Leg Length Measurements Research Articles

Comparative Study of Alternative Methods for Measuring Leg Length Discrepancy after Robot-Assisted Total Hip Arthroplasty.

Our study addresses the lack of consensus on measuring leg length discrepancy (LLD) after total hip arthroplasty (THA). We will assess the inter-observer variability and correlation between the five most commonly used LLD methods and investigate the use of trigonometric principles in overcoming the limitations of current techniques. LLD was measured on postoperative AP pelvic radiographs using five conventional methods. CT images created a 3D computer model of the pelvis and femur. The resulting models were projected onto a 2D, used to measure LLD by the five methods. The measurements were evaluated via Taguchi analysis, a statistical method identifying the process's most influential factors. The approach was used to assess the new trigonometric method. Conventional methods demonstrated poor correlation. Methods referenced to the centers of the femoral heads were insensitive to LLD originating outside the acetabular cup. Methods referencing either the inter-ischial line or the inter-obturator foramina to the lesser trochanter were sensitive to acetabular and femoral components. Trigonometry-based measurements showed a higher correlation. Our results underscore clinicians' need to specify the methods used to assess LLD. Applying trigonometric principles was shown to be accurate and reliable, but it was contingent on proper radiographic alignment.

Identifying Lower Extremity Deformities in the Coronal Plane: Lessons From Remote Learning During the COVID-19 Pandemic.

Introduction During the COVID-19 pandemic, the AO Foundation, an orthopedic education organization, had to transition its live education programs to an online format. Skills that were previously evaluated and corrected in person by educators were now assessed through online lectures and discussion groups. Our goal was to evaluate an online course designed to teach the skill of "leg length and coronal deformity measurement" and to assess participants' ability to demonstrate this skill using online software. Methods An IRB-approved study was conducted during an online osteotomy course. A total of 176 participants were instructed on how to measure length and angulation through the course lectures and planning tutorials. The Bonesetter App (Detroit Bonesetter, Detroit, Michigan, USA) was used as the digital planning tool. Participants analyzed four cases of coronal deformity using long-leg standing radiographs. They were required to identify any deformities present, specify the type of deformity, and determine whether it affected the femur, tibia, or joint. Additionally, participants needed to calculate the deformity as part of the osteotomy planning process. Their measurements and drawings were saved and subsequently evaluated by two independent observers. Results Out of 176 online participants, 76% (315 out of 417) correctly completed the four exercises. The most frequent errors occurred in measuring total deformity and joint deformity. The average standard deviation of length measurements was ±0.29 cm (based on 244 measurements), while for angular measurements, it was ±0.71 degrees (based on 688 measurements). The intraclass correlation coefficient was greater than 0.96. Conclusions The online course effectively taught coronal deformity measurement, although participants struggled most with measuring joint angles and total deformity. Future courses should provide more detailed explanations for these measurements.

Risk Factors for Trochanteric Bursitis Following Total Hip Arthroplasty: A Radiographic Analysis

BackgroundTrochanteric bursitis (TB) is a prevalent complication following total hip arthroplasty (THA), with increased offset hypothesized as a potential risk factor. This study investigated potential TB predictors in THA patients, including radiographic measurements of offset and leg length, comorbidities, and patient characteristics. MethodsIn this retrospective cohort study, all THA patients from a single academic tertiary care center between 2005 and 2021 were reviewed. Exclusion criteria included less than one-year follow-up, osteonecrosis, or fracture. Manual radiographic measurements of offset (acetabular, femoral, and total) and leg length from preoperative and postoperative antero-posterior pelvis X-rays were taken, with scaling using femoral cortical diameter. Univariable and multivariable Cox proportional hazard models were employed to estimate TB risk. ResultsOf 1,094 patients, 103 (9.4%) developed TB, with a median (Q1, Q3) time to presentation of 41.8 weeks (25.5, 66.9). In univariable models, only sex was associated with increased TB risk, with women exhibiting a 1.79 times increased risk (hazard ratio: 1.79 (1.16, 2.76), P = .009). Changes in acetabular offset, femoral offset, total offset, and leg length between preoperative and postoperative radiographs were not associated with an increased risk of developing TB in the univariate or multivariate models. Furthermore, various offset thresholds were evaluated, with no amount of increased offset showing increased TB risk. ConclusionsThis study found no relationship between femoral, acetabular, or total offset and TB following THA. These findings suggest that surgeons may consider adding offset for increased prosthetic stability in high-risk cases. However, given that this is a retrospective study, the authors are not advocating for the routine use of increased offset. The study identified women as a risk factor with a 1.79 times higher TB risk, highlighting the importance of counseling women patients on this heightened risk.

