by Joyce Jaixen, PT, GCS, C/NDT
Effective stroke rehabilitation requires a multidisciplinary team approach in order to capitalize on the brain’s ability to reorganize following disruption. Clinicians incorporate a variety of task-specific interventions which provide the repetition needed to acquire skill and reduce burden of care. One goal is to create symmetry and balance in order to minimize inefficient compensatory movement patterns, to decrease fall risk, and to avoid additional chronic health issues in the patient. Ironically, this applies to therapists as well. Rehabilitation technologies used as adjunct to handling skills enable therapists to facilitate head and trunk control, midline orientation, motor sequencing, and coordinated movement patterns in patients with stroke who are difficult to handle safely or benefit from refining their skills.
Partial body weight-supported treadmill training is useful for increasing step repetition, improving cardiovascular function, and enabling patients to refine their gait patterns. Patients who demonstrate enough trunk control to avoid sagging into the harness and who are able to initiate lower-extremity limb movement with no more than a minimal to moderate amount of facilitation are best suited to engage in training. Diminished need for unweighting and facilitation from hip and leg trainers, as well as increased gait speed with improved kinematics, demonstrates progress. Those who require additional assist train at the cost of therapists who are at risk of developing repetitive stress injuries.
Consider a patient who weighs 250 pounds, with roughly 16% (40 pounds) of his or her body weight represented in one lower limb. A therapist acting as “leg trainer” is confronted with facilitating and guiding placement of that limb in a repetitive fashion from a seated position, which results in significant muscle strain at the hips, back, and shoulders. Training bouts are frequently limited by therapist discomfort rather than patient activity tolerance. Many researchers are devoted to reconciling safe patient handling with therapeutic handling. They offer clinically innovative options to enhance therapist longevity and patient recovery, which are also less labor-intensive in terms of number of clinicians needed to carry out training.
Therapeutic Performance and Safe to Use
A motorized rehabilitative elliptical trainer, such as the ICARE, is an example of such a device. It closely approximates a normal gait pattern with or without unweighting via an overhead pulley system. It provides motor assist as needed in a closed chain pattern of movement and enables, if desired, reciprocal movement of upper extremities. It is offered as a cost-effective means of improving cardiovascular fitness as well as motor recovery for appropriate patients recovering from stroke. It is designed to be especially beneficial once a patient has enough trunk and hip control to avoid either crouching in the system or depending on the therapist to sustain alignment of joints in all planes without excessive lateral sway. It also can be effective in addressing ataxic movement patterns whereby limbs follow established patterns of motion while the therapist facilitates co-activation at the trunk. Outcome measures include patients’ ability to override the motor assist; time tolerated for each bout of training; vital sign responses; stride length settings as a representation of increased dynamic range of motion at the hips; ability to use the reciprocating lever arms rather than maintaining upper-extremity support on the fixed bar; the need for unweighting through the harness; and functional measures related to standing balance and transfers before, during, and after training.
Robotic Assistive Devices
Locomotion therapy supported by a robotic assistive orthosis device on a treadmill enables partially unweighted patients to step with a normal gait pattern for longer bouts. Therapists’ hands are more available to facilitate key muscle groups in the trunk and limbs with diminished strain. Patients exhibiting trunk control deficits are able to engage in gait training sooner. Those with perceptual deficits such as contraversive pushing benefit from orientation to midline while vertical. Typical patients with stroke benefit from increases in sustained weight-bearing input on more involved limbs while stepping through with their less-involved limbs during gait training, although the ability to fully weight shift is nulled by the fixed position of the gait orthosis. Dynamic stretching of tight joints occurs as range of motion settings are adjusted through the computer. Hypertonicity is controlled to some degree through “air walking” initially, followed by gradual increases in controlled weight bearing on the treadmill with care taken to avoid activating force sensors which are designed to shut off the machine for patient safety.
Electronic assessment tools measure passive hip and knee range of motion, spastic responses to passive movement, and patient-initiated flexion and extension forces. These measures objectify and justify small but important gains which impact function. Other documentation of progress within and between sessions includes reduction of weight supported during training in either dynamic or static modes; reduced guidance force required by the orthosis to maintain an appropriate gait pattern; and increases in gait speed, distance, and time. Functional outcome measures include improvements in postural control and limb activation during transfers and overland gait, which translate to better balance and diminished assist levels for mobility. Patients who are completely offloaded to don and fit robotic assistive devices on a treadmill must demonstrate hemodynamic stability as part of the screening process. This is achieved through use of a standing frame if necessary to establish 15 to 20 minutes of upright standing tolerance with stable vitals.
