An eight-week golf-specific exercise program improves physical characteristics, swing mechanics, and golf performance in recreational golfers

The purpose of this study was to determine the effects of an 8-week golf-specific exercise program on physical characteristics, swing mechanics, and golf performance. Fifteen trained male golfers (47.2 +/- 11.4 years, 178.8 +/- 5.8 cm, 86.7 +/- 9.0 kg, and 12.1 +/- 6.4 U.S. Golf Association handicap) were recruited. Trained golfers was defined operationally as golfers who play a round of golf at least 2-3 times per week and practice at the driving range at least 2-3 times per week during the regular golf season. Subjects performed a golf-specific conditioning program 3-4 times per week for 8 weeks during the off-season in order to enhance physical characteristics. Pre- and posttraining testing of participants included assessments of strength (torso, shoulder, and hip), flexibility, balance, swing mechanics, and golf performance. Following training, torso rotational strength and hip abduction strength were improved significantly (p < 0.05). Torso, shoulder, and hip flexibility improved significantly in all flexibility measurements taken (p < 0.05). Balance was improved significantly in 3 of 12 measurements, with the remainder of the variables demonstrating a nonsignificant trend for improvement. The magnitude of upper-torso axial rotation was decreased at the acceleration (p = 0.015) and impact points (p =0.043), and the magnitude of pelvis axial rotation was decreased at the top (p = 0.031) and acceleration points (p = 0.036). Upper-torso axial rotational velocity was increased significantly at the acceleration point of the golf swing (p = 0.009). Subjects increased average club velocity (p = 0.001), ball velocity (p = 0.001), carry distance (p = 0.001), and total distance (p = 0.001). These results indicate that a golf-specific exercise program improves strength, flexibility, and balance in golfers. These improvements result in increased upper-torso axial rotational velocity, which results in increased club head velocity, ball velocity, and driving distance.     

Effects of physical conditioning on intercollegiate golfer performance

This investigation was conducted to determine the effects of a physical conditioning program on clubhead speed, consistency, and putting distance control in 10 men and 6 women National Collegiate Athletic Association Division I golfers. Supervised strength, power, and flexibility training was performed 3 times per week for 11 weeks. Performance tests were conducted before and after the training period. Significant (p < 0.05) increases were noted for all strength, power, and flexibility tests from pre- to posttraining of between 7.3 and 19.9%. Clubhead speed increased significantly (1.6%), equating to approximately a 4.9-m increase in driving distance. Putting distance control significantly improved for the men-only group (29.6%), whereas there was no significant difference in putting distance control for the total and women-only groups. Eleven weeks of golf-specific physical conditioning increased clubhead speed without a negative effect on consistency or putting distance control in intercollegiate men and women golfers.     

Effects of an 18-week strength training program on low-handicap golfers' performance

The purpose of this study was to determine the effects of an 18-week strength training program on variables related to low-handicap golfers' performance. Ten right-handed male golfers, reporting a handicap of 5 or less, were randomly divided into two groups: the control group (CG) (N = 5, age: 23.9 ± 6.7 years) and the treatment group (TG) (N = 5, age: 24.2 ± 5.4 years). CG players followed the standard physical conditioning program for golf, which was partially modified for the TG. The TG participated in an 18-week strength training program divided into three parts: maximal strength training including weightlifting exercises (2 days a week for 6 weeks), explosive strength training with combined weights and plyometric exercises (2 days a week for 6 weeks), and golf-specific strength training, including swings with a weighted club and accelerated swings with an acceleration tubing system (3 days a week for 6 weeks). Body mass, body fat, muscle mass, jumping ability, isometric grip strength, maximal strength (RM), ball speed, and golf club mean acceleration were measured on five separate occasions. The TG demonstrated significant increases (p < 0.05) in maximal and explosive strength after 6 weeks of training and in driving performance after 12 weeks. These improvements remained unaltered during the 6-week golf-specific training period and even during a 5-week detraining period. It may be concluded that an 18-week strength training program can improve maximal and explosive strength and these increases can be transferred to driving performance; however, golfers need time to transfer the gains.     

