A modern approach to stretching
David Fleckenstein's Low load, long duration (LLPD) stretching method
David Fleckenstein from www.physiopt.com wrote an interesting paper concerning stretching, and how most of us have been doing it wrong for a long time. He describes a protocol called Low load, long duration (LLPD). It's described here.
David is a physical therapist practicing in Boise, Idaho. His clients have included World and U.S. champions, Olympic athletes and numerous professional athletes. He received his B.S. in Biology/Genetics from Penn State and his Master's degree in Physical Therapy from Emory University. He specializes in manual medicine treatment and specific retraining of spine and joint stabilization musculature. He is a former Cat I road racer and Expert mountain biker.
At aboc we want to stress that static stretching while it may be
of benefit to cyclists, should not be done prior to racing or training
- a number of studies have shown that as well as having no effect on
injury rates it actually reduces athletic performance if performed
prior to training or racing. stretch afterwards, not before, your
race or training session.
The following is edited and lifted from a discussion on cyclingnews.com and was written by David, the following is published here with his permission :
I completed a thesis in graduate school regarding effects of different stretching techniques on various tissues. If you would like to see the bibliography I would be happy to send it to you.
The main question here is what is the most effective way to lengthen collagen, the primary building block of connective tissue? I like to think of collagen as an unusual type of spring. With stretching we are trying to lengthen, or deform the spring. While force is the most effective way to deform a regular spring (how hard we pull it apart), time is the most effective way to deform the spring of collagen. Healthy, mobile tissue generally looks like nicely combed hair under the microscope - all the fibres are aligned in parallel, allowing the 'spring' of collagen to be mobile in certain directions and resistant in others. Restricted tissue tends to look like fibres of a furnace filter - randomly aligned (which is actually the cross-linking of collagen tissue) and generally resistant to any motion.
My overall thoughts regarding stretching are as follows, based on research and my clinical experience:
1) Low load, long duration (LLPD) stretches are the most effective ways to permanently lengthen tissues - in simple terms, time is a more effective way to lengthen tissues than force.
An interesting observation is that there are certain tissues that we want to stretch and certain ones that we don't. The same way that time is an effective way to lengthen the hamstrings, prolonged slumping (either sitting in a chair or sitting on a bike) can also lengthen the collagen fibres of the disc and supportive ligaments of the spine. This results in a loss of integrity of the disc and premature breakdown. If you notice in the stretch sheet, the spine is always in a neutral alignment in my pictures to protect it.
2) 30 second stretches, contract/relax stretches, AIS stretching, etc., does not permanently lengthen tissue, but can result in transient improvements in flexibility.
My clinic is full of patients who have performed this type of stretching for years, notice a short term benefit, but no cumulative improvement. Why? Because I don't think collagen is affected with these stretches, the nervous system is. The nervous system plays an important role in regulating how tissue moves. These types of stretches affect mechanisms that regulate the tone of muscle tissue - how much contraction is going through tissue at one time. These can be effective ways to reduce spasm or provide short term increases in mobility.
A couple of stretches that I listed in the PDF are 30 second stretches because these are structures that are also highly intertwined with specific nerves and most people aggravate themselves with LLPD stretches of these structures if left to themselves. Clinically, I can progress these individuals to LLPD stretches under guidance with excellent results.
3) There is an optimum amount of flexibility. If there is not some resistance present in the connective tissues, we don't transmit forces well - it is dispersed within the tissue. Indeed, some professional athletes that I have seen demonstrate marked tightness, but they are able to prevent those forces from transmitting to structures that are not designed to disperse stress. I think that these are the athletes who picked their parents well and have a physical gift. I certainly have patients that are too flexible as well, but it is generally not their hamstrings, hip musculature, and hip flexors that are too mobile. It is usually the musculature and structures surrounding the spine, and this is not good.
4) Flexibility is not something that should just occur when we are "warmed up," it should be present permanently. This enables us to move correctly throughout our day, through all motions. My general rule is that I want local spine stability (to protect and maintain optimum alignment of these highly reactive structures) and lumbopelvic musculature flexibility, so that our pelvis can move correctly and provide a well-aligned base for the spine. I will be writing more this fall [or this spring in the southern hemisphere - ed.] on stability issues.
So, what seems simple is not so simple, after all. In many of the studies that found negative results of stretching, tissues that should not have been stretched were lengthened, creating problems. I often see athletes selecting very poor stretching techniques, such as bending forward to touch their toes thinking that they are stretching their hamstrings when they are actually placing huge forces and stretch on the disc and ligaments of the spine.
The PDF is a very generic start to a very complex issue. Ideally, we would all have a very individualized system of stretching and stability based on our specific needs, but the stretches given are ones that I feel 'do no harm' and lengthen the most commonly shortened structures that I feel promote pathology.