A Clinical Evaluation of Four Lower-Limb Orthoses
Maurice A. LeBlanc, C.P. *
Adapted from Report E-5 of the Committee on Prosthetics Research and Development, National Academy of Sciences. This work was supported by the Social and Rehabilitation Service, Department of Health, Education, and Welfare under the terms of Contract SRS-71-8.
In recent years there have been many new developments in lower-limb orthotics. On March 9-12, 1970, the Committee on Prosthetics Research and Development of the National Research Council sponsored a workshop on lower-limb orthotics  where nineteen different designs were presented, demonstrated on patients, and discussed. As a result of that meeting and subsequent meetings of the Subcommittee on Evaluation, a clinical evaluation of the four orthoses listed below was undertaken in late 1970. \
- University of California Biomechanics Laboratory (UC-BL) Shoe Insert
- New York University (NYU) Insert Orthosis
- UC-BL Dual-Axis Ankle Orthosis
- Veterans Administration Prosthetics Center (VAPC) Single-Bar Above-Knee Orthosis
The following seven clinics were selected originally to participate in the evaluation project:
- NYU Prosthetics and Orthotics Northwestern University Prosthetic-Orthotic Center
- Rancho Los Amigos Hospital Texas Institute for Rehabilitation and Research
- University of California at Los Angeles Prosthetic - Orthotic Program
- University of Miami Department of Orthopedics and Rehabilitation
- VAPC Patient Service Clinic
The VA Hospital in West Los Angeles was added later to the list of participating clinics. NYU and VAPC were not involved in evaluation of the orthoses developed in their own organizations.
UC-BL Shoe Insert (Fig. 1 )
Fig. 1
Purpose
The UC-BL shoe insert was designed to hold the foot in position of function in the shoe. It was developed originally to control the foot when fitting the UC-BL dual-axis ankle-control system. .
Description
The shoe insert is a laminated plastic shell that is contoured to the foot. The insert accomplishes its purpose by stabilizing the foot in a position of proper alignment. It can be used without a brace or a brace may be attached to it (p. ).
Prescription
The UC-BL shoe insert is used to provide correction of nonrigid varus and valgus deformities of the subtalar joint, for painful subtalar joint motion secondary to arthritic changes, and for inflammation of the plantar fascia. It is contraindicated when fixed bony deformities exist.
Fabrication
The general procedure is that a plaster cast is taken of the foot with weight-bearing, and the shell is laminated over the plaster male model. The fabrication of the shoe insert is covered in detail by Henderson and Campbell. .
NYU Insert Orthosis (Fig. 2)
Fig. 2
Purpose
The NYU insert orthosis combines the advantages of the UC-BL shoe insert with the conventional below-knee brace to stabilize the foot in the shoe while providing control of motion about the ankle joint. At the same time cosmesis is improved and interchange of shoes can be made easily because no connection to the shoe is required.
Description
The insert orthosis is a conventional below-knee orthosis with the metal stirrup laminated into a shoe
insert that provides alignment of the foot in the shoe. Standard ankle joints provide A-P control of the ankle, and double uprights with a calf band provide M-L stability of the ankle. A slightly larger shoe may be required when the orthosis is used because of the thickness of the insert and stirrup.
Prescription
The insert orthosis is indicated for flaccid or mildly spastic paralysis of the ankle joint musculature, and for nonrigid varus or valgus deformities of the foot. It is contraindicated when severe spasticity or fixed varus or valgus deformity of the foot is present.
Fabrication
A plaster cast is taken of the foot according to UC-BL procedures for the shoe insert . The ankle joint is aligned on the plaster model, and the stirrup is laminated into the plastic shell over the model. The ankle joints and metal uprights with calf band are attached to the stirrup. Fabrication procedures are detailed by New York University .
UC-BL Dual-Axis Ankle Orthosis (Fig. 3)
Fig. 3
Purpose
The UC-BL dual-axis ankle orthosis was designed to duplicate and control the combined motions of the ankle and subtalar joints in such a way that there is no relative motion between the orthosis and the patient at the points of attachment .
