O&P Library > Orthotics and Prosthetics > 1977, Vol 31, Num 1 > pp. 29 - 50

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Evaluation Of The Ortho-Walk Type B Pneumatic Orthosis On Thirty-Seven Paraplegic Patients

Michael J. Quigley, C.P.O. *

The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the Councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the Committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
This study was supported by Contract V101 (134) P-350 between the Veterans Administration and the National Academy of Sciences, and Contract SRS 500-75-0001 between the Social and Rehabilitation Service, HEW, and the National Academy of Sciences.

PREFACE

The evaluation of the Ortho-Walk Pneumatic Orthosis was requested by the Veterans Administration (VA) and the Rehabilitation Services Administration (RSA), Department of Health, Education, and Welfare. The Veterans Administration originally became interested in pneumatic orthoses after contacts with the French developers of the Ortazur Orthosis, the forerunner of the Ortho-Walk.

Dr. George Morel of Berck Plage, France, introduced the Ortazur Pneumatic Orthosis in 1965. Although the orthosis was originally used quite successfully on children with osteogenesis imperfecta, Dr. Morel later used it on a three-year-old child with traumatic paraplegia. The orthosis was used still later with positive results by a number of French physicians to stand patients with Duchenne Dystrophy, cerebral palsy, and paraplegia. In most cases, the primary goal of these physicians was to support the knee and hip joints in order to bring the patient to an erect position, with a secondary goal of ambulation.

In March 1973, the vice president of the Aerazur Company, manufacturer of Ortazur in France, and four other staff members visited the Castle Point VA Hospital in New York and fitted three patients with the pneumatic orthosis. A fourth orthosis was fitted subsequently to another patient at this hospital, and all patients were asked to provide feedback to the Veterans Administration Prosthetics Center concerning the utility of the orthoses. This informal evaluation demonstrated that the high paraplegic may be able to use the orthosis for standing, although ambulation was impractical.

A study of both the Ortho-Walk and the Ortazur pneumatic orthoses on 11 patients at Bird S. Coler Hospital, New York, by Maurycy Silber, M.D. , identified several positive physiological outcomes from regular use of the pneumatic orthoses, and underscored the need for a large scale, formal evaluation of the Ortho-Walk pneumatic orthosis on paraplegic people.

The ILC Dover Company* obtained an exclusive license to manufacture and distribute the pneumatic orthosis in the United States, and first introduced a modified version of the Ortazur Pneumatic Orthosis, called the Ortho-Walk, in October 1973 at a combined meeting of the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation in Washington, D.C. ILC Dover is the Division of ILC Industries, Inc. that was the sole designer and manufacturer of the space suits for Project Apollo and Skylab.

National interest in this new orthosis was high, not only because of the large amount of publicity it was given, but also because the Type B Ortho-Walk Pneumatic Orthosis appeared to be of real benefit to people with paraplegia, since it stabilizes the knee, hip, lower spine, and to some extent, the ankle.

The Veterans Administration recognized the possible benefits for the 20,000 paraplegic and quadriplegic patients under its care and requested the Committee on Prosthetics Research and Development (CPRD), National Research Council, to conduct a large structured evaluation of the Ortho-Walk Type B Pneumatic Orthosis on people with paraplegia in VA and other hospitals.

THE POPULATION OF PEOPLE WITH PARAPLEGIA

The National Center for Health Statistics (NCHS) report "Prevalence of Selected Impairments — 1971" states that in the civilian noninstitutionalized population there are approximately 1.4 million people with paralysis, complete or partial. Of this number, about 102,000 people have paraplegia, or 0.5 people per 1,000 persons. Since many paraplegics are institutionalized, the estimate is probably low. Assuming that about 10 percent of the paraplegic population was institutionalized or in a noncivilian status at the time of the 1971 survey, there would be about 112,000 persons with paraplegia in this country at that time. In 1975, there are probably from 120,000 to 140,000 persons with paraplegia in the United States.

According to Peter C. Hofstra, M.D. , Chief of the VA Spinal Cord Injury Services, the population of spinal-cord-injured people is increasing by 10,000 to 20,000 persons per year. The highest incidence of spinal-cord injury occurs in young males between the ages of 15 and 35 years. Approximately 50 percent are paraplegics and 50 percent are quadriplegics.

PRESENT USE OF ORTHOSES FOR PERSONS WITH PARAPLEGIA

The history of the orthotic treatment of paraplegia does not go back much further than World War II, since previous to that time about 90 percent of the spinal-cord-injured persons died from genitourinary infections. The development of antibiotics to combat these infections reversed the fatality rate shortly after World War II .

The physiological benefits of standing persons with paraplegia were first mentioned by Abramson in 1948, who stated that an hour of standing each day will prevent osteoporosis in the lower limbs and helps to prevent urinary calculi and genitourinary infections. In 1964, Rusk , stated that "circulation and nutrition, as well as morale, are also aided by keeping the patient in the upright position for several hours each day."

Rusk also recommended that the tenth thoracic vertebra be used as a landmark when prescribing orthoses; lesions at or superior to this level are usually given double-bar long-leg orthoses with a pelvic band and Knight spinal attachment (current terminology is LSHKAFO, or lumbo-sacral-hip-knee-ankle foot orthosis); lesions inferior to this level are provided with the same orthoses without the spinal attachment, and lesions inferior to L1, are fitted without the pelvic band.

