By Dr. David LaPlaca, PhD, RSCC
Stretching was first introduced to the general public during a sports coaching program on television in Japan during the 1980s leading to the publication of several stretching-related books (Nakamura, Kodama, and Mukaino, 2014). The act of stretching is intended to improve joint range of motion, otherwise known as flexibility, decrease muscle tension, improve circulation, relieve muscle pain, prevent injury, and improve athletic performance (Nakamura, Kodama, and Mukaino, 2014).
Static stretching is one specific type of stretching that involves the act of forcefully lengthening a particular muscle. For example, to statically stretch one’s hamstrings a typically recommended technique is to perform a toe touch, in either a standing or seated position, whereby the individual attempts to touch their toes with their fingertips. Guidelines suggest holding this position for 30 seconds while reaching slowly to avoid an initial level of pain or discomfort due to activation of the stretch reflex (Baechle and Earle, 2008). This initial pain/discomfort is a result of a natural protective mechanism in our bodies that involves what are called muscle spindles. Read more about muscle spindles here.
These muscle spindles sense when our muscles have been stretched too far and send a signal to the central nervous system telling us to stop. However, the idea behind static stretching is to teach our body to bypass such a signal so that we can continue to stretch our muscles further in order to achieve a greater degree of flexibility (Baechle and Earle, 2008). A greater amount of flexibility makes sense since studies have shown that restricted levels of flexibility may result in greater risk of injury (Clark, Lucett, Kirkendall, 2010). However, a certain level of stiffness in our skeletal muscles is necessary in order to optimize stability, especially in areas such as our spine (Gardner-Morse, Stoke, and Labile, 1995). Read more about flexibility and mobility training here.
Whether we’re talking about athletes or individuals looking to be functional in everyday life, our muscles need to have a certain degree of flexibility in order for us to move properly. If our muscles are too short and stiff we will have a more difficult time moving (Holland, 2002). A primary purpose of our muscles is to contract and elongate, transferring energy into the tendon in order to move our bones and thus our entire body. With reduced flexibility the range of motion our bones are able to move through is less than optimal and attempts to move through a greater range of motion may result in an increased risk of injury (Clark, Lucett, Kirkendall, 2010). Therefore, a typical recommendation to improve flexibility around a joint is to perform some type of stretch, such as static stretching or PNF stretching. While this recommendation may help achieve a greater degree of flexibility around the joint, it raises two primary concerns. First, we do not know how far we should stretch our muscles in order to achieve an optimal amount of flexibility (read more about optimal range of motion here). Second, these traditional forms of stretching typically isolate one muscle at a time (Baechle and Earle, 2008).
Because we don’t know how far too stretch in order to achieve optimal flexibility when we do perform static or PNF stretching we essentially try to stretch as far as possible (under pain free conditions). However, this can also lead to too much flexibility. While too much flexibility may allow us to move more freely, this hypermobility can also result in compromised proprioceptive feedback, decreased strength and power output, and the adoption of biomechanically unsound limb positions which may eventually result in degenerative joint conditions (Batista, 2009; Hall et al., 1995; Mallik et al., 1994). So, while we want to be able to move freely and function, too much flexibility may be an issue. Read more about pain and muscle function here.
The second issue, stretching muscles in isolation, relates to how our body functions as a whole. If we examine the movements involved in the daily tasks we perform outside of the weight room, we find multiple muscle groups either working synergistically or supporting each other in some fashion. Walking, running, sitting, standing up, jumping, picking something up off the ground, or even opening/closing a door involve multiple muscles working together. Even if we were to perform an isolation exercise in the weight room, such as a bicep curl or triceps extension, other muscles in addition to the targeted muscle act as stabilizers to support this movement.
In contrast, during a static stretch of our hamstrings, the goal is to relax as much as possible in order to disengage the surrounding muscle groups and generate a greater stretch from our hamstrings. Studies support the fact that this static stretching strategy can improve the flexibility of the hamstrings, but do not take into account the effect it has on the surrounding musculature, and the fact that surrounding muscles, such as the glutes, are needed to work along with the hamstrings during functional movements (O'Sullivan, Murray, and Sainsbury, 2009; Worrell and Perrin, 1992).
When looking to improve the flexibility of our hamstrings it is imperative we also improve the flexibility of the surrounding musculature. Doing so will ensure optimal levels of flexibility and stability around our joints or risk excessive stiffness or instability. It is important to remember that the joint is an attachment site with tendons on each side that attach to muscles (Baechle and Earle, 2008). Continually lengthening one muscle in a muscle group while maintaining the surrounding muscles in the group relatively constant in terms of muscle elongation could eventually lead to a lack of stability around the joint and lead to potential injury (Hall, 1995). Therefore, if the objective is to generate an optimal level of flexibility in our hamstrings and glutes, this muscle group should be stretched synergistically.
One method that can be used to accomplish this is eccentric isometric weight training. This method was first popularized by Dr. Joel Seedman of Advanced Human Performance, and recently explained in the article Therapeutic Weight Lifting (LaPlaca, 2018) on T-Nation. The fundamental principal of eccentric isometric weight training is to control the eccentric phase of the movement, pause in the stretched position for several seconds, and then powerfully complete the concentric phase. The idea is to focus on feeling the movement, allowing us to sense the lengthening of our muscles during the eccentric phase and reach its point of maximal tension at the bottom stretched position.