Description
The dual-axis ankle orthosis has two mechanical joints—the lower of which attaches to the shoe — with one metal upright which attaches to a calf band. It accomplishes its purpose by alignment of the mechanical joints to the anatomical ankle and subtalar joints, and by using rubber-band and spring assists about the joints.
Prescription
The UC-BL orthosis is indicated for flaccid paralysis of the plantar flexors, dorsiflexors, inverters, and everters of the foot.
It is contraindicated when pain exists due to increased ankle or subtalar joint motions or when there are rigid deformities of the ankle or subtalar joints. Also, in its present configuration, it cannot be used where weight-bearing is necessary. (A weight-bearing design is under development.)
Fabrication
The general procedure is to take a plaster cast or the toot and lower leg and very carefully align the mechanical joints to the cast which is positioned in the shoe. The joints are then attached to the shoe, the calf band is positioned on the cast, and the upright bent and connected to the joints and calf band. Fabrication of the dual-axis ankle orthosis is covered in detail by Campbell et al. .
VAPC Single-Bar Above-Knee Orthosis (Fig. 4 )
Fig. 4
Purpose
The VAPC single-bar AK orthosis is intended to stabilize the knee and ankle in M-L and A-P directions during stance phase of gait. It is designed to be a light, modular-type orthosis that can be fitted easily .
Description
Stability of the leg is provided during stance by a locked knee. Weight-bearing is not provided. The single-bar construction has the advantage of reducing weight and bulk. The orthosis is comprised of the following components: a half stirrup with ankle joint mounted to the shoe; a lateral, round, stainless-steel upright; a metal calf cuff which extends upward medially to the tibial condyles; a locked knee joint with posteriorly offset center of rotation; and a metal thigh cuff which spirals downward medially to encompass two thirds of the thigh. The cuffs are covered with leather and closed with Velcro. The modular system permits the following: various diameter uprights for strength; posterior or anterior ankle stops; telescoping uprights that accommodate axial and rotational movement; proximal extension of uprights to include the hip joint; and free knee if the patient is able to use it.
Prescription
The VAPC device is indicated for instability of the knee and ankle when functional control of the hip is present. It can be used bilaterally, thereby eliminating both medial uprights present on conventional above-knee braces.
It is contraindicated where there is lack of hip control, fixed deformities of the knee or ankle, need for weight-bearing, or presence of marked spasticity.
Fabrication
Fabrication procedures are similar to those for a conventional above-knee brace except that the thigh and calf cuffs are shaped and fitted so as to provide appropriate reaction forces on the medial side normally provided by the medial uprights .
Fig. 5
Evaluation Procedure
Orientation Sessions
An orientation session was held on August 24-28, 1970 at UCLA for the developers to familiarize clinic teams with the two UC-BL orthoses and for CPRD staff to familiarize clinic teams with evaluation procedure. A similar orientation session was held on October 26-30, 1970, at NYU covering the VAPC and NYU orthoses.
Selection of Patients, Clinical Fittings, and Evaluation Forms
Following the orientation sessions, the clinics returned home and selected patients according to the developers' prescription criteria. The patients were fitted with the new orthoses for a one-month trial-wear period. Before and after this time, evaluation forms were completed by the clinic teams to report the results. The instructions and evaluation forms for this procedure are attached as Appendix A.
Site Visits
The CPRD staff made site visits to all the clinics once during the interim period and once at the completion of the evaluation. When possible, developers accompanied the CPRD staff in seeing patients and talking with the clinic teams. These site visits were valuable in assessing the progress of the evaluation, in resolving minor fabrication and fitting problems, and in supplementing the information recorded on the evaluation forms.
Subcommittee on Evaluation Meeting
A meeting of the clinics, developers, and members of the Subcommittee on Evaluation was held August 5-6, 1971, in Washington, D.C., to discuss the results of the evaluation.
Results
Number of Clinical Fittings
A total of 84 fittings was made by the participating clinics as shown below.
