The severity of injury determines the use of treatment methods ranging from topical analgesics to electrical stimulation.

It is not uncommon for weekend athletes to overexert themselves and sustain injuries. Though the injuries these weekend athletes face are not uncommon in professional athletes, they take longer to heal due to the weekend athletes’ lack of training and conditioning. Two of the most common types of injuries include tennis elbow (lateral epicondylitis) and golfer’s elbow (medial epicondylitis). Treatment of the pain caused by these conditions depends on the varying severities of the patients’ conditions and ranges from the use of topical analgesics to electrical stimulation.

Basics Brush-Up

The lateral epicondyle is the outside bony portion of the elbow, where large tendons attach to the elbow from the muscles of the forearm. These tendons can be injured, especially with repetitive motions of the forearm, such as using a manual screwdriver, washing windows, or hitting a backhand in tennis play. Tennis elbow results with inflammation of the tendons, causing pain over the outside of the elbow, occasionally with warmth and swelling, but always with local tenderness. The elbow maintains its full range of motion, as the inner joint is not affected, and the pain can be particularly noticed toward the end of the day. Repeated twisting motions or activities that strain the tendon typically elicit increased pain. X-rays are usually normal, but can reveal calcium deposits in the tendon or other unforeseen abnormalities of the elbow joint.

The treatment of lateral epicondylitis includes ice packs, resting the involved elbow, and anti-inflammatory medications. Bracing the elbow can help. Local cortisone injections are given for persistent pain. Activity involving the elbow is resumed gradually. Ice application after activity can reduce or prevent recurrent inflammation. Occasionally, supportive straps can prevent reinjury. In severe cases, an orthopedic surgical repair is performed.

Medial epicondylitis is inflammation at the point where the tendons of the forearm attach to the bony prominence of the inner elbow. This tendon can become strained in a golf swing, for example, but many other repetitive motions can injure the tendon. Golfer’s elbow is characterized by local pain and tenderness over the inner elbow. The elbows range of motion is preserved because the elbow’s inner joint is not affected. Those activities, which require twisting or straining the forearm tendon, can elicit pain and worsen the condition. X-rays for epicondylitis are usually normal but can indicate calcifications of the tendons if the tendinitis has persisted for extended periods of time. The treatment often involves ice packs, resting the elbow, and medications including aspirin and other nonsteroidal anti-inflammatory drugs.

In many cases, the pain is very intense and can be associated with muscle spasm. The area is aggravated by movement and can cause severe disability. A quick and effective method to overcome the problem is to pinpoint the area and inject it with a local anesthetic and a small amount of steroid. In most instances of lateral and medial epicondylitis, a trigger point is a focal point of pain. It is an area of irritation in the vicinity of a joint and may include the joint. The irritation is usually caused by a strain in athletes, and it can also be caused by fibromyositis (inflammation of the muscle or tendon), or in association with arthritis. The anesthetic provides immediate relief, and the steroid provides more lasting relief. The shots may have to be repeated, but many patients experience long-term relief from this treatment. Using a strap can prevent reinjury. After a gradual rehabilitation exercise program, return to usual activity is best accompanied by ice applications after use. This helps to avoid recurrent inflammation.

Electrical Stimulation Options

When injuries beyond tennis and golfer’s elbow occur, and the pain grows to a chronic condition, electrical stimulation, such as trans-cutaneous electrical nerve stimulation (TENS), may be used. TENS is a battery-powered electrical unit that uses electrodes in the form of sticky patches placed onto the skin to deliver electrical impulses to the nerve fibers, which lie underneath the skin’s surface. It is used to provide pain relief by blocking pain signals to the brain via the spinal cord and peripheral nervous system, and also to stimulate the production of endorphins—the body’s own pain-relieving mechanism. Usually, the electrodes are placed around the pain area or on acupressure points. A slight tingling sensation, which is not painful, will be felt during treatment.

The effects are cumulative and also encourage the release of endorphins. TENS is safe and does not produce side effects such as nausea or drowsiness. It can be administered while you are going about your normal activities, and it is not addictive. Occasionally, the self-adhesive electrode patch sites can become irritated due to the adhesive, but this can be overcome by using a different brand of patch.

TENS can be applied in several different ways, including sensory level, motor level, subsensory level, and noxious level. The different stimulation methods are produced by the altering of three parameters of the TENS unit: pulse rate/frequency, pulse width/duration, and intensity/amplitude.

Sensory-level TENS (or “conventional TENS”) is the most commonly used method. This method is considered to work via the gate-control mechanism. Conventional TENS is typically used during the acute stages of an injury, but it may also be used for controlling chronic pain. Pain relief is typically expected within 5 minutes of initiation, but it usually does not last more than 1 hour after the treatment is stopped. Interferential current at beat frequencies of about 80 Hz or higher is also believed to work via gate control; however, the pain relief that is associated with interferential currents usually lasts longer than that from TENS.

