Muscle Testing And Function Florence Kendall 37.pdf !!INSTALL!!
MMT is the most commonly used method for documenting impairments in muscle strength. Limited muscle testing methods are taught in a number of chiropractic schools around the world, however in 2006 a major "stand alone" chiropractic technique that employs MMT for the evaluation of patients known as applied kinesiology chiropractic technique (AK), turned 42 years old. We propose in this review to look at the research status of MMT in the manual examination of the nervous system's status. The early years of the AK method are related elsewhere in detail [3]. The specific protocols and clinical objectives of the technique have been described in previous publications [3-9].
Muscle Testing And Function Florence Kendall 37.pdf
A basic understanding of operational definitions is required in order to make judgments about the methods used in articles and to know which research findings should be implemented in practice. For example, how should we judge the value of the MMT for the gluteus maximus or gluteus medius muscles in cases of sacroiliac joint pain and dysfunction, knowing that statements range from "weakness of the gluteals is usually present in dysfunction of the sacroiliac joint" (Janda 1964) [18] to "the results of this study cast doubt on the suitability of manual muscle testing as a screening test for strength impairments"? (Bohannon 2005) [19].
"Manual muscle tests evaluate the ability of the nervous system to adapt the muscle to meet the changing pressure of the examiner's test. This requires that the examiner be trained in the anatomy, physiology, and neurology of muscle function. The action of the muscle being tested, as well as the role of synergistic muscles, must be understood. Manual muscle testing is both a science and an art. To achieve accurate results, muscle tests must be performed according to a precise testing protocol. The following factors must be carefully considered when testing muscles in clinical and research settings:
MMT procedures are also commonly employed in clinical neurology as a means of subjectively evaluating muscle function. The examiner in the application of force to the subject's resistance evaluates the muscle groups being studied as subjectively "weak" or "strong" on a 5-point scale [24].
MMT is employed by physical therapists to determine the grades of strength in patients with pathological problems and neurologic or physical injuries (strokes, post-polio syndromes, fractures, post-surgical disabilities, etc.). The physical therapist's patients are often initially examined by a medical doctor who supervises the physical therapist's rehabilitation programs that may involve isometric, isokinetic, and isotonic muscle training regimes for the gradual rehabilitation of muscle function (often involving instruments and machinery).
MMT, when employed by AK chiropractors, is used to determine whether manipulable impairments to neurological function (controlling muscle function) exist. For example, chiropractic management using MMT for a patient with carpal tunnel syndrome could involve assessment of the opponens policis and flexor digiti minimi muscles (innervated by the median and radial nerves), and then adjustment as indicated to the carpal bones, the radius and ulna, attention to an inhibited (on MMT) pronator teres muscle, adjustment of the cervical or thoracic spines, and evaluation of cranial nerve XI through MMT of the sternocleidomastoid and upper trapezius muscles. Any or all of these factors may require treatment in order to strengthen the inhibited opponens policis and flexor digiti minimi muscles that are evidence of the carpal tunnel syndrome. This "continuous nervous system" thinking and testing may allow the identification of contributing sites to a pain state.
When performed by an examiner's hands MMT may not be just testing for actual muscle strength; rather it may also test for the nervous system's ability to adapt the muscle to the changing pressure of the examiner's test. A nervous system functioning optimally will immediately attempt to adapt a muscle's activity to meet the demands of the test. There appears to be a delay in the recruitment of muscle motor units when the nervous system is functioning inadequately [66,71-73,82,90,102]. This delay varies with the severity of the nervous system's impairment, and influences the amount of weakness shown during the MMT.
Because of the variability possible during a MMT, several studies examining MMT have used specialized instrumentation to provide support for the extremity tested and for standardization of joint position. Throughout its history manual muscle testing has been performed by practitioners' hands, isokinetic machines, and other handheld devices. However, isokinetic machines and dynamometers for more objective testing of muscles are still too expensive or cumbersome for clinical use, but this equipment is useful for research purposes [20-23].
"As tools, our hands are the most sensitive, fine tuned instruments available. One hand of the examiner positions and stabilizes the part adjacent to the tested part. The other hand determines the pain-free range of motion and guides the tested part into precise test position, giving the appropriate amount of pressure to determine the strength. All the while this instrument we call the hand is hooked up to the most marvelous computer ever created. It is the examiner's very own personal computer and it can store valuable and useful information of the basis of which judgments about evaluation and treatment can be made. Such information contains objective data that is obtained without sacrificing the art and science of manual muscle testing to the demand for objectivity."