Table 1
Summary of Clinical Fittings Of the UC-BL Shoe Insert
- Patients: 31 fittings on 21 patients (10 bilateral); 11 male, 10 female; age range 7-78
- Diagnosis:
| flat feet |
5 |
| plantar fasciitis |
4 |
| polio |
3 |
| metatarsal pain |
2 |
| arthritis |
1 |
| weak arches |
1 |
| subtalar joint pain |
1 |
| hemiplegia |
1 |
| talipes cavus |
1 |
| talipes varus incomplete |
1 |
| quadriplegia |
1 |
- Patient Preference: 17 preferred this orthosis (11 were previous wearers and 6 were not; 3 did not prefer this orthosis (1 was a previous wearer and 2 were not); 1 indifferent
- Clinic Team Opinions: 17 cases —the orthosis was satisfactory; 3 cases—the orthosis was not satisfactory; 1 case—questionable
- Main Advantages: relief of pain; proper support of foot
- Main Disadvantages: requires wider shoe in some cases; difficult to fit well; some became loose-fitting with wear
- Remarks:
- Of the 3 patients who did not prefer this orthosis
1 (arthritis) rejected because of severe swelling
1 (flat foot) rejected because needed only after a long day on feet
1 (heel spurs) was unable or unwilling to participate in the evaluation - The weight of the orthosis is negligible.
- There was a general problem with fitting and trim lines.
- Several inserts were successfully modified with metatarsal bars or pads.
- Two inserts were used in lieu of ankle-foot orthoses, and three inserts were used with ankle-foot orthoses.
- Recommendations for Improvement of Orthosis:
- A thinner (and stronger) material is needed for the insert.
- It would be preferable to be able to reshape the insert.
- Eliminate use of turntable stand and use mirror for correction of foot during casting.
- One suggestion was made to bring the insert up and over the instep of the foot with flexible material for greater comfort and security rather than trimming low on the medial and lateral aspects. This technique might be especially applicable when a stirrup for uprights is to be incorporated into the insert.
- Indications and Contraindications:
The insert appears to be a very worthwhile orthosis for a variety of foot conditions. The only contraindication appears to be the presence of fixed bony deformities or swelling. - Consensus:
It was the consensus that this orthosis is a most valuable addition to patient service. In order to fit it successfully, however, thorough knowledge of how it works and training in fabrication are necessary.
Summary of Clinical Fittings Of the NYU Insert Orthosis
- Patients:
18 fittings on 15 patients (3 bilateral)
10 male, 5 female age range 11-59 - Diagnosis:
| hemiplegia |
5 |
| peroneal nerve loss |
5 |
| paraplegia |
2 |
| arthritis |
1 |
| multiple sclerosis |
1 |
| disc herniation |
1 |
- Patient Preference:
9 preferred this orthosis (6 were previous wearers and 3 were not)
6 did not prefer this orthosis (all 6 were previous wearers) - Clinic Team Opinions:
10 cases—the orthosis was satisfactory
4 cases—the orthosis was not satisfactory
1 case—questionable - Main Advantages:
good control of foot and ankle
lighter
more cosmetic
can change shoes - Main Disadvantages:
wider shoe required in many cases difficult to fabricate and fit well - Remarks:
- of the 6 patients who did not prefer this orthosis,
2 disliked it because of the wider shoe needed
2 had fitting problems with insert portion
1 had swelling and pain with insert
1 preferred previous wire brace - Weight: NYU orthosis—average 2 1/4 lb. conventional orthosis—average 2 1/2 lb.
- There was a general problem of adequately fitting the insert which is crucial to the success of the orthosis
- Recommendations for Improvement of Orthosis:
- A thinner (and stronger) material is needed for the insert.
- It would be preferable to be able to reshape the insert.
- Eliminate the medial bar for light-duty applications to simplify fitting and joint placement.
- Modify the cast to provide more support for the longitudinal arch and to prevent planovalgus and excess pressure along the medial border of the insert.
- Use Loctite to prevent loosening of ankle joint screws.
