How Adaptive Muscle Shortening (AMS) Causes Pain, Dysfunction and Injury


Adaptive muscle shortening (AMS) is a pervasive clinical finding that affects the entire population. Simply put, muscles are made of tiny strands of connective tissue that have a natural tendency to spontaneously undergo semi-permanent shortening. This shortening is more notable in the athlete, although AMS is occurring even in the sedentary individual. While taking a walk or riding your bike may seem like a good way to "loosen up", these activities only lubricate your joints with synovial fluid, while actually promoting additional shortening of the muscle tissue. The only clinically proven method for offsetting this natural tendency for muscle tissue to shorten is to deliberately perform a daily stretching program. Unfortunately, most stretching programs fail to cite a correct amount of stretching, falling far short of reader's goal of attaining normal flexibility. In other cases, no end-goals are set, and the reader is encouraged to acquire hyper-flexibility of the muscles, which ironically results in premature arthritis, due to mechanical instability of the joints.

Nearly all muscle and joint pain syndromes can be directly linked to AMS. First it is the muscle tissue that shortens. Then the ligaments and joint capsule retract. This results in increased joint compression which produces and accelerates arthritis. Additionally, local muscle inflammation can occur, as can bursitis. While there are over 100 types of arthritis, all are aggravated by AMS. Fibromyalgia Syndrome (FMS, which is not a form of arthritis), is directly linked to shortened musculature. Any FMS patients I have treated have obtained full or nearly complete resolution of pain symptoms after following this program. Instances of carpal tunnel syndrome (CTS), back, neck, shoulder, wrist, hip, knee and ankle pain can be either resolved or the pain functionally reduced through performance of this exercise program.


Medical treatment of fall-related injuries currently costs the American economy $3 billion per year. Then take into account the millions of dollars that are wasted on unnecessary CAT and MRI scans in cases where the only culprit is shortened muscle tissue! And let's not forget the millions of lost man hours and workmen's compensation claims. And the billions of dollars worth of medical bills that are based upon symptomatic treatment, such as the overuse of prescriptive and over-the-counter pain and anti-inflammatory medication, hot packs, ultrasound, high-voltage electrical stimulation, etc. (these treatments can be justified on an individual basis during the acute stage of pain, i.e., 1-3 weeks; after that, all most patients really need is a full-body stretching program and exercises to promote correct posture).

With medical costs rising at least 10% per year (California recently saw a 13% annual increase) the rising cost of health-care is increasing at a rate of around five times the rate of inflation.  Generic braces that are mass-produced and not custom-fitted to the patient custom several hundreds of dollars, and are largely fabricated from plastic materials.  Greed has resulted in fiscal directives over-riding ethical choices in the health care management arena.  CEOs continue to making legendary record-setting salaries, while allied health professionals have seen their salaries frozen for the past five years or more.  Health care has become a game of semantics, and if you aren't familiar with basic medical terminology and anatomy, you are at risk of being the victim of a snow-job.  If an evil cabal of medical institutions agrees to fix wages of professional staff at $5/hour vs. $25/hour, they can honestly state that they offer "competitive" wages.  This disrespectful treatment of professional staff promotes poor morale and decreased clinical standards.  Understaffing results in medical negligence and litigation, detracting from the short term anticipated savings in slashed payroll.


It is a national tragedy that elderly individuals prematurely lose their physical independence due to a condition that is so easily avoidable (and reversible) as AMS. For most subjects, a short period of daily stretching would ensure a fulfilling and physically independent lifestyle well past the eighties. Unfortunately, once the lower extremity musculature shortens sufficiently, step length is decreased, and in time this inherently results in a slower (and therefore less stable) walking speed. Slower walking speed results in general deconditioning, including muscle weakness and weakening of the cardiopulmonary system. Cardiopulmonary function is allowed to decline due to reversible limitations in skeletal muscles.