Influence of strength training on adult women's flexibility

The purpose of the current study was to investigate the effect of 10 weeks of strength training on the flexibility of sedentary middle-aged women. Twenty women were randomly assigned to either a strength training group (n = 10; age, 37 +/- 1.7 years; body mass, 65.2 +/- 10.7 kg; height, 157.7 +/- 10.8 cm; and body mass index, 25.72 +/- 3.3 kg x m(-2)) or a control group (n = 10; age, 36.9 +/- 1.2 years; body mass, 64.54 +/- 10.18 kg; height, 158.1 +/- 8.9 cm; and body mass index, 26.07 +/- 2.8 kg x m(-2)). The strength training program was a total body session performed in a circuit fashion and consisted of 7 exercises performed for 3 circuits of 8 to 12 repetitions maximum (RM), except for the abdominal exercise which was performed for 15 to 20 RM. Flexibility measurements were taken for 10 articulation movements pre and post training: shoulder flexion and extension, shoulder horizontal adduction and abduction, elbow flexion, hip flexion and extension, knee flexion, and trunk flexion and extension. Pre and post training, 10 RM strength significantly increased (p < 0.05). Of the movements examined, only shoulder horizontal adduction, hip flexion and extension, and trunk flexion and extension demonstrated significant increases (p < 0.05). Neither elbow nor knee flexion showed a significant change with weight training. The control group showed no significant change in any of the flexibility measures determined. In conclusion, weight training can increase flexibility in previously sedentary middle-aged women in some, but not all joint movements.     

Resistance training vs. static stretching: effects on flexibility and strength

Morton, SK, Whitehead, JR, Brinkert, RH, and Caine, DJ. Resistance training vs. static stretching: Effects on flexibility and strength. J Strength Cond Res 25(12): 3391-3398, 2011-The purpose of this study was to determine how full-range resistance training (RT) affected flexibility and strength compared to static stretching (SS) of the same muscle-joint complexes in untrained adults. Volunteers (n = 25) were randomized to an RT or SS training group. A group of inactive volunteers (n = 12) served as a convenience control group (CON). After pretesting hamstring extension, hip flexion and extension, shoulder extension flexibility, and peak torque of quadriceps and hamstring muscles, subjects completed 5-week SS or RT treatments in which the aim was to stretch or to strength train the same muscle-joint complexes over similar movements and ranges. Posttests of flexibility and strength were then conducted. There was no difference in hamstring flexibility, hip flexion, and hip extension improvement between RT and SS, but both were superior to CON values. There were no differences between groups on shoulder extension flexibility. The RT group was superior to the CON in knee extension peak torque, but there were no differences between groups on knee flexion peak torque. The results of this preliminary study suggest that carefully constructed full-range RT regimens can improve flexibility as well as the typical SS regimens employed in conditioning programs. Because of the potential practical significance of these results to strength and conditioning programs, further studies using true experimental designs, larger sample sizes, and longer training durations should be conducted with the aim of confirming or disproving these results.     

Functional training improves club head speed and functional fitness in older golfers

Functional training programs have been used in a variety of rehabilitation settings with documented success. Based on that success, the concept of functional training has gained popularity in applied fitness settings to enhance sport performance. However, there has been little or no research studying the efficacy of functional training programs on the improvement of sport performance or functional fitness. Thus, it was the purpose of this study to determine the effect of a progressive functional training program on club head speed and functional fitness in older male golfers. Eighteen male golfers (age: 70.7 +/- 9.1 [SD] years) were randomly assigned to an exercise (N = 11) or control (N = 7) group. The exercise group participated in an 8-week progressive functional training program including flexibility exercises, core stability exercises, balance exercises, and resistance exercises. Pre- and postmeasurements included club head speed of a driver by radar (exercise and Control) and Fullerton Senior Fitness Test measurements (exercise only). One-way analysis of covariance was performed on club head speed measurements using pretest measurements as the covariate. Paired t-tests were performed to analyze Senior Fitness Test variables. After the intervention, maximal club head speed increased in the exercise group (127.3 +/- 13.4 to 133.6 +/- 14.2 km x hr(-1)) compared with the control group (134.5 +/- 14.6 to 133.3 +/- 11.2 km x hr(-1); p < 0.05). Additionally, improvements (p < 0.05) were detected for most Senior Fitness Test variables in the exercise group. In summary, this functional training program resulted in significant improvements in club head speed and several components of functional fitness. Future research should continue to examine the effect of functional training programs on sport performance and functional fitness in older adults.     

