite similar, as assessed by absolute and percent error. The gracilis and sartorious were reasonably well defined in those individuals with more than 8% body fat. The results are discussed in terms of possible applications of the CT scanner in sports medicine research.