The history of short-tailed whip scorpions: changes in body size and flagellum shape in Schizomida

Representatives of Schizomida, known as short-tailed whip scorpions, are an understudied group within Megoperculata. They are found subterraneanly in tropical and sub-tropical regions. They lack eyes, have superior mobility, and possess a flagellum which is relevant to their mating, but in general little is known about their general biology. Fossil representatives of Schizomida from a variety of time periods are available for study. Using 23 fossil specimens (14 of which are described here for the first time) and 86 extant individuals from the literature, changes in both body size and flagella shape in Schizomida were compared over time. Measurements of prosoma length and leg length were used as a proxy for body size, and a comparative size analysis was carried out. Individuals from the Cretaceous period were found to be significantly smaller than extant individuals, contrary to our expectations. For flagellum shape, images were used to create reconstructions, which were then analysed using an elliptic Fourier analysis followed by a principal component analysis. The morphological diversity of the male flagellum shape was found to have decreased between the Cretaceous and modern fauna. We discuss potential explanations for our findings, although a greater understanding of the general biology of Schizomida is required to properly interpret our results.

Do all short stem types restore biomechanical parameters of the hip? Comparison according to femoral neck osteotomy levels.

There is no consensus on ideal short femoral stem design. A classification system proposed by Feyen and Shimmin divides short stems in two types according to femoral neck osteotomy levels: subcapital (IIIA) and standard (IIIB). The study aims to determine which design type is more successful in restoring native biomechanical parameters and whether stem type has an impact on clinical results. In this retrospective comparative study, patients that have undergone short stem hip arthroplasty were evaluated according to stem types: type IIIA (n = 52, 66.7%) (Mathys Optimys) and IIIB (n = 26, 33.3%) (Implantcast Aida and Smith & Nephew SMF). Pelvis X-rays were assessed in terms of femoral neck length, horizontal and vertical hip centres of rotation, horizontal and vertical femoral offsets, abductor lever arm lengths, leg lengths, and stem-shaft angles. Improvement in Harris hip scores, differences between post-operative and pre-operative measurements, and stem-shaft angles were evaluated and compared between two groups. Mean femoral neck resection (8.27 ± 6.68mm in IIIA and 15 ± 6.33mm in IIIB) was significantly different between both groups (p < 0.001). Harris hip scores were increased at post-operative six months in both groups with no difference (84.4 ± 6.4 and 84.6 ± 5.5, p = 0.4). The absolute values of differences between pre-operative and post-operative horizontal centres of rotation (p = 0.63), vertical centers of rotation (p = 0.75), horizontal femoral offsets (p = 0.78), vertical femoral offsets (p = 0.83), abductor lever arm distances (p = 0.63), and leg length (p = 0.21) measurements were not different between both groups. Stem positions were both varus with no statistically significant difference between groups (p = 0.14). We found no difference regarding restoration of biomechanical parameters between short stem designs with different levels of neck osteotomy. Additionally, short stem can mostly result in varus component positioning regardless of the level of neck osteotomy.

The Correlation of Leg Length, Jump Height, and Leg Muscle Explosive Power Toward Sprint Ability