Hahn , Scott , Edberg , and Warren et al., , do not advocate the use of the pelvic band on paraplegic patients. Edberg feels that the pelvic band must apply excessive pressure against the skin to be effective, that it causes difficulty in donning the orthosis, limits flexibility and adds excessive weight. Hahn and Scott state that the two most important considerations for orthotic design for paraplegics are ease of donning and control of ankle dorsiflexion, hence the so-called Craig-Scott design KAFO has no pelvic band, only one thigh band, and a fixed but adjustable ankle joint.

Another method of providing standing mobility to paraplegic people is by using standing frames. Motloch has demonstrated success with the "parapodium," a jointed standing frame for spinal-cord-impaired children. Prast is working on an adult version of Motloch's parapodium, which will provide standing stability and allow "pivot walking," which is a combination of rotating and sliding the base of the device in the desired direction. A "mobile, portable, collapsible set of standing bars" is the way Peizer and Bernstock described another device, called the "Stand-Alone."** In an evaluation of the device on 32 patients, the Stand-Alone proved to provide "hand free" independent standing and mobility on level and slightly sloped surfaces for most paraplegics up to the level of T₈, providing the person could tolerate the standing position.

Despite the various orthotic designs available, and the philosophies that accompany each design, the majority of paraplegic persons will either reject their orthoses or not have them prescribed. There are many reasons for this, the main one being the excessive energy expenditure needed to ambulate in an orthosis. The donning procedure for most orthoses is difficult and time consuming, and once the orthoses are on the patient they often interfere with transfer activities. In addition, crutches are needed for stability while standing and ambulating, which limits the use of the hands and arms. Other problems with standing ambulation for paraplegic patients are the lack of bladder control while standing and the obviously abnormal walking pattern.

Hussey and Stauffer studied the ambulatory function of 164 spinal-cord-injured patients and stated that "no patient achieved any form of functional ambulation without pelvic control*** and there appeared to be no effective method of bracing patients to overcome this deficit." The nerve supply for the pelvic control muscles is affected by a thoracic lesion.

Rosman and Spira reported similar problems in ambulating patients with thoracic lesions. In a study of 35 patients with lesions from the T1 to T11 level who were fitted with orthoses for ambulation, only one patient was ambulating out of the hospital, and five used the orthosis for standing only. The report concluded "that there is an essential difference between the 'occupation' of walking in the non-pressured rehabilitation environment and walking when faced with the problems of everyday life." It further concludes that "some disabled persons with unusual strength, willpower, and motivation for walking will successfully overcome the difficulty, effort, and social strain involved in the continuous use of braces," but that "most will eventually relinquish these goals because the effort proves too great."

Initial studies on pneumatic orthoses showed promise, espeically for patients with thoracic lesions. Silber reported on 11 patients, nine of them with lesions at T12 or superior, in 1975. All patients in the study were inpatients. He stated that all patients could transfer independently, all but one patient could don the orthosis independently, and all could stand and ambulate, although not always independently. Of the six patients who also received conventional metal orthoses, five could not don the orthosis independently. However, after about two weeks training with the pneumatic orthosis, all of them could don it without help. All patients felt that the pneumatic orthosis was more comfortable than the conventional orthosis, and found that it made activities-of-daily-living (ADL) functions much easier. Silber used both the Type A Pneumatic Orthosis which stabilizes the knee only, and the Type B, which stabilizes the trunk, hip, and knee in his study. He also used both the French Ortazur style and its American counterpart, the Ortho-Walk.

Ragnarsson et al., , at the Institute of Rehabilitation Medicine, New York University Medical Center, studied 14 patients using the Ortho-Walk and the French Ortazur pneumatic orthoses. Eleven of these patients were also fitted with conventional metal orthoses. Energy consumption of three patients may have been less with pneumatic orthoses than with conventional orthoses, although it is not clear that the devices were evaluated on comparable tasks. Patients could, however, ambulate further and for a longer time in the pneumatic orthosis. However, only one of ten patients preferred the pneumatic orthosis over the conventional orthosis because of inadequate support at the knees and hips, zipper failures, and most of all, inflation problems. The study concludes that for many reasons the pneumatic orthosis is especially suitable for early ambulation training, but severe mechanical problems limit its usefulness for community ambulation.

In summary, many designs of orthoses are presently prescribed for paraplegic adults but in nearly every case, when a thoracic level lesion is present, the orthoses prove to be impractical and are rejected. Wheeled standing frames are being used successfully on children, and are beginning to gain acceptance with adults. Initial results with pneumatic orthoses were promising, and therefore an evaluation of this orthosis has been conducted.

DESCRIPTION AND FITTING OF THE PNEUMATIC ORTHOSIS

The Ortho-Walk Type B Pneumatic Orthosis (Fig. 1 ) is available in six standard sizes. Each orthosis has three pneumatic beams on the anterior and posterior aspect of each leg. A model with four pneumatic beams on the anterior and posterior aspect of each leg is also available and is recommended for people weighing over 160 pounds. The garmet is made of nylon, and the pressure bladders in the pneumatic beams are polyurethane. The orthosis incorporates values for inflation and deflation, a series of straps and laces for fitting and adjustment, zippers for donning and doffing, and toe lifter straps, which attach to the shoes.

