Calf Girth Research Articles

The effect of posture on body circumferences in older adults

Standards for anthropometrical assessment define that measurements must be carried out with the subject in the standing position, although this is not always possible. The effect of body position on girth measurement has not been evaluated, even though this issue is clinically relevant because it may bias nutritional assessment results. The present study aimed to evaluate the effect of body position and symmetry on girth measurement. A cross-sectional study was conducted on 102 older adults aged ≥65years from care homes and tertiary hospitals. Right and left arm, waist, hip mid-thigh and calf girths were obtained with the subject standing or in the supine position. Mini-Nutritional Assessment Short-Form (MNA-SF) score and reference data percentiles (NHANES IV) misclassification according to girths assessed in the supine position was evaluated. A high intraclass correlation coefficient (ICC>0.97) and quartiles agreement (k>0.89) were found between girth measurements conducted on participants in the standing and supine positions. According to MNA-SF, 23.5% of the participants were undernourished and 51% were at risk of undernutrition. A high agreement between MNA-SF score using calf circumference measured on standing or supine position was found (k=0.96). A relevant agreement for NHANES IV girth percentiles by sex and age was also found (ICC>0.89). Agreement between girth measurements on standing and supine positions among older adults is high and differences do not have any clinically relevant impact on MNA-SF classification and reference data percentiles.

The Effects of Wearing Lower Body Compression Garments During a Cycling Performance Test

Compression garments have been commonly used in a medical setting as a method to promote blood flow. Increases in blood flow during exercise may aid in the delivery of oxygen to the exercising muscles and, subsequently, enhance performance. The aim of the current study was to investigate the effect of wearing lower body compression garments during a cycling test. Twelve highly trained cyclists (mean ± SD age 30 ± 6 y, mass 75.6 ± 5.8 kg, VO2peak 66.6 ± 3.4 mL · kg-1 · min-1) performed two 30-min cycling bouts on a cycle ergometer in a randomized, crossover design. During exercise, either full-length lower body compression garments (COMP) or above-knee cycling shorts (CON) were worn. Cycling bouts involved 15 min at a fixed workload (70% of VO2max power) followed by a 15-min time trial. Heart rate (HR) and blood lactate (BL) were measured during the fixed-intensity component of the cycling bout to determine the physiological effect of the garments. Calf girth (CG), thigh girth (TG) and perceived soreness (PS) were measured preexercise and postexercise. COMP produced a trivial effect on mean power output (ES = .14) compared with CON (mean ± 95% CI 1.3 ±1.0). COMP was also associated with a lower HR during the fixed-workload section of the test (-2.6% ± 2.3%, ES = -.38). There were no differences between groups for BL, CG, TG, and PS. Wearing compression garments during cycling may result in trivial performance improvements of ~1% and may enhance oxygen delivery to the exercising muscles.

Interrelationships Between Strength, Anthropometrics, and Strongman Performance in Novice Strongman Athletes

The sport of strongman is relatively new; hence, specific research investigating this sport is currently very limited. The purpose of this study was to determine the relationships between anthropometric dimensions and maximal isoinertial strength to strongman performance in novice strongman athletes. Twenty-three semiprofessional rugby union players with considerable resistance training and some strongman training experience (age 22.0 ± 2.4 years, weight 102.6 ± 10.8 kg, height 184.6 ± 6.5 cm) were assessed for anthropometry (height, body composition, and girth measurements), maximal isoinertial performance (bench press, squat, deadlift, and power clean), and strongman performance (tire flip, log clean, and press, truck pull, and farmer's walk). The magnitudes of the relationships were determined using Pearson correlation coefficients, and interpreted qualitatively according to Hopkins (90% confidence limits ∼±0.37). The highest relationship observed was between system force (body mass + squat 1-repetition maximum) and overall strongman performance (r = 0.87). Clear moderate to very large relationships existed between performance in all strongman events and the squat (r = 0.61-0.85), indicating the importance of maximal squat strength for strongman competitors. Flexed arm girth and calf girth were the strongest anthropometric correlates of overall strongman performance (r = 0.79 and 0.70, respectively). The results of this study suggest that body structure and common gymnasium-based exercise strength are meaningfully related to strongman performance in novice strongman athletes. Future research should investigate these relationships using more experienced strongman athletes and determine the relationships between changes in anthropometry, isoinertial strength, and strongman performance to determine the role of anthropometry and isoinertial strength in the sport of strongman.