The study purpose was to investigate the relationship between sprint ability at elementary school and leg length, jump height and leg explosive power. Sports coaching starting at the school level, where students are led and trained to have a strong, skilled, nimble, and agile mentality, athletic is very appropriate. One factor, specifically leg length (anatomy), jump height, and leg explosive power (physiology) in sprinting, affects an athlete's performance. The method Cross-sectional quantitative descriptive research is the method used in this study. A total of 61 male students between the ages of 10 and 12 made up the research sample. Measurements of leg length, jump height, leg explosive power, and a 40-meter sprint are used to obtain data. The normality test, correlation test, and table presentation were used in the descriptive data analysis. The results The results stated that the average leg length was 83.46 ± 5.43 cm, the average jump height was 17.91 ± 5.52 cm, the average explosive power of leg was 1451.61 ± 399.45 watts, and the average speed was 8.70 ± 1.61 m/s. If the calculated r value is less than the r table value, then there is a very weak correlation between the leg length variable and the speed variable. The results of the correlation test between leg length and speed obtained r count 0.137 and r table 0.254. There is a weak correlation between the leg explosive power variable and the speed variable, is evidenced by the correlation test results between leg power and speed, which were r count -0.369 and r table 0.254. There is a strong correlation between the jump height variable and the speed variable, as evidenced by the correlation value test results between the jump height value and the speed value, which show a correlation coefficient value of -0.715 and a sig value of 0.000, which is smaller than 0.05. According to the study's findings, sprint students at elementary school have a correlation between leg length, leg muscle explosive power, and jump height. Keywords: Leg length, Explosive Power, Jump Height, and Sprint

Two- and three-dimensional measurements of leg length change using an accelerometer-based portable navigation system in total hip arthroplasty

BackgroundThe aim of this study was examining the accuracy of accelerometer-based portable navigation systems (HipAlign) when measuring leg length changes using two-dimensional (2D) and three-dimensional (3D) methods.MethodsInclusion criteria were patients ≥ 20 years old with symptomatic hip disease who underwent primary total hip arthroplasty (THA) in the supine position using HipAlign between June 2019 and April 2020. The exclusion criteria were patients who underwent THA via a posterior approach. We examined correlations between the leg length change measurement with HipAlign and either 2D or 3D measurement. We performed a multivariate analysis to determine which factors may have influenced the absolute error results.ResultsThis study included 34 patients. The absolute error in leg length change between the HipAlign and 3D measurement (4.0 mm) was greater than the HipAlign and 2D measurement (1.7 mm). There were positive correlations between leg length change with HipAlign and 2D and 3D measurements. Male patients had larger errors with 2D measurement. No significant factors were identified for 3D measurement.ConclusionHipAlign provided acceptable measurement accuracy for leg length changes.

Comparison of Pelvic Landmarks for Leg Length Discrepancy Measurement With Robotic Arm-Assisted Total Hip Arthroplasty

BackgroundLeg length discrepancy (LLD) is a common complication after total hip arthroplasty (THA) leading to significant morbidity and dissatisfaction for patients. A popular system for robotic arm-assisted THA utilizes preoperative computed tomography (CT) scans for surgical planning. Accurate measurement of leg length is crucial for restoring appropriate patient anatomy during the procedure. This study investigates the interobserver and interlandmark reliability of 3 different pelvic landmarks for measuring preoperative LLD. MethodsWe compiled preoperative pelvic CT scans from 99 robotic arm-assisted THAs for osteoarthritis. Radiologic leg length measurement was performed using the robotic arm-assisted THA application by 2 orthopaedic residents using reference lines bisecting the following pelvic landmarks: the anterior superior iliac spines, acetabular teardrops, and most inferior aspect of the ischial rami. ResultsOn multivariate analysis, there was no significant difference found (P value = .924) for leg length measurement based on the 3 different pelvic anatomical landmarks. Leg length measurements showed interobserver reliability with significant Pearson correlation coefficients (r = 1.0, 0.94, 0.96, respectively) and nonsignificant differences in LLD means between subjects on paired sample (P value = .158, .085, 0.125, respectively) as well as between landmarks on pairwise comparison. ConclusionsThe 3 pelvic landmarks used in this study can be used interchangeably with the lesser trochanter as the femoral reference point to evaluate preoperative LLD on pelvic CT in patients undergoing robotic-arm assisted THA. This study is the first of its kind to evaluate the interobserver and interlandmark reliability of anatomical landmarks on pelvic CT scans and suggests interchangeability of 3 pelvic landmarks for comparing leg length differences.