- Indications and Contraindications:
The only significant addition to those cited by the developer is that this orthosis is contraindicated where swelling in the foot exists. - Consensus:
It was the consensus that this orthosis is a valuable addition to patient service and that its most beneficial use is on patients with M-L instability and/or marked spasticity. The developer made note of minor improvements suggested by clinicians. Remarks made about the UC-BL shoe insert are also applicable to the insert portion of this orthosis.
Summary of Clinical Fittings of the UC-BL Dual-Axis Ankle Orthosis
- 1. Patients:
19 fittings on 18 patients (1 bilateral)
13 male, 5 female
age range 15-71 - Diagnosis:
peroneal nerve loss—7
hemiplegia or hemiparesis—6
incomplete paraplegia or quadriplegia—3
polio—2 - Patient Preference:
14 preferred this orthosis (8 were previous wearers and 6 were not)
4 did not prefer this orthosis (2 were previous wearers and 2 were not) - Clinic Team Opinions:
11 cases—the orthosis was satisfactory
4 cases—the orthosis was not satisfactory
3 cases—questionable - Main Advantages: freedom of movement lighter >more cosmetic
- Main Disadvantages: fabrication is difficult special alignment jigs are necessary insufficient dorsiflexion assist loosening of subtalar joint protrusion at heel
- Remarks
- Of the 4 patients who did not prefer this orthosis,
2(1 peroneal nerve loss and 1 hemiparesis) with no previous orthoses rejected because of poor motivation
1 (polio) preferred cosmesis of IRM spiral orthosis
1 (hemiplegia with spasticity) preferred conventional orthosis due to M-L instability - Weight:
UC-BL orthosis — average 2 lb.
conventional orthosis — average 2 1/2 lb. - One UC-BL orthosis preferred by the patient had been modified to include double uprights for increased dorsiflexion assist.
- Recommendations for Improvement of Orthosis:
- Include frictional control of subtalar joint.
- Consider use of stops at subtalar joint.
- Increase dorsiflexion assist by using double uprights or by rotating stirrup.
- Need stronger ankle assembly.
- Indications and Contraindications:
This orthosis apparently can be fitted to dropfoot conditions of various origins. However, it appears contraindicated where there is M-L instability, sensory loss, or heavy-duty application. - Other Experiences:
The UC-BL staff completed evaluation forms on 7 additional fittings. The results are similar to those described above.
- 5 preferred
-
- 2 did not prefer—
- 1 due to M-L instability
- 1 due to poor motivation
- Consensus
Patients preferred the dual-axis ankle orthosis because of freedom of motion at the subtalar joint and because it is lighter and more cosmetic than the conventional ankle-foot orthosis. While it was difficult to assess the relative merit of the dual-axis feature itself, it was clear that patients very much like it providing they have sensation and sufficient eversion control of the subtalar joint. In particular, patients said they liked it when getting in or out of a car, going over uneven but not too rough ground, and in turning around. It was also evident that several patients did not use the subtalar joint motion when walking, e.g., patients with "old- age" gait or with deformities and limited ranges of subtalar joint motion due to long-standing muscular imbalance of the inverters and everters.
Fig. 6
The patients found the dual-axis orthosis very easy to don and doff. However, it was the strong feeling of all patients that they would like to have an orthosis which fits inside the shoe and is interchangeable with different shoes.
The dual-axis ankle orthosis seems ideally suited for patients who need dorsiflexion and eversion assistance and who have M-L stability and sensation, assuming they have a range of subtalar joint motion to make good use of the orthosis. In practice, most of the long-term polio, peroneal-nerve injury and hemiplegic patients have deformities and limited ranges of subtalar joint motion and therefore are contraindicated. It is also contraindicated in cases of moderate to severe spasticity where the subtalar joint goes into uncontrollable inversion. Its prime use, therefore, seems to be on relatively new cases of peroneal nerve loss where there is the opportunity to allow and maintain subtalar joint motion. Its application can also include patients with stabilized, mild spasticity and a therapeutic device for peroneal nerve injuries where there is a gradual return of function.