Comparison of Physiological and Anthropometrical Variables of University Volleyball Players

The purpose of this study is to compare the physiological and anthropometrical variables of inter university female volleyball players. 75 North-East Zone Intervarsity Volleyball players 15 from each university including stand byes players i.e. Banaras Hindu University Varanasi, Lucknow University Lucknow, G.N.D.U. Amritsar, Panjab University Chandigarh and Manipur University Manipur, were selected for this study. The average age of the selected players was 18 to 25 years. Four physiological variables i.e. vital capacity, maximum expiratory pressure, breath holding capacity and pulse rate and seven anthropometrical variables i.e. height, weight, leg length, foreleg length, thigh length, calf girth and thigh girth were selected for this study. For statistical analysis of the data mean, was computed and one way ANOVA was utilized to compare the selected physiological and anthropometrical variables among the different university players. Level of significance was set at 0.05 level of confidence. Study concluded that in physiological variables, significant differences were found among the different team of volleyball players in vital capacity and breath holding capacity. In anthropometrical variables, significant differences were found among the different team of volleyball players in foreleg length, thigh length, weight, thigh girth and calf girth. In other physiological variables i.e. max, expiratory pressure and pulse rate, and in other anthropometrical variables i.e. height and leg length there were no significant differences were found among the different team of volleyball players. It means in these variables all five university players are more or less the same.

Risk factors and prognostic indicators for medial tibial stress syndrome

The objective of the study was to examine the risk factors and prognostic indicators for medial tibial stress syndrome (MTSS). In total, 35 subjects were included in the study. For the risk factor analysis, the following parameters were investigated: hip internal and external ranges of motion, knee flexion and extension, dorsal and plantar ankle flexion, hallux flexion and extension, subtalar eversion and inversion, maximal calf girth, lean calf girth, standing foot angle and navicular drop test. After multivariate regression decreased hip internal range of motion, increased ankle plantar flexion and positive navicular drop were associated with MTSS. A higher body mass index was associated with a longer duration to full recovery. For other prognostic indicators, no relationship was found.

Effect of Contrast Water Therapy Duration on Recovery of Running Performance

To investigate whether contrast water therapy (CWT) assists acute recovery from high-intensity running and whether a dose-response relationship exists. Ten trained male runners completed 4 trials, each commencing with a 3000-m time trial, followed by 8 × 400-m intervals with 1 min of recovery. Ten minutes postexercise, participants performed 1 of 4 recovery protocols: CWT, by alternating 1 min hot (38°C) and 1 min cold (15°C) for 6 (CWT6), 12 (CWT12), or 18 min (CWT18), or a seated rest control trial. The 3000-m time trial was repeated 2 h later. 3000-m performance slowed from 632 ± 4 to 647 ± 4 s in control, 631 ± 4 to 642 ± 4 s in CWT6, 633 ± 4 to 648 ± 4 s in CWT12, and 631 ± 4 to 647 ± 4 s in CWT18. Following CWT6, performance (smallest worthwhile change of 0.3%) was substantially faster than control (87% probability, 0.8 ± 0.8% mean ± 90% confidence limit), however, there was no effect for CWT12 (34%, 0.0 ± 1.0%) or CWT18 (34%, -0.1 ± 0.8%). There were no substantial differences between conditions in exercise heart rates, or postexercise calf and thigh girths. Algometer thigh pain threshold during CWT12 was higher at all time points compared with control. Subjective measures of thermal sensation and muscle soreness were lower in all CWT conditions at some post-water-immersion time points compared with control; however, there were no consistent differences in whole body fatigue following CWT. Contrast water therapy for 6 min assisted acute recovery from high-intensity running; however, CWT duration did not have a dose-response effect on recovery of running performance.

Anthropometric characteristics and gait transition speed in human locomotion

The purpose of this study was to investigate the relationship between anthropometric parameters and the preferred transition speed (PTS) in human locomotion, in both genders. Previous studies exploring body measures as possible determinants of the PTS were biased toward longitudinal body dimensions, while the relationship between the PTS and transverse body dimensions has so far not been examined. Longitudinal and transverse anthropometric parameters were measured in 48 physical education students (21 males, 27 females), and an exercise test was performed for determination of the PTS. The relationship between the PTS and the anthropometric variables was determined using Pearson product-moment correlations and stepwise multiple regression analysis. Weak to moderate correlations between several body size and body shape variables and the PTS were found. In males, significant negative correlations (p<.05) between transverse body dimensions scaled to body height (calf girth, shoulder, bicristal and bitrochanteric diameters) and the PTS were found (r=−.51 to −.63). In females, calf girth and thigh girth scaled to height were significantly negatively correlated with the PTS (r=−.61 and −.42, respectively; p<.05). The results of the study suggest that gait transition speed in humans is related to both transverse and longitudinal body dimensions, and that sexual dimorphism in body size and shape should be taken into consideration for a proper interpretation of the PTS.

