Maximal Swing Research Articles

Russian vs. American Kettlebell Swing – Which One to Choose?

Kettlebell swing exercises have been proposed as a method for developing power, strength, endurance, and aerobic capacity. There are two distinctive techniques or styles of kettlebell swing: Russian (RKBS) and American (AKBS), and the purpose of this study was to quantify the specific differences within each exercise. The aim of this paper was to determine which style offers greater mechanical output in the form of power, velocity and momentum, with consideration of energy expenditure and injury risk, and which represents a safer version of training operator for developing specific dimensions of strength and power along with muscular endurance. The selected population of physically active men (n=15; age: 27.5±4.5 years; height: 185.9±14.1 cm; weight: 96.1±11.1 kg; kettlebell swing experience: 3.6±2.4 years) were recruited to perform kettlebell swings of both styles. They performed eight maximal swings using a 24 kg kettlebell (~25% bodyweight), during which the concentric and eccentric phases and their respective amplitude, duration, peak and mean velocity, momentum and average power were analysed. The results of the paired sample t-test showed a statistically significant difference between styles in cycle duration, momentum, amplitude and velocities, while power generated was similar for both styles. In conclusion, both styles are viable training options, though the RKBS style presents a potentially safer alternative due to its biomechanical properties.

Relationship Between Diaphragmatic Electrical Activity and Esophageal Pressure Monitoring in Children.

Mechanical ventilation is an essential life support technology, but it is associated with side effects in case of over or under-assistance. The monitoring of respiratory effort may facilitate titration of the support. The gold standard for respiratory effort measurement is based on esophageal pressure monitoring, a technology not commonly available at bedside. Diaphragmatic electrical activity can be routinely monitored in clinical practice and reflects the output of the respiratory centers. We hypothesized that diaphragmatic electrical activity changes accurately reflect changes in mechanical efforts. The objectives of this study were to characterize the relationship between diaphragmatic electrical activity and esophageal pressure. Prospective crossover study. Esophageal pressure and diaphragmatic electrical activity were simultaneously recorded using a specific nasogastric tube in three conditions: in pressure support ventilation and in neurally adjusted ventilatory support in a random order, and then after extubation. Children in the weaning phase of mechanical ventilation. The maximal swing in esophageal pressure and esophageal pressure-time product, maximum diaphragmatic electrical activity, and inspiratory diaphragmatic electrical activity integral were calculated from 100 consecutive breaths. Neuroventilatory efficiency was estimated using the ratio of tidal volume/maximum diaphragmatic electrical activity. Sixteen patients, with a median age of 4 months (interquartile range, 0.5-13 mo), and weight 5.8 kg (interquartile range, 4.1-8 kg) were included. A strong linear correlation between maximum diaphragmatic electrical activity and maximal swing in esophageal pressure (r > 0.95), and inspiratory diaphragmatic electrical activity integral and esophageal pressure-time product (r > 0.71) was observed in all ventilatory conditions. This correlation was not modified by the type of ventilatory support. On a short-term basis, diaphragmatic electrical activity changes are strongly correlated with esophageal pressure changes. In clinical practice, diaphragmatic electrical activity monitoring may help to inform on changes in respiratory efforts.

The Effects of Various Weighted Implements on Baseball Swing Kinematics in Collegiate Baseball Players.

Williams, CC, Gdovin, JR, Wilson, SJ, Cazas-Moreno, VL, Eason, JD, Hoke, EL, Allen, CR, Wade, C, and Garner, JC. The effects of various weighted implements on baseball swing kinematics in collegiate baseball players. J Strength Cond Res 33(5): 1347-1353, 2019-The purpose of this study was to investigate the effects of different warm-up (WU) devices on bat swing parameters including maximal resultant velocity (MRV), resultant velocity at ball contact (RVBC), time difference between MRV and RVBC, bat angle at MRV, bat angle at RVBC, and perceptual differences of each WU implement used by National Collegiate Athletic Association Division-I baseball players. Fifteen varsity baseball players completed 1 experimental session during fall training. Retroreflective markers were placed on the bat and tee to measure basic bat kinematics during the swing. Participants completed a general calisthenics WU before being counter-balanced into 1 of 4 WU conditions: standard bat (SB) (33 in/30 oz), fungo (10.6 oz), weighted gloves with SB (weighted gloves) (55.6 oz) and donut with SB (donut) (55.6 oz). Each participant was asked to perform their normal on-deck routine over a 2-minute period, finishing with 5 practice swings with the designated condition. After completion of the WU, a 1-minute rest period (simulating normal game conditions) was given to allow each participant to get set to perform 5 maximal swings with a SB. Five, 1 × 4 (group × condition) repeated measures analysis of variance examined the aforementioned variables. There were no significant differences in MRV, RVBC, time difference between MRV and RVBC, and bat angle at MRV and RVBC between all WU conditions. If presented with the current options, athletes should choose the WU implement with which they are most comfortable using before an at-bat situation.