Adjusment Basketball Facilities and Infrastructure for Children 10-12 Years Old Through Anthropometric Comparison

Implementation of physical education is allowed to modify instructional media. Physical education requires facilities and infrastructure specifically designed to promote physical activity. The aim of this research is to develop adjustments to basketball facilities and infrastructure for children aged 10-12 years through anthropometric comparisons. This research uses simple development research because it is still in the form of an initial design. The total research sample involved was 691 people. The sample underwent height, arm span, leg length, and finger span measurements. The results are that the comparison ratio of facilities and infrastructure for adults and children aged 10-12 years is the same as the anthropometric ratio of the study sample. Sports facilities and infrastructure adjustments are indispensable to the growth and development of children aged 10-12. By providing spaces where children can engage in physical activities tailored to their age and interests, we lay the foundation for healthy lifestyles, holistic skill development, cognitive growth, and emotional well-being.

The Relationship Between Leg Muscle Explosive Power And Limb Length On The Results Of Flop Style High Jump In Jakarta State Athletic KOP Students

This study aims to determine whether there is a relationship between leg muscle explosive power and leg length on high jump results in KOP athletics students of Jakarta State University. The design of this study is a quantitative study that uses a series of tests, namely the measurement of leg length, vertical jump test and flop style high jump test. There were a total of 20 subjects studied and only 18 met the instrument test. Data processing using SPSS version 20 with Correlation found a correlation result of leg muscle explosive power of 0.673 and a significance value of 0.000 where the significance value was smaller than 0.05 indicating a strong relationship between leg muscle explosive power and high jump results. Then based on the results of the correlation test the correlation result of the length of the limb of 0. 818 and the significance value of 0.000 where the significance value was smaller than 0.05 The variable correlation value shows a positive value and shows a very strong relationship between leg length and high jump results. Then based on the results of the f test, it is known that the significance value in this f test has a value of 0.000 less than 0.05 so it can be concluded that there is a relationship between the explosive power of the leg muscles and the length of the tugkai together with the high jump results of KOP athletics students of Jakarta State University.

Restoration of Hip Geometry after Femoral Neck Fracture: A Comparison of the Femoral Neck System (FNS) and the Dynamic Hip Screw (DHS).

The femoral neck system (FNS) was introduced as a minimally invasive fixation device for managing femoral neck fractures. To compare radiographic, clinical, and patient-reported outcome measures (PROMs) of femoral neck fracture patients following FNS compared to dynamic hip screw (DHS) implantation combined with an anti-rotational screw. Patients who underwent closed reduction and internal fixation of a femoral neck fracture between 2020 and 2022 were retrospectively included. We measured leg length, femoral offset, and centrum-collum-diaphyseal (CCD) angle in plain radiographs. Scar length, Harris Hip Score, short-form health survey 36-item score (SF-36), and Numeric Rating Scale (NRS) were assessed during follow-up visits. We included 43 patients (22 females) with a median age of 66 (IQR 57, 75). In both groups, leg length differences between the injured and the contralateral side increased, and femoral offset and CCD angle differences were maintained over time. FNS patients had shorter scars and reported fewer emotional problems and more energy. There were no differences between groups regarding the remaining SF-36 sub-scores, Harris Hip Score, and NRS. The FNS allows for a comparable leg length, femoral offset, and CCD angle reconstruction while achieving similarly high functional and global health scores to the DHS.

The reliability of clinical tools with and without ultrasound guidance to measure leg-length inequality.

To determine and compare the reliability and efficiency of various methods of leg-length measurement. A total of 88 leg-lengths were measured among 50 subjects (79%-84% female, mean age = 30-33 years). Leg-lengths were measured in both supine and standing positions using multiple devices, including a tape measure, a LASER distance meter, and diagnostic ultrasound. All methods of leg-length measurement using the middle of the femoral head as a reference point, identified via ultrasound, demonstrated excellent reliability (intraclass correlation coefficient = 0.95-1.00). Measurements performed in supine, using the anterior superior iliac spine as a reference point, with a tape measure, demonstrated good-to-excellent reliability (intraclass correlation coefficient = 0.86-0.95, standard error of the measurement = 16.1-19.9 cm). Standing measurements using the anterior superior iliac spine as a reference point, using a tape measure, demonstrated fair-to-excellent reliability (intraclass correlation coefficient = 0.71-0.95). Ultrasound-guided landmark identification appear to be a more reliable method compared to palpation of the anterior superior iliac spine for measurement of leg-length using clinical tools. When coupled with ultrasound guidance, a hand-held LASER distance meter/pitch locator apparatus or a retractable tape measure appears to be acceptable alternatives to a fixed LASER distance meter on a linear actuator for leg-length measurement.

