To s t r e t c h or not to Stretch??
There has been lots of conflicting information about stretching in recent years and many clients report that they are confused about how much is good for them and when they should do it. This blog will look at the indications for stretching and the research that is available.
Why should I stretch?
The main aim of stretching is to maintain or improve flexibility. Flexibility is influenced by the following factors:
o the type of joint. Some joints, for example the shoulder, which is designed for manipulation, should be more flexible than others, like the hip, which is principally for weight bearing and stability.
o the elasticity of muscle tissue –this can be influenced by scarring from previous injuries.
o the elasticity of tendons and ligaments (these structures should not stretch much at all)
o the elasticity of skin
o the ability of a muscle to relax and contract to achieve the greatest range of movement
o the temperature of the joint and associated tissues ( better flexibility at body temperatures that are 1 to 2 degrees higher than normal)
o gender-females are generally more flexible than males
What does Stretching do?
When we perform stretches the main aim is to reduce the resistance of the muscle fascia to movement of the joint. Stretching increases the length of the musculotendinous unit by increasing the distance between a muscle’s origin and insertion (Page 2012). Stretching is found to be relatively ineffective for contractures of the joint (Katalinic et al 2010)). That is to say that stretching does not have a great impact on fibrous structures like the joint capsule, ligaments and tendons. In fact it is usually inadvisable to stretch these passive structures of the joint as they are responsible for the stability of the joint itself.
Age and Flexibility-Stretching to stay young!
Remember how you could easily execute forward and backward rolls in your school PE lessons? Why is it a pain in the neck just thinking about that movement now?? How many adults over 40 can perform the splits? Is it still possible to learn these movements?
There is a natural decline in flexibility with age and many relate this to the increased incidence of arthritis, back, knee and hip problems in old age. The following age related tissue changes are important:
• Increased calcium deposits, adhesions, and cross-links in the body
• Dehydration of tissues
• Replacement of muscle fibres with fatty, collagenous fibres.
Regular stretching stimulates the production or retention of lubricants between the connective tissue fibres, thus preventing the formation of adhesions and helping to combat the natural decline in flexibility.
Studies suggest you can still improve flexibility with increasing age but it should be a slower and more careful process (Page 2012). Theoretically it might take a long time but with dedication those splits might still be possible! More realistically as we get older we need to stretch more regularly in order to prevent or minimise the ageing effects of our tissues.
The American College of Sports medicine recommends that the average adult should stretch the major muscle groups at least 2-3 days a week. If you have lost some flexibility then daily stretching is recommended. Stretches should be held at the point of slight discomfort and held for 10-30 seconds. Older people are recommended to hold stretches for longer 30-60 seconds. However they also advise that a flexibility programme is individually tailored.
There is no denying that it is harder to improve your flexibility as you get older so consider the following external factors which might help the process:
o the temperature of the place where you are training (a warmer temperature is more conducive to increased flexibility)
o the time of day (most people are more flexible in the afternoon than in the morning, peaking from about 2:30pm-4pm)
o ability to perform a particular exercise (practice makes perfect)
o your commitment to achieving flexibility
o water intake – believed to contribute to increased mobility, as well as increased total body relaxation.
Types of stretching
• Static Stretching
The most common type of stretching, holding the joint at end range
• Dynamic Stretching
This is often sports specific and takes the joint actively through range with the muscle contracting, rather than holding a position at end range.
• Passive stretching
A mechanical device, another person or even gravity is used to stretch the joint.
• Ballistic Stretching
This involves bouncing the joint into a range without preparing the muscle. It can be dangerous and should be done under supervision.
• PNF ( Proprioceptive neuromusclular Facilitation)stretching
This usually involves either a Hold Relax technique (the joint is taken towards end of range and resistance is applied for 3-6 seconds to prevent further increase in range, the joint then moves further and the process is repeated several times) or a Contract Relax technique (the joint is moved as for the hold relax technique but immediately after the contraction, resistance is applied to the antagonist (muscle moving in the opposite direction) for 3-6 seconds and then range is increased).
Which type of stretching is most effective?
The Cochrane review found that all these types of stretching are effective. There were no significant differences noted in long term effectiveness although for short term benefits PNF type stretching was found to be slightly more beneficial (Page 2012).
