The “Cornerstone” Treatment

Even to those who are unacquainted with the particulars of physical therapy, stretching is a widely accepted treatment for a variety of presentations. Quite often when I have asked patients what they have done to improve their pain I have been given a response that includes some form of self stretching. This method seems to be thought of as a cornerstone of physical therapy by practitioners and patients alike, possibly due to its prevalence in manual techniques. As we progress through our curriculum, this form of treatment may seem to be a so-called ‘given’, but a more critical approach should always be taken with anything we guide patients through. Within today's edition, we will explore the ins and outs of stretching while asking if it is really a critical intervention to do in the clinic.

Stretching Fascinations and Falsehoods

Potentially the most common thought when using stretching as an intervention is to exploit it for the changes in tissue extensibility that it yields. Benefits beyond extensibility are prevalent with research showing increased muscle performance (with caveats) and recognizing stretching to be essential for general fitness⁴. However, the advantage that catches my eye is decreased pain.  How could stressing muscle fibers by pulling them away from each other make us feel better? Without diving into the current theories on this question it almost seems contradictory. As it turns out, the science behind the analgesic effect of stretching is all too interesting. 

 The three main proposals that have been made all find common ground with signal disruption as a main mechanism. The Gate Control Theory formed by Melzack and Wall proposes that the release of an inhibitory neurotransmitter known as gamma aminobutyric acid (GABA) occurs in response to stretching. This blocks any ongoing pain signals coming down the line which leads to pain relief for the patient. Another idea suggests that stretching harnesses the power of the parasympathetic system by activating exteroceptive and cutaneous nerve receptors. The increased ‘rest and digest’ type signals then go on to have global pain suppressing effects. My favorite proposition comes from the idea that we can figuratively ‘fight fire with fire’. Our bodies have a natural response to counteract pain that involves the release of endogenous opioids. The Pain Reduces Pain theory advocates that we can exploit the body into releasing more pain relieving neurotransmitters by adding some uncomfort to the affected area via stretching².

As with most good things, not all of the proposed benefits can be true. A common reason for stretching that was pushed by many of my coaches, especially in my track and field days, was injury prevention. But is there any evidence to bolster this standard belief? The hard answer is no. While decreased flexibility has been linked to higher injury rates, stretching right before athletic events has not been shown to meaningfully fight the odds of an injury. In the clinic, this translates to an important piece of patient education for our athletes to differentiate between the results of stretching once before activity (acute stretching) and stretching as a part of a program (chronic stretching) leading to that activity. Muscle performance is another half truth in the benefits that it receives. Evidence from a systematic review shows that acute stretching offers no or even decreased muscle performance. This is especially true with static stretches lasting longer than 90 seconds. However, chronic stretching has been shown to improve strength and power by altering the length-tension relationship of muscle fibers⁴.

Tips on Evidence Based Stretching

While it may seem that there is little to do incorrectly, an exercise as simple as stretching is actually quite nuanced. What is the proper time to hold a stretch? What intensity should patients stretch with? When should stretching be done in relation to a therapy session? As students of human movement, we must have clear answers to these essential questions. Before starting any flexibility program, a proper physiological environment must be established first. Studies have shown that a local increase in body temperature from 98.6℉ to a range between 104-113℉ is ideal to make plastic changes.  The culmination of many studies have shown that the most effective stretching results come from a low load, thirty second stretch for four repetitions³. 

 Is there a catch to this seemingly silver bullet? Of course. Stretching that is done in the clinic does not truly affect muscle fascicle length. Even with the proper technique, what we are able to achieve in the clinic is actually a down regulation of the neural stretch responses from muscle golgi tendon organs and spindle fibers⁵. Plastic deformation of collagen fibers is only achieved with consistent stretching two times per week in healthy adults, and more for those with a range of motion pathologies. In addition, these results last for several weeks to one month after ending a consistent routine³.

Utilizing Stretching in Clinical Practice

Given what we know about the long term results from picture perfect stretching there is still a large problem. Patients do not need to just get better for a couple weeks or a month, they want to return to their previous activities and get back to their livelihood for the foreseeable future. So why would we use an intervention in the clinic that does not have beneficial long term effects? The short answer is, we don’t have to. 

Stretching is a fundamental component of our formal education just as it should be a fundamental part of patient education from day one. In a study published in 2022 by the American Academy of Orthopedic Surgeons, 57 participants with plantar fasciitis were enrolled in a randomized control trial to observe the difference in outcome between a self stretching home program and guided physical therapy to resolve their condition. Therapists were instructed to follow a stretching protocol and encouraged to use their clinical judgement on incorporating standard of care practices. The results of this study show that there is almost equal achievement of the same satisfaction in outcomes using both methods¹. What this tells us is that stretching is a vital part of patient care but a somewhat dispensable part of clinical care if it is properly being completed at home. 

Practically, we are discussing a total of two minutes of your time per stretch direction. However, two minute increments start to add up quickly when multiple joints are involved, a joint has multiple motions lacking flexibility or a combination of the two arises. We suggest that when stretching starts to detract from clinic time that could be spent with functional training, it is better to make it the focus of the patient’s home exercise program.

Parting Thoughts

Despite the setting that you are or intend to practice in, stretching will continue to be a critical intervention due to its numerous benefits. What we encourage you to do is think critically about how you are managing time in the clinic to optimize your patient’s achievements. Exercising your creativity to incorporate stretching into functional tasks or possibly using it as a form of active rest between sets are just two examples of efficiency. We know from our clinical experience that it comes down to the small parts of care that truly make a big difference in patient outcomes.

We would be ecstatic to hear your thoughts about stretching in clinical practice in the comments below to further the collective knowledge in our community. What have your clinical experiences been with stretching? How have you used evidence based methods in your practice?