Using force measurements from both practitioner and patient, Leisman and Zenhausern demonstrated a significant difference in "strong" versus "weak" muscle testing outcomes and showed that these changes were not attributable to decreased or increased testing force from the practitioner performing the tests [49].
From the original work of Lovett (1915) [25,26] who developed MMT as a method to determine muscle weakness in polio patients with damage to anterior horn cells in the spinal cord, to the measurement of physical weakness from faulty and painful postural conditions, injuries, and congenital deformities [20-23,59,60], to neurologists who adopted MMT as part of their physical diagnostic skills, [24] to the use of MMT by some chiropractors beginning with AK technique to diagnose structural, chemical, and mental dysfunctions, the concept of manually examining the nervous system's status through MMT continues to evolve and gain adherents to this method [61]. The validity of Lovett's original MMT methods was based on the theoretical construct that properly innervated muscles could generate greater tension than the partially innervated muscles present in patients with anterior horn cell damage.
Chiropractic AK research has also suggested that there are five factors or systems to consider in the evaluation of muscle function: the nervous system, the lymphatic system, the blood vascular system, cerebrospinal fluid flow, and the acupuncture system [3,6].
There have been a number of papers that have specifically described the validity of MMT in relationship to patients with low back pain. The correlation between "inhibited" or "weak" MMT findings and low back pain has been well established in the research literature. Several papers have shown that MMT is relevant and can be employed in a reliable way for patients with low back pain [63,66]. In a paper by Panjabi, it is proposed that the function of muscles, as both a cause and a consequence of mechanoreceptor dysfunction in chronic back pain patients, should be placed at the center of a sequence of events that ultimately results in back pain [67]. This paper argues that as a result of spinal dysfunctions (articular dysfunction, spinal lesions, and somatic dysfunction are terms also employed), muscle coordination and individual muscle force characteristics are disrupted, i.e. inhibited muscles on MMT. The injured mechanoreceptors generate corrupted transducer signals (that research suggests may be detected by EMG, dynamometers, and MMT), which lead to corrupted muscle response patterns produced by the neuromuscular control unit.
Lund et al (1991) [70] reviewed articles describing motor function in five chronic musculoskeletal pain conditions (temporomandibular disorders, muscle tension headache, fibromyalgia, chronic lower back pain, and post-exercise muscle soreness). Their review concluded that the data did not support the commonly held view that some form of tonic muscular hyperactivity maintains the pain of these conditions. Instead, they maintain that in these conditions the activity of agonist muscles is often reduced by pain, even if this does not arise from the muscle itself. On the other hand, pain causes small increases in the level of activity of the antagonist. As a consequence of these changes, force production and the range and velocity of movement of the affected body part are thought to be reduced.
This paper describes with fascinating similarity one of the major hypotheses in MMT and chiropractic, namely that physical imbalances produce secondary muscle dysfunction, specifically a muscle inhibition (usually followed by overfacilitation of an opposing muscle). A paper by Falla et al (2004) described a similar model but involving patients with chronic neck pain [71]. A paper by Mellor et al (2005) presented this model in relationship to anterior knee pain [72], and Cowan et al (2004) in relationship to chronic groin pain with another paper demonstrating this mechanism in patellofemoral pain syndrome [73,74].
Leisman et al (1995) showed that chiropractic muscle testing procedures could be objectively evaluated through quantification of the electrical characteristics of muscles, and that the course of chiropractic treatments can be objectively plotted over time [49].
Understanding normal neuromuscular mechanisms is essential to identifying abnormal and also being able to physically test them. In this way the practitioner may be able to specifically determine areas of dysfunction and thereby individualize the treatment given. More importantly, MMT may allow the neuromuscular system to be used interactively (by examiner and patient) and as a key element in the assessment and treatment of the functional disorders of the patient. This ability to "manipulate" the neuromuscular system, with an aim of changing the patient's muscular function, postural balance and strength, and to measure the outcome is conceptually an important component of the chiropractic and AK approach to health care. If a patient's injury causes pain and dysfunction, an effective therapy may not only be in the elimination of pain but also an improvement in muscle function as evidenced by the same method of assessment originally used to diagnose the problem. This may add an important measure of objectivity to clinical practice, and potentially increase a patient's awareness about their body and their body's ability for improvement as a result of the therapy given.