Dual X-ray Absorptiometry As A Method To Measure Leg Length In Adolescence

Dual X-ray Absorptiometry As A Method To Measure Leg Length In Adolescence

Validity of leg length measurement in the supine and standing position compared with pelvic survey X-ray after total hip arthroplasty

IntroductionThe correct adjustment of leg length is a major goal in the implantation of total hip replacements (THRs). Differences in leg length can lead to functional impairment and patient dissatisfaction. By determining leg length at an early stage, before the patient is discharged from hospital, compensatory measures such as the production of special insoles or orthopaedic footwear can be initiated promptly if there is a difference in leg length. Due to shortening of the period of time spent in hospital, the traditional measurement of leg length in a standing position may be increasingly subject to error. A protective posture immediately after surgery or the presence of a twisted pelvis, for example, due to scoliotic spinal misalignments, falsifies the measurement result in the standing position. Here, the measurement of leg length in the supine position may prove to be accurate immediately postoperatively, regardless of potential sources of error, and is to be compared with measurement in the standing position versus radiological measurement on the AP pelvic survey.Material and methodsThe present retrospective study included 190 patients who had undergone primary total hip arthroplasty. The leg length difference (LLD) of the patients was determined pre- and postoperatively both in the supine and standing position and compared with the postoperative radiological pelvic survey image.ResultsPostoperatively, it was shown that the mean length measured was 0.35 mm too long in the supine position and 0.68 mm too short in the standing position (p value < 0.001). Determination of the average absolute measurement error produces a deviation of 4.06 mm in the standing and 4.51 mm in the supine position (p value 0.126).ConclusionsIt is shown that the postoperative measurement of LLD in the supine and standing position is equally valid and sufficiently accurate, compared with the gold standard of measurement on a radiograph.

Accuracy of Leg Length and Hip Offset Measurements Using a Fluoroscopic Grid During Anterior Approach Total Hip Arthroplasty.

Minimizing leg length (LLD) and hip offset (OD) discrepancies is critical for tissue tension and implant longevity in total hip arthroplasty (THA). The direct anterior approach (DAA) helps surgeons recreate these values under fluoroscopy. Several methods to accomplish this have been described, with no consensus on which is superior. This study evaluated the ability to minimize LLD and OD using a surgeon-controlled, adjustable fluoroscopic grid. We hypothesized that this tool would recreate parameters to within 10 mm of the contralateral side. One hundred eleven primary THAs performed with an adjustable radiopaque grid to equalize leg length and hip offset were retrospectively reviewed. These values were measured on postoperative radiographs and compared to the contralateral hip. Patients were excluded if they had inadequate imaging, revision arthroplasty, preexisting deformities, or underwent approaches other than DAA. Mean age was 59.1±11.1 years, 63.1% of patients were female, and average body mass index was 27.8±7.0. Mean LLD was 3.7±3.0 mm, while mean OD was 4.6±3.6 mm. 95.5% of hips showed LLD < 10 mm, while 93.7% of hips had OD < 10 mm. Furthermore, 76.6% of hips had LLD < 5 mm, while 62.2% of hips had OD < 5 mm. The described technique restored limb length and hip offset during DAA THA. This technique yields consistent results and offers an inexpensive alternative to costly digital software and more cumbersome fixed grid systems.

Accuracy of Leg Length and Offset Measurements During Total Hip Arthroplasty Using an Imageless Navigation System.