Position-specific and Team-ranking-related Morphological Characteristics in German Amateur Soccer Players - a Descriptive Study - Anthropometry in Amateur Soccer Players -

The purpose of this study was to describe the morphological characteristics in German amateur soccer players based upon their ranking in the championship table and the position of the players. Seventy-two male Fifth Division soccer players from four clubs volunteered for this study. The examination of the teams was conducted within 10 days of the preparation period for the second half of the season when teams A through D were ranked 6 th , 5 th , 2 nd and 11 th in the Division. Anthropometric measurements included body weight and height, skinfold thickness (biceps, triceps, subscapular, suprailiac, calf), biepicondylar humerus and femur breadths, upper arm (flexed and tensed), thigh and calf girths. Somatotypes were calculated using the Heath-Carter equations.No differences were found between the means of the different anthropometric variables of the four teams (p <.05). In all groups, the somatotype means of the soccer players were mesomorph-endomorph. Compared to field players, goalkeepers showed higher values for body height, body weight and arm girth (p <.05).This study showed that there were no anthropometric and somatotype differences between the soccer teams of different club ranking. Compared to field players, goalkeepers showed higher body height and weight, higher biepicondylar femur and humerus breadths, hig8her arm, thigh and calf girths, and higher mesomorphy. Discriminant function analyses were unable to separate the players’ position on the basis of body composition or somatotype. No differences were found between the means of the different anthropometric variables of the four teams (p < .05). 1)gan

Sexual dimorphism of anthropometrical measurements in judoists vs untrained subject

This study aims to evaluate the sexual dimorphism in the body composition and somatotype of Polish elite judoists and comparison with untrained subjects. Twenty-two males and 12 female judoists have participated in this study. Their ages and judo experiences are respectively 23 vs. 22 years old and 12 vs. 11 years. Ten required measurements were taken to establish the individual's somatotypes (SiberHegner Machines SA, Zurich, Switzerland instruments). To compare the 165 males and 153 females untrained, abdominal skinfold thickness was measured with Skinfold Caliper. Mean height and weight, somatotype and body mass index, fat free mass index, fat mass index, and fat percentage were calculated. The two-step ratio of sexual dimorphism index (SDI) was used. Sixteen out of the 21 measurements and anthropometric indices showed a reduction of sexual dimorphism in judoists compared with the untrained subjects. Highest differences were found in the fat mass and fat percentage. Conversely, a very low difference of SDI was observed for height-weight ratio, ectomorphy, fat free mass percentage and calf girth. Average SDI in untrained subjects was higher than in judoists. Évaluer le dimorphisme sexuel de la composition corporelle et somatotype de l’elite polonaise de judo et les comparer avec des sédentaires. Trente-quatre judokas (22 hommes et et 12 femmes) ont participé à notre étude. Leur âge et leur éxperience sont respectivement de 23,1 versus 22,2 ans et 12,7 versus 11,0 ans. Afin de déterminer les somatotypes individuels et les comparer avec des sédentaires (165 hommes et 153 femmes), dix mesures ont été prises (SiberHegner Machines SA, Zurich, instruments Suisse), le pli cutané abdominal a aussi été mesuré. La moyenne de la taille et du poids, les somatotypes et l’indice de masse corporelle, l’indice de masse maigre, l’indice de masse grasse et le pourcentage de la masse grasse corporelle ainsi que les deux indices du dimorphisme sexuel (IDS) ont été calculés. Seize sur 21 mesures et indices anthropométriques calculées ont montré une réduction du dimorphisme sexuel chez les judokas versus sédentaires. Des différences significatives ont été observées pour la masse grasse et le pourcentage de graisse. Toutefois, une faible difference de l’IDS a été relevée pour le rapport taille-poids, ectomorphe, le pourcentage de la masse maigre et la circonférence du mollet. L’IDS est moins important chez les judokas que chez les sédentaires.

