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Post by tomd on Sept 15, 2005 13:26:28 GMT 1
You shouldn't stretch the shoulder prior to throwing in a competition:
Noffal, G. J., Knudson, D., & Brown, L. (2004). Effects of stretching the upper limb on throwing speed and isokinetic shoulder torques. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 937.
This study determined the effects of static stretching of upper limb muscles on overarm throwing speed and isokinetic torque of shoulder internal rotators at two velocities (3.14 and 5.24 rad/s). Ss (N = 40) were randomly assigned into control and stretching groups. The experimental protocol consisted of two test sessions scheduled a week apart. Ss in the experimental group performed static stretching (S) exercises with their dominant limb in one session and no stretching (NS) in the other. Ss in the control group did not stretch in either of their two sessions. Following warm-up and S or NS, Ss were tested for throwing speed and concentric isokinetic torque of the shoulder internal rotation musculature at two velocities. Throwing speed was measured with a radar gun and shoulder internal rotation torques were measured with an isokinetic dynamometer. Speed and torque were compared.
Significant interactions were found for throwing speed and isokinetic torque at 3.14 rad/s (but not for isokinetic torque at 5.24 rad/s). Stretching reduced throwing velocity and shoulder isokinetic torque at the slower isokinetic speed.
Implication. Static stretching of the arm before a high speed movement, such as throwing, reduces subsequent throwing velocity. Stretching should not be part of a throwing or pitching warm-up.
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Post by tomd on Sept 15, 2005 13:27:32 GMT 1
And another:
Fry, A. C., McLellan, E., Weiss, L. W., & Rosato, F. D. (2003). The effects of static stretching on power and velocity during the bench press exercise. Medicine and Science in Sports and Exercise, 35(5), Supplement abstract 1460.
High school athletes (N = 40) were tested for bench press 1 RM at one session. In two other sessions, a general and exercise-specific warm-up, and a maximum velocity bench press at 85% 1 RM were performed. Static stretching was randomly implemented immediately before the tested lift in either session 2 or 3.
Static stretching significantly impaired bench press mean power and mean velocity.
Implication. Static stretching in close proximity to maximum power and strength activities has a detrimental effect on performance.
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Post by Jim on Sept 15, 2005 13:57:01 GMT 1
Very interesting that, i'd read a similar study on the effect of static stretching before sprinting and the results were the same.
There has been a big move in the past few years away from static stretching and these studies seem to confirm that theory, however, shouldn't static streatching still be a part of our training to maintain and improve flexability?
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Post by Administrator on Sept 15, 2005 14:28:40 GMT 1
Static stretching certainly has its role but only ast the right times. Like these studeis prove, it is not effective to perform static stretches prior to powerful and explosive movements but static stretching as part of a planned routine helps to maintain muscles, reduce muscle soreness and of course increase/maintain flexibility. Stretching after a weights session is advisable to reduce delayed muscle soreness and finding a time outside of throwing training to stretch the body is also beneficial. Remember to always make sure the muscles are ready to be stretched though!
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Post by slinger on Sept 15, 2005 14:41:25 GMT 1
i also read something similar to this tom, but i think it was about baseball pitchers, i suppose it's right because at the end of the day when performing explosive movements, lifting, jumping, sprinting, throwing etc you want a degree of tension in the muscle so cotractions can be made and if one was to stretch like crazy then they would lose that desired tension. i can remember a few years ago i went to see janine midgley for a phsio session and apparently my legs were very tight so she did a load of pnf stretching. the plan was to go and see mike morley for a throwing session after the phsio session and to say i threw like a tosser is an understatement!!! my muscles were that loose in my legs i couldn't feel a thing!!! and maybe that's the problem with a lot of athletes that they are TOO flexible!!! for example my shoulder and chest flexibilty is rubbish - yet i can still get into a decent jav position. my way of thinking is if you can get into the desired throwing positions then why try to become even more flexible, surely you could be doing more beneficial things with your time. as for static stretching, i think that stretch reflex actions are far more important for example firing a medi ball against a wall, catching it letting the muscle stretch, tense, and firing it back is far more beneficial, as it's more specific to javelin throwing. as a rule though i would always do abit of static stretching to warm up, and i'm sure every single athlete on here does too. interesting subject though tom and well put i'd even say you worded it better than parker words his pieces and thats saying sommat!
