The Physiological Effects of Passive Movements - Essay Example

Describe the physiological effects of passive movements and explain how physiotherapists can make use of these effects. Introduction A wide range of passive movements are used for various clinical purposes, as in neuromuscular reeducation and prevention of immobalisation complications. These passive movement techniques have evolved over the decades and have apparently had considerable success. But though treatment techniques used by physiotherapists have been a source of considerable interest to medical researchers, sufficient research has not yet been conducted to scientifically corroborate the effectiveness of passive movements. As such, the precise nature of their efficacy remains debated. To optimise the benefits from the passive movements and passive therapeutic exercises, more experimental evidence needs to be gathered in order to better understand things like specific tissue effects and physiological mechanims of action involved (Frank et al. 1987). The art and science of passive movements in the context of physiotherapeutic managament falls under the category of manual therapy. Manual therapy has been defined as: A clinical approach utilizing skilled, specific hands-on techniques, including but not limited to manipulation and mobilization, used by the physical therapist to diagnose and treat soft tissues and joint structures for the purpose of modulating pain; increasing range of motion (ROM); reducing or eliminating soft tissue inflammation; inducing relaxation; improving contractile and non-contractile tissue repair, extensibility, and/or stability; facilitating movement; and improving function (AAOMPT, 1999). Some recent research has demonstrated significantly better outcomes for patients who used manual therapy in conjunction with other forms of therapy, such as exercise and proprioception training, than when manual therapy was used alone (Jull et al. 2002). Within manual therapy, the administration of passive movements is generally denoted by the term "mobilization". The APTA (American Physical Therapy Association), and the AAOMPT (American Academy of Orthopedic Manual Physical Therapy) define mobilization as a manual therapy technique comprised of a continuum of skilled passive movements to joints and/or related soft tissues that are applied at varying speeds and amplitudes, including a small amplitude/high velocity therapeutic movement (Olson, 2004). In this essay, we are specifically concerned with joint mobilization, which differs from soft-tissue mobilization (massage therapy) or manipulation (chiropractic). We shall be discussing the specific physiological pathways underlying the manifest effects of passive movements. We shall begin, though, by better familiarizing ourselves with the nature and scope of passive movements as they are employed in a clinical setting. Neurophysiological Response to Joint Mobilization Physiotherapy aims to bring about musculoskeletal rehabilitation. To this end, PT prominently involves the use of a combination of exercise and manual therapy techniques. Joint mobilization is a manual therapy procedure involving loosening up of the restricted joints and increasing their range of motion by providing slow velocity and increasing amplitude movement directly into the barrier of a joint, moving the actual bone surfaces on each other in ways which individuals with compromised musculoskeletal function cannot move by themselves. By subjecting motion-restricted joints to gentle movement through a particular segment of the full range, joint receptors can be by and by reeducated to allow a range of motion. Such release from stiffness happens with a concomitant relief from pain in most cases. Administation of passive movements to an affected joint can lead to restoration of the optimal length of muscle fibres, besides resulting in the reduction of the pain-spasm cycle (American Academy of Orthopaedic Surgeons, 1991). A joint can primarily move in two ways: a) in physiological movements consisting of extension, flexion, abduction and adduction and b) in accessory movements consisting of spins, rolls and slides or glides. Joint mobilization strokes consist of basic and advanced mobilizations, as well as traction and gliding. Joint mobilization is graded based on amplitude of movement and where within the available range of movement (ROM) the pressure is applied. Grade I indicates smaller amplitude rhythmic oscillating movement at the beginning of range of movement, while grade II indicates larger amplitude rhythmic oscillating movement within the medium range of movement. Grade III stands for even larger amplitude rhythmic oscillating movement up to the ROM point of limitation, while grade IV signifies small amplitude rhythmic oscillating movement at the very end range of movement. Grades I and II are meant to be used for managing pain and spasm, while grades III and IV are meant to be used for effecting an increase in motion within the joints. Grades I and II are generally used both before and after treatment with grades III and IV (Williams). Because of its widely acknowledged benefits, manual therapy emphasisizing on joint movement and exercise has become increasingly important for the treatment of pain and musculoskeletal dysfunction. However, the rationale used to explain the success of manual therapy has changed significantly over the years. Many early explanations, which included notions such as adjusting of joint subluxations and the restoring of bony alignment have turned out to be unfounded in reality. Regardless, a good amount of more recent biomedical research has brought out the importance of movement, both passive and active, in maintaining the health and strength of collagenous, muscular, and bony tissues; thus stressing on the need for regular and sufficient joint movement A rationale for the treatment of back pain and joint pain by manual therapy (Twomey, 1992). Indeed, today, the need for regular activity throughout the years of life has become a axiomatic concept. The simple fact is that the musculoskeletal system thrives on stress and movement, and reacts poorly to conditions of prolonged rest or other kind of immobilization. Publicized