Literacy review
The topic that this literacy review is looking into is based on my research project on lower body flexibility the affect it has on speed of young female athletes. The athletes will play either football or rugby at participation or performance level and aged between 16-19. This literacy review will include 10 pieces of research, 5 abstracts and 5 other sources. I will be reviewing previous research in order to gain an idea of the results I am looking to achieve in my own project and whether there have been any significant results previously. It will also enable me to look at the methods used and may be used as support in my final conclusions. Each abstract or other source will be related to my project aim by relating to one or more of the following; the population: females aged between 16-19; the measure: flexibility; the variable: sprinting speed
Chandler et al. (1990) studied the difference flexibility of junior elite tennis players compared to other athletes. They conducted the research by obtaining measurements from tests that included a sit and reach flexibility, quadricep flexibility, hamstring flexibility, gastrocnemius flexibility, shoulder internal rotation, and shoulder external rotation. Their population was 86 junior elite tennis players and 139 athletes who were involved in other sports. Chandler et al. found that the flexibility differences in tennis players suggest adaptations to the musculoskeletal demands of their sport. The method used by Chandler et al. will support the research design of my project as it looked at a range of lower body flexibility as well as younger athletes which are both specific to my research.
Bauman et al. (1991) studied preseason strength and flexibility imbalances that have been associated with athletic injuries, in female college athletes. They conducted their research by administering preseason strength and flexibility tests and monitored for any injuries obtained during their sports seasons. Strength was measured as the maximal isokinetic rotation of the right and left knee flexors and knee extensors and flexibility was measured by the range of motion of several lower body joints. The population for this research was 138 female college athletes, participating in eight weight bearing sports. They found that athletes experienced more lower extremity injuries if they had: a right knee flexor 15% stronger than the left knee flexor at; a right hip extensor 15% more flexible than the left hip extensor; or a knee flexor/knee extensor ratio of less than 0.75 at 180 deg/sec. The research by Bauman et al. has indicated that when I compare lower body flexibility to speed I will need to take into account the differences between the left and right side; and bear in mind whether the athlete is left-side or right-side dominant.
Leite et al. (2014) researched into the influence of strength and flexibility training, combined or isolated, on strength and flexibility gains. The research was conducted by dividing the participants into four equal groups; strength training, flexibility training, combination of strength and flexibility, and combination of flexibility and strength. All groups were assessed before and after training for the Sit-and-Reach test, goniometry, and ten rep max (10RM) in both bench press and leg press exercises. Each group had a training programme which included training sessions on alternate days and was made up of eight exercises which were performed at different intensities. The flexibility training consisted of dynamic stretching which lasted for 60 minutes. The research was conducted on 28 trained, middle aged women. The results showed significant strength gains in all groups in the leg press exercise. All groups except the flexibility improved in bench press strength, and there was found to be no significant differences in flexibility with in any group, in any of the comparisons. The method used by Leite et al. will inform my research design as I should take into account, what positions they play within their chosen sport and whether they need flexibility or strength.
Bruce et al. (2004) Conducted research in order to see if there was an effect of static stretching in a warm-up on hip flexor and quadriceps flexibility and foot speed at impact in kicking a football with maximum effort. They used 16 Australian Rules Football players in their research, who each performed two different warm-ups on different days. The first warm-up involved five minutes of sub-maximum running and seven practice kicks, the second also included four and a half minutes of static stretching of the hip flexors and quadriceps after the running. A modified Thomas test was conducted before and after each warm-up, and then players were videotaped to determine the ROM of the kicking leg and foot speed at impact with the ball. Bruce et al concluded that stretching had no influence on kicking ROM or foot speed. They based this on the complexity of the kicking skill; flexibility had no effect as well as the Thomas test not being sensitive enough. The conclusion found by Bruce et al will inform my research that I need to ensure that the tests I conduct are accurate and sensitive enough in order for me to gain reliable and valid results. The method also has informed me that all participants will need to take part in the same warm up and stretching. I will also need to conduct my flexibility tests either all before or all after exercise.
Ramiz (2008) want to see the affect that lower-limb massage had after a warm up. He conducted research in order to study the acute effects of pre- performance lower limb massage after warm-up on explosive and high-speed motor capacities and flexibility. Each participant was assigned each a massage, stretching and rest in a randomized order. Before and after each of these the participants was asked to complete a 10 meter acceleration, a flying start 20 meter sprint, a 30 meter sprint from standing position, a leg reaction time, a vertical jump and sit & reach test. There were 24 participants involved in the study, all male of Caucasian ethnicity. Results indicated that after stretching and massaging there was significant improvement in the sit-and-reach test, however had a negative effect on speed. The method used by Ramiz will inform my research design as it contains tests I am looking to use and has achieve significant results using these.
