What is stretching?
Simply put, stretching is the practice of elongating a muscle or muscle group to its optimal length. Stretching has many known health benefits, including increased athletic performance, improved posture, improved recovery after a workout, and reduced muscle tightness that causes pain.4 Range of motion is the measure of available movement at each joint (where two bones meet and create motion) in our body. The range of motion is limited by the joint itself (bone and ligamentous structures) and muscle. Muscle tightness can result from either passive tension (muscle shortening due to postural adaptation, surgery, scarring, etc.) or active tension (the force generated with a muscle contraction). Regardless of its cause, tightness limits movement at the respective joint and creates imbalance in the body’s movements.
Muscle length and strength between opposing muscle groups must be balanced for normal movement and function. Muscles that are either shortened (due to muscle tightness) or lengthened (due to poor posture) cannot generate maximum contractile force and, as a result, decrease your activity performance. There is a direct correlation in the length-tension curve between the length of a sarcomere (the contractile unit of muscle) and the tension that can be generated. Peak tension is produced when the filaments (actin and myosin) bind together to create a muscle contraction. Higher levels of force output are generated when the respective muscle is at an ideal length.4 Research has proven that stretching is an effective method for muscle elongation and achieving the ideal muscle length.4
Three primary stretching techniques are routinely discussed in literature: static, dynamic and pre-contraction.1 See the categories below and the respective example using the hamstring muscle group to better understand the different stretch techniques.
Static stretches are the most common and traditional type of stretch. This stretch technique puts the muscle in a lengthened state until a pull sensation is achieved and then typically held under tension for anywhere from 10 to 60 seconds. An example of a static stretch for your hamstrings involves laying on your back with a yoga strap around your targeted foot, using your upper body to lift the leg into the air until you feel the desired level of mild tension throughout the back of the leg.
Dynamic stretches are movement-based stretches where you repeatedly move a limb through its complete range of motion. A walking high kick is an example of a dynamic hamstring stretch. Put your hands out in front of you, keep your knee locked out, and kick the leg up in the air until you feel tension through the back of the thigh – repeat 15 walking high kicks per side.
Pre-contraction is contracting the muscle you intend to stretch or its antagonist (the muscle that performs the opposing muscle movement) before you stretch the muscle itself. This technique is also known as proprioceptive neuromuscular facilitation (PNF) stretching. This style of stretching has been shown to produce immediate gains in muscle length.4 An example of a PNF stretch is creating tension in the hamstrings by pushing your leg against the wall for 10 seconds at 75-100% effort, releasing the tension, and then moving closer to the wall or more deeply into the static stretch for another 30 seconds.
When and how to stretch?
The key to realizing the maximum benefits of stretching is consistency. Develop a daily stretch routine or, at a minimum, a routine before and after activity. Studies have shown benefits with static stretching and dynamic stretching before a workout.3 In contrast, alternative studies have found that a dynamic stretch warm-up before athletic competition optimizes exercise performance, whereas static can hinder muscle force production.4
Be gentle when initiating any stretch. Be sure to breathe deeply and relax as you stretch to reduce muscle tension. There will be tautness with stretching, but the action should not be painful. The muscle should be warm when stretching to achieve desired results, taking advantage of increased muscle extensibility, blood flow, and oxygen to large muscle groups.
Why is stretching so important?
This brings us back to the importance of stretching. Let’s use the hamstring muscle group as an example. Sitting for prolonged periods can lead to tightness in the hamstring muscle group.5 The passive muscle tightness challenges the ability to extend your leg or straighten your knee when walking and can influence stride length. Furthermore, the added demand of your body to execute powerful movements for sports such as running, jumping, or cutting results in decreased power output from the muscle. The stress from the high-demand activity damages the muscle itself (muscle strain) or the tendinous insertion on the bone (tendonitis).
The American Heart Association (2020) and ACSM (2021) have promoted stretching as a mandatory component of exercise programs.2 The American College of Sports Medicine recommends static stretching for most individuals, preceded by an active warm-up, at least 2 to 3 days per week. Each stretch should be held for 15-30 seconds and repeated 2 to 4 times.2 Stretching directly increases muscle flexibility to an optimal resting length, increasing force production and improving athletic performance. Stretching facilitates effective muscle contraction, permits pain-free movement throughout the day, and most importantly decreases injury risk. It is essential to include stretching in your fitness routine and make it a priority as a part of your health overall.
Please direct any specific questions regarding your stretch routine or specific joint restrictions to your SHIFT physical therapist, Avis (firstname.lastname@example.org) or simply schedule an appointment here: Schedule Physical Therapy Session.
In Real Health,
Avis Jason, PT, DPT
SHIFT Physical Therapist
- Page P. Current concepts in muscle stretching for exercise and rehabilitation. Int J Sports Phys Ther. 2012 Feb;7(1):109-19. PMID: 22319684; PMCID: PMC3273886.
- ACSM (2021). ACSM’s Guidelines for Exercise Testing and Prescription, 11th Edn. Philadelphia, PA: Wolters Kluwer.
- Burstein, Albert H. PhD. Basic Biomechanics of the Musculoskeletal System. 3rd ed.. The Journal of Bone & Joint Surgery: September 2001 – Volume 83 – Issue 9 – p 1455
- David G. Behm, Anthony J. Blazevich, Anthony D. Kay, and Malachy McHugh. Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review. Applied Physiology, Nutrition, and Metabolism. 41(1): 1-11. https://doi.org/10.1139/apnm-2015-0235
- Yadav, R. & Basista, R. Effect of Prolonged Sitting on Hamstring Muscle Flexibility and Lumbar Lordosis in Collegiate Student. International Journal of Health Sciences and Research. 2020 Sept; 10(9). www.ijhsr.org.