Motor-level TENS, or “acupuncture-like TENS,” is more commonly used to control chronic pain. Unlike sensory TENS, motor-level TENS should produce visible muscle contractions. Motor-level stimulation is believed to work via the opiate-mediated mechanism of pain control, with the low rate stimulation causing the release of endorphins. Likely, this mechanism is also what occurs with interferential currents in which the beat frequencies are about 10 Hz or lower. The lower-frequency interferential current may or may not produce a muscle contraction. Pain relief with motor-level TENS should be expected to take longer than with conventional TENS (15 to 60 minutes), but the relief likely will last longer (more than 1 hour). The longer period of pain relief associated with motor-level TENS may be attributed to the time it takes the released endorphins to reabsorb into the bloodstream.

Noxious-level TENS stimulation is often the last treatment choice in the application of TENS, because as the name implies, it is not a comfortable procedure for patients. There is no counterpart for noxious TENS in interferential current. Typically, noxious stimulation is used for chronic pain. This method of TENS, which is similar to motor-level stimulation, is believed to work via the opiate-mediated theory. The onset of analgesia is usually swift, typically within seconds or minutes, and pain relief is expected to last more than 1 hour.

However, while sensory-level and motor-level TENS may be applied for 1 hour or more, noxious-level TENS is usually applied for only several minutes because of the difficulty associated with tolerating it. This shorter application time may result in shorter periods of pain relief compared to motor-level TENS. The goal of applying noxious stimulation to an area is to produce the maximum amount of discomfort that the patient can tolerate to allow for a quicker onset of analgesia. Noxious-level stimulation may or may not result in a muscle contraction, depending on the location of the electrodes and the exact parameters that are programmed.

Because of the severe amount of discomfort associated with noxious stimulation, it is recommended that it be applied to patients only by a clinician who is experienced in the clinical application of TENS.

Most interferential units that are used today have the capacity to perform a “premodulated” current. The amplitude of the single channel that is used is altered to produce a current that is similar to the beat frequency produced by true interferential current. However, this form of stimulation operates similarly to TENS because the units cannot produce the same field effects as when the two channels in interferential cross.

Determining Necessity

The decision on whether to use TENS will likely be based on the depth of the tissue being targeted and on experimenting with what works best for the patient. Most weekend athletes, at the most, experience overuse injuries, in which they overextend their muscles and tendons, resulting in inflammation.

If your patient’s condition allows you to use TENS, it is important to note that the location of the electrodes will have a major impact on the success of the modality. Typically, the electrodes are placed either directly over or immediately surrounding the painful area. However, these locations may not be appropriate for everyone. Some patients may be in too much pain to tolerate any stimulation in that area, the location is contraindicated, or placing the electrodes over the area does not provide the maximum amount of pain relief. In this case, other locations should be attempted. Other locations where the electrodes may be placed are along neurologically related areas, including involved nerve roots; along the course of a specifically involved peripheral nerve; trigger points; and acupuncture or acupressure points.

The best results will likely be found by trying to place the electrodes over different appropriate areas and finding what works best for your patient. The distance between the electrodes is related to the intensity that the patient is usually able to tolerate. Decreasing the distance typically decreases the tolerance for the current. This may be due to the fact that when the electrodes are placed closer together, the current travels more superficially than when the electrodes are placed farther apart. Thus, the electrodes should never be placed less than 1 cm apart to avoid blistering and burning of the skin.

Selection of an appropriate electrical-stimulation unit should be based on questions such as the unit’s size, weight, and shape; ease of use; and price. Some therapists may look into other features that are becoming more common in home devices, such as patient compliance and effectiveness recording.

Electrical stimulation is a modality that is designed to control patients’ pain so that they can continue with their lives with fewer restrictions or limitations. Unfortunately, home use is often considered only when all other treatment options have been exhausted. Usually, the device is used on the patient’s last day with only one setup of the unit being attempted. Since there are so many different ways that TENS can be applied and so many variables to consider, one training visit is likely to be insufficient. Thus, two or three therapy visits are recommended to properly ensure that each patient is getting the maximum benefit from the TENS device.

For weekend athletes who are relentless in overexerting themselves physically, a home device may be the most effective way to ensure they treat their pain. To avoid the need for regular use of such modalities, therapists should encourage weekend athletes to condition their bodies with increased frequency of activity to avoid serious injuries.

Suzanne Bowman, PT, is an independent physical-therapy consultant in the Seattle area.