Introduction Leg length and offset are important considerations in total hip arthroplasty (THA). Navigation systems are capable of providing intra-operative measurements of leg length and offset, and high accuracy has been shown in experimental studies. This study assesses the accuracy of an imageless navigation system with a pinless femoral array (Hip 5.1, BrainLAB, Feldkirchen, Germany) in measuring leg length and offset changes in vivo. Methods A prospective, consecutive series of 37 patients undergoing navigated THA were included in the study. Intra-operative measurements of leg length and offset were recorded using the navigation system. For each patient, pre- and post-operative digital radiographs were scaled and analyzed to provide radiographic measurements for comparison. Results Measurements of leg length change made by the navigation system showed a strong correlation with the size of change measured radiographically (R = 0.71; p<0.0001). The mean difference between the radiographic and navigational measurement was 2.6mm ± 3.0mm (0.0-16.0mm) (mean, SD, range). The navigation system was accurate to within 1mm of the radiographic measurement in 49% of cases, within 2mm in 66% of cases, and within 5mm in 89% of cases. Measurements of offset change by the navigation system also showed a correlation with radiographic measurements, albeit less pronounced (R = 0.35; p=0.035). The mean difference between navigational and radiographic measurements was 5.5mm ± 4.7mm (0.0-16.0mm) (mean, SD, range). The navigation system was accurate within 1mm of the radiographic measurement in 22% of cases, within 2mm in 35% of cases, and within 5mm in 57% of cases. Conclusions This research demonstrates in vivo that an imageless, non-invasive navigation system is a reliable tool for intra-operative leg length (accurate within 2mm) and to a lesser extent offset measurement (accurate within 5mm) when compared to standard practice of plain film radiographs.

Relationship of Pelvic Positional Change with Leg Length and Offset Measurement in Experimental Total Hip Arthroplasty

During total hip arthroplasty (THA), both pelvic and femur positions affect leg length (LL) and offset (OS) measurements because LL and OS calipers depend on the fixed reference points on the pelvis and femur, respectively. However, LL and OS measurement errors because of pelvic positional changes have not been described. This study aimed to clarify the effects of pelvic positional changes on LL and OS measurements in relation to the pelvic reference using a THA simulator. We developed an experimental THA simulator using Sawbones models of the hemipelvis and femur that facilitated modification of the obliquity, tilt, and rotation of the pelvis. Using an LL and OS caliper, LL and OS measurement errors due to pelvic positional changes were determined with the femoral position fixed. Measurements were performed from two pelvic reference positions: the iliac tubercle (P1) and the top of the iliac crest intersecting the line of the femoral long axis (P2). Concerning pelvic obliquity, the total error of LL was 25.0 mm in P1 and 26.5 mm in P2, while the total error of OS was 13.0 mm in P1 and 10.9 mm in P2. For pelvic tilt, the total error of LL was 9.0 mm in P1 and 3.8 mm in P2, while the total error of OS was 0.5 mm in P1 and 1.0 mm in P2. Regarding pelvic rotation, the total error of LL was 13.8 mm in P1 and 3.2 mm in P2, while the total error of OS was 3.8 mm in P1 and 4.0 mm in P2. Pelvic positional changes alter LL and OS measurements. The acceptable range (error <2 mm) on LL and OS measurement errors of pelvic obliquity was only 2°, regardless of the pelvic reference position. The pelvic reference position should be at the top of the iliac crest intersecting the line of the long axis of the femur because of a small LL measurement error with pelvic tilt and rotation.

Intrarater Reliability and Analysis of Learning Effects in the Y Balance Test.

While the general reliability of the Y balance test has been previously found to be excellent, earlier reviews highlighted a need for a more consistent methodology between studies. The purpose of this test-retest intrarater reliability study was to assess the intrarater reliability of the YBT using different methodologies regarding normalisation for leg length, number of repetitions, and score calculation. Sixteen healthy adult novice recreational runners aged 18-55 years, both women and men, were reviewed in a laboratory environment. Mean calculated scores, intraclass correlation coefficient, standard error of measurement, and minimal detectable change were calculated and analysed between different leg length normalisation and score calculation methods. The number of repetitions needed to reach a plateauing of results was analysed from the mean proportion of maximal reach per successful repetition. The intrarater reliability of the YBT was found to be good to excellent, and it was not affected by the method of score calculation or leg length measurement. The test results plateaued after the sixth successful repetition. Based on this study, it is suggested to use anterior superior iliac spine-medial malleolus length for leg length normalisation because this method was proposed in the original YBT protocol. At least seven successful repetitions should be performed to reach a result plateau. The average of the best three repetitions should be used to mitigate possible outliers and account for the learning effects seen in this study.