A Direct Swing Constraint-based Trajectory Planning Method for Underactuated Overhead Cranes

This paper proposes a novel swing constraint-based trajectory planning method for nonlinear overhead crane systems. To enhance the efficiency and security of the transportation process, some desired trajectories are designed to achieve the following merits: 1) leading the trolley to reach the destination sufficiently fast; 2) keeping the payload swing in an acceptable domain; 3) eliminating the residue swing when the trolley stops at the desired position. Specifically, the trajectories are divided into three stages. For each stage, the desired curve of the swing angle is directly constructed in accordance with anti-swing and zero-residual swing requirements, based on which the trolley trajectory is then obtained by analyzing the nonlinear kinematics of the crane system. An optimization mechanism is introduced to make intelligent compromises among the indices of transportation time, maximal swing angle, and so on. Both simulation and experimental results are provided to demonstrate the performance of the proposed direct swing constraint-based trajectory planning method.

The effect of femoral offset modification on gait after total hip arthroplasty

Background and purpose — A decrease of 15% in femoral offset (FO) has been reported to generate a weakness of the abductor muscle, but this has not been directly linked to an alteration of gait. Our hypothesis was that this 15% decrease in FO may also generate a clinically detectable alteration in the gait.Patients and methods — We performed a prospective comparative study on 28 patients who underwent total hip arthroplasty (THA) for unilateral primary osteoarthritis. The 3D hip anatomy was analyzed preoperatively and postoperatively. 3 groups were defined according to the alteration in FO following surgery: a minimum decrease of 15% (9 patients), restored (14), and a minimum increase of 15% (5). A gait analysis was performed at 1-year follow-up using an ambulatory device. Each limb was compared to the contralateral healthy limb.Results — In contrast to the “restored” group and the “increased” group, in the “decreased” group there was a statistically significant asymmetry between sides, with reduced range of motion and a lower maximal swing speed on the operated side.Interpretation — A decrease in FO of 15% or more after THA leads to an alteration in the gait. We recommend 3-D preoperative planning because the FO may be underestimated by up to 20% on radiographs and it may therefore not be restored, with clinical consequences.

Effect of Warm-up With Different Weighted Bats on Normal Baseball Bat Velocity

Traditionally, baseball players have used a heavy bat for warm-up before competition. Because bat velocity is an essential component to hitting a baseball, and because players warm up differently, there is a need to investigate the best way to maximize post warm-up bat velocity. The purpose of this study was to determine the effects of warm-up with different weighted bats on normal baseball bat velocity. Nineteen recreational male baseball players (age, 24.5 +/- 3.9 years; height, 181.1 +/- 8.4 cm; body mass, 87.9 +/- 18.4 kg) participated in this study. Three different randomized warm-up conditions were completed and analyzed for velocity and for their effect on post warm-up normal baseball bat velocity. Subjects were instructed to perform 5 maximal swings with each of 3 different weighted bats-light (LB = 9.6 oz), normal (NB = 31.5 oz), and heavy (HB = 55.2 oz)-followed by 30-second rest and then 5 swings of the NB. Analysis of variance revealed that warm-up velocity of the LB (63.57 +/- 3.58 mph) was significantly (p < 0.05) faster than that of NB (51.25 +/- 3.01 mph) and HB (41.79 +/- 3.01 mph), whereas warm-up velocity of NB was also significantly faster than that of HB. For post warm-up, LB (52.29 +/- 2.68 mph) and NB (50.60 +/- 3.04 mph) produced significantly faster velocity of the normal bat than the HB (48.26 +/- 2.98 mph). Warming up with 5 swings of a light or normal bat appears to increase post warm-up velocity of the normal bat when compared with warming up with a heavy bat after a rest period of 30 seconds. Within the bat weight spectrum of this study, it is suggested that when preparing to hit, 5 warm-up swings with either a light or normal bat will allow a player to achieve the greatest velocity of their normal bat.

