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       Since 1950 when the profession of Athletic Training began, acute traumatic

injuries were treated with rest, ice, compression and elevation (RICE). 4 This

method is still used today because it is clinically proven to be effective to treat

edema and manage pain. Preventing and treating edema can be difficult and time

consuming, especially for Athletic Trainers trying to rehabilitate athletes back into

the game. “Edema is the result of an imbalance in the filtration system between the

capillary and interstitial, which causes venous obstruction, increased capillary

permeability, and increased plasma volume secondary to sodium and water

retention.” 13 Edema is commonly encountered in clinical setting of Athletic

Trainers. “It usually results from an imbalance of forces controlling fluid

exchange.”8 Edema is characterized as a buildup of excessive fluids in a interstitial

space in the body due to an underling injury to muscle tissue. 8 Edema mostly

affects lower extremities like the foot and ankle. Blood circulation of the involved

limb is obstructed and can possibly be very painful. It also affects the healing

process, causing it to delay and can develop ischemia. Edema can also increase the

chance of a skin infection, which can be dangerous if left untreated.

Protocols with Electrical Stimulation on Edema

      Over the years, clinicians frequently use electrical stimulation to prevent and

reduce postacute edema. Today’s research supports the use of electrotherapy for

curbing and reducing edema. Electrical stimulation may increase venous return and

deplete lymphatic fluids when exercise cannot be performed. Using electric
stimulation creates a muscle contraction that may reduce edema. 7,14 Studies have

been done on several animals to find out the effectiveness on quite a few varieties of

electrical stimulation (ES), but high-voltage pulsed current is used mostly for

controlling acute posttraumatic edema.10 High-voltage pulsed current (HVPC) was

designed to manage edema with sensory level stimulation. “It provides a

monophasic current with a twin peak waveform, a relatively short pulse duration

with a long interpulse interval and an amplitude range above 150 mVolts”.7 The

most effective method for edema control is to initiate treatment within six hours

after injury. Using high sensory-level electrical stimulation to treat edema can

increase lymphatic flow, but does not decrease limb volume. 10

      Another method to mange swelling is using a motor-level stimulation for

edema reduction. This protocol generates repetitive muscle contractions to assist in

lymphatic and venous return by forcing fluids out from the involved limb. With a

low pulsed frequency and a comfortable muscle contraction can increase the muscle

milking effect to relieve edema. One research study experimented on the effect of

neuromuscular stimulation (NMES) on ankle swelling. NMES is used frequently to

decrease swelling in the early period of the inflammatory phase of the healing

process.9 Neuromuscular electrical stimulation is mostly designed for muscle re-

education to prevent atrophy. The electrodes are placed on healthy muscles and the

intensity creates muscle contractions similar voluntary muscle contractions.
Effects of High-Voltage Electric Stimulation on Edema Prevention

      Over the years experimental studies revealed that cathodal high-voltage

pulsed current (CHVPC) at 120 pulses per second and 90% of motor threshold is

successful in curbing acute edema development in laboratory animals. 9 One

experiment’s objective treatment effects with ibuprofen and (CHVPC) on acute

edema formation with treatment of ibuprofen and CHVPC after direct trauma. The

subjects used for this study were 21 Zucker Lean rats. It is believed that rats in

general probably serve as useful models for humans with regard to aspects of the

inflammatory response.3 Recent studies confirm positive treatment effects with

Zucker Lean rats than any other rat specie. 3 Measurements were taken before and

after blunt trauma. Measurements of limb volumes of each participant were also

taken every thirty minutes over the four hours of treatment. The procedure to form

edema consisted of a steel rod being dropped on each of the subject’s foot. The

precipitants were then divided into three groups. Group one consisted of taking a

nonsteroidal anti-inflammatory drug; group two received electrotherapy and group

three received a combination of both. Animals who received ibuprofen was injected

100mg of IBU per 5mL to the stomach. Animals in group two received three

received continuous hours of CHVPC at 120 pulses per second and 90% of motor

threshold in water for four hours. 4

      The results of the experiment confirmed that the treated limbs were smaller

than those of untreated limbs for all treatments after 30 minutes. The results

remained the same throughout the four hour experiment. The measurements also
concluded that swelling was reduced to 50% compared to the untreated limbs, but

no treatment was more effective than the other.