Effect of training and recovery methods on vo2max athletes of unsika rowing club by controlling the effect of leg length

A well-executed training program using the right training method will result in an athlete's performance if the athlete gets sufficient recovery to recover from post-exercise fatigue. To find out the athlete's performance by knowing the oxygen volume capacity by using the balke test but the leg length of each athlete is suspected of contributing in carrying out the test so researchers want to examine the Effect of Training and Recovery Methods on VO2max of UNSIKA Rowing Club Athletes by Controlling the Effect of Leg Length. quasi-experimental method with a 2 x 2 factorial design. The research variables consisted of: (1) the dependent variable, namely VO2max Athlete Rowing Club UNSIKA (2) independent variables, namely the treatment variable (A1: Cross country method, and A2: Fatlek) and attribute variables ( B1: Passive Recovery and B2: Active Recovery) and (3) the covariate variable, in this study was Leg Length. So that the total number of research samples is 80 people. The Balke test is the test instrument used in collecting Vo2max data. as well as a tape measure to measure leg length. Hypothesis testing was carried out using two-way covariate analysis (ANKOVA) with a 2x2 factorial design. The results of the first hypothesis testing showed that the Vo2max results of the UNSIKA rowing club athletes between the athlete group using the cross country method were higher than the athlete group using the fatlek method after controlling for leg length. Thus the cross-country training method used in this study can improve the Vo2max results of UNSIKA rowing club athletes which are better than the fatlek method.

Caloric Restriction Decreases Radiation-Induced Normal Tissue Toxicity

<h3>Purpose/Objective(s)</h3> Improvements in radiation delivery are limited by normal tissue toxicity. Studies show that the patient's metabolic state affects radiation toxicity. It has previously been shown that caloric restriction can be used to induce radiation sensitivity in treating breast and prostate tumors. Here we investigate the effect of caloric restriction on radiation induced normal tissue toxicity in two murine models. <h3>Materials/Methods</h3> To determine the role of diet on radiation induced normal tissue toxicity two toxicity models were used to assess mice fed either an ad libitum (AL), caloric restriction (CR: 30% reduction of calories) or ketogenic diet (KD: 60mg fat). A leg shortening model was used to assess acute and long-term skin toxicity by treating one leg of 9-week old Balb/c mice with a single- fraction of 30Gy of irradiation (320kV) with the rest of the body shielded and the contralateral leg serving as an unirradiated control. Measurements of leg length of irradiated compared with control leg length were performed. To assess differences in bone marrow, gastrointestinal and cardiac toxicity, total body radiation was administered to Balb/c mice using a dose of 6.5Gy (LD 50/30) with cohorts from each experimental diet. Histologic evaluation of small intestines and bone marrow was performed after tissue collection at 0, 1, 72 hours as well as 16-18 days post TBI. Small intestinal histology was reviewed by a gastrointestinal pathologist. Serum was evaluated for cardiac troponin 1 levels using ELISA at the same time points. Statistical comparisons were made using students t-test. <h3>Results</h3> The leg shortening model revealed radiation acute skin toxicity at 2 weeks post an ad libitum or ketogenic diet with skin peeling, hair loss, and moist desquamation that lasted 3 weeks compared to the mice treated with CR that had a delayed acute skin toxicity that only lasted 1 week. Long term, the irradiated leg was notably shortened and decreased by 22% and 20% relative to the contralateral leg in the AL and KD groups with 14% leg shortening and decreased fibrosis at 120 days post treatment in the CR groups (p<0.01). Gastrointestinal toxicity was decreased after TBI in mice on CR diet with less denuded villi epithelium and less obvious change in villi length at 72 hours compared to AL diet. The CR mice at 72 hours also had less variation in nuclear size within the epithelium and less changes in Paneth cells. Bone marrow was more hypocellular in the TBI mice on ad libitum diet compared with mice in the CR cohort. Acute cardiac toxicity was evaluated with serum troponin and was less elevated 72 hours post radiation in the CR group, 0.16ng/ml compared to 0.25ng/ml in the AL mice (p=0.03). <h3>Conclusion</h3> Dietary changes impact radiation induced toxicity. Our data show that caloric restriction decreases acute skin toxicity, fibrosis, gastrointestinal and cardiac toxicity. Future research is warranted to translate this strategy to decrease radiation induced normal tissue toxicity.