Intra-articular injection of tranexamic acid reduces not only blood loss but also knee joint swelling after total knee arthroplasty

This is a randomised controlled trial to examine whether intra-articular injection of tranexamic acid (TXA) decreases blood loss, as well as reducing leg swelling after total knee arthroplasty (TKA). We performed 100 TKA in osteoarthritis patients. At closure, a total of 2,000mg/20ml TXA was injected into the knee joint through a closed suction drain (TXA group). For the control group, the same volume of physiological saline was injected. The pre-operative condition of the patients, post-operative haemoglobin (Hb) levels, discharge volumes from drain, D-dimer and needs for transfusion were compared between these two groups. Furthermore, leg diameters (thigh, suprapatellar portion and calf girth) were measured pre- and post-operatively to investigate whether TXA has an influence on leg swelling after surgery. The results revealed that post-operative decrease in Hb level was significantly reduced in the TXA group. Furthermore, knee joint swelling after operation was significantly suppressed in the TXA group compared to the control group. The results revealed intra-articular administration of TXA decreased not only blood loss, but also knee joint swelling after TKA.

Medial tibial stress syndrome

Lecture 9Medial tibial stress syndrome (MTSS) is an enigmatic condition with confusing terminology, the term often being used interchangeably with shin splints. It is suggested that MTSS and shin splints...

Physical Characteristics and Somatotype of Soccer Players according to Playing Level and Position

Physical Characteristics and Somatotype of Soccer Players according to Playing Level and Position The purpose of this study was to assess the physical characteristics of soccer players according to playing level and position. A total of 305 professional male soccer players [Turkish Super League (SL) (n = 161) and Turkish First League (FL) (n = 144)] were involved in this study. All data were gathered at the beginning of preparatory period of mid-season. Height, weight, flexed and tensed upper arm and calf girths, humerus and femur biepicondylar breadths, and four skinfold thicknesses (triceps, subscapular, supraspinale, and medial calf) were measured. Somatotypes were estimated using the Heath-Carter method. SL players were older (p≥0.002), and heavier (p≥0.007) than FL players, while height (p ≤ 0.497) was similar between SL and FL groups. There were significant differences for BW (p≥=0.000), and height (p≥0.000) between playing positions. Goalkeepers were taller (p≥0.000), and heavier (p≥0.001) than other players. Midfielders were shorter (p≥0.013) than other players, however, they were lighter than forwards (p≥0.008). The mean somatotype of the overall players was 2.4-4.8-2.3 (0.9-0.8-0.7) in SL and was 3.0-4.5-2.6 (0.9-0.9-0.8) in FL. SL players were more mesomorphic (p≥0.01), less endomorphic (p≥0.000), and less ectomorphic (p≥0.001) than FL players. Except for goalkeepers, there were significant differences in paired means between whole somatotype means of the SL and FL according to playing positions. The results of the present study demonstrate that both physical characteristics and somatotype of players were significantly different between playing levels and positions. Although the somatotype of soccer players in both levels was dominated by the mesomorph category, players at the higher playing level were more mesomorphic, and less endomorphic and ectomorphic than players at the lower level at all playing positions.

Rehabilitation of the Operated Achilles Tendon: Parameters for Predicting Return to Activity

Return to activity (RTA) following Achilles tendon surgery assessment criteria has not been generally adopted. A well-defined postsurgical rehabilitation regimen with 3 distinct criteria, yet easy to measure, can be used to assess the ability of patients undergoing Achilles tendon surgery to return to activity. We studied whether if patients were able to meet all 3 criteria, would this show significance in predicting the ability to RTA within a normal range. A total of 219 patients undergoing surgery on the Achilles tendon from 1990 to 2005 were retrospectively studied to evaluate for the ability to perform 5 sets of 25 single-legged concentric heel raises, along with symmetry of calf girth and ankle range of motion. Time of RTA and the ability to meet all 3 parameters was studied. If patients could meet all 3 criteria, they were allowed to RTA. This time postsurgery was recorded in weeks. Of the 219 surgeries reviewed, 149 were on males and 70 on females. Fourteen patients were unable to meet all 3 parameters evaluated above within the proposed time frames. The inability to meet all 3 criteria resulted in a delay to RTA ( P = .03). Eleven females had a delay in RTA as compared with 2 males ( P < .0001). RTA was different based on procedure. Meeting all 3 criteria was helpful in assessing if patients were able to RTA in the normal range. Patients who were unable to meet all 3 had a delay in RTA. Females were more likely to have a delay in RTA.

