The Influence of the Inter-Relationship of Leg Position and Riding Posture on Cycling Aerodynamics

Aerodynamics is an important factor affecting cyclist performance, as at the elite level 90% of rider energy is used to overcome aerodynamic drag. As such, much effort has been channeled into understanding the detailed flow around cyclists, since small gains can produce large rewards. Previous studies have shown that cycling aerodynamic drag is sensitive to leg position during the pedaling cycle; however, a systematic analysis comparing the impact of leg position between different riding postures is yet to be undertaken. To address this question, we compare the impact of leg position for two elite-level riding postures: the standard sprint and pursuit body positions. The comparison shows that the effect of leg position on drag is not consistent between the two riding postures, as the altered flow associated with different leg positions is influenced by the wakes from and proximity of other upstream or nearby components, such as the arms. This study reveals the inter-relationship between leg position and riding posture; and suggests that the flow associated with varied leg position should include surrounding geometrical components to obtain and understand the full aerodynamic impact. Practically, the results are valuable for optimizing the posture and improving skin-suit design for drag minimization.

Lower Leg Injury Mechanism Investigation During an IED Blast Under a Vehicle Using an Anatomic Leg Model

Attacks with improvised explosive device (IED) constituted the main threat to, for example, Polish soldiers in Iraq and Afghanistan. Improving safety during transport in an armored vehicle has become an important issue. The main purpose of the presented research is to investigate the mechanism of lower leg injuries during explosion under an armored vehicle. Using a numerical anatomic model of the lower leg, the analysis of the leg position was carried out. In all presented positions, the stress limit of 160 (MPa) was reached, which indicates bone damage. There is a difference in stress distribution in anatomic elements pointing to different injury mechanisms.

Application of a new position in endoscopic combined intrarenal surgery: modified prone split-leg position

Background: Endoscopic combined intrarenal surgery (ECIRS) well established as a minimally invasive procedure for is treatment of multiple urolithiasis. The position is the key to the perfect combination of Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Galdakao-modified supine Valdivia (GMSV) and prone split-leg position are widely used. However, both positions have their own advantages and disadvantages. This study aimed at evaluating the effect of ECIRS in the treatment of multiple urolithiasis in the modified prone split-leg position.Patients and methods: Total 96 patients with multiple urolithiasis underwent ECIRS in modified prone split-leg position from September 2017 and January 2021. Relevant demographic and clinical data were analysed retrospectively. Clinical outcomes such as stone free rate, complications and postoperative hospital stay were evaluated. Factors predicting stone free rate were also evaluated. Chi-square test was used to compare categorical variables and Student t test was applied for continuous variables of the treatment groups.Results: The mean renal stones size was 32.5 ± 10.7 mm and renal stone surface area was 712.2 ± 264.8 mm2. The mean ureteral stones size was 24.8 ± 12.3 mm. The mean surgical time was 82.2 ± 38.3 min. The incidence of complications was 16.7%, mainly grade 1 and grade 2. No complications occurred above grade 3. The stone was completely removed in 75 (78.1%) patients in a single operation. The risk factors affecting the stone free rate of ECIRS were analyzed, only the number of involved calyces by stone was found to be significant (p=0.01).Conclusion: ECIRS is safe and effective in the treatment of multiple renal calculi or multiple renal calculi with ipsilateral ureteral calculi in the modified prone split-leg position. The modified of prone split-leg position makes the retrograde operation more convenient, which is conducive to the combination of RIRS and PCNL.