Fig. 7
It was estimated by the clinics that 5-10 per cent of patients referred for ankle-foot orthoses could be fitted successfully with the dual-axis orthosis.
Summary Of Clinical Fittings Of VAPC Single-Bar Above-Knee Orthosis
Fig. 8
- Patients:
16 fittings on 12 patients (4 bilateral)
8 male, 4 female
age range 12-55 - Diagnosis:
polio—6
paraplegia or paresis—4
osteoarthritis—1
sciatic nerve loss—1 - Patient Preference:
4 preferred this orthosis (1 was a previous wearer and 3 were not)
8 did not prefer this orthosis (7 were previous wearers and 1 was not) - Clinic Team Opinions:
4 cases—the orthosis was satisfactory
8 cases—the orthosis was not satisfactory - Main Advantages: useful for bilaterals more cosmetic
- Main Disadvantages:
insecure feeling
heavy
lack of interchangeability of shoes - Remarks:
- Of the 8 patients who did not prefer this orthosis,
5 felt unstable
2 disliked the knee lock
1 found it difficult to don and doff - Weight
VAPC orthosis—average 5 1/2 lb.
conventional orthoses—average 3 1/2 lb. (aluminum); average 5 1/4 lb. (steel) - On most fittings the free transverse rotation caused excessive internal rotation of the foot, and therefore this motion was eliminated in the orthosis.
- On most fittings the heavier (3/8" diameter) rod was needed.
- Kneecaps were used on several fittings.
- Recommendations for Improvement of Orthosis:
- Eliminate transverse rotation and spring.
- Place transverse rotation at level of subtalar joint.
- Extend the tibial flare more proximal for increased M-L stability and make cuff of plastic for better contour.
- Modify orthosis to increase stability.
- Improve methods of measurement and fabrication.
- Cast whole leg and fabricate orthosis over cast.
- Provide stronger, lighter material for upright.
- Indications and Contraindications:
Those proposed by developer appear to be satisfactory, though clarification is needed in certain cases. - Other Experiences:
This orthosis is also being fitted for evaluation at several VA orthopedic brace facilities. Results are not yet available. - Consensus:
Most of the patients who did not prefer this single-bar orthosis were previous wearers of a conventional, double-upright, knee-ankle orthosis. Most of the criticism of the new orthosis was that the patients felt "insecure" or "unstable." Upon closer examination patients seemed to feel either that the knee was going to buckle or that there was inadequate M-L stability. These remarks seemed to stem from the shape and location of the calf and thigh shells and from the "springiness of the one upright.
As with the UC-BL orthosis, it was the strong feeling of all patients that they would like to have the orthosis fit inside the shoe and be interchangeable with different shoes. Also, several patients objected to the difficulty of changing clothes with the VAPC single-bar orthoses because it is not readily detachable from the stirrup and shoe.
The VAPC orthosis seems best intended for "light duty" use to hold the lower limb in proper alignment for supporting weight without the need to provide large corrective forces. Except for its weight, the orthosis also seems well indicated for bilateral use since it eliminates both of the medial uprights. It appears contraindicated where there is more than slight varus or valgus of the knee, knee-flexion contracture, severe spasticity, or "heavy duty" use because the single-bar and calf-and-thigh shell construction is not strong enough for these applications.
It is not clear from the developer's prescription criteria or from the 16 clinical trial fittings just what the hip musculature should be to use the orthosis effectively. However, it is clear that at least some hip-flexor power is required. In general, the orthosis was more difficult to fit and align than a conventional double-upright type, but, once fitted, it was easier to make adjustments because only one upright is involved. Also, with only one upright, ankle-joint placement is simplified and it can be placed obliquely to closer simulate anatomical ankle motion. All of the clinics liked the idea of using just one side bar, but all said they would not use this orthosis without making major design changes.
Recommendations
UC-BL Shoe Insert
The UC-BL shoe insert orthosis should be included in the educational program. The manual appears to be satisfactory, though it is possible to use a few alternate techniques in fabrication. The bio-mechanical and fitting principles must be learned well for success to be achieved with the shoe insert.