Anthropometric, body composition and somatotype differences of Iranian elite female basketball and handball players

The aims of the this study were: (A) to determine the anthropometric profile, body composition and somatotype of female basketball (B), and handball (H) players, (B) to compare the mean scores among H and B and (C) to detect possible differences in relation to competition level. A total of 28 female athletes (B=15, H=13), all members of the Iranian national teams, participated in this study. Anthropometric measures required for the calculation of body composition indexes and somatotype components were obtained according to the established literature. These measurements were height, weight, triceps, subscapular, suprailiac, thigh and calf skinfolds, bi-epicondylar diameter of femur and humerus, and flexed biceps and calf girths. All skinfold measurements were taken on the right side of the body with the Yagamy skinfold caliper. Measurements were taken during the peak of the competition season. Subjects' somatotypes were determined by using the Heath-Carter anthropometric method. Somatotype was calculated using the Heath-Carter method.1 Data were analysed using t test with significance accepted at p&lt;0.05. There was no significant difference of body mass index, waist-to-hip ratio, fat weight, fat per cent, fat-free weight, waist to hip ratio and stature, weight and triceps skinfold thickness among B and H group. Although B and H group had homogeneity in somatotype characteristics (p&lt;0.05). There was a difference somatotype characteristics among B and H group (p&lt;0.001). Somatotype characterised as mesoendomorph in B group (3.6, 3.5, 2.4) and H athletes' somatotype was mesoendomorph (3.6, 4.7, 1.7). Anthropometric and body composition variables of elite female basketball and handball players were same, but they had different somatotype characteristics. Selection criteria, hours of training and sport-specific physiological demands during the game could explain the observed differences.

Velocity and starting block variables during a 30 m sprint run

Performance in sprinting is mainly determined by the ability to accelerate, to increase maximal velocity and to maintain velocity during the race. These factors are strongly influenced by structural and...

Effect of Functional Resistance Training on Muscular Fitness Outcomes in Young Adults

As functional resistance training becomes a more popular method to improve muscular fitness, questions remain regarding the effectiveness of functional training compared to traditional resistance training. PURPOSE: The purpose of this study was to determine whether functional training has similar effects on muscular strength and endurance, flexibility, agility, balance, and anthropometric measures in young adults as traditional resistance training. METHODS: 38 healthy volunteers, aged 18-32 yr, were randomly placed into a control group (traditional (n = 19)) and an experimental group (functional (n = 19)). The participants were tested prior to and after completing the 7-week training study. The testing battery included: weight, girth measurements, flexibility, agility, lower back flexion and extension endurance, push-up test, sit-up test, 1 leg balance, 1-RM bench press, and 1-RM squat. RESULTS: There were significant (p <.05) increases in push-ups, back extension endurance, 1-RM bench press, 1-RM squat, and 1 leg balance within each group following training. Traditional training also elicited significant (p <.05) increases in bicep girth, forearm girth, calf girth, and sit-ups, while the functional training group experienced significant (p <.05) increases in shoulder girth and flexibility. Forearm girth changes following training were the only parameter where there were significant (p <.05) differences between training groups. CONCLUSIONS: These results suggest that both programs are equally beneficial for increasing endurance, balance, and traditional measures of strength. However, changes in various girth measures and flexibility appear to be program specific.

Effect of Functional Resistance Training on Muscular Fitness Outcomes in Young Adults

As functional resistance training becomes a more popular method to improve muscular fitness, questions remain regarding the effectiveness of functional training compared to traditional resistance training. Therefore, the purpose of this study was to determine whether functional training has similar effects as traditional resistance training on muscular strength and endurance, flexibility, agility, balance, and anthropometric measures in young adults. In this study, 38 healthy volunteers, aged 18-32 years, were randomly placed into a control group [traditional (n = 19)] and an experimental group [functional (n = 19)]. The participants were tested prior to and after completing the 7-week training study. The testing battery included: weight, girth measurements, flexibility, agility, lower back flexion and extension endurance, push-up test, sit-up test, one-leg balance, one-repetition maximum (1-RM) bench press and squat. Results indicated significant (p < 0.05) increases in push-ups, back extension endurance, 1-RM bench press, 1-RM squat, and one-leg balance within each group following training. Traditional training also elicited significant (p < 0.05) increases in bicep girth, forearm girth, calf girth, and sit-ups, while the functional training group experienced significant (p < 0.05) increases in shoulder girth and flexibility. Forearm girth and flexion test time changes following training were the only parameter where there were significant (p < 0.05) differences between training groups. Collectively, these results suggest that both programs are equally beneficial for increasing endurance, balance, and traditional measures of strength. However, changes in various girth measures, torso flexor endurance and flexibility appear to be program-specific.

