Technology in Physical Medicine and Rehabilitation practice BME days 2006 ITB.
Multidisciplinary Sinergy: Towards Better Community Health Care Bandung, 13-15 November 2006
Marina Moeliono, MD, Physiatrist
Dept of Physical Medicine and Rehabilitation
Faculty of Medicine, Padjadjaran University – Hasan Sadikin Hospital
Abstract
The higher life expectancy and advances in medical care and technology have resulted in an increased proportion of dependent individuals, who require extensive intervention in rehabilitative care. PM&R manages persons with impairment, disabilities and handicaps through the use of medications, physical modalities, assistive devices, therapeutic exercises and experential training approaches
For this purpose various technologies are developed to aid in the diagnosis of disabilities and to find the best treatment for a certain disability.
Introduction
Physical medicine and rehabilitation (PM&R) is a branch of medicine dealing with functional restoration of a person affected by physical disability.
Scope of Physical Medicine and Rehabilitation involves the management of disorders that alter the function and performance. Management is focused on restoring the health and the optimization of functional abilities of people with impairments, disabilities and handicaps, as the result of an illness or injury, through the combined use of medications, effective physical medicine and rehabilitation therapies including physical modalities, and experiential training approaches.
Advances in medical care and technology have resulted in an increase in the elderly population, mostly encumbered with chronic and degenerative diseases, survival of babies with congenital anomalies, and the number of persons surviving an acute illness or injury such as stroke, heart surgery, amputation, joint replacement, sports injuries, occupational injuries, spinal cord injuries or other spinal disorders resulting in an increasing proportion of dependent individuals, who require extensive intervention in rehabilitative care.
For this purpose various technologies are developed to aid in the diagnosis of disabilities and to find the best treatment for a certain disability. Technologies in PM&R includes electrodiagnostics (EMG and NCV studies) to diagnose and provide prognosis for various neuromuscular disorders; gait analysis for interpretation and diagnosis of normal and pathological human locomotion and in the end to optimize and improve performance; CPM (continuous passive movement) machines to aid in treatment of muscles and joints; assistive devices to use in activities of daily living; biofeedback used in diagnosis and therapeutic exercises; treatment modalities using heat, cold and electrical current; and the technology used in making orthotics and prosthetics
History
was recognized as a medical specialty by the American Board of Medical Specialties and the American Medical Association in 1947.
This specialty expanded rapidly after World War II, when many soldiers with severe disabilities returned and physicians were necessary to treat and manage chronic debilitating conditions. Polio epidemic in the early 1950s and advances that allowed longer survival from disorders as varied as spinal cord injury and stroke also helped establish the value of physiatrists in management of neuromuscular disorders.
In Indonesia the first physiatrists, who graduated from Santo Thomas University in Manila, Philippines, began working in 1981 but not until 1992 were PM&R departments declared as independent departments in those hospitals. Education for future specialists in PM&R started in 1987.
The development of PM&R is accordance with the change in current medical services, characterized by comprehensive treatment and includes preventive, curative, promotive and rehabilitative measures.
Rehabilitation medicine itself encompasses promotive rehabilitation, preventive rehabilitation and curative rehabilitation,
Purpose of promotive rehabilitation is to increase or maintain functional status, and includes education of healthy living, education to prevent and avoid disabilities and increasing the overall condition. Preventive rehabilitation is to prevent disabilities, includes the prevention of secondary and tertiary disabilities such as weakness, atrophy of unused muscles, stiffness or contractures of joints, osteoporosis, abnormalities of gait, misalignment of the spine, problems in mobilization and performing the activities of daily life.
Curative rehabilitation is to diminish disabilities and uses medications, rehabilitative nursing, physiotherapy, speech therapy, occupational or vocational therapy and orthotics and prosthetics to help persons to function optimally within the limitations placed upon them by a disease process for which there is no cure or by the disabilities or handicaps caused by the disease. The general emphasis is not on the full restoration to the premorbid condition, but rather the highest level of independency and optimization of the quality of life for those who may not achieve full restoration.
Technology in Physical Medicine and Rehabilitation practice
In the USA, the science of biomechanics and biomedical/biomechanical engineering research have developed rapidly in the last 20-25 years. Research came from the fields of biomechanics, and established medical sciences like neurology, orthopedics and rehabilitation medicine.
Because functional status is closely linked to movement of the body, the study of biomechanics or the study of musculoskeletal, neuromuscular and sensory disorders that are associated with abnormal control of posture and movement, is of particularly importance for diagnostics and therapeutic purposes in rehabilitation medicine
The research has helped in the development of artificial limbs (prosthetics), the study of motor control of the human body, biomechanics, computer modeling, and robotics. The latest achievement is the first sip-and-puff wheelchair control system, enabling quadriplegics to operate motorized wheelchairs independently
planning of surgery and in the rehabilitation department, for diagnostics and to construct a good rehabilitation program.
The focus of gait analysis is locomotion, which is the act of moving from one point to another, while gait is a method of locomotion, using alternative and rhythmic movement of both legs, to provide both support and propulsion. While the gait pattern can be very individual owing to body proportion, habits, coordination and motivation, human gait, because of similar anatomical and physiological factors, is accomplished in a similar manner by all healthy adults.
