Physiology, Muscle Energy

Muscle energy technique (MET) is a type of osteopathic manipulative medicine (OMM) developed by Fred Mitchell, Sr, DO. In 1948, Dr. Mitchell first described the kinematic motion of the pelvis. From this concept, and inspired by the work of the neurophysiologist Charles Sherrington, Dr. Mitchell developed a modality to treat muscular action dysfunction using the patient's muscle action. Sherrington's observation was that the contraction of an antagonistic muscle would help relax the agonistic muscle. He named the modality Muscle Energy, which was designed to improve musculoskeletal function by mobilizing joints and stretching tight muscles and fascia; this reduced pain and improved circulation and lymphatic flow.  MET can be applied in all body joints except the cranium. MET is a nontraumatic modality, and its application helps treat key lesions that are the root cause of many dysfunctions in the body. Understanding the intricacies of MET involves understanding the biomechanics of the human body; this knowledge can help make treatments with other modalities easier. For example, those with an in-depth understanding of human biomechanics can treat lesions of high velocity using less force and more precision. Though Dr. Mitchell's initial concept of MET involved muscle activation with post-isometric relaxation, many other physiological principles for MET have been developed. In today's MET, there are a total of 9 different physiological principles: crossed, extensor reflex, isolytic lengthening, isokinetic strengthening, joint mobilization using muscle force, respiratory assistance, oculocephalogyric reflex, reciprocal inhibition, muscle force in one region of the body to achieve movement in another and post-isometric relaxation. Of the 9 approaches, the most utilized is post-isometric relaxation. We will delve further into these principles in later chapters. MET is a safe technique and can be used with inpatients to help decrease hospital stays. MET with post-isometric relaxation is generally contraindicated in patients with low vitality, certain post-surgical patients, or those in the ICU. They would benefit from MET using reciprocal inhibition, respiratory assist, or the oculocephlogyric reflex.  Patients with a history of eye surgery are contraindicated for MET with oculocephalogyric reflex. As the treatment requires patient cooperation, patients should be able to understand and communicate easily with the clinician. Complications can be avoided if the clinicians correctly diagnose, localize the lesions, and use appropriate force. Understanding muscle physiology is essential for MET. There are 4 types of muscle contraction: isometric, concentric, eccentric, and isolytic. Isometric contraction is when the muscles contract without having the origin and insertion of the muscles approach each other. Concentric contraction is when the muscles shorten with contraction. Eccentric contraction is when the muscle lengthens with contraction, and isolytic contraction is when an external force lengthens muscle contraction. The physiology of muscle contractions best explains the mechanism of action in MET.