Effects of creatine supplementation on body mass and muscle girths in bodybuilders

Effects of creatine supplementation on body mass and muscle girths in bodybuilders Study aim: To find out whether a 6-week creatine supplementation would significantly augment body mass and muscle circumferences in male bodybuilders. Material and methods: A group of 14 male bodybuilders aged 16 - 29 years were randomly divided into two groups: experimental (E) and control (C), 7 subjects each. Group E received creatine monohydrate, Group C - placebo, 10 g daily for 6 weeks without saturation phase. The experimental design was a double-blind one. All subjects were on strictly controlled diet, the daily intakes amounting to 2.3 - 2.8 g of protein, 1.0 - 1.2 g of fat and 5 - 6 g/kg body mass of carbohydrate, and 3200 - 4000 kcal. All subjects trained 3 days a week, each session lasting 120 min, in the ‘Power, Rep-Range, Shock’ mode. Chest, waist, arm, forearm, thigh and calf girths were measured in the relaxed and contracted states, together with body mass, before and after the study. Results: Significant, training-induced changes were noted in almost all body circumferences studied in both groups and muscle states, those in the chest, biceps and thigh girths being the most pronounced ones and significantly (p&lt;0.05) greater in the experimental than in control group in the contracted muscle state. In the relaxed state the between-group differences were significant for the chest and thigh girths. The increments in body mass were significantly (p&lt;0.01) higher in the experimental than in control group (4.3 ± 1.3 and 2.1 ± 0.7 kg, respectively). Conclusions: The observed changes may have been brought about by creatine administration.

Medial Tibial Stress Syndrome

Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise, with pain on palpation of the tibia over a length of at least 5 cm. Histological studies fail to provide evidence that MTSS is caused by periostitis as a result of traction. It is caused by bony resorption that outpaces bone formation of the tibial cortex. Evidence for this overloaded adaptation of the cortex is found in several studies describing MTSS findings on bone scan, magnetic resonance imaging (MRI), high-resolution computed tomography (CT) scan and dual energy x-ray absorptiometry. The diagnosis is made based on physical examination, although only one study has been conducted on this subject. Additional imaging such as bone, CT and MRI scans has been well studied but is of limited value. The prevalence of abnormal findings in asymptomatic subjects means that results should be interpreted with caution. Excessive pronation of the foot while standing and female sex were found to be intrinsic risk factors in multiple prospective studies. Other intrinsic risk factors found in single prospective studies are higher body mass index, greater internal and external ranges of hip motion, and calf girth. Previous history of MTSS was shown to be an extrinsic risk factor. The treatment of MTSS has been examined in three randomized controlled studies. In these studies rest is equal to any intervention. The use of neoprene or semi-rigid orthotics may help prevent MTSS, as evidenced by two large prospective studies.

Physiological and Anthropometric Correlates of Tackling Ability in Rugby League Players

This study investigated the relationship between physiological and anthropometric qualities and tackling ability in rugby league players. Twelve rugby league players (mean +/- SD age, 24.4 +/- 3.5 years) underwent a standardized 1-on-1 tackling drill in a 10-m grid. Video footage was taken from the rear, side, and front of the defending player. Tackling proficiency was assessed using standardized technical criteria. In addition, all players underwent measurements of anthropometry (stature, body mass, sum of 7 skinfolds, arm, chest, waist, gluteal, thigh, and calf girths, and biepicondylar humerus and femur breadths), somatotype (endomorphy, mesomorphy, and ectomorphy), acceleration (5- and 10-m sprint), change-of-direction speed (modified 505 test), lower-body muscular power (vertical jump), and upper-body muscular power (overhead medicine ball throw). Differences in tackling ability and physiological and anthropometric qualities between the best (N = 6) and worst (N = 6) tacklers were compared using the Cohen effect size (ES) statistic. Eta coefficients (eta) were used to determine the relationships among physiological and anthropometric qualities and tackling proficiency. Better tacklers were older (ES = 1.9), more experienced (ES = 1.0), shorter (ES = 1.2), lighter (ES = 2.3), and leaner (ES = 1.3) than players with poor tackling proficiency. Better tacklers also had greater levels of mesomorphy (ES = 0.3), acceleration (ES = 2.3), and change-of-direction speed (ES = 0.5) than poor tacklers. The strongest correlates of tackling ability were age (eta = 0.70), skinfold thickness (eta = -0.68), body mass (eta = -0.72), waist girth (eta = -0.79), gluteal girth (eta = -0.74), and level of endomorphy (eta = -0.65). These findings demonstrate that well-developed physiological and anthropometric qualities contribute to effective tackling ability in rugby league players.