Effect of torso rotational strength on angular hip, angular shoulder, and linear bat velocities of high school baseball players

This investigation examined the effect of torso rotational strength on angular hip (AHV), angular shoulder (ASV), linear bat-end (BEV), and hand velocities (HV) and 3 repetition maximum (RM) torso rotational and sequential hip-torso-arm rotational strength (medicine ball hitter's throw) in high school baseball players (age 15.4 +/- 1.2 y). Participants were randomly assigned to 1 of 2 training groups. Group 1 (n = 24) and group 2 (n = 25) both performed a stepwise periodized resistance exercise program and took 100 swings a day, 3 days a week, for 12 weeks with their normal game bat. Group 2 performed additional rotational and full-body medicine ball exercises 3 days a week for 12 weeks. A 3RM parallel squat and bench press were measured at 0 and after 4, 8, and 12 weeks. Participants were pre- and posttested for 3RM dominant and nondominant torso rotational strength and medicine ball hitter's throw. Angular hip velocities, ASV, BEV, and HV were recorded pre- and posttraining by a motion capture system that identified and digitally processed reflective markers attached to each participant's bat and body. Groups 1 and 2 increased (p < or = 0.05) BEV (3.6 and 6.4%), HV (2.6 and 3.6%), 3RM dominant (10.5 and 17.1%) and nondominant (10.2 and 18.3%) torso rotational strength, and medicine ball hitter's throw (3.0 and 10.6%) after 12 weeks. Group 2 increased AHV (6.8%) and ASV (8.8%). Group 2 showed greater improvements in BEV, AHV, ASV, 3RM dominant and nondominant torso rotational strength, and medicine ball hitter's throw than group 1. Groups 1 and 2 increased predicted 1RM parallel squat (29.7 and 26.7%) and bench press (17.2 and 16.7%) strength after 12 weeks. These data indicate that performing additional rotational medicine ball exercises 2 days a week for 12 weeks statistically improves baseball performance variables.     

The benefits of regular kinesiotherapy once a week for postmenopausal women: an aged-matched study

Regular exercise training improves overall physical fitness and quality of life in postmenopausal women. The exigent training frequency depends on a user-specified training aim. The aim of this study was to confirm the benefits of regular once a week exercise training for the maintenance of fitness in postmenopausal women. The test group included 20 postmenopausal women (65 +/- 3.1 years) who have been attending the exercise training program conducted by the physiotherapist once a week for three years. The age-matched control group included 20 healthy women (65.5 +/- 2.4 years) who did not regularly attend the training program. The outcomes were: right and left lateral trunk flexion, right and left shoulder flexion, right and left grip strength, endurance capacity of the trunk extensors, lower limb muscle strength (1' chair stand test), and balance (one-leg standing duration time with eyes open and closed). Women from the test group achieved statistically significant better results in the following outcomes: right lateral trunk flexion (15.4 cm: 12.6 cm, p < 0.001), left lateral trunk flexion (15.4 cm: 12.6 cm, p = 0.001), trunk extension muscle endurance (53.4 s: 40.5 s, p < 0.001), lower limb muscle strength (28.4 x: 25 x, p < 0.001), and one-leg standing duration time with open eyes (33.5 s: 19.7 s, p < 0.001). The results suggest that a regular once a week exercise training program designed and conducted by the physiotherapist, may be helpful in the improvement or maintenance of flexibility, muscle strength and capacity, and balance in postmenopausal women. The better fitness proved by our study could be a result of other causes and not solely that of the designed training program.     

Full-body exercise training improves fitness and quality of life in survivors of breast cancer

This study evaluated the safety and effectiveness of an 8-week full-body resistance and aerobic exercise program for 27 survivors of breast cancer (age, 57.7 +/- 7.2 years; years posttreatment, 0.8- 21.0) with prior upper-body conditioning. Physical fitness and quality-of-life (QOL) measures were obtained before and after the training period. Lymphedema, evaluated via arm volume measurement at baseline, was self-monitored throughout the trial. Sum of skinfolds, waist girth, and hip girth were significantly reduced posttraining (p < 0.01), although body weight did not change. Significant improvements (p < 0.01) were observed in upper-body strength (35.6 +/- 16.4%) and endurance (167.4 +/- 55.4%), lower-body strength (50.7 +/- 32.3%) and endurance (273.1 +/- 120.7%), Vo(2peak), trunk flexibility, and flexibility of the ipsilateral (surgical) and contralateral shoulder joint. Psychological QOL and overall QOL, evaluated via the World Health Organization Quality of Life Assessment Scale-Abbreviated Version. Inventory also improved significantly (p < 0.01). No incidents of lymphedema or injury were reported. These findings suggest that survivors of breast cancer can safely benefit from engaging in a full-body exercise regimen.     