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Post by tomd on Sept 15, 2005 16:25:00 GMT 1
A counter to the theory that stretching reduces post exercise soreness:
Herbert, R. D., & Gabriel, M. (2002). Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. British Journal of Sports Medicine, 325, 468-470.
"The results of five studies . . . imply that stretching reduces soreness in the 72 hours after exercising by, on average, less than 2 mm on a 100 mm scale. Most athletes will consider effects of this magnitude too small to make stretching to prevent later muscle soreness worth while" (p. 470). "The pooled estimate from two studies was that stretching decreased the risk of injury by 5%. This effect was statistically non-significant. . . On average, about 100 people stretch for 12 weeks to prevent one injury and (if the hazard reduction was constant) the average subject would need to stretch for 23 years to prevent one injury" (p. 470). Implication. Stretching does not do what it is supposed to do. It does not protect against post-exercise muscle soreness nor does it provide practical reduction in the risk of injury.
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Post by tomd on Sept 15, 2005 16:26:06 GMT 1
One on more effective stretching (better than static/ballistic stretching) for improving flexibility:
FLEXIBILITY Wallin, D., Bjorn, E., Grahan, R. & Nordenborg, T. (1985). Improvement of muscle flexibility: A comparison between two techniques. The American Journal of Sports Medicine, 13, 263-268.
Males (N = 47) were formed into four groups. All groups trained three times per week using a modified contract-relax (CR) method or ballistic stretching. After 30 days, one of the CR groups (N = 10) trained once a week, another (N = 10) three times a week, and the third group (N = 10) five times a week. The fourth group (N = 17) trained with traditional ballistic stretching. After 30 days (14 training sessions), the ballistic group switched to the contract-relax method. Retests were performed after 60 days since commencement. Once a week contract-relax stretching was enough to maintain flexibility. Training three to five times per week was necessary to increase flexibility. Ballistic stretching improved flexibility, but not as effectively as the contract-relax method. When the ballistic group switched to contract-relax, flexibility improved further and that group caught up to the others who had only been performing contract-relax activities. Implication. Contract-relax (PNF) stretching is more effective for increasing flexibility than is ballistic stretching. Only one PNF session per week is needed to maintain flexibility.
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Post by tomd on Sept 15, 2005 16:29:14 GMT 1
And another interesting bit, although on running eceonomy, some useful information on baseball throwing and trunk flexibility. There is also the caveat on being too inflexible (ie excessive tightness):
PROBLEMS WITH STRETCHING MYTHS AND THEORY
Wilkinson, M., & Williams, A. (2003). Too much of a good thing? Why increased joint flexibility may damage your distance performance. Peak Performance, 175, 5-6.
This is a well presented review article that looks at the research covering stretching and its effect on running economy. A number of statements concerning beliefs and theories regarding flexibility are made.
"There is little evidence to support the claim that non-pathological [naturally endowed] muscle tightness reduces running economy, so impairing performance" (p. 5). "There is a growing body of evidence to suggest . . . that a lack of flexibility in certain areas of the body may be linked with increased running economy. And it is interesting to note that studies of competitive distance runners have shown them to be less flexible than non-runners" (p. 5) Decreased flexibility in the trunk and hip prevented trunk rotation and hip turn-out while running, both restrictions improving running economy. Decreased flexibility in the ankle (tightness in the calf and soleus muscles), and the lower back/hamstrings were associated with better running economy. One explanation why a lack of flexibility actually increases running performance is that it reduces energy expenditure by enhancing elastic energy storage and return in the Achilles tendon and calf muscles.
