Muscle Energy Technique (MET) is commonly used by osteopathic physicians for the correction of somatic dysfunction that causes pain and discomfort, especially in but not limited to the thoracic spine.[1][2] MET is an osteopathic manipulative technique that can classify as either direct or active.[3] A direct technique engages a restrictive barrier. An active technique requires patient participation. In the case of MET, the patient performs a controlled isometric muscle contraction in the direction of the treating physician. MET encompasses several subtypes, but only Post-Isometric Relaxation and Reciprocal Inhibition will be discussed here with respect to the treatment of thoracic vertebrae.
The goal of Post-Isometric Relaxation is to relax and lengthen a hypertonic muscle causing restriction of motion and pain. The force that is generated by the patient towards the “freedom” or “direction of ease” is met with an equal and opposite counterforce from the physician resulting in an isometric contraction of the agonist muscle causing restriction at a given vertebral segment. Physiologically, this activates the tension-sensitive Golgi tendon organs (GTO) of the hypertonic muscle’s tendon through sustained, controlled tension. Group Ib afferent neurons relay this sensory information from GTOs to synapse with inhibitory interneurons in the spinal cord at the respective level of the muscle and produce a reflex relaxation of the targeted agonist muscle.[4]
Reciprocal inhibition relies on a different mechanism, but like Post-Isometric Relaxation also aims to lengthen a hypertonic muscle and relieve restriction. This technique requires the relay of sensory information gathered by muscle spindles and functions to inhibit or relax antagonistic muscle groups during sustained contraction of a given muscle.[5] Group Ia sensory afferent nerve fibers are activated by shortening of the muscle spindle synapse with inhibitory interneurons in the spinal cord.[6] An example of this is the relaxation of elbow extensors for flexion of the elbow joint. Therefore, the reciprocal inhibition reflex arc provides relaxation of the agonist muscle group causing somatic dysfunction. An indirect method for reciprocal inhibition can also be performed but will not be a topic of discussion here.
MET is contraindicated in patients who may not tolerate the added exertion or be able to actively participate in the treatment, such as critically ill, post-surgical patients, and those at an increased risk of bleeding. Patients with impaired integrity of bones, joints, and/or tendons should be considered as a relative contraindication to MET.
Muscle Energy Technique (MET) is a hands-on osteopathic manipulative treatment that requires a stable, firm surface, preferably an adjustable-height, cushioned table for optimal treatment positioning and patient and physician comfort.
Informed patient consent is necessary for any procedure, including OMT, after a discussion of the risks, benefits, and alternative treatment options.
Before touching the patient, the provider should consider explaining what he/she will be doing.
Treatment will begin following a static and dynamic evaluation of the segments of the thoracic spine.
If there are significant muscle texture changes, physicians may choose to use soft tissue techniques prior to initiating direct techniques such as MET.[9]
When treating the thoracic spine with MET, the targetted segment of the spine must be localized and isolated. In the upper thoracic spine (T1-T4), it is common to use the head and neck as a lever. The lower thoracic spine segments (T5-T12) can be localized by manipulating the position of the patient's trunk. Localizing the dysfunctional segment involves monitoring the posterior transverse process for motion throughout the treatment through palpation. The following two treatment techniques will begin by engaging the restrictive barrier or, put another way, moving the patient in opposite directions to those of the somatic dysfunction of the targeted vertebral segment.
Post-Isometric Relaxation Muscle Energy
Example Osteopathic Diagnosis: T3 F RS Right
Step 1. Set Up. Stand behind the supine or seated patient with the left hand upon the head used to achieve the desired vector and the right hand upon the patient's spine monitoring for motion at the posterior transverse process of T3.
Step 2. Engage the barrier. Move the patient's head posterior to extend the spine until motion is felt at the transverse process of T3. Then, side bend the patient's head to the left until the motion is felt at the transverse process. Finally, rotate the patient's head to the left until motion is felt at the transverse process.
