Adaptive Therapy and Bracing in CMT (continued)

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Reciprocating Gait Orthoses

This is a particular type of hip-knee-ankle-foot orthosis in which flexion of one hip is mechanically linked to extension of the other. This type of brace, which is rarely indicated in adults due to the high energy cost of ambulation, is well-tolerated in children and often enables patients with spinal cord injury or myelodysplasia to ambulate.

Knee Orthosis

The KO is primarily used for musculoskeletal conditions; however, it is also used in patients with isolated quadriceps weakness resulting in recurvatum; nevertheless, when sufficient, a cane is often the best orthosis. The prototypical KO for recurvatum is the articulated Swedish knee cage, which uses a three-point design to create a flexion force at the knee. One or two anterior bands above and one below the knee are connected by lateral uprights to a hinge joint at the knee, where a posterior band is placed. A major problem with most KO is the cylindrical shape of the leg that makes it difficult to avoid significant longitudinal and rotational movement of the brace, often making other bracing strategies such as AFO preferable.

Quadriceps-Assist Orthosis

In patients with DMD without plantar flexion contractures, knee buckling may be a significant factor limiting ambulation. Gluteus maximus weakness precludes the use of hip extension to substitute for quadriceps weakness, and the quadriceps assist orthosis may be useful (2). This brace consists of a neoprene knee sleeve with anterior
spring steel stays that are wound to assist knee extension.

Functional Electrical Stimulation

The use of functional electrical stimulation (FES) in paralysis dates back to the 1960s (12). An intact motor unit is required. Electrical stimulation of the common peroneal nerve can be used to improve gait and obviate the need for bracing in UMN lesions causing foot drop. The device consists of electrodes placed behind or below the fibular head, a battery-operated stimulator, and a switch placed between the heel and the shoe. When the | heel is off the ground, the circuit is activated, resulting in dorsiflexion and thus clearance of the foot in the swing phase. At heel strike, the circuit is broken, allowing the foot to land flat (11). More complex FES packages are available and are in limited use for patients with paraplegia. New interest and promise have arisen in this field with the recent advances in electronics and biotechnology. Nevertheless, FES is still in the research phase. Major barriers include failure of electrodes, nonphysiologic recruitment pattern, early fatigability, technical limitations of sensors, and, in paraplegics, the high energy cost of ambulation. FES can be used when there is minimal or no spasticity. Furthermore, because bracing provides a far simpler, more reliable, and cost-effective approach to paralysis, FES may never become a wide spread alternative.

PATIENT EVALUATION

Team Approach

This time-consuming approach is advantageous in the long run because inappropriate prescription of adaptive equipment or orthoses is ineffective, costly, and can delay the patient's functional recovery. This can be a significant source of frustration for the patient, sometimes straining the relationship with their physician, therapists, family, and caretakers. Furthermore, if the wrong brace is ordered, it can be difficult to obtain funding for a replacement. The physician is best trained to advise on prognosis, contraindications, or other disease-specific issues. Physiatrists are ideal in this role because they are knowledge able in gait and bracing, neuromuscular and musculoskeletal function, and the long-term effects of disease. Neurologists, primary care providers, and orthopedists may also assume this role. A physical or occupational therapist trained in many of these areas will spend a significant amount of time with the patients and therefore have insight into their physical and cognitive abilities. The orthotist will fabricate the orthosis and is able to advise on bracing strategies and the biomechanical characteristics and limitations of a given design. The patient will often go directly to the orthotist for minor adjustment, repair, or modification of the brace. It is imperative to have communication and accessibility between the patient and the orthotist. Social services may be required at times to assist in resolving issues such as funding for equipment and orthotist services. Involvement of family members in the initial evaluation may improve patient compliance, particularly in-children. When bracing needs are straight forward, the full team approach is not always necessary.

Preprescription Evaluation

A preprescription evaluation is crucial in determining the appropriate brace for the patient and in establishing the ROM, strength, tone, and stability. ROM testing for two-joint muscles, as for example in the gastrocnemii, hamstrings, tensor fascia lata, and rectus femoris, should include a notation of the position in which testing was done, as for example, dorsiflexion tested with knee flexed or extended, particularly given the tendency of two-joint muscles to become tight. For normal gait, 5° of ankle dorsiflexion is necessary and 10° is ideal. Plantar flexion contractures of more than 5° interfere with ambulation and if possible should be stretched before bracing. If a plantar flexion contracture is not correctable, the brace will have to accommodate it. ROM at the hip must be considered when prescribing AFO or KAFO because hip flexion contractures increase lumbar lordosis and reduce stride length, thereby reducing the speed and efficiency of ambulation. Assessment of tone is extremely important because the presence of spasticity or clonus can limit bracing options. Severe spasticity and clonus of the gastrocsoleus may preclude the use of certain AFO. Treatments include stretching and antispasticity medications and, in selected cases, nerve or muscle blocks with phenol or botulinum toxin.

Conditions involving weakness or ligamentous laxity can affect stability of the joint with an increased risk of injury requiring orthotic intervention. Anteroposterior and mediolateral stability should be assessed in the knee and ankle; mediolateral instability of the ankle, for example, may indicate that a solid or hinged AFO is more appropriate than a PLSO.

It is next necessary to observe the patient walking. The knees should be visible to assess for buckling or recurvatum. Often, problems will not be apparent for a few minutes until muscle imbalance and fatigue lead to the emergence of a foot slap, spastic foot dragging, knee buckling, or genu recurvatum, especially when observations are made on more demanding conditions such as on different terrains and at various speeds of walking. When it is unclear exactly what type of brace is necessary, a trial of one or the other may be appropriate either in a brace clinic or for more extended periods with a physical therapist. A stock PLSO or Veterans Administration Prosthetic Center clip-on AFO may be used to determine whether a simple dorsiflexion assist brace will suffice. More complex bracing may require an adjustable double- upright trial AFO strapped to the patient's shoe. The prescription should be as detailed and specific as possible, and a copy should be kept in the patient's record. Communication between the patient and orthotist should be open so that frequent adjustments can be made and financial problems can be quickly resolved.

Checkup and GaitAnalysis After Delivery

Upon delivery of the brace, the physician should compare it with the written prescription, noting any discrepancies. The brace is put on the patient, observing any undue pressure areas and checking the location of the orthotic joints and fit of the shoes. The patient should walk for several minutes while the team observes for unexpected gait deviations. It is best to take a systematic approach, observing the patient along proximal to distal points, or vice versa, to avoid missing subtle gait deviations. After the brace has been worn for at least 15 minutes, it is removed and the skin is examined. If any redness is observed, the brace should be modified to reduce pressure on affected areas. Any complaints or questions should be addressed at this time (11).

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