Physical demands, injuries, and conditioning practices of stock car drivers

The purpose of this study was to assess the physical demands, injuries, and conditioning practices of stock car drivers. Forty stock car drivers from 27 states in the United States participated in the interviews for 43.9 ± 13.9 minutes. The interviews examined background information, the physical demands of racing, injuries associated with racing, and the athletic and fitness background and practices of the subjects. Numerical data were analyzed using Pearson's correlation coefficients. Responses to open-ended questions were analyzed using inductive content analysis. Results revealed significant correlation between track points standings and the length of the resistance training sessions (R = -0.71, p = 0.002) and subject self-assessment of their fitness (R = -0.53, p = 0.045). Results also revealed that "upper-body strength" was identified as the most important physical demand. Extreme fatigue was the most common feeling after a demanding race. Subjects reported that shoulder fatigue was the most common form of muscle soreness experienced after a race. Back and torso injuries were the most common injury, although head injuries most frequently required medical attention. The subjects' biggest fear was fire, followed closely by head and neck injury. The bench press and running were the most commonly performed resistance training and cardiovascular exercises, respectively. Subjects reported that their highest motivation for training was to improve their racing performance. Many subjects had athletic backgrounds with football identified as the sport they had most commonly participated in. This study provides additional detailed information. Results of this study can assist strength and conditioning professionals in the development of strength and conditioning programs for performance enhancement and injury prevention that are specific to the needs of this population of athletes.     

Physiological and performance characteristics of adolescent club volleyball players

The objective of this investigation was to examine the physical and performance characteristics of adolescent club volleyball players. Twenty-nine adolescent girls, aged 12 to 17 years (14.31 +/- 1.37) were participants in this investigation. All athletes were members of a competitive volleyball club. The following group values were obtained: height (HT) = 1.69 +/- 0.08 m, weight (WT) = 59.6 +/- 8.2 kg, body fat percentage (BF%) = 20.9 +/- 4.5, lean body mass (LBM) = 46.7 +/- 4.9 kg, modified sit-and-reach (MSR) = 38.7 +/- 7.1 cm, shoulder rotation (SR) = 29.4 +/- 5.6 cm, isometric hand grip (IHG) = 34.5 +/- 5.5 kg, isometric leg strength (ILS) = 77.4 +/- 18.1 kg, vertical jump (VJ) = 35.5 +/- 6.2 cm, standing broad jump (SBJ) =178.8 +/- 20.3 cm, 1-minute sit-ups (SU) = 47.0 +/- 6.7, T-test (TT) = 11.2 +/- 0.8 seconds., shuttle test (SHT) = 9.7 +/- 0.4 seconds, stork stand (SS) = 8.1 +/- 4.1 seconds, serving velocity (SVV) =16.1 +/- 4.5 m.s(-1), and spiking velocity (SKV) = 16.9 +/- 2.4 m.s(-1). For purposes of analysis, players were divided into 2 age groups: 12 to 14 years (group A) and 15 to 17 years (group B). Significant differences (p < 0.05) were found between age groups for the following values: HT, WT, LBM, IHG, ILS, SBJ, and SVV. Values for group B were greater for each variable. Significant correlations include age and IHG (r = 0.75), age and ILS (r = 0.51), age and SBJ (r = 0.67), age and SVV (r = 0.71), LBM and IHG (r = 0.90), LBM and ILS (r = 0.62), LBM and SVV (r = 0.58), SVV and IHG (r = 0.60), and SKV and SS (r = 0.60). Our results suggest that age, experience, LBM, shoulder, hip, and thigh girths, strength, and balance are key physical performance characteristics of adolescent girls who play volleyball. Potentially, this type of information will allow coaches and athletes to identify physical and performance data specific to age groups for purposes of evaluation and player development.     