by the media and the books, this widely accepted truth is sinking deeper into our psyche every day. Life is movement! Stagnation is death! However, to give a more scientific basis to what has become common knowledge these days, immobilization makes way for decreased joint mobility, which in turn leads to reduced filling volume of the joint cavity and raised intra-articular pressure during movement (Schollmeier et al. 1996). At this point, a significant loss of water and glycoaminoglycans takes place, though without significant loss of collagen mass in periarticular connective tissue. Such dichotomy leads to decreased spacing and lubricating properties as well as to anomalous collagen cross-links. Cross-links between fibres inhibit their normal gliding and this leads to restricted joint movement and stiffness (Donatelli et al. 1981). And so, eventually, any situation that leads to protracted immobilization can cause serious degree of degenerative changes in the musculoskeletal framework. The absence of physiological stress during the period associated with immobilization alters the morphologic, biochemical, and biomechanical characteristics of various components of synovial joints. In such circumstances, physiotherapeutic mobilization techniques may be applied to normalise nutrition and lubricative properties of the joint, as well as to improve mobility. Passive repetitive translatoric movement is used to improve nutrition, circulation and lubrication in the joint structures. Gentle slow mobilization, when taken far enough into resistance, is used to obtrude cross-link formation and generate change. The end purpose of passive mobilization is to reverse the negative changes that set in the joints under the influence of immobilization, and to effectively normalise arthrokinematic gliding and rolling movement. This increased gliding will gradually normalise osteokinematic rotation and enable the use of active physiological stress in the process of rehabilitation (Sipila). Passive movements are but precursors to active exercises. When it comes to pain management, the gate control theory of pain describes the mechanism in which afferent and efferent pathways can modulate sensory transmission by inhibitory mechanisms in the central nervous system. One of the oldest methods of pain relief has been hyperstimulation analgesia which works by peripheral activation of mechanoreceptors. A brief stimulus can seemingly miraculously relieve chronic pain for long periods, and at times even permanently. Closing the "gate" in the brainstem reticular formation may also relieve pain. Prolonged relief may require the disruption of reverberatory neural circuits that form the basis for the "memory" of pain. Hyperstimulation normalizes neural function, which helps to prevent the recurrence of the abnormal neural activity (Meltzak, 1981). Mechanoreceptor fibres transmit to the posterior horn of the spinal cord. They synapse with neurons of apical spinal nucleus, which connect with presynaptic terminals of the nociceptive afferent fibers located in basal nuclei. And these nociceptive impulses can be inhibited when the apical interneurons release an inhibitory transmitter substance at the synapse. It is within this context that passive movements of joint mobilization can modulate pain, which phenomenon seems to happen by presynaptic inhibition of nociceptive afferent activity (Shaefer, 1987). Conclusion No one can dispute that physiological stress, load and movement are essential for the development, maintenance, and continuing health of the musculoskeletal tissues. Inactivity or trauma can result tissue changes with abnormal symptoms and dysfunction. The greater the inactivity, both in terms of intensity and duration, the greater the damage. If healing has to take place, a tissue response has to be incited so as to restore tissue structure and function, and this can basically be facilitated by loading and motion. Joint mobilization consisting of passive movements is an important part of the treatment stimulating tissue healing. A variety of passive movements such as oscillation and repetitive traction modulate pain, enhance muscle tone, increase nutrition available to the tissues, and perceptibly reverse the effects of decreased mobility. As even common sense tells us, passive movements cannot of course be anywhere nearly as effective as active movement and exercise. However, in situations where active exercises cannot be undertaken, and in spite of the lack of conclusive scientific evidence to support their efficacy, passive movements and exercise motions can do a ton of good, provided they are performed with due care and knowledge. By better understanding the physiological processes involved in the admininstration of passive movements of joint mobilization, physiotherapists can streamline their techniques on a more rational and scientific basis. References: American Academy of Orthopaedic Manual Physical Therapists. 1999. Orthopaedic Manual Therapy: Description of Advanced Clinical Practice. 29 American Academy of Orthopaedic Surgeons. 1991. Athletic training and sports medicine (2nd ed.). Rosemont, IL: American Academy of Orthopaedic Surgeons. Donatelli R, Owens-Burkhart H. 1981. Effects of immobilization on the extensibility of periarticular connective tissue. J Orthop Sports Phys Ther. 3: 67-72. Frank C, Akeson WH, Woo SL, Amiel D, Coutts RD. 1987. Effects of immobilization on joints. Clin Orthop. 219: 28-38. Olson KA. IFOMT 2004: Building Bridges. 2004. Articulations (official publication of AAOMPT) 10 (2) 1 Jull G, Trott P, Potter H, Zito G, Niere K, Emberson J, Marschner I, Richardson C. 2002. A randomised control trial of physiotherapy management of cervicogenic headache. Spine 27: 1835-1843. Meltzak R. 1981. Myofascial trigger points: relation to acupuncture and mechanism of pain. Arch Phys Med Rehabil. 62: 114-117. Schafer RC. 1987. Clinical Biomechanics, Musculoskeletal Actions and Reactions. 2nd ed. Baltimore, MD. Williams & Wilkins Schollmeier G, Sarkar K, Fukuhara K, Uhthoff HK. 1996. Structural and functional changes in the canine shoulder after cessation of immobilization. Clin Orthop. 323. 310-315. Sipila V. 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