Sifferlin (2013) has written an article on why stretching may not help before exercise. The article looked into and explains that static stretching before exercise doesn’t prevent injuries, and can impair strength and speed in some athletes. The writer of the article has found various research that support her theory including research conducted by University of Zagreb. This study reviews 104 studies of people who only practiced static stretching as their warm-up and found that stretching reduced muscle strength by 5.5%. This article by Sifferlin indicates that flexibility may decrease their speed.
O’Donovan (2009) has written an article about stretching. I am interested in the section based on the effects of stretching before exercise and flexibility training on endurance performance. There were results that found static stretching did not significantly reduce endurance performance. This was based on a study of 11 students who were physically active. It did however reduce running economy and endurance performance in a study of 10 trained distance runners. Another study of 34 international-standard distance runners found that the least flexible runners were also the most economical.
Geriatr et al. (2004) has written an article based on vibration training. The athletes were split between a vibration group 13 athletes who trained three times a week for eight weeks and a control group of 11 athletes. At the end of this time they were tested on: countermovement jump, leg extension strength, horizontal leg press, and flexibility. The researchers discovered that the vibration group displayed a significant improvement in leg extension strength, countermovement jump performance and flexibility.
Conclusions
There were similarities across selected articles that mainly agree that if flexibility is improved, speed is decreased. A lot of these articles used a sit and reach test; this is beneficial as this is one of the test I plan to carry out and therefore will be able to compare my research to this.
There were many differences across the articles and this makes them hard to compare them against each other. Some studies were carried out over a few weeks whereas others were longitudinal and based over a longer amount of time. The types of sports that the athletes competed in were also different, this means that they athletes require different aspects in their training and there body types; I can’t compare a tennis play to a weight lifter because they are training for different goal. Another aspect which varied across the groups is their size. There were also different ethnic groups in the various studies which makes it hard to rule out cultural differences.
One of the weaknesses of many of the sources was that they only linked to one of my criteria whether this is the population, variables or measurement. They are not specific enough to the research that I want to carry out of and therefore affect the amount that I can use these when backing up my own research. It was hard to find the specific participation/performance level for my chosen sports and therefore I will need to bear this in mind when relating back to this research.
Another weakness is that the sources didn’t always use sensitive enough tests, therefore any significances that were minute may not have been picked up on.
After completing my literature review I found that I need to look more carefully at what I’m measuring and how outside factors will affect my results. I need to make sure that I take into consideration that all my results may be affected by the different positions that my athletes play in their chosen sports. This is because difference positions require different aspects within the sport. My research has shown that athletes that require more strength rather than speed will be less flexible and I will need to consider this when I gather participants as I will need a fair range of positions from the two sports. I need to consider whether I am doing the lower body flexibility of both legs or just the dominant leg and how I am going to define this. I will need to ensure that all the participants warm up and stretch, if this is required, in the same manner. After conducting the research I understand that my project doesn’t require a control group as I am not testing the athletes over time but based on how they are in the present.
A key question that I need to look into more is why when flexibility is increase; stability may decrease as I feel it will be important to my research.
Before conducting this research I thought that the more lower body flexibility a person had the faster they would be however, after researching into this further my hypothesis is that the more flexible a person the slower they will be.
Bauman et al. (1991) Pre-season strength and flexibility imbalances associated with athletic injuries in female collegiate athletes, The American Journal of Sports Medicine, 19 (1) pp. 76-81
Bruce et al. (2004) Acute effects of static stretching on hip flexor and quadriceps flexibility, range of motion and foot speed in kicking a football, Journal of science and medicine in sport, 7 (1) pp. 23-31
Chandler et al. (1990) Flexibility comparisons of junior elite tennis players to other athletes, The American Journal of Sports Medicine, 18 (2) pp. 134-136
Geriatr et al. (2004) Potentiation and vibration training [online] available at <http://www.pponline.co.uk/encyc/vibration-training-to-enhance-speed-power-and-flexibility-39279> [Accessed 15th February 2015]
Leite et al. (2014) Influence of strength and flexibility training, combined or isolated, on strength and flexibility gains, Journal of Strength & Conditioning Research
O’Donovan (2009) Stretching and endurance performance [online] available at<http://www.pponline.co.uk/encyc/warming-up-the-latest-research-into-stretching-42328> [Accessed 10th February 2015]
Ramiz (2008) Acute Effects of Pre-Event Lower Limb Massage on Explosive and High Speed Motor Capacities and Flexibility, Journal of sport science and medicine, 7 (4) pp. 549–555.
Sifferlin (2013) Why Stretching May Not Help Before Exercise [online] available at<http://healthland.time.com/2013/04/08/why-stretching-may-not-help-before-exercise/> [Accessed 10th February 2015]
Worthing College Sport and Exercise Science 