Effects of strength training on muscle strength characteristics, functional capabilities, and balance in middle-aged and older women

Progressive strength training can lead to substantial increases in maximal strength and mass of trained muscles, even in older women and men, but little information is available about the effects of strength training on functional capabilities and balance. Thus, the effects of 21 weeks of heavy resistance training--including lower loads performed with high movement velocities--twice a week on isometric maximal force (ISOmax) and force-time curve (force produced in 500 milliseconds, F0-500) and dynamic 1 repetition maximum (1RM) strength of the leg extensors, 10-m walking time (10WALK) and dynamic balance test (DYN.D) were investigated in 26 middle-aged (MI; 52.8 +/- 2.4 years) and 22 older women (O; 63.8 +/- 3.8 years). 1RM, ISOmax, and F0-500 increased significantly in MI by 28 +/- 10%, 20 +/- 19%, 31 +/- 34%, and in O by 27 +/- 8%, 20 +/- 16%, 18 +/- 45%, respectively. 10WALK (MI and O, p < 0.001) shortened and DYN.D improved (MI and O, p < 0.001). The present strength-training protocol led to large increases in maximal and explosive strength characteristics of leg extensors and in walking speed, as well to an improvement in the present dynamic balance test performance in both age groups. Although training-induced increase in explosive strength is an important factor for aging women, there are other factors that contribute to improvements in dynamic balance capacity. This study indicates that total body heavy resistance training, including explosive dynamic training, may be applied in rehabilitation or preventive exercise protocols in aging women to improve dynamic balance capabilities.     

Changes in fitness and shipboard task performance following circuit weight training programs featuring continuous or interval running

Pre- and post-physiological data were collected on 57 Navy men (mean age = 19.5 years) who participated in either circuit weight training/continuous run (CWT/CR) (N = 31) or circuit weight training/interval run (CWT/IR) (N = 26) programs. Measured variables included 4 measures of upper torso dynamic strength (one repetition maximum [1 RM] for arm curl, bench press, shoulder press, and lat pull-down); two measures of lower torso dynamic strength (1 RM) for knee extension and leg press); one measure of power (number of revolutions completed on an arm ergometer (Monark) at maximum drag); three measures of muscular endurance (number of repetitions at 60% 1 RM for bench press and leg press and maximal number of bent-knee sit-ups in 120 s); one stamina measure (time to exhaustion on a cycle ergometer (Monark) maximal work capacity [MWC] test; and three simulated shipboard tasks: manikin shoulder drag, open/secure a water tight door and paint bucket carry. Composite shipboard performance derived from the summed time (s) required to complete the three tasks was also calculated. Results show performance on the manikin shoulder drag and majority of evaluative fitness measures was significantly (p less than 0.05) enhanced following both circuit weight training/run formats. Significantly (p less than 0.05) higher values for shoulder press (F = 7.2), arm ergometer (F = 5.3), and sit-ups (F = 6.8) and lower values for leg press muscular endurance (F = 5.1) were observed in CWT/IR when compared to CWT/CR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spatial, temporal and muscle action patterns of Tai Chi gait.

This study was to quantitatively characterize the spatial, temporal, and neuromuscular activation patterns of Tai Chi gait (TCG). Ten healthy young subjects were tested. The kinematics of TCG and normal gait (NG) were measured using a marker-based motion analysis system and two biomechanical force plates. Surface electromyography (EMG) was recorded from six left-side muscles: tibialis anterior, soleus, peronaeus longus, rectus femoris, semitendinosus, and tensor fasciae latae. The results showed that TCG had (1) a longer cycle duration (11.9+/-2.4 vs. 1.3+/-0.2 s) and a longer duration of single-leg stance time (1.8+/-0.6 vs. 0.4+/-0.05 s); (2) a larger joint motion in ankle dorsi/plantar flexion (40+/-9 degrees vs. 20+/-8 degrees), knee flexion (82+/-8 degrees vs. 53+/-10 degrees), hip flexion (81+/-7 degrees vs. 24+/-4 degrees), and hip abduction (20+/-8 degrees vs. 0+/-3 degrees); (3) a larger lateral body shift (>25% vs. 5% body height); and (4) significant involvement of ankle dorsiflexors, knee extensors/hip flexors and hip abductors, as indicated by significantly higher peak (88+/-14%, 80+/-18% and 83+/-17% vs. 35+/-10%, 14+/-8% and 28+/-19% peak amplitude, respectively) and root-mean-square values of their EMG (37+/-6%, 32+/-7% and 33+/-7% vs. 23+/-7%, 11+/-8% and 22+/-11% peak amplitude, respectively), longer proportions of action (76+/-19%, 68+/-8% and 65+/-19% vs. 59+/-23%, 16+/-23% and 40+/-32% gait cycle duration, respectively), longer proportions of isometric and eccentric actions, and longer proportions of co-activations. These results demonstrate that the biomechanical characteristics of TCG can be quantified. The quantification of TCC movements is important for understanding its effect on balance, flexibility, strength, and health.     