Analisis Gerakan Forehand Pada Tenis Meja Di Klub PTM Elektra Kab Demak

The background is because the athlete only uses a forehand to defend, whereas a forehand is good for attacking. The formulation of the problem, how to analyze the biomechanics of forehand motion in table tennis and how good hand movements, body position and leg position using forehand movements, whether the 9 angles of the movement affect the entry or absence of the ball. The aim of this research is to know how the biomechanical analysis of forehand motion in table tennis and to find out how good hand movement, body position and leg position using the forehand movement of the 9 angles affect the entry or absence of the ball. Based on processing using statistics, there is a significant difference in comparisons when the ball position hits the bet; 1) wrist position 167.875o-223.8o; 2) bending of the right elbow 82,9o-92,1o; 3) bending of the left elbow 86.24o-95.82o; 4) opening of the upper arm of the right hand 71.06o-78.95o; 5) opening of the upper arm of the left hand 45.45o-50.5o; 6) leaning body 145.54o-161.71o; 7) right leg bending 152.6o-169.5o; 9) distance of both feet 44.05o-48.94o. Keywords: Forehand, Table Tennis. ABSTRAK Latar belakang karena atlet hanya menggunakan pukulan forehand untuk bertahan, padahal pukulan forehand bagus untuk menyerang. Rumusan masalah, bagaimana analisis biomekanika gerakan forehand pada cabang olahraga tenis meja dan bagaimana gerakan tangan, posisi badan dan posisi kaki yang baik dengan menggunakan gerakan forehand apakah dari 9 sudut gerakan tersebut mempengaruhi masuk atau tidaknya bola. Tujuan penelitin ingin mengetahui bagaimana analisis biomekanika gerakan forehand pada cabang olahraga tenis meja dan untuk mengetahui bagaimana gerakan tangan, posisi badan dan posisi kaki yang baik dengan menggunakan gerakan forehand apakah dari 9 sudut gerakan tersebut mempengaruhi masuk atau tidaknya bola.Berdasarkan pengolahan dengan menggunakan statistik, terdapat perbedaan perbandingan yang signifikan saat posisi bola mengenai bet; 1) posisi pergelangan tangan 167,875o-223,8o; 2) tekukan siku kanan 82,9o-92,1o; 3) tekukan siku kiri 86.24o-95.82o ; 4) bukaan lengan atas tangan kanan 71,06o-78,95o ; 5) bukaan lengan atas tangan kiri 45,45o-50,5o; 6) kecondongan badan 145,54o-161,71o; 7) tekukan kaki kanan 152,6o-169,5o ; 9) jarak kedua kaki 44,05o-48,94o. Kata kunci: Forehand, Tenis Meja.

OBSTETRIC GYNECOLOGICAL SOCIETY IN KIEV

MO Kleinman reported "a case of a vaginal septum obstructed during labor." A fleshy septum, thick as a goose feather, going from the anterior wall of the vagina to the posterior wall, prevented the forward movement of the child, who was in the second leg position in the anterior view. When the child was removed, the septum first caught on the gluteal fold, and then on the right axillary cavity; it was cut with scissors between two ligatures.

Motor Programs as Indicators of Penalty Direction in Soccer

Introduction: Many football games are decided on penalties and usually in championship final games. When seeking to anticipate movements, differences in amplitude can harm players because the informational movement appears to be spread "globally" throughout the action and should be coded at several levels. Thus, it would be interesting to analyze the entire period of the kick, since the player begins his run to approach the ball to recognize the motor patterns used in the kick that identify his direction. Objective: The objective of this study is to identify patterns of behavior in penalty kicks that may indicate the direction of their action / kick and in my moment they appear. Methodology: The sample consisted of 21 subjects hitting a penalty kick, 18 males and 3 females with an average age of 22.18 ± 2.44 years and two goalkeepers with college football experience. The tests consisted of a battery of two penalty kicks for each subject in order to score. The kicks were recorded by a video camera with a front view of the goal goal and the back of the batter. The kick phases were divided into the starting leg position; first step leg; angle of the elbow in relation to the body seen from behind; angle of the elbow in relation to the displacement line seen from above; direction of the tip of the supporting foot and position on the goal where the kick was. Each kick was preceded by a start signal. The data were analyzed from the registration of each variable and the position of the goal in which the ball was kicked, considering it in three sectors: left, right and central. Results: The main results indicated that the variable “Leg of the first step” had 81% of the kicks associated with the direction of the goal; 52.4% of second kicks had repeated the pattern of behavior and 84.6% had repeated the pattern of behavior regardless of the goal position. The variable “Elbow angle in relation to the body seen from behind” had 81.8% repeated behavior pattern regardless of the goal position and the variable “Elbow angle in relation to the displacement line seen from above” had 81% association with the sector of the goal in which the ball was kicked; 52.4% of second kicks had repeated the pattern of behavior and 91.7% had repeated the pattern of behavior regardless of the goal position. Conclusions: The main conclusions indicate that it is possible to relate the kick location with the batter's body information; the start of the race seems to indicate that there is a prior intention of movement programs; the decision of where to hit the penalty appears to be made before contact with the ball and more closely to the placement of the support foot and with this relationship, the size of the goal to be defended by the goalkeeper could be reduced, increasing the possibility of defense.