Stretching for injury prevention and performance
Most of the confusion about stretching relates to its’ use before and after sport. So far research has not been able to conclude satisfactorily that stretching prevents injury during sporting activity. The physiology of the musculotendon unit might suggest that stretching is more beneficial before activities with a high intensity of stretch shortening cycles for the tendon, e.g football. Stretching can enhance the viscoelastic properties of the tendon making it more compliant and perhaps less at risk of injury in these sports. (Witvrouw et al 2004). However there is no hard evidence to support this theory and other researchers argue that increased compliance is not associated directly with a reduced injury risk.
Some authors report that static stretching before explosive exercise such as sprinting could be detrimental to performance as it may cause weakness of the muscle tendon unit. Indeed for certain sports a degree of tightness in some muscle groups may be needed for muscle strength and power.
One of the clear problems in making general recommendations for stretching seems to be that stretching needs vary between individuals and with the requirements of the sport itself. Warm up exercises involving some dynamic stretches are more universally accepted as beneficial before exercise. These should be geared towards the flexibility which will be required during performance.
Returning to sport after an injury
If you have injured muscle tissue it will take time to regain the pre-injury elasticity of the tissues. In most cases athletes return to sport before this has occurred. In these instances where there is a notable difference in flexibility to normal (on comparison to the other side for example) stretching before exercise is likely to be more indicated. This should be done as part of the warm up process and dynamic stretches are more favourable at this time.
Will stretching before and after exercise stop me feeling sore?
A Cochrane review of the literature in 2011 found no clinically important differences in delayed onset muscle soreness as a result of stretching before and after exercise (Herbert et al 2011). Generally the trend has moved away from routine stretching particularly before exercise. There are many factors which may influence the soreness felt after exercise, whilst stretching is not thought to be significant, the soreness is usually more apparent if the exercise is new or at an increased intensity to normal. A gradual increase in exercise intensity through training is therefore one of the best approaches to avoid overly sore muscles from exercise.
The exact relationship between stretching and injury risk is not clearly defined. However it is important to note that after a strenuous work out microdamage to the muscles’ connective tissues reduces elasticity and overall flexibility. There are known increased injury risks with lack of flexibility in certain muscle groups. For example, quadriceps and hamstring tightness have both been linked to an increased incidence of patellofemoral pain syndrome. Therefore there is still a strong argument for stretching after exercise, even if it does not change the immediate soreness felt, as it could be important in preventing an overall shortening of the muscle over time.
• Flexibility declines with age, inactivity and following injury.
• All types of stretches are effective for improving flexibility
• Stretching is important to combat the decline in flexibility which occurs with age, inactivity or after injury.
• Routine stretching before and after sport is not shown to have specific benefits and may be detrimental for certain sports.
• Your physiotherapist can assess you for any specific flexibility issues and prescribe appropriate stretches to reduce your injury risk.
By Nikki Richards MPHTY(Sports) BSs(hons)Physio
Page, P (2012) CURRENT CONCEPTS IN MUSCLE STRETCHING FOR EXERCISE AND REHABILITATION. ) Int J Sports Phys Ther. 2012 Feb; 7(1): 109–119
Katalinic OM, Harvey LA, Herbert RD, Moseley AM, Lannin NA, Schurr K. Stretch for the treatment and prevention of contractures. Cochrane Database Syst Rev. 2010;9:CD007455.
Hakkinen A, Kautiainen H, Hannonen P, Ylinen J. Strength training and stretching versus stretching only in the treatment of patients with chronic neck pain: a randomized one-year follow-up study. Clin Rehabil. Jul 2008;22(7):592–600
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Herbert, RD, de Noronha, M, Kamper, SJ (2011). Stretching to prevent or reduce muscle soreness after exercise. Editorial Group: Cochrane Bone, Joint and Muscle Trauma Group..
Witvrouw E1, Mahieu N, Danneels L, McNair P.(2004). Stretching and injury prevention: an obscure relationship. Sports Med. 2004;34(7):443-9.
Shrier, I. (2000). Stretching before exercise: an evidence based approach. Br J Sports Med 2000;34:324-325
Anderson, JC (2005). Stretching Before and After Exercise: Effect on Muscle Soreness and Injury Risk. J Athl Train. 2005 Jul-Sep; 40(3): 218–220.
Flexibility Exercise-american college of sports medicine guidelineshttp://www.acsm.org/about-acsm/media-room/news-releases/2011/08/01/acsm-issues-new-recommendations-on-quantity-and-quality-of-exercise