Obviously the time has now come to take greater accountability for one's own health, in the manner of making wise preventative choices.  This includes striving to attain ideal body weight, maintaining good nutrition and fluid balance, obtaining aerobic exercise for twenty minute bouts three days per week and following a sound stretching program to optimize walking speed and thereby cardiopulmonary status (most seniors walk slow because the leg muscles have shortened, which is also an increased risk for falls...but is also an entirely reversible condition!).  Strength training with weights helps to prevent osteoporosis.  Psychologically and emotionally, there is a much greater quality of life to be attained through the prudent selection of preventative health measures.  In the earlier part of my career, I made house calls for many years.  Quite frequently I was able to provide a modified independent or independent lifestyle to patients well into their 90s.  Several of my patients were centenarians...and were walking in an independent manner at the completion of my care.

Calf pain encountered during prolonged walking is frequently related to AMS, being reversible.

This figure depicts the extensive blood supply to the calf musculature. A frequent complaint of seniors is the experience of calf pain during prolonged walking. In rare instances this may be related to intermittent claudication (inadequate circulation due to arteriosclerosis).

However, a much more prevalent cause of generalized calf pain during walking is that muscle tissue becomes painful due to a transient decrease in circulation related to increased pressure being exerted upon local muscular blood vessels by shortened calf musculature. People minimize walking. General deconditioning occurs, with further muscle shortening and loss of strength. There is an increased prevalence of falling down. Longevity is decreased.

Muscle shortening is reversible! This suffering is unnecessary, as age is not a limitation per se; as long as there is no notable joint limitation, there is absolutely no reason why an 80 year old wouldn't be able to attain normal muscle and joint flexibility. In fact, upon completing the program, I have frequently observed that my octogenarian patients have much better flexibility than my new 25 year old patients!




The figure on the left depicts correct postural alignment. Here the presence of normal muscle strength and flexibility counteract the force of gravity in the most efficient manner. From the side view, a plumb line attached to the ceiling should pass through the opening of the ear canal, through the bodies of the cervical and lumbar vertebrae, slightly posterior to the center of the hip joint, slightly anterior to the center of the knee joint, and just anterior to the ankle. Since the ideal posture is one consisting of perfect vertical alignment of the body against the forces of gravity, anything less is analogous to a poorly stacked pile of building blocks. You can only build off-center for so long before the tower falls.

In the human body, ideally it is muscle tone that maintains the bony segments in correct vertical alignment. When certain muscles are preferentially used due to occupation or sport, and there is no adequate stretching program in place, there will be a distortion of posture. This results in much of the body's weight literally hanging off the muscle tissue, which then acts like a guide-wire, resulting in cramps, muscle fatigue and pain. Those are the local muscular effects.

When faulty posture is left uncorrected, within a few months semi-permanent changes begin to occur within the dense connective tissue known as fascia. This deeper fascia separates muscle groups and encases delicate blood vessels and nerves. Since delicate blood vessels and nerves (see lumbo-sacral nerve plexus, below) perforate most muscle tissue, disturbance of posture due to muscle shortening is likely to disrupt functioning of the nervous system and the internal organs, in addition to causing myofascial dysfunction.



Medical consumers need to carefully evaluate health-care providers to ensure that they will receive proper treatment. Some unethical physicians refer patients to physical therapists that are in their employ. It is always prudent to verify that your physician does not have any subsidiary financial interest in the physical therapist he refers you to, because you may be subjected to excessive and unnecessary treatments that provide symptomatic, but no long-term relief. It is always the patient's right to receive treatment from the therapist of their own choosing. You can be fairly confident in your physical therapist if they: 1) can relate your pain to your faulty posture; and 2) emphasize corrective and progressive exercises as the primary content of your treatment plan.


Taking medication (including topically applied creams) to treat muscle and joint inflammation and pain is only treating the SYMPTOMS. It is only through exercise that the body can become biomechanically efficient, resolving the original CAUSE of the inflammation and pain!

This figure depicts the lumbo-sacral nerve plexus.

A vast number of nerves exit the spinal cord and either lie in close approximation with the hip musculature, or in many instances, actually pierce the hip musculature. When excessive amounts of sitting, jogging or bicycling are performed and no corrective stretching is performed, shortenening of the hip musculature can create compression of the lumbar nerve plexus indirectly, by hyper-extending the lumbar spine and distorting vertebral alignment, or directly, through compression created by shortened muscle fibers. No medication can resolve shortened musculature, or the resultant pain symptoms. Only a personal commitment to performing a daily stretching program can promote optimal wellness.




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site last updated on February 11, 2010 by Paul J. Fransen, P.T.


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