The size of the orthosis needed for a particular patient is determined by relating ten measurements of the patient to a sizing chart, and then choosing the size that most nearly corresponds to the measurements. Custom orthoses are available for people who do not fit into the standard-size range due to obesity, excessive height, etc. The manufacturer recommends that long cotton underwear be worn under the orthosis. Regular clothes may be worn over the orthosis.

Two types of air compressors are available, an AC compressor and a DC compressor. The AC compressor is used as a stationary item, generally used in the household. The DC compressor is termed "portable," and comes with a carrying case, 12-volt battery, and charger. It may also be operated from an automobile cigarette lighter. Other types of inflation techniques, such as small compressed gas cartridges and pumps, have proved to be impractical, although larger cylinders similar to scuba tanks, may be used.

Fitting of the orthosis is generally done by an orthotist, preferably on a waist-high bed or tilt table. The zippers covering the adjustment laces and straps are opened and the orthosis is spread out on the table. The patient (wearing shoes and long underwear) is then positioned supine on the orthosis and the heel straps are secured around his shoes. The position of the patient on the orthosis is then checked, as is the length of the orthosis. The posterior pneumatic beams are aligned in a straight line; then long and short zippers are closed.

The orthosis is inflated to straighten the pneumatic beams and the laces and straps are adjusted to maintain this alignment (Fig. 2 ). The zippers covering the adjustment straps and laces are then closed and the toe lifter strap is fastened to the shoe and tightened until the ankle is held at approximately 90 degrees.

A final alignment check is made when the patient is standing, and two or three additional fitting and adjustments are usually required before an acceptable fitting is obtained.

Wearers of the orthosis may then don it by positioning themselves over the outspread orthosis, attaching the heel straps and closing the long- and short-leg zippers and the abdominal zipper (Fig. 3 ). They then turn on the air compressor, which should be positioned close to the patient, and clamp the inflation hose to the corresponding valve on the orthosis. Once the orthosis is inflated to the recommended pressure of 32 pounds per square inch (psi), as noted on a guage on the compressor, the inflation hose is removed. The patient can then push himself to the end of the bed and uses crutches to push up to a standing position (Fig. 4 ). An alternate technique is to inflate the orthosis while in a sitting position and pull up to a standing position by grasping parallel bars (Fig. 4 ). A "drag-to", "swing-to", or "swing-through" gait can be used. A four-point gait is difficult, if not impossible, to achieve.

In order to deflate the orthosis the wearer positions himself ready to sit in a chair or lay on a bed, opens the deflation valve, and slowly lowers himself.

The orthosis may be worn deflated in a sitting position for the entire day.

Wearers of the pneumatic orthosis are cautioned to avoid burning the material, and to keep sharp objects away from the material.

The orthosis may be washed by hand using a mild detergent, and should be inspected periodically for tears, broken stitches or abraded fabric. The orthosis is mailed back to the supplier whenever repairs are needed.

THE PURPOSE AND ORGANIZATION OF THE EVALUATION

The primary purpose of the clinical evaluation was to determine the indications, training needs, advanatages and disadvantages of the pneumatic orthosis in the hospital, home, and community. The results of the study are to be used by the Veterans Administration and the Department of Health, Education, and Welfare to determine policy, by educational institutions as instructional material and by medical and paramedical practitioners as a guide for patient management.

A steering committee was formed which met in New York on May 1, 1974. The members of the committee were Heiner Sell, M.D., Assistant Director, and Meg McGarrity, Physical Therapist, Institute of Rehabilitation Medicine, New York; Maurycy Silber, M.D., Director of Rehabilitation, and Nancy Hivry, Physical Therapist, Bird S. Coler Hospital, New York; Thomas Pirrello, Jr., Orthotist-Prosthetist, Veterans Administration Prosthetics Center, New York.

At the steering committee meeting the evaluation participants were chosen, the protocol and timetable were set, and other logistical matters were discussed.

EVALUATION CENTERS

The evaluation was a cooperative effort between VA and civilian hospitals. Centers were chosen for various reasons, e.g., past cooperation with CPRD or VA, proximity to another participating hospital of the opposite category (i.e., VA and civilian), or, simply, expression of interest in the study. The centers were:

VA Spinal Cord Injury Services

Miami VA Hospital

Jorge Jacobi, M.D.

David Dupree, C.P.

Evelyn Carrasquillo, P.T.

Betsy Powers, C.C.T.

Richmond VA Hospital

Charles Lamb, M.D.

Hallie Ratliffe, Orthotist

Daniel Kahsar, R.P.T.

Hines VA Hospital

David Stern, M.D.

Wilbur Pearson, C.O.

Helaine Hull, R.P.T.

Palo Alto VA Hospital

Inder Perkash, M.D.

Maurice LeBlanc, C.P.

Deborah Wilson, P.T.

Civilian (non-VA) Evaluation Centers

University of Miami (Jackson Memorial)

Jerry Enis, M.D.

William Sinclair, C.P.O.

Robin Smith, R.P.T.

Northwestern University (Rehabilitation Institute of Chicago)

Bupend Agrawal, M.D.

David Thullen, C.O.

Steve Huber, R.P.T.

Craig Rehabilitation Hospital

Harry Hahn, M.D.

Alton Scott, C.P.O.

Joan Polack, R.P.T.