      It is interesting how each of the three groups that were treated differently for

curbing edema resulted in the same measurements. Researchers did measurements

every thirty minutes for the four hour treatment. If measurements were taken

twenty four hours after the experiment, the findings from the day after treatment

might have shown different results from each of the three groups. This hypothesis

can determine what treatment was more effective.

      Another research study was to determine to find the best approach to control

edema with high-voltage electrical stimulation with cool water immersion, in both

alone and in combination of treatment. This experiment used thirty-four

anesthetized Zucher Lean rats as subjects. Each of the subject’s limbs was

measured for volume before and after direct trauma to create edema.

Measurements were also recorded after each of the four treatments and rest

periods. Each participant were randomly received treatment of cold water

immersion, cathodal high-voltage pulsed current or combination of both techniques.

Both feet of the thirty four subjects were traumatized by dropping a steel rod that

weighed 85.5 g with a height of 30cm. The subjects were then assigned to one of the

three groups. The thirty minute rest periods started as soon as each of the rat’s

limbs were traumatized and edema was formed. The cool-water immersion,

cathodal high-voltage electric stimulation, and simultaneous application of these
treatments were effective in curbing edema after blunt injury. The combination of

CWI and CHVPC was not more effective than either CWI or CHPC alone. 2

      The combination of the cool water immersion and high-voltage electrical

stimulation wasn’t more effective due to the result of gravity. Immersing an acute

traumatic ankle in water is a fight against gravity. High-voltage pulsed electrical

stimulation would have the best results if it was performed with some elevation.

Elevating the injured site above the heart alone will reduce the formation of edema.

Effect of Neuromuslcular Electrical Stimulation on Edema

      A variety of treatment protocols are used to control swelling in the postacute

phase of an injury. It is thought that neuromuscular electrical stimulation (NMES)

that stimulates muscle contractions can compress venous and lymphatic vessels.

This mechanical effect may assist in the resolution of posttraumatic and chronic

edema. 9 Provoking muscle contractions by using neuromuscular electrical

stimulation may increase venous return and lymphatic flow, which may reduce

edema. Ivy Man studied neuromuscular electrical stimulation on edema. The

purpose of his experiment was to evaluate neuromuscular electrical stimulation

effectiveness of decreased swelling in the acute phase of an ankle sprain.

      Thirty-four subjects within 18 to 60 years of age were used as subjects for

Man’s study. All participants were recovering from an ankle sprain. Measurements

were taken from each subject. Body mass, height, and ankle girth were measured.

Ankle girth was measured with the figure eight tape technique. The participants

were then submersed their leg into a jug of water. The displaced water was collected
and weighed. The same jug was used in each trial to collect the displaced water and

was used before and after each trial. 9 The purpose of placing the injured leg into a

jug of water signifies amount of swelling in each of the subject’s ankle.

      The subjects were then placed into three groups and scheduled for three

sessions at 30 minute treatments. The participants were not informed on what type

of treatment they were going to be assigned. The three groups were set up with four

electrodes applied over the tibialis anterior muscle and the gastroenemius. Group

one received NMES and group two received submotor electrical stimulation. Group

three was given sham treatment. For the subjects in the NMES group, the intensity

of ES was set to the subjects' maximum level of tolerance and was adjusted if

necessary throughout the 30-minute test period. 7 The submotor electrical

stimulation groups had a total of 360 cycles, with each cycle lasting 5 seconds.