"Previous work has suggested that elastic recoil of muscle and tendons can contribute 25-40% of the energy necessary for subsequent movements in a maximally stretched muscle [Cavagna,G. A., Saibene, F. P., & Margaria, R. (1964). Mechanical work in running. Journal of Applied Physiology, 19, 249-256; Cavagna, G. A., & Margaria, R. (1966). Mechanics of walking. Journal of Applied Physiology, 21, 271-278.] (p. 6). "It is reasonable to suggest that inflexibility around the ankle joint would result in a greater relative stretch of the tight muscles and tendons, storing more elastic energy for subsequent recoil and reducing the active work of the muscles" (p. 6). "Musculoskeletal tightness can also explain the beneficial effects of limited hip/trunk flexibility . . . Limited external hip rotation could enhance running economy by stabilizing the pelvic region at the time of foot impact. Since running occurs primarily in a forward direction, rotational motion is potentially energy-wasting as it does not contribute to forward movement" (p. 6) [Thus, actions in baseball that are aligned to produce forward momentum on a ball do not need to have above-natural flexibility. So exercises that stretch abdominal muscles laterally and forward and backward would only serve to reduce the elastic energy potential of a segmented action because other muscular contributions would be required to halt the "softened musculature" from moving.] "There is a cut-off point where inflexibility ceases to be tightness within a normal range of motion and becomes excessive to the point of increasing injury risk. Clinically, excessive muscle tightness is believed to be an important cause of such injuries as muscle strains and inflammation of tendons" (p. 6) Implication. ". . . while general stretching, designed to maintain existing levels of flexibility and muscle function, should remain an important aspect of every runner's warm-up and cool-down routines, improving flexibility beyond levels normal [natural] for runners is likely to impair rather than improve performance" (p. 6)
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Post by tomd on Sept 15, 2005 16:31:23 GMT 1
And one that may help to explain Slingers problems when he was felt up by the physio and couldn't run properly (although directed more to running economy and joggers it has a useful application for us Gods of the athletic world):
Craib, M. W., Mitchell, V. A., Fields, K. B., Cooper, T. R., Hopewell, R., & Morgan, D. W. (1996). The association between flexibility and running economy in sub-elite male distance runners. Medicine and Science in Sports and Exercise, 28, 737-743.
The purpose of this study was to examine the association between nine measures of limb and trunk flexibility and running economy. Within a week before running economy assessment, and after 10 min of jogging at 3.13 m/sec, trained male sub-elite distance runners (N = 19) underwent two complete sets of lower limb and trunk flexibility assessments. Ss then completed two 10-minute running economy assessment sessions on consecutive days at 4.13 m/sec following two 30-minute sessions of treadmill accommodation at 4.13 m/sec.
Dorsiflexion (r = 0.65) and standing hip rotation (r = 0.53) were significantly associated with the mean aerobic demand of running, such that less flexible runners were more economical. Although speculative, these results suggest that inflexibility in certain areas of the musculoskeletal system may enhance running economy by increasing storage and return of elastic energy and minimizing the need for muscle-stabilizing activity.
Implication. Running economy needs natural tightness in lower leg muscles and connective tissues to maximize the storage and return of elastic energy and reduce the need for stabilizing activity.
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Post by tomd on Sept 15, 2005 16:39:32 GMT 1
Oh and one on the benefits of stretching after strength training:
STRETCHING IMPROVES WEIGHT TRAINING GAINS
Kokkonen, J., Nelson, A. G., Tarawhiti, T., Buckingham, P., & Glickman-Weiss, E. (2000). Stretching combined with weight training improves strength more than weight training alone. Medicine and Science in Sports and Exercise, 32(5), Supplement abstract 649.
The effects of weight training alone and weight training plus stretching on lower body strength were investigated in college males and females. The weight training group (M = 7: F = 7) lifted three times per week using a program of 3 x 6 repetitions with 85% 1 RM for 8 weeks. The weights plus stretching group (M = 7; F = 7) was pair-matched for strength with the weight training alone group. Stretching was performed twice per week for the eight-week period.
The weights plus stretching group improved significantly more than the weights alone group in both flexibility and strength measures.
Implication. Stretching exercises add to strength and flexibility improvements in weight training programs.
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Post by tomd on Sept 15, 2005 16:59:06 GMT 1
And another on the benefits of static stretching on DOMS:
STRETCHING DURING RECOVERY
Burkoer, K. C., & Schware, J. A. (1989). Does postexercise static stretching alleviate delayed muscle soreness? The Physician and Sportsmedicine, 17(6), 65-83.
The use of static stretching as part of postexercise recovery to alleviate muscle soreness was found to be ineffective and no different to a group who did no stretching at all.
Implication. Stretching as a recovery activity does not reduce muscle soreness.
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Post by Patience on Sept 15, 2005 19:57:47 GMT 1
I wonder what the impact of age has on these static exercise studies?
I find, these days, there are some static exercises I have to do before I can move onto the dynamic ones. I don't need to do many, and they don't need to e a particularly long or deep stretch, but without them the dynamic stuff is pants and hurts.
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