The study normal and pathological gait can be applied in many rehabilitation programs. For example, gait training for persons with impairments affecting the gait pattern like hemi paresis after stroke or traumatic brain injury, elderly persons with impairment of balance and/or equilibrium, persons with Parkinson disease, pathological conditions of the feet and lower extremities
Gait analysis began in the early part of 19th century, with sequential photographs and observational studies. Later, dynamic electromyography was added to record the internal forces (kinetics) to record the activity of muscle groups during walking. More detailed analysis was made possible with the development of computer technology, used in analysis of massive amounts of data obtained simultaneously from a variety of different sources: force transducers, foot switches, EMG amplifiers, electrogoniometers, spotting systems
These specialized transducers transform a physical variable into an electric signal that can be converted to a digital signal. The digital signals are recorded by a computer and displayed as dependent variables of time on a graph with a common time axis. These data can be analyzed with the direction and level of analysis depending on the specific questions being asked. The context in which the data are analyzed is critical in planning, performing and interpreting the study.
In gait analysis muscle action cannot be measured directly, so EMG studies were added to gait analysis. The electromyography (EMG) allows indirect measurement of muscle activity. A typical kinesiological (dynamic) EMG represents the activity of multiple motor units of various muscle groups. Single motor units are analyzed routinely in clinical electrodiagnostic studies, but this level of analysis is not performed as part of a routine gait analysis.
In clinical situations, electrodiagnostic testing or EMG studies of the peripheral nerve system is done an adjunct to the history, physical examination and other additional examinations in the overall evaluation of neuromuscular disorders.
Basically electrophysiology or electromyography is the study of the physiologic functioning of muscle and nerve fibers which are the two basic excitable tissues in the human body. Results are obtained through application of electrical stimulation and recording of the responses. The practitioner must be aware of how the instrument detects and displays the recorded physiological potentials
Physiology of MUAP, all living cells have a potential difference across the cell membrane with the intracellular region negative compared to the extracellular environment. When there is no action potential present, the cell is in a resting state and the difference in action potential is called resting membrane potential. A mathematical statement of the potential states that this resting potential is -75 mV (-70 – 90mV), meaning that intracellular is 75 mV more negative than the extracellular region. In this state, concentration and electrical forces are balanced and the cell will attempt to maintain this state.
Muscle and unmyelinated nerve contain both sodium and potassium voltage gated channels. These gates are closed at the resting membrane potential.
Application of electrical, mechanical or chemical stimulation which reaches the threshold of the membrane, 15-20 mV less negative than the resting potential, causes the channels to open, resulting in an increased permeability of sodium ions, a process known as sodium activation. This massive shift in transmembrane potential is referred to as depolarization. The process will then continue along the length of the cell. Once the process begins, it is self sustaining as long as there are sufficient ion channels to repeat the process of depolarization. If not, the sodium gates automatically close with a return of the resting membrane potential, referred as repolarization The voltage generated by the depolarization induced current flows generates all of the potentials we observe on the instrument’s cathode ray tube screen.
Nerve conduction studies is another feature of the electrophysiology studies. Motor nerve conduction is recorded by applying stimulation along a nerve and record the time of conduction using a pick up electrode on the muscle innervated by that specific nerve. Sensory nerve conduction is done the same, with the stimulus given along the nerve with pick up electrodes on the sensory organ.
Nerve conduction velocity is calculated by dividing the time needed by the electrical current to reach the end organ from the point of stimulation by the length of nerve fiber.
The result of EMG studies confirms whether the impairment comes from muscle or nerve, and in many neuromuscular disorders, can aid in the planning of management.
Based on the normal physiological process that normal muscle contraction is initiated by propagation of depolarization from the alpha motor neuron, its axon, to the muscle fiber it innervates, one of the modalities used in neuromuscular disorders is electrical stimulation.
The interest in electrical stimulation began with an experiment by Galvani which showed that placement of a metal connector between the spinal cord and muscle could produce a twitch.
Electrical stimulation was used as a therapeutic modality throughout the 1980s. There was great debate about the type of stimulation, galvanism, faradism and franklinism, but the therapeutic claims were never substantiated. In the 1990s electrical stimulation was used again with use of the alternating current generation.
Effective application of functional electrical stimulation, a form of electrical stimulation, in a rehabilitation setting began with the stimulation to the peroneal nerve to produce ankle dorsiflexion.
Since the 1970s, FES or functional electrical stimulation for gait restoration after an upper motor neuron lesion has progressed from feasibility studies to the development of a commercially available, FDA-approved ambulation system. FES ambulation systems range from totally external devices to more experimental systems that are virtually completely implanted.
Typical components of the FES system include a power source plus cables, a control mechanism, stimulator with cables and electrodes. Additionally, FES system requires a feedback mechanism. Types of feedback mechanism include input from external sensors, EMG of muscle, sensory areas or the brain. The most common and practical sensors are externally mounted devices that feedback information regarding limb position and movement. More sophisticated automatically incorporate feedback from changes in the muscles or fatigue, directly back into the FES system
Despite considerably progress, a number of barriers remain that continue to render this cumbersome clinical application of technology. In addition to requiring a user friendly system, the ideal FES gait system should be safe, reliable, sufficiently functional to provide community ambulation, inexpensive and cosmetically acceptable. Many of these goals have not been realized.
The Physical Medicine and Rehabilitation Department in Hasan Sadikin Hospital has a few of those technologies mentioned, although not the gait analyzer. Gait analysis is done in the traditional observational method. Electrical stimulation is done routinely in the management of various disorders, but FES is done only for the small muscles of the upper extremity. EMG studies for diagnostic purposes is mainly done by the neurologist, while in the rehabilitation setting it is used for biofeedback purposes. We do not develop the equipment but are the user of equipment and technology from Japan, the Netherlands and America. There are not many research programs ongoing, primarily restricted by inadequate funding.