Using this lifting technique when performing all the fundamental movement patterns one can generate an optimal level of flexibility throughout the entire body. The fundamental movement patterns include: squat, hinge, lunge, horizontal push/pull, and vertical push/pull. These movements will engage all of the major muscle groups in our body from our quadriceps to our lats. Going back to our earlier example, i.e. generating flexibility in our hamstrings and glutes simultaneously, one way to accomplish this would be through a hinge movement such as a Romanian deadlift (Seedman, 2018).
The reason this method helps an individual find their body’s optimal point of flexibility is because instead of causing the muscle spindles to desensitize during a traditional static stretch, eccentric isometrics maximally activates them, allowing one to sense when the maximal amount of stretch and tension has built up in the muscle at the end range of the eccentric phase. The pause at the end of the eccentric phase is what can be referred to as a “functional stretch” where one is maximizing muscular tension while the muscles and joints engaged in this movement are being trained to be flexible enough to move through this range of motion. In order to fully sense the optimal range of motion one must actively control their body and maximize tension throughout the eccentric isometric movements, and avoid collapsing through the eccentric phase and thus desensitizing muscle spindles. Learn more about proper range of motion here.
By using this eccentric isometric protocol to enhance our body’s sense of feel and fine-tune our technique when performing the fundamental movement patterns, we can improve our flexibility over time, eventually helping us find our optimal level of flexibility. Performing movement patterns with less than optimal technique will result in inadequate joint alignment and poor flexibility. Inadequate joint alignment and poor flexibility can result from poor performance on any fundamental movement pattern whether it is due to improper elbow and shoulder positioning during the bench press or faulty hip alignment and body mechanics during a lunge. Fortunately eccentric isometrics help teach us how to master these movements and optimize our mechanics. Read more about eccentric isometrics in Dr. Seedman’s Book MOVEMENT REDEFINED.
The fundamental movement patterns of the squat, hinge, lunge, horizontal push/pull, and vertical push/pull can translate to almost any functional movement we perform in everyday life or during athletic competition. Finding our optimal point of flexibility through these movement patterns will provide us with the level of flexibility needed to move efficiently outside of the weight room whether we are completing a daily task like standing up out of a chair or competing in our sport such as sprinting down a football field. Thus, when looking to improve flexibility one should consider implementing eccentric isometric training protocols as they will allow us to find our optimal level of flexibility and will benefit us no matter what our physical goals are outside or inside of the weight room.
About The Author
Dr. David LaPlaca
Dr. David LaPlaca earned his PhD in Kinesiology with a cognate in Nutrition from the University of Georgia, where he completed his dissertation “The Characteristics that Differentiate Expert, Competent, and Beginner Strength and Conditioning Coaches.” David has over seven years of experience as a strength and conditioning coach. He has worked at NCAA Division I FBS, Division I FCS, and the Division III levels, as well as in the private sector, where he has worked with professional athletes and over 20 different team sports. He’s also written many performance articles and been featured in prominent magazines such at T-Nation and STACK magazine. In addition, he has earned close to a dozen strength and conditioning related certifications and distinctions including becoming a Certified Strength and Conditioning Specialist and Registered Strength and Conditioning Coach through the National Strength and Conditioning Association. Follow David on social media at
References
Baechle, T. R., & Earle, R. W. (Eds.). (2008). Essentials of strength training and conditioning. Human kinetics.
Batista, L. H., Vilar, A. C., de Almeida Ferreira, J. J., Rebelatto, J. R., & Salvini, T. F. (2009). Active stretching improves flexibility, joint torque, and functional mobility in older women. American journal of physical medicine & rehabilitation, 88(10), 815-822.
Clark, M., Lucett, S., & Kirkendall, D. T. (2010). NASM's essentials of sports performance training. Lippincott Williams & Wilkins.
Hall, M. G., Ferrell, W. R., Sturrock, R. D., Hamblen, D. L., & Baxendale, R. H. (1995). The effect of the hypermobility syndrome on knee joint proprioception. Rheumatology, 34(2), 121-125.
Holland, G. J., Tanaka, K., Shigematsu, R., & Nakagaichi, M. (2002). Flexibility and physical functions of older adults: a review. Journal of Aging and Physical Activity, 10(2), 169-206.
LaPlaca, D. (2018). Therapeutic Weight Lifting: Eccentric Isometrics – Recovery and Functional Stretching. T-Nation. Retrieved from: https://www.t-nation.com/training/therapeutic-weight-lifting.
Mallik, A. K., Ferrell, W. R., McDonald, A. G., & Sturrock, R. D. (1994). Impaired proprioceptive acuity at the proximal interphalangeal joint In patients with the hypermobility syndrome.
Nakamura, K., Kodama, T., & Mukaino, Y. (2014). Effects of active individual muscle stretching on muscle function. Journal of physical therapy science, 26(3), 341-344.
O'Sullivan, K., Murray, E., & Sainsbury, D. (2009). The effect of warm-up, static stretching and dynamic stretching on hamstring flexibility in previously injured subjects. BMC musculoskeletal disorders, 10(1), 37.
Seedman, J. (2018). Movement Redefined: Transforming Exercise for Advanced Human Performance. Advanced Human Performance.
Worrell, T. W., & Perrin, D. H. (1992). Hamstring muscle injury: the influence of strength, flexibility, warm-up, and fatigue. Journal of Orthopedic & Sports Physical Therapy, 16(1), 12-18.