PROTOCOL

Both specific and general guidelines for patient selection were made. Specific Criteria:

1.  Patients had complete spinal-cord lesions.
2.  The etiology was trauma.
3.  The lesions were between the T1 and T12 vertebral levels.
4.  Severe deformities of the limbs (over 20 degrees) were contraindications.
5.  Patients were selected for size and weight to fit the standard-size Ortho-Walk.
6.  Patients were inpatients while being fitted and trained.

General Criteria:

1.  A sample of patients should be ready for discharge during the study so an evaluation in both the hospital and home setting is possible.
2.  A sample of patients who have had previous experience with conventional metal orthoses would be desirable.

Number of Fittings

The Veterans Administration was to provide up to 35 pneumatic orthoses for evaluation. A pair of orthopaedic shoes, an AC, and a DC compressor were provided with each orthosis. Each of the seven clinics was therefore allowed up to five orthoses. In cases when a patient would not be using his orthosis, other patients could be fitted with it. A minimum of 35 patients were to be evaluated.

Orientation Session

All participants of the evaluation met in New York on July 1-2, 1974. The guidelines were explained to the group, and a final draft of the evaluation form was made. The orthotists and therapists were then taught fitting and training by Dr. Silber, Nancy Hivry, and Melvin Bailey of Bird S. Coler Hospital, and Meg McGarrity of the Institute of Rehabilitation Medicine. The facilities and patients at Coler Hospital were used for the training sessions.

Clinical Trials

The first patients were fitted approximately six weeks following the orientation session. Site visits were made to each center by the CPRD staff, and in two cases by the staff of ILC Dover.

It was apparent that the protocol was too rigid for some of the centers since they were not able to recruit patients. In one spinal-cord-injury center with 160 beds, over 100 patients were quadriplegic. Of the remaining number of paraplegics, over half were hospitalized for pressure sores and most of the remainder were in for urinary problems, surgery, or would soon be moving to a distant city. Only three patients could be recruited in this center during the first few months of the evaluation, despite the fact that it had more beds for spinal-cord-injured patients than the other centers. The protocol was relaxed in order to allow outpatients who could come in for daily therapy to be included.

An interim meeting was held in Miami, Florida, on December 15, 1974. One participant from each center attended this meeting. At this time, six and one-half months into the evaluation, 35 patients had been fitted. Many problems and misunderstandings were taken care of and the date of the final meeting was set.

DATA ANALYSIS

In February, 1974, all centers were requested to send in the completed evaluation forms. The data was then tabulated and prepared for the final meeting.

Table X

PHYSIOLOGICAL EFFECTS

Blood Pressure and Pulse Rate

Each center was requested to take blood pressure and pulse rate measurements with the patient supine and standing, without the orthosis and then with the orthosis. Three patients were not able to reach an upright position on the tilt table without the pneumatic orthosis, before orthostatic hypotension would cause dizziness and an average blood pressure of 92/75. However, with the orthosis on, all three patients were able to reach a 90-degree upright position with a stable blood pressure averaging 113/79 with no sign of dizziness. On one patient the pulse rate decreased by 20 pulses per minute when the orthosis was worn, but the change was inconsequential on the other two patients.

On 17 patients the blood pressure, with the orthosis on in a standing position, rose an average of 4 mm Hg when compared to the readings taken in the same position with the orthosis off. The averages were 117/79 mm Hg with the orthosis off and 121/84 mm Hg with the orthosis on. Average pulse rate on the same 17 patients decreased from 89 to 87 pulses per minute when the orthosis was worn. The comparative blood pressure and pulse rate data was consistent throughout the evaluation, i.e., the blood pressure increased slightly with the orthosis on, and the pulse rate remained stable.

Decubitus Ulcers

Five patients with decubitus ulcers were fitted with the orthosis. There were no complaints concerning retarded healing or aggravation of these ulcers, and no indication that they healed faster in the orthosis. No ulcers were caused by the pneumatic orthosis during the evaluation, even though redness over the knee was noted on many occasions.

Bowel and Bladder Function

Clinics were requested to make general observations concerning bowel and bladder function and catheterization attributable to the orthosis. The orthosis seemed to have no effect on bowel or bladder movements, or on the type of catheterization used.

Pain

One patient could not wear the orthosis because it hurt her back, and another complained of bruises acquired while wearing it. All but three of the other patients felt that the orthosis was immediately comfortable. However, these three patients felt that the orthosis was comfortable after wearing it from 15 to 30 minutes. For two patients with back pain, the orthosis offered considerable relief; one also had scoliosis, so the trunk support was of great benefit.

Spasticity

Two patients reported relief from severe spasticity while wearing the orthosis, although they also stated that the spasticity recurred in a greater than normal amount after the orthosis was removed. In two cases excessive spasticity caused the patients to reject the pneumatic orthosis. Adduction contractures in another patient could not be adequately controlled. Spasticity of the hip flexors kept a second patient off balance to such an extent that he was exhausted after ambulating only ten yards. In general, patients felt that their spasticity was slightly decreased while wearing the orthosis.

Heat

One patient rejected the orthosis because he felt it was "too hot." Another preferred to wear it only on cool days. Five complaints concerning heat retention were made.