Robotic exoskeleton devices enable patients with stroke to re-establish the ability to weight shift sufficiently to unweight the opposite limb for adequate swing while moving through space. It is patient-driven and provides both support and facilitation as dictated by the therapist, who gives frequent verbal and tactile cues and adjusts settings, allowing for increased degrees of freedom of movement as patients demonstrate an increase in control. Training is physically demanding and requires active attention to engage use of more affected limbs. It is also useful for addressing contraversive pushing with the added benefit of emphasizing need for anterolateral weight shift during the stance phase of gait. The screening process for establishing appropriateness for patient use is extensive to ensure proper fit and safety.
Functional electrical stimulation (FES) units designed for both upper and lower leg provide for stimulation of either quadriceps or hamstrings along with pre-tibial muscles. This can be applied in either training or gait modes to improve initiation, timing, and sustained activation of muscles during functional tasks. Patients with neglect due to sensory deficits develop awareness of muscle contraction and increase their attention to more involved limbs while working with the unit. Patients exhibiting obligatory patterns of movement learn to control limbs with functional rather than abnormal synergy. Patients who are hypersensitive may not tolerate the intensity of stimulation required for muscle activation; those who are hyposensitive require skin checks to maintain skin integrity under electrodes and at the site of the heel switch apparatus. Patients lacking tibial control and exhibiting foot drop benefit from neuro re-education distally while therapists facilitate proximally to ensure adequate trunk control and step length on the less involved limbs.
Cycling with neuromuscular electrical stimulation provides similar benefits to patients affected by stroke with regard to limb awareness. Electrodes can be reassigned unilaterally to stimulate muscles in the trunk as well as the lower limb to address postural control with limb motion when treating lower-level patients early in their recovery. Patients who have respiratory compromise improve their circulation and cardiovascular tolerance to activity with greater breath support as they focus on sustaining upright sitting posture. They also learn to use appropriate breathing strategies and to pace activity using rates of perceived dyspnea and exertion.
Stroke treatment programs may also benefit from the use of dynamic stair trainer technologies. These devices include models built with steps that raise and lower electronically, and can be adjusted to match an individual’s functional ability. Handrails may be built into the devices to enhance safety, and have the ability to convert into parallel bars. These technologies can have particular utility in therapy for patients who have steps in their homes, and who need to improve balance and gain confidence in a controlled environment prior to discharge.
Braces and Orthoses
Regardless of the assistive technology used for early mobilization, overland gait training is essential for addressing the need for translation of weight forward and diagonally during stance to achieve active, dynamic, sustained alignment of shoulders, hips, and knees for balanced gait. Skilled input through key points of control at the trunk, pelvis, hip, and knee help to reinforce this specific aspect of gait. If safety is at issue, overhead pulley/harness systems designed to move with the patient help diminish anxiety for both patient and therapist during initial bouts of standing and gait training overland. They also allow for more vigorous balance training with reduced risk of injury to either patient or therapist.
Judicial use of orthotic devices helps to manage lower limbs and ankles when it is necessary to increase control distally in order to emphasize proximal input at the trunk and hip. Correctly choosing appropriate orthotic devices for persons with stroke is challenging. It is best to start with devices which are minimally restrictive, such as air splints, which offer medial/lateral ankle stability, and toe straps with surgical booties, which facilitate easier advancement of limbs during swing. Polypropylene ankle foot orthoses designed to hinge do not inhibit translation of the tibia forward as eccentric ankle plantar flexor motor control improves. Carbon fiber ankle foot orthoses provide lightweight, dynamic assistance for clearing the foot but also restrict normal gait kinematics with respect to the tibia, which in turn affects joints up the kinematic chain.
As tempting as it is to “block” the knee with an orthosis during stance, it proves detrimental to patients in the long run as they are slower to develop their own muscle control. Comorbidities which contribute to stroke provide challenges to bracing inside shoes with respect to peripheral sensory and vascular deficits. Edema management and regular skin checks help to prevent wounds.
The combined use of technology as adjunct to skilled handling helps capitalize on positive aspects of each. Success depends on a delicate balance between supporting and facilitating functional movement patterns while achieving functional goals in a manner safe for both patients and therapists. RM
Joyce Jaixen, PT, GCS, C/NDT, is an inpatient physical therapist at Madonna Rehabilitation Hospital, Lincoln, Neb. For more information, contact [email protected].