Resistance training and detraining effects on flexibility performance in the elderly are intensity-dependent

The present investigation attempted to determine whether resistance exercise intensity affects flexibility and strength performance in the elderly following a 6-month resistance training and detraining period. Fifty-eight healthy, inactive older men (65- 78 yrs) were randomly assigned to 1 of 4 groups: a control group (C, n = 10), a low-intensity resistance training group (LI, n = 14, 40% of 1 repetition maximum [1RM]), a moderate-intensity resistance training group (MI, n = 12, 60% of 1RM), or a high-intensity resistance training group (HI, n = 14, 80% of 1RM). Subjects in exercise groups followed a 3 days per week, whole-body (10 exercises, 3 sets per exercise) protocol for 24 weeks. Training was immediately followed by a 24-week detraining period. Strength (bench and leg press 1RM) and range of motion in trunk, elbow, knee, shoulder, and hip joints were measured at baseline and during training and detraining. Resistance training increased upper- (34% in LI, 48% in MI, and 75% in HI) and lower-body strength (38% in LI, 53% in MI, and 63% in HI) in an intensity-dependent manner. Flexibility demonstrated an intensity-dependent enhancement (3-12% in LI, 6-22% in MI, and 8-28% in HI). Detraining caused significant losses in strength (70-98% in LI, 44-50% in MI, and 27-29% in HI) and flexibility (90-110% in LI, 30-71% in MI, and 23-51% in HI) in an intensity-dependent manner. Results indicate that resistance training by itself improves flexibility in the aged. However, intensities greater than 60% of 1RM are more effective in producing flexibility gains, and strength improvement with resistance training is also intensity-dependent. Detraining seems to reverse training strength and flexibility gains in the elderly in an intensity-dependent manner.     

Fitness levels of firefighter recruits before and after a supervised exercise training program

Federal law prohibits pre-employment physical examination of firefighter recruits, but these workers must perform intense exercise in arduous environments. Components of physical fitness of rookie firefighters (n = 115; 104 men, mean +/- SD: age = 28.3 +/- 4.3 years; height = 1.76 +/- 0.07 m; weight = 83.2 +/- 13.9 kg; percent body fat = 17 +/- 8%) were measured upon being hired and following a 16-week exercise training program (1 h.d(-1), 3 d.wk(-1)) designed to improve physical fitness. Maximum aerobic capacity (VO2max) was estimated from submaximal cycle ergometry, body composition from skinfold tests, flexibility from a sit and reach test, strength by hand grip dynamometry, and muscle endurance by a push-up test. The results are as follows (*, p 相似文献   

Influence of moderately intense strength training on flexibility in sedentary young women

The present study is the first to examine whether moderately intense resistance training improves flexibility in an exclusively young, sedentary women population. Twenty-four, young, sedentary women were divided into 3 groups as follows: agonist/antagonist (AA) training group, alternated strength training (AST) group, or a control group (CG). Training occurred every other day for 8 weeks for a total of 24 sessions. Training groups performed 3 sets of 10 to 12 repetitions per set except for abdominal training where 3 sets of 15 to 20 reps were performed. Strength (1 repetition maximum bench press) and flexibility were assessed before and after the training period. Flexibility was assessed on 6 articular movements: shoulder flexion and extension, horizontal shoulder adduction and abduction, and trunk flexion and extension. Both groups increased strength and flexibility significantly from baseline and significantly when compared with the CG (p ≤ 0.05). The AST group increased strength and flexibility significantly more than the AA group (p ≤ 0.05) in all but one measurement. This study shows that resistance training can improve flexibility in young sedentary women in 8 weeks.     