ORTHOTIC INFORMATION

Fitting and Adjustments

All orthoses were the Ortho-Walk Type B, three-tube standard suits. The length of time to measure patients for the orthosis ranged from 15 to 30 minutes, and averaged 20 minutes. Fitting times ranged from 20 minutes to two hours, and averaged 50 minutes. Three readjustments are usually needed, and can be done by either the therapist or the orthotist. The average time needed per adjustment is 20 minutes, or a total of 60 minutes for all three. However, some patients needed no readjustments while others needed up to five, and in one case three hours and 20 minutes were spent readjusting the laces.

The reasons readjustments are needed are usually 1) the patient was fitted while supine and the fit changes when he stands, and 2) the laces and straps are new, and "give" slightly when stressed. The most common clinical indication that a readjustment is needed is bending at the knees and/or hips, which can be corrected by either tightening the laces and/or placing special pads in the area of the instability.

Equipment

In all cases but one, the orthoses and compressors were received from the manufacturer in excellent condition. In one case, a suit was returned because of a leak, although the manufacturer stated he could not find the leak. In two other cases, at different clinics, a slow loss of pressure (5 psi lost in 10 minutes) was reported. A possible cause for the pressure problems was the high altitude, since most of these problems occurred in Denver. Another patient caused a leak after burning through the fabric of the orthosis with a cigarette. In no instance did a loss of pressure occur so suddenly that the safety of the patient was jeopardized.

The most common and most serious equipment failure concerned the zippers. In five cases the seam attaching the zipper to the nylon fabric failed. In one case the zipper came off track. The zipper failures were sudden and caused one patient to fall. Another patient had a zipper give way while he was training to descend stairs. The therapist fortunately caught him.

Equipment repairs were made by ILC Dover. All repairs were made satisfactorily, but the length of time required for shipping the orthosis back and forth and for repairs ranged from two to four weeks. Two patients lost interest in the evaluation while their suits were being repaired.

Previous Orthotic Experience

Twelve patients were using metal orthoses prior to the evaluation. Five patients were ambulatory and the remaining seven used them for standing only. Patients wearing orthoses spent from eight to ten hours daily in bed, from two and one-half to three hours standing, and the remaining time sitting. Patients who had not been fitted spent an average of 15 hours daily in bed and nine hours in a chair.

Four patients had an inadequate range of motion. One patient who had bilateral 15-deg. knee-flexion contractures and a 10-deg. limitation of ankle dorsiflexion was fitted and did well in the orthosis. Another patient with a 30-deg. hip-flexion contracture could not stand independently in the orthosis and could ambulate only at great energy expense, but kept the orthosis as a therapeutic device.

THERAPY INFORMATION

Inflation, Standing, Transfers

Seventeen patients preferred to inflate the orthosis while they were in the supine position, and then push themselves over the edge of the bed until their feet contacted the floor. They then grab one crutch, push themselves upright, and pick up the second crutch.

Sixteen patients preferred to inflate the orthosis while they were sitting and either pull themselves up by grasping parallel bars or push themselves up by turning around in front of the wheelchair and pushing up from the armrests. Three patients were brought to 90 degrees on the tilt table before inflating the orthosis.

Joint Stability

Three patients did not receive enough trunk support, and 11 patients did not have enough knee stability (Fig. 5 ). The normal posture in the pneumatic orthosis differs considerably from the extended posture seen with metal orthoses. The trunk and hips are in a neutral position in the Ortho-Walk, rather than extended, and the knees stay slightly flexed. This different type of posture undoubtedly caused many to think that inadequate stability was provided.

Seven patients thought the lack of ankle stability was a problem. The Ortho-Walk prevents plantarflexion by having an anterior strap extend to the shoe laces, but allows free dorsiflexion.

Time and Distance

Patients wore the orthosis for an average of 20 minutes a day deflated, and 30 minutes a day inflated. The average distance traversed was 54.0 yards in 24 minutes, or 6.75 feet per minute. One patient, however, covered 300 yards in 45 minutes, which is a rate of 20 feet per minute. This patient was 5 feet 11 inches tall, weighed 160 pounds, 26 years of age and was able to press 260 pounds when weightlifting.

Donning and Doffing

Twenty-three patients were able to don the orthosis independently; seven needed major assistance and three needed minor assistance. The time needed to don the orthosis ranged from eight to 60 minutes and averaged 25.5 minutes.

Twenty-seven patients could doff the orthosis independently; two needed major assistance and five needed minor assistance. The average time needed was nine minutes and ranged from three minutes to 20 minutes.

Fifteen patients could independently don clothes over the orthosis; three needed assistance.

Transfers, Stairs, Recoveries

Transfers from a sitting position to a standing position were made independently by 18 patients. Fourteen needed assistance. Approximately five therapy sessions of 30 minutes each were needed before patients could transfer independently. All but six patients could deflate from a standing position independently. Patients were able to achieve this after about four therapy sessions of 20 minutes duration.

No patients were able to climb stairs independently, although seven could climb them with assistance. Six patients could handle a six-inch step or curb independently.

Eight patients attempted to learn fall recoveries, but only one could recover independently. He achieved this by first unfastening the abdominal zipper of the orthosis, then jacknifing and climbing his walker.

Gait Patterns

The most commonly used gait pattern was the "swing-to" pattern, which 17 patients adopted. Nine preferred to "drag-to" and nine used the "swing-through" pattern (Fig. 6 ).