Step 3. Isometric contraction. Instruct the patient to gently, but continuously attempt to return her head to an upright, neutral position, while the physician applies an equal counterforce. Maintain this position for 3 to 5 seconds before instructing the patient to relax and remain in the position.
Step 4. Engage the new restrictive barrier. Move the patient's head gently farther in the three planes of restricted motion to the new barrier.
Step 5. Repeat Steps 3 and 4 three to five times with a passive stretch into the restrictive barrier with no patient involvement following the final round of treatment. Passively return the patient to a neutral position.
Step 6. Reassess for improvement in symmetry of the treated segment by palpating the transverse processes of T3 for the example given.
Reciprocal Inhibition
If the treating physician chooses to perform Reciprocal Inhibition on the above patient, during Step 3, the patient would be instructed to direct a force towards the engaged barrier. In the example above, the patient would be instructed to rotate her head to the left, side bend left, and extend. Generally, the force of contraction required for Reciprocal Inhibition is of lesser magnitude than that of Post-Isometric Relaxation.
Patients undergoing treatment with MET should understand that they may experience muscle soreness and fatigue after treatment. The physician may suggest increasing water intake following treatment.
Somatic dysfunction of the thoracic spine commonly results in back pain and discomfort, causing patients to seek medical advice. Osteopathic techniques, including MET, provide a conservative, non-pharmacological avenue for the alleviation of pain and correction of musculoskeletal somatic dysfunctions in the thoracic spine leading to an increased range of motion in affected joints.[1][10]
Understanding of osteopathic medicine has increased with more osteopathic physicians practicing in the United States; however, may patients and healthcare workers are still unfamiliar with osteopathic manipulative treatment and its role in medicine. The healthcare team must understand the role of OMT in the treatment of symptoms. When a skilled provider performs OMT in an appropriate situation, it is safe and may also speed symptom resolution.
[1] | Thomas E,Cavallaro AR,Mani D,Bianco A,Palma A, The efficacy of muscle energy techniques in symptomatic and asymptomatic subjects: a systematic review. Chiropractic [PubMed PMID: 31462989] |
[2] | American Osteopathic Association Guidelines for Osteopathic Manipulative Treatment (OMT) for Patients With Low Back Pain. The Journal of the American Osteopathic Association. 2016 Aug 1; [PubMed PMID: 27455103] |
[3] | Jonas C, Musculoskeletal Therapies: Osteopathic Manipulative Treatment. FP essentials. 2018 Jul; [PubMed PMID: 29963843] |
[4] | Korr IM, Proprioceptors and somatic dysfunction. The Journal of the American Osteopathic Association. 1975 Mar; [PubMed PMID: 124754] |
[5] | Yavuz UŞ,Negro F,Diedrichs R,Farina D, Reciprocal inhibition between motor neurons of the tibialis anterior and triceps surae in humans. Journal of neurophysiology. 2018 May 1; [PubMed PMID: 29384455] |
[6] | Crone C, Reciprocal inhibition in man. Danish medical bulletin. 1993 Nov; [PubMed PMID: 8299401] |
[7] | Will JS,Bury DC,Miller JA, Mechanical Low Back Pain. American family physician. 2018 Oct 1; [PubMed PMID: 30252425] |
[8] | Johnson SM,Kurtz ME, Conditions and diagnoses for which osteopathic primary care physicians and specialists use osteopathic manipulative treatment. The Journal of the American Osteopathic Association. 2002 Oct; [PubMed PMID: 12401039] |
[9] | Johnson SM,Kurtz ME, Osteopathic manipulative treatment techniques preferred by contemporary osteopathic physicians. The Journal of the American Osteopathic Association. 2003 May; [PubMed PMID: 12776762] |
[10] | Noto-Bell L,Vogel BN,Senn DE, Effects of Post-Isometric Relaxation on Ankle Plantarflexion and Timed Flutter Kick in Pediatric Competitive Swimmers. The Journal of the American Osteopathic Association. 2019 Sep 1; [PubMed PMID: 31449303] |