Effect of adding plyometric training to physical education sessions on specific biomechanical parameters in primary school girls

Objectives:The study aimed to determine the effect of adding a school-based plyometric training program (PMT) to physical education (PE) sessions on the strength, balance, and flexibility in primary school girls.Methods:Students from grades 3-6 were randomized equally to a plyometric or control group. In the control group, students took their regular PE classes twice a week. In the plyometric group, students performed PMT twice a week during the initial 20 minutes of every PE session. The Lido Linea closed kinetic chain isokinetic dynamometer, Star excursion balance test (SEBT), and sit-and-reach test were used to assess muscle strength, balance, and flexibility, respectively, before and after nine weeks of training.Results:The improvement in extension peak force (p=0.04) and extension total work (p<0.001) was more prevalent in the PMT group than in the control group. SEBT scores had improved significantly (p<0.05) for all directions in the PMT group, except in the anterior direction, which was highly significant (p<0.001). Hamstring and lower back flexibility had improved more in the PMT group than in the control group (p<0.001).Conclusion:Adding PMT to regular PE classes has a positive and notable effect on muscle strength, balance, and flexibility in primary school students.     

A kinetic and electromyographic comparison of the standing cable press and bench press

This study compared the standing cable press (SCP) and the traditional bench press (BP) to better understand the biomechanical limitations of pushing from a standing position together with the activation amplitudes of trunk and shoulder muscles. A static biomechanical model (4D Watbak) was used to assess the forces that can be pushed with 2 arms in a standing position. Then, 14 recreationally trained men performed 1 repetition maximum (1RM) BP and 1RM single-arm SP exercises while superficial electromyography (EMG) of various shoulder and torso muscles was measured. The 1RM BP performance resulted in an average load (74.2 +/- 17.6 kg) significantly higher than 1RM single-arm SP (26.0 +/- 4.4 kg). In addition, the model predicted that pushing forces from a standing position under ideal mechanical conditions are limited to 40.8% of the subject's body weight. For the 1RM BP, anterior deltoid and pectoralis major were more activated than most of the trunk muscles. In contrast, for the 1RM single-arm SP, the left internal oblique and left latissimus dorsi activities were similar to those of the anterior deltoid and pectoralis major. The EMG amplitudes of pectoralis major and the erector muscles were larger for 1RM BP. Conversely, the activation levels of left abdominal muscles and left latissimus dorsi were higher for 1RM right-arm SP. The BP emphasizes the activation of the shoulder and chest muscles and challenges the capability to develop great shoulder torques. The SCP performance also relies on the strength of shoulder and chest musculature; however, it is whole-body stability and equilibrium together with joint stability that present the major limitation in force generation. Our EMG findings show that SCP performance is limited by the activation and neuromuscular coordination of torso muscles, not maximal muscle activation of the chest and shoulder muscles. This has implications for the utility of these exercise approaches to achieve different training goals.     

A comparison of lower-body flexibility, strength, and knee stability between karate athletes and active controls

The purposes of this study were to compare the lower-body flexibility, strength, and knee stability of karate athletes against that of non-karate controls and to determine whether regular karate training results in adaptations that may result in an increased risk for knee injury. Flexibility measurements included knee flexion and extension, hip flexion and extension, hip internal and external rotation, and foot inversion and eversion. Nine karate athletes (4 women and 5 men, age = 24.3 +/- 6.7 years) and 15 active, non-karate controls (7 women and 8 men, age = 22.1 +/- 3.2 years) participated. No subjects reported recent knee surgery or chronic or acute knee pain. Concentric quadriceps and hamstrings strength and endurance were measured using a Biodex II isokinetic dynamometer at 60 degrees .s(-1) and 180 degrees .s(-1). Eccentric strength was measured at 150 degrees .s(-1) and 250 ft-lb (339 N.m). Knee stability was measured via varus and valgus stress and anterior drawer testing. Karate athletes demonstrated a significantly greater right hip flexion (p 相似文献