ACCEPTANCE

Fourteen of the 37 patients chose to accept the orthosis for regular, if in some cases limited, use. The remaining 23 rejected it.

All of the patients accepting the Ortho-Walk were males. The average age of this group was 34 years, whereas the average age of those rejecting the orthosis was 30 years.

The height and weight of the patients accepting the orthosis averaged 69.6 inches and 141.5 pounds. Four of the patients were described as having normal body builds, four were listed as thin and six were muscular. All three patients who were considered obese rejected the orthosis. The average height of patients rejecting the orthosis was one-half inch less than those accepting it, and the average weight of those who rejected it was four pounds greater.

The age of injury (time from date of onset of paraplegia to fitting with the Ortho-Walk) for patients who accepted the pneumatic orthosis was two years less than those who rejected it (23 months versus 47 months).

The average lesion level for patients who accepted the Ortho-Walk was T₈-T₉, whereas the level of those who rejected it was T₅-T₆.

The follow-up time for all patients was from one month to eight months. Two of the patients who were only followed for one month were listed as accepting the orthosis.

Of the 23 patients who rejected the orthosis, the most common reasons for rejection were excessive energy consumption and inadequate stability at the knees, hips, and ankles. Two patients needed to have their ankles bound together in a "hobble" to prevent their legs from abducting excessively (Fig. 7 ); lack of motivation rated next as the reason for rejection. The motivational problems generally occurred once the patient realized the amount of effort required for standing and ambulation. Four patients started out highly motivated, but were listed as having poor motivation when they rejected the orthosis.

Poor cosmesis was listed as the reason for rejection by three patients, who stated that the thoracic section was too bulky, and that wearing clothes over the orthosis was impractical (Fig. 8 ).

Six patients preferred their metal knee-ankle-foot orthoses (KAFO'S) to the Ortho-Walk, and in three cases the reverse was true. Of the six preferring the metal KAFO'S, three patients used the Craig-Scott design orthosis and three used conventional designs.

Three patients listed donning problems as one reason for the orthosis being rejected. These patients had higher lesions (T₄) and it took them from 25-60 minutes to don the orthosis independently. With assistance, the donning time was considerably shortened.

Ten patients took the orthosis home. Of these ten patients, two use it daily outside of the household, for school, work, and social activities. Three of these patients use the orthosis daily for household ambulation. Of the remaining five patients who took the Ortho-Walk home, one uses it two to three hours a week in the kitchen; another uses it one hour a day for exercise; one patient uses it once a week for 30 minutes of exercise, and two patients use it rarely, i.e., about once a month.

In summary, patients who accepted the Ortho-Walk pneumatic orthosis were those in good physical condition with thin to muscular builds. A positive attitude towards standing and ambulating, combined with good motivation, also appeared to underlie acceptance. Perhaps these patients experienced a significant psychological boost from being upright, which justified for them this relatively inefficient technique of standing and ambulating.

It should also be noted that only those patients who fitted into the standard Ortho-Walk-size range were selected for the study. If a random selection process had been used, a larger number of patients would have fallen outside the average height and weight range (69.6 inches and 141.5 pounds) of those patients accepting the orthosis; and, therefore, a higher rejection percentage would have resulted.

COMPARISON BETWEEN VA AND NON-VA PATIENTS

The average age of VA patients in the study was 8.8 years greater than that of non-VA patients (35.6 years vs 26.8 years), mainly because there were five VA patients who were 45 years of age or older, with injuries incurred a number of years previously. None of the non-VA patients were of this age. Ages of injuries were also highest in the VA groups, averaging 51 months vs 11 months for non-VA patients. Older patients with "long-standing" injuries were more prevalent in the VA population because they generally kept in closer contact with the local VA hospitals, were aware that the study was going on, and requested to be participants.

Ten of the 23 VA patients, or 43 percent, accepted the pneumatic orthosis for the trial period, while only four of the 14 non-VA patients (28 percent) accepted it. The probable reason for the slightly higher acceptance rate at VA hospitals lies in the longer period of training they provided and their general tendency to be freer with their time. The private hospitals had problems justifying financially long training sessions over many weeks. Also, a few of the VA patients who were listed as accepting the orthosis were still in training at the end of this study, and may have rejected it later. In general, the private hospitals provided less training and discharged patients earlier than VA hospitals.

CONCLUSIONS

On March 17-18, 1975, all participants of the evaluation met at Craig Rehabilitation Hospital in Englewood, Colorado, to discuss the results of the evaluation (Appendix E). The participants met in a plenary session, then divided into three groups: physicians, therapists, and orthotists, to draw conclusions and make recommendations from the evaluation.

No age limit was set for patients who wish to use the orthosis, but the height and weight were determined to be crucial factors. The participants agreed with the manufacturer that patients taller than six feet and in excess of 160 pounds require a four-tube suit instead of the standard three-tube design. Patients who are obese will have a minimal success rate and should have a custom suit designed if a good fit and proper support are to be expected. Patients with thin to muscular body builds have the best chance to achieve functional standing and walking.

People who work or study seem to make more use of the Ortho-Walk because of their desire to be active. Lack of accessibility to wheelchairs on a job, or employment requiring a standing position are both indications for lower-limb orthoses, including the Ortho-Walk design.