Effect of Core Stabilization Training on Fitness, Swing Speed, and Weight Transfer in Older Male Golfers

1421 Previous research has shown that swing speed in golfers is improved by circuit weight training and flexibility programming. However, no research has investigated core stabilization training, common in many applied fitness settings, as a mode of training to improve golf performance. Additionally, although increasing age has been shown to decrease center of pressure transfer (i.e., weight transfer) during a golf swing, no research has investigated the effect of an exercise training program on center of pressure transfer variables. PURPOSE: To determine the effect of a core stabilization training program on fitness, swing speed and weight transfer in older male golfers. METHODS: Seventeen male golfers (mean ± SD, age: 70.7 ± 9.1 years, weight: 85.9 ± 8.8 kg) were randomly assigned to an Exercise (N = 11) or Control (N = 6) group. The Exercise group participated in an eight week progressive core stabilization training program including static and dynamic exercises utilizing mats, foam rollers, stability balls, elastic cables, and medicine balls. Subjects were required to attend 16 or more sessions during the eight weeks and averaged 22 ± 3 sessions. Pre and Post measurements included: Fitness measurements via the Fullerton Senior Fitness Test (Exercise Group Only), driver swing speed via radar, center of pressure transfer distance and center of pressure transfer velocity on the downswing via force plate. Group comparisons were made using One-Way ANCOVA with Pre-test measurements as covariates. Fitness measurements in the Exercise group were analyzed with Paired Samples T-Tests. RESULTS: Maximal swing speed increased in the Exercise group (127.3 ± 13.4 km • hr−1 hr to 133.6 ± 14.2 km • hr−1 hr) but not in the Control group (134.5 ± 14.6 km • hr−1 hr to 133.3 ± 11.2 km • hr−1 hr) (p< 0.05). Analysis of center of pressure transfer distance and velocity failed to detect differences between groups (p>0.05). Significant improvements (p<0.05) were detected for several Fullerton Senior Fitness Test components (2-minute march, 8-foot up and go test, arm curl, and back scratch test) but not for others (30-second chair stand, sit and reach test). CONCLUSIONS: This core stabilization program resulted in improvements in several components of fitness as well as swing speed improvements similar to previous studies utilizing circuit weight training. A lack of golf-specific power exercises during the majority of the training program may have contributed to the lack of improvement in weight transfer variables.

Development of the factors that have effects upon gaining ball speed in kicking motion

The purpose of this study is to investigate the development of factors that have effects upon gaining ball-speed in kicking motion under two different ball conditions: stationary and tee-up. Fifty one boys aged from 5 to 12 years, were filmed by the use of a high-speed camera operated at 64fps while they were kicking. Multiple regression analysis was applied to get interrelationship among ball speed, maximal swing speed, swing speed, ankle angles and knee angles at the impact. At each stage, from 5 to 12 years of age, the ball speed depended on the maximal swing speed as a whole, especially remarkable under 9 years of age. At the stage of 9 and 10 years of age, ball speed was supposed to depend upon other technical factors as well. At stage of 11 and 12 years of age, in addition to the maximal swing speed, other muscular factors might also be related to the ball speed.

Respiratory mechanics and timing during sleep in occlusive sleep apnea.

Six human obese subjects with the sleep apnea hypersomnolence syndrome associated with upper airway occlusion (UAO) were studied during sleep to characterize respiration. Measurements included the timing components of ventilation, pulmonary resistance, flow, and esophageal and gastric pressures before and during UAOs. During the period between UAOs, the resistance progressively increased (9.4-18.1 cmH2O/l(-1) . s, P less than 0.05) as the ventilation decreased (1.82-0.77 l/s, P less than 0.05), but without changes in esophageal pressure swings. During this period, inspiratory time-to-total cycle time decreased (0.42-0.25 s, P less than 0.05) due to expiratory phase prolongation. The apnea began after expiration and terminated on inspiration with the maximal swings in esophageal and gastric pressure near the termination. During the UAO, the respiratory cycle time decreased slightly, but the expiratory pause time was significantly shortened immediately before ventilation. We suggest that the UAO is but one aspect of this syndrome and that a decrease in central nervous system activity diminishes the respiratory drive before the onset of the UAO.