TENS and EMS
One of the most used modalities in physical rehabilitation is Electrical Stimulation (ES). It is effective for treating various orthopedic and neurological diseases and especially conditions causing acute and chronic pain, and muscle atrophy. Low frequency pulsed altering currents are commonly used in therapeutic applications.
Biological effects resulting from the application of electrotherapy can be listed in three categories: Motor Response, Hyperemia and Analgesia.
Motor response: The response of normally innervated muscle to electrical stimulation varies according to frequency – thus the higher the frequency (20 – 80Hz), the better the tetanic contractions and increase in muscle strength. Frequency above 100Hz, will result in rapid fatigue of the neuromuscular system.
Hyperemia: Active hyperemia is the increase in organ blood flow that is associated with increased metabolic activity of an organ or tissue. An example of active hyperemia is the increase in blood flow that accompanies muscle contraction which is also called exercise or functional hyperemia in skeletal muscle. Blood flow increases because of the increased oxygen consumption during muscle contraction that stimulates the production of vasoactive substances that dilate the resistance vessels in the skeletal muscle.
Analgesia: The analgesic effects of electrical stimulation are mainly attributed to the following mechanisms: Gate control theory proposed by Melzack; Reduction of tone in tense muscles; Stimulation of blood flow; Stimulation of endogenous endorphin release.
Indications for Electrical Muscle Stimulation include but is not limited to: pain management in arthritis, spondylosis, spondylarthrosis, post-surgical conditions and nerve generation. It is also effective for fracture healing, strengthening muscles, increasing muscle tone, muscle reeducation and muscle spasm reduction. Lastly it is beneficial for edema reduction, increased range of motion (ROM), improvement of structural abnormalities and greatly accelerate wound healing. Lastly, we use electrotherapy for enhancing transdermal administration of medication.
Stimpod – Neuromodulation
Non-Invasive Pulsed Radio Frequency (PRF) – The therapeutic effect of the Stimpod waveform is based on the cellular metabolic activity observed when a neuropathic nerve is subjected to electromagnetic effects caused by pulsed radio frequency (PRF). This cellular metabolic activity seems to change the characteristics of the nerve, which in many cases causes the nerve to recover back to its normal function.
Typically, there are four phases associated with a pulsed radio-frequency procedure:
- A stunning phase, which provides immediate relief.
- Occasionally there may be a phase of post procedure discomfort.
- A phase of beneficial clinical effect.
- A possible phase of recurrence of pain or paralysis.
With nerve location using a nerve stimulation, as with invasive PRF procedures, one big challenge is to locate nerves using PRF. The Stimpod delivers this PRF waveform by means of a non-invasive probe, which is applied transcutaneously to the affected nerve. Many peripheral nerves are combined motor/sensory nerve bundles and have some locations where they are superficial, which makes them easy to locate using simple nerve stimulation techniques. The Stimpod combines the PRF waveform with a monophasic square wave, which is used to locate the nerve. When the nerve mapping probe is close enough to a motor nerve and the current is set appropriately the stimulation will cause a fasciculation of the relevant muscle. The closer the probe is positioned to the nerve the stronger the fasciculation will be.
In situations where pure sensory nerves are to be located the user will need to rely on the feedback of the patient. The closer the nerve mapping pen gets to the sensory nerve the stronger the sensation will be.
The Stimpod is a useful tool, assisting with diagnosis. The shape of the applied waveform is such that it creates discomfort in a healthy sensory nerve, however, the sensation to a neuropathic nerve is usually very comfortable. This feature further allows the therapist to make an accurate diagnosis of the affected nerve.
The recovery of sensory nerves can be measured by the comfort level experienced at different levels of intensity of the stimulus. It may be comfortable to treat a neuropathic nerve at a current of around 30 mA at the first treatment, however, as the nerve recovers the current intensity would have to be reduced in subsequent treatments in order to maintain a comfort level for the patient. This provides the therapist with a quantifiable means to measure progress. The same goes for motor nerves, but rather than the sensation, a progress judgment can be made on the intensity level of the fasciculation.
Ultrasound is sound waves at frequencies above the human hearing range. These sounds consist of mechanical vibrations generated by an acoustic source and these vibrations are propagated longitudinal to the sound source.
There are various coupling and application techniques, and the technique applied will depend on the required outcome that we would like to achieve such as heat application for acute and superficial conditions or heat application for chronic and deeper conditions. In short, when applying ultrasound for heating tissues, mechanical energy in tissue is converted to heat. The degree of tissue warming will depend on the distance to the transducer head. A deep heating agent, such as US can evaluate tissue temperature at depths of 2 cm or more. This leads to increased elasticity of fibrous tissue, improved joint mobility, pain reduction and reduced muscle tension.
At Paws-itive Paws-abilities, various electrotherapy modalities are being used in our rehabilitation approach and each modality has its own special contribution.
- Transcutaneous Electrical Nerve Stimulation (TENS),is widely used to identify stimulators that modify pain.
- Electrical Muscle Stimulation (EMS), is indicated for direct stimulation of a denervated muscle via its muscle fibers.
- Neuromuscular Electrical Stimulation (NMES),has been identified with muscle re-education, prevention of muscle atrophy and enhanced joint movement.
- Non-Invasive Pulsed Radio Frequency (PRF),Stimpod works on the same principles as TENS, and has been indicated for symptomatic relief and management of chronic intractable pain and/or as an adjunctive treatment in the management of post-surgical pain, post traumatic acute pain problems, as well as an adjunct for pain due to rehabilitation.
- Therapeutic Ultrasound (US),This is an effective treatment modality for the rehabilitation of musculo-skeletal conditions such as restricted ROM resulting from joint contractures and scar tissue, pain and muscle spasm, tendinitis, and bursitis.