Patients who need to be very mobile, i.e., in and out of cars, planes, different businesses, will generally be hampered by lower-limb orthoses. The Ortho-Walk is contraindicated for these people due to the problems with inflation, deflation, and transfers.

Previous orthotic experience does not seem to affect the acceptance of the pneumatic orthosis, as six patients who wear metal KAFO'S preferred them to the Ortho-Walk, but the reverse was true for three patients. All patients who use the Ortho-Walk outside of the hospital should also be wheelchair independent. It was recommended that patients having success with previous orthoses are doing well enough and should not be encouraged to change to the Ortho-Walk.

The etiology of the lesion did not affect the results in the orthosis, nor did the level of the lesion. In fact, of those who accepted the orthosis, the three patients with the highest lesions were among the most successful users. More experience during the medical stabilization phase is needed with patients with high lesions before any conclusions can be made about the use of the orthosis in this situation.

A small study at the Miami VA Hospital indicated the Ortho-Walk did aid venous return and increased the blood pressure and volume to the kidneys. Therefore, cardiovascular conditions do not contraindicate the use of the orthosis for standing, but these patients should be watched closely, especially if ambulation is attempted.

The Ortho-Walk did not impair the respiration of any patient, and aided one patient in this respect.

Spasticity is not a contraindication to using the Ortho-Walk. In most cases, patients stated and therapists observed that the severity of spasticity was decreased or eliminated shortly after the application of the pneumatic orthosis.

The presence of decubitus ulcers does not necessarily contraindicate use of the Ortho-Walk. Five patients with decubiti in areas covered by the orthosis did not have any problems, and healing continued at a normal rate. On the other hand, there were indications of substantial increases in pressure under the suit, and (as noted earlier) reddening in several areas was observed after use.

A positive attitude of both the patient and the rehabilitation team is of utmost importance. A negative attitude towards standing or towards the different type of orthosis by the members of the team will quickly pass on to the patient, and the chances of functional standing and ambulation will be decreased.

The orthotists concluded that there were no problems with the recommended measurements, that the range of standard sizes was adequate and that the initial fitting procedure was good. No mechanical problems were encountered with the pneumatic beams, the AC and DC compressors, or the inflation valves. It was recommended that the deflation valve be redesigned so it can be left open, thereby freeing up the patient's hands while the suit is deflating. This would also allow air to continue escaping while the wearer is seated.

Miniaturization of the inflation mechanism was recommended. The portable compressor in the present system is too bulky and heavy to be carried by a paraplegic while he is standing, and the user must have a compressor available any time he wishes to stand. Small C0₂-type cartridges have been used in the past with minimal success, and it is recommended that a similar approach to inflation be perfected.

The donning procedure proved to be one of the major problems with the orthosis. Patients who could don the orthosis independently were often too exhausted to transfer, stand, and ambulate. No solution to this problem could be found during the evaluation.

The lack of a dorsiflexion stop at the ankle caused a few patients to feel unstable, and made it necessary for patients to use crutches when standing. Patients who expect to use the orthosis outside of the hospital for functional standing should also receive ankle-foot orthoses to provide anterior stability at the ankles.

PRACTICALITY FOR THERAPEUTIC USE

The Ortho-Walk pneumatic orthoses are practical for therapeutic use in the medical stabilization and rehabilitation phases of patient care in spinal injury when standing and ambulation are desired goals. Certain temporary psychological advantages seem to be offered, and it provides the rehabilitation team with one method of evaluating a patient standing before any further orthotic prescriptions are made. The adjustability and modularity of the suits allow them to be used on many patients. A stock of three to six suits can be fitted to most patients.

It is recommended that, whenever possible, any patient who may be a candidate for the Ortho-Walk receive a minimum of 40 hours of physical therapy in a stock suit of the correct size before a suit is ordered specifically for him.

PRACTICALITY FOR HOME AMBULATION

The Ortho-Walk Type B pneumatic orthosis has no real advantages over conventional orthoses in functional ambulation. The advantages of light weight is offset by the inconvenience of inflation and deflation, and the added difficulty of climbing stairs and recovering from falls. For use on level surfaces in the home, the Ortho-Walk has proved to be practical.

PRACTICALITY FOR COMMUNITY AMBULATION

The Ortho-Walk pneumatic orthosis has no real advantages over conventional orthoses for community ambulation. In the community, the disadvantages of the inflation system and of cosmesis are more apparent than in the home. The user must either have a number of compressors strategically located in the home, car, office, or school, or have an assistant carry a compressor with him. The noise of the compressor when inflating and of air escaping when deflating has drawn attention to the user of the orthosis in public places.

SUMMARY AND RECOMMENDATIONS

Based upon data collected from seven hospitals and 37 paraplegic patients with thoracic lesions, the following conclusions and recommendations were made concerning the Ortho-Walk Type B pneumatic orthosis:

ADVANTAGES

•  Less weight than conventional orthoses.
•  Temporary positive psychological reaction.
•  Cost is reasonable when used as stock item on many patients.
•  Adjustability and adaptability allows rapid application in the early treatment phase.
•  Possible energy expenditure savings during ambulation.
•  Adequate trunk support.