“Each cycle consisted of 400 pulses having different combinations of pulse-to-pulse

intervals and duration values.” 7 The participants in the sham electrical stimulation

group were informed that they shouldn’t feel anything during the 30 minutes of


      The data was collected and calculated from all the subjects. The results

showed no significant difference among the three different treatments. This

experiment implies that the NMES has no beneficial results compared to the other

two groups.

Stimulation on Edema Reduction

      Edema that continues for several weeks can be frustrating to reduce

especially if it involves with the upper extremity. 6 Many studies have been done to
find the best protocol to reduce edema. Mohr is one of the early researchers who

experimented on the effect on edema reduction on rats with high voltage electrical

stimulation. 11 Mohr discovered that muscular movement can increase venous

drainage, lymphatic flow, and increase blood flow. 11 “Newton compared changes in

edema and range of motion in patients with posttraumatic hand edema when HVPC

was combined with placement of the affected hand in cool water.” 6 The result of

Newton’s study shown that range of motion progressed but edema did not diminish

after treatment with high-voltage pulsed current.

      One particular study focuses on the results of Mohr’s experiment, and

compares the effectiveness of intermittent pneumatic compression (IPC), High

voltage pulsed current and placebo HVPC with chronic hand edema. The

participants in this study include thirty patients with chronic posttraumatic hand

edema. The subjects were randomly assigned to one of the three groups where they

received one day of treatment for a thirty minute period. “During HVPC treatment,

one active electrode was placed over the median nerve in the antecubital fossa, with

another over the ulnar nerve at the medial epicondyle.”6 According to Bolter, he

revealed an increase in lymphatic flow using a 10 pps frequency to induce

continuous muscle contractions. This experiment used a set frequency of 8 pps. It is

significant to elicit minimal contractions of the hand muscles to prevent fatigue. 6

      The hand volume measurements before and after treatment found no

significant difference between HVPC and the placebo HVPC treatment. However,

the results of intermittent pneumatic compression indicated a significant edema
reduction in some participants after one 30 minute treatment. The researchers for

this experiment believe protocols needed to be rearranged with the high-voltage

pulsed current treatment. They believe a longer treatment time and a different

electrode placement may have shown greater results with edema reduction with

HVPC treatment. The researchers stated that the next step is to further evaluate

the effectiveness of IPC and HVPC for reduction of posttraumatic hand edema.

Most Effective Treatment

      The measurements with the use of NSAIDs and HVPC concluded that edema

was reduced by almost half compared to the untreated limbs, but no treatment was

more effective than the other. This confirms ibuprofen and high-voltage electrical

stimulation is effective for curbing edema but the combination of the two doesn’t

show a greater effect. The data collected from the subject experimented on NMES

verified no beneficial results with controlling swelling in the ankle. The study that

measured hand volume between HVPC and the placebo treatment concluded no

significant difference. However, a significant amount of edema was reduced when

compared with the results with the IPC treatment. This shows the most effective

treatment when out of all of the following experiments.


      Edema formation can cause pain and reduce range of motion. It obstructs the

healing process and is frustrating and difficult to manage. Clinical research studies

focused on finding on a protocol that benefits best with curbing and reducing edema.

      Clinical experiments have been performed to curb and reduce edema.
Research tried using certain protocols to treat edema in the postacute phase of an

injury with electrotherapy. Electric stimulation is proven to be successful in curbing

acute edema formation in animals. 2 Other research studies experimented and

shown cryotherapy high-voltage electrical stimulation and NSAIDs reduce

permeability of lymphatic flow. From the preceding research studies discussed,

electrical stimulation had little or no effect when it comes reducing edema.

However, the most effective protocol for curbing edema was the intermittent

pneumatic compression and high-voltage pulse current.

      The true purpose of all the clinical experiments was to find a technique that

would be most effective to curb edema after acute trauma. By creating a better

healing environment from controlling edema, athletes can recover more quickly

from a minor acute injury. Today, the best method for dealing with edema is RICE,

which is being used for over fifty years. However, it is understandable that further

research is needed involving electric stimulation treatment on edema.

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