NYU Insert Orthosis
The NYU insert orthosis should be included in the educational program with the observation that it is particularly worthwhile for patients with M-L instability and/or marked spasticity. The manual appears to be satisfactory, though minor changes in the stirrup hardware need to be made.
UC-BL Dual-Axis Ankle Orthosis
On selected patients, the dual-axis ankle motion afforded by this orthosis is a definite benefit to and is desired by those patients.
The principle of the dual-axis motion and the associated biomechanics of the foot and ankle are very important and should be included in the curricula of the prosthetic and orthotic schools.
Because of the relative time and complexity in fabricating this orthosis and because of the minority of patients for whom it appears indicated, it is doubtful whether it would find wide acceptance by the orthotic field.
There is promise that a simpler, lighter, more cosmetic, plastic, shoe-insert type of ankle-foot orthoses can be designed to incorporate the dual-axis motion. If this can be done, the benefits to the pattient would be improved materially.
This orthosis has established a sound principle for providing an analogue motion of the ankle and subtalar joints, and is regarded as a prototype to be considered in future designs of all joints.
It is recommended that further development and/or production of the UC-BL dual-axis ankle orthosis be held in abeyance while effort is undertaken immediately to find a more optimal way of providing the dual-axis motion using the principles developed by UC-BL.
VAPC Single-Bar Above-Knee Orthosis
The concept of using a single bar is a worthy one and should be further explored, but a major redesign seems to be required before the present design is apt to be accepted widely.
It is suggested that future design and development efforts consider the following points:
- The Nitschke single-bar above-knee orthosis has worthwhile features which might be utilized in the VAPC orthosis; namely, the shoe insert, the strap posterior to knee which tightens when standing and loosens when sitting, the Polysar pretibial cuff, and the Silesian belt for hip control and unweighting.
- The calf shell might be made as a pretibial or half shell. The thigh shell might be made in quadrilateral shape with posterior openings as allowed by patient circumstances.
- The calf and thigh shells might be made of plastic formed over a model from a cast of the leg, thus utilizing plastic instead of leather and obviating the shaping of the metal bands on the patient.
- The stirrup might be attached to a shoe insert made of plastic, giving the advantages of stabilizing the foot inside the shoe and a more cosmetic appearance, and allowing interchangeability of shoes.
Summary Of The Findings
Results of the evaluation indicated that the UC-BL shoe insert and the NYU insert orthosis are worthwhile devices, are ready for clinical use, and are recommended for inclusion in educational programs. The UC-BL dual-axis ankle orthosis was accepted in principle as providing a beneficial function and as a forerunner in allowing anatomical motion; however, it is recommended that its practical application be held in abeyance while efforts to accomplish the same purpose more effectively are completed. The VAPC single-bar above-knee orthosis has some worthy features, but it is the consensus of the subcommittee that a major redesign is required to meet clinical requirements.
References:
- Campbell, J.W., W.H. Henderson, and D.E. Patrick, UC-BL dual-axis ankle-control system: Casting, alignment, fabrication, and fitting, Bull. Pros. Res., BPR 10-11, 184-235, Spring 1969.
- Committee on Prosthetics Research and Development, Report of Seventh Workshop Panel on Lower-Extremity Orthotics of the Subcommittee on Design and Development, National Academy of Sciences, March 1970.
- Henderson, W.H., and J.W. Campbell, UC-BL shoe insert: Casting and Fabrication, Bull. Pros. Res., BPR 10-11, 215-235, Spring 1969.
- Inman, V.T., UC-BL dual-axis ankle-control system and UC-BL shoe insert: Biomechanical considerations, Bull. Pros. Res., BPR 10-11, 130-145, Spring 1969.
- Lamoreux, Larry W., UC-BL dual-axis ankle-control system: Engineering design, Bull. Pros. Res., BPR 10-11, 146-183, Spring 1969.
- New York University insert orthosis fabrication manual (draft), undated.
- VAPC Draft Manual, Single-bar leg and leg-thigh braces, Sept. 15, 1970.
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