DISADVANTAGES

•  Difficult and time-consuming to don.
•  Inflation-deflation system is impractical.
•  Provides less support to lower limbs than conventional orthoses.
•  Cosmesis is poor, especially for women. Conventional orthoses are more cosmetic.
•  Mobility is decreased. Stair-climbing and transfers are more difficult than with conventional orthoses.
•  Maintenance and repairs must be made by the manufacturer, necessitating long waits due to mailing time.
•  Cost is higher than conventional orthoses when used for one patient only.

RECOMMENDED IMPROVEMENTS

1.  Improvement of the inflation-deflation system by miniaturizing the pressure source. An alternative solution may be the addition of knee and hip joints.
2.  More ankle stability be provided, specifically to prevent dorsiflexion.
3.  Ventilation of the suit.
4.  The color of the suit (blue) is not cosmetic and could be improved.

RECOMMENDATIONS FOR FUTURE STUDIES

1.  A study of the pressures at the interface between the pneumatic suit should be made. Redness usually occurs over bony areas when the suit is worn and clinicians are fearful that long-term standing may lead to skin breakdown.
2.  More basic bioengineering is needed if pneumatic orthoses are to be made practical and be universally accepted.
3.  Evaluation of other systems of mobilizing paraplegic patients should be made, such as that undertaken by Lehman et al. on the Craig-Scott design knee-ankle-foot orthosis, which is used successfully in the Denver area. A quantitative study would be useful to compare pneumatic orthoses with standard knee-ankle orthoses used in paraplegic ambulation.
4.  A careful study should be done to verify and document reported psychological and physiological benefits accruing from the use of various orthoses.

CONCLUDING STATEMENT

The concluding statement of the participants in the evaluation was that the Ortho-Walk Type B pneumatic orthosis has the potential for being a tool in the early rehabilitation of spinal-cord-injured patients. Its relative adaptability and ease of use in the early rehabilitative phase has the advantages of a temporary psychological lift, early screening of potential candidates for orthoses, and possibly aiding and improving the physical status of these patients. When considering candidates for the pneumatic orthosis, individualization of patients is a must, just as with conventional orthoses.

This study has shown that, as with all new ideas, the Ortho-Walk is not a panacea. Many improvements must be made before it can equal the merits of conventional metal orthoses. The idea of pneumatic splinting for paralyzed people is a feasible one, but it still needs much work. The fact that a private manufacturer can research, develop, and market such an innovative device without outside support is an accomplishment in itself. Ideas such as the Ortho-Walk can stimulate research teams in different disciplines to work jointly for the ultimate goal of better care for the spinal-cord-injured patient.

ACKNOWLEDGMENTS

The Committee on Prosthetics Research and Development wishes to thank Maurycy Silber, M.D., and his staff at Bird S. Coler Hospital for providing the training for evaluation participants; G. Heiner Sell, M.D., and his staff at the Institute for Rehabilitation Medicine, for lending their expertise to steer the evaluation along with Dr. Silber. Harry Hahn, M.D., and his staff at Craig Rehabilitation Hospital also receive our thanks for hosting the final meeting of the evaluation. The evaluation could not have been conducted without a great amount of effort, which was contributed by seven physicians, seven orthotists, and eight therapists, to whom the Committee is most grateful.

Table 1, Table 2

*ILC Dover Company, 350 Pear Street, Dover, Delaware 19901

**Stand Alone, Corporation for Medical Engineering, 8472 East Garvey Ave., San Gabriel, California 91771.

***The Term "pelvic control" used here refers to the ability of the abdominals to move the pelvis when body weight is on the crutches

References:

1. Abramson, S.A., Bone disturbances in injuries to spinal cord and cauda equina (paraplegia). J. Bone and Joint Surg. 30-A:982-987, October 1948.
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3. Hahn, Harry, Personal communication, March 1975.
4. Hofstra, Peter C., The clinical engineer and the spinal-cord-injured person. Bull. Pros. Res. 10-22:37-40, Fall 1974.
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7. Motloch, W.M., The Parapodium: An orthotic device for neuromuscular disorders. Artif. Limbs 15:2:36-47, Autumn 1971.
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10. Ragnarsson, K.T., G. Heiner Sell, Margaret McGarrity, and Reuven Ofir, Pneumatic orthosis for paraplegic patients'. Functional evaluation and prescription considerations. Arch. Phys. Med. Rehab. 56:11:479-483, November 1975.
11. Rosman, N., and E. Spira, Paraplegic use of walking braces: A survey. Arch. Phys. Med. Rehab. 55:7:310-314, July 1974.
12. Rusk, Howard A., Rehabilitation Medicine, Second Edition. C.V. Mosby Co., St. Louis, Missouri, p. 503, 1964.
13. Scott, Bruce A., Engineering principles and fabrication techniques for the Scott-Craig long leg brace for paraplegics. Orth. and Pros. 25:4:14-19, December 1971.
14. Silber, Maurycy, Tae-Soo Chung, George Varghese, Catherine Hinterbuchner, Milton Bailey, and Nancy Hivry, Pneumatic orthosis: Pilot study. Arch. Phys. Med. Rehab. 56:1:27-32, January 1975.
15. Warren, C.G., J.F. Lehmann, and B.J. DeLateur, Use of the pelvic band in orthotics for adult paraplegic patients. Arch. Phys. Med. Rehab. 56:5:221-223, May 1975.

O&P Library > Orthotics and Prosthetics > 1977, Vol 31, Num 1 > pp. 29 - 50