Patient uses a triggered NMES to assist with grasping and then releasing balls into a container.

by Heidi Nash, MOT, OTR/L, and Danielle Wilt, OTR/L, OTD

Paralysis affects approximately 1.7% of the United States population; more than 5 million people. The leading cause of paralysis is stroke, followed by spinal cord injury and multiple sclerosis.1 Each year, approximately 795,000 people in the US have a stroke,2 with the most common deficit being hemiparesis of the upper limb.3 There are approximately 17,730 new cases of spinal cord injury each year. Similar to stroke, spinal cord injuries often involve upper extremity deficits, with incomplete tetraplegia being the most common neurologic category.4 Incomplete tetraplegia is characterized by deficits in all limbs with preservation of some sensory and/or motor function below the level of injury.5

Historically, upper limb rehabilitation has focused on maintaining range of motion, managing spasticity, strengthening available muscles, and compensatory strategies for loss of motor function.

Rehabilitation of the upper limb has been limited to the clinician’s ability to manually facilitate motor recovery and movement patterns, making it difficult to achieve high repetition and clear feedback regarding performance and progress. Advanced technology opens the door to immediate feedback to a variety of systems, as well as more refined input and facilitation of movements that cannot be provided by a therapist.

What is Advanced Technology?

Advanced technology for upper limb restoration ranges in level of physical assistance provided to the patient, as well as the sophistication of the device. This includes detecting active movement through sensors, providing motion assist, and providing feedback to a variety of patient systems — visual, tactile, proprioceptive. Advanced technology provides a unique contrast to traditional therapy as it allows for high repetition of quality movement and immediate feedback, it is highly engaging and increases patient motivation, and it decreases physical demands on the clinician.

Exploring the Options

Upper limb impairments are common in patients with neurologic injury. Proximal stability and function is imperative for distal function and coordination for participation in daily tasks. Improved strength and mobility across joints allows for increased independence with tasks including self care, mobility, and community access. Interventions for patients with limited active movement have traditionally focused on passive range of motion or labor-intensive, clinician-assisted motor relearning. Advanced technologies provide a gravity-reduced environment that can be paired with virtual tasks that increase patient motivation and feedback. They improve efficiency of therapy delivery due to reduction in need for a therapist’s continual effort and guidance. There is a continuum of devices for upper extremity rehabilitation designed for varying degrees of impairments that can be utilized from the acute phase through long-term recovery.

Traditionally, the mobile arm support has been the primary device available offering gravity-reduced support, allowing patients with proximal weakness to improve functional workspace. Newer technologies, including sensor-based systems, can be used alone for patients with anti-gravity movements or in combination with a mobile arm support for patients requiring gravity-assist. Sensors used to measure position or acceleration communicate with a computer to provide feedback in a virtual environment. The advantage to this type of technology includes portability and adaptability to different settings. Devices such as these could be utilized bedside in the acute care setting, in the home environment, or in an outpatient clinic.

Next-tier devices include an exoskeletal component for the upper limb. One such device is an exoskeleton that provides gravity compensation at the shoulder and forearm and has built-in sensors at each joint, including a grip force sensor. The design of this device allows for high repetition, self-initiated movement training in a three-dimensional workspace that can be tailored to the patient’s available movement. Taking technology one step further is a robotic exoskeleton that provides assisted movement to the upper extremities. In each of these devices the augmented environment provides real-time performance feedback.6 The therapist can tailor the therapy session to target joint-specific goals and movement patterns to best meet the patient’s functional goals. The advantage of more complex, exoskeletal devices is the ability to measure and track range of motion and forces during training sessions more accurately due to the ability to standardize the set-up.

In line with an exoskeleton, another technology manufacturer offers a wearable myoelectric orthosis that uses EMG-driven sensors to target elbow and hand re-education. It allows patients to self-initiate and control movements of a weakened or partially paralyzed arm using their own muscle signals.7 The therapist can control sensitivity of the EMG threshold in order to capture even minimal muscle activation. This allows for isolated strengthening versus compensatory training. After successful trial in the clinic, a patient may obtain a custom orthotic that can be worn for participation in daily life. While this device does not provide shoulder re-training, it does offer support through a strap similar to a sling. This would not be appropriate for patients without detectable muscle activation.

Restoring hand function after neurologic insult provides a multifaceted challenge to clinicians due to its complexity. In the clinical setting, facilitating natural movement patterns is unachievable without advanced technologies. A recent advancement in hand rehabilitation is a robotic hand and finger retraining device. Its ability to capture isolated individual finger and thumb movements allows for highly customized hand rehabilitation. This device offers assessment of range of motion, strength, and spasticity for tracking patient progress. Therapy programs can be customized by the clinician including a range of programs progressing from passive movement, active-assisted movement, to resisted strengthening; as well as sensitivity training using vibration and coordination training in a one- or two-dimensional workspace. It allows high repetition, as well as visual and proprioceptive feedback.8

Building the Treatment Plan

Patient is a 65-year-old male C4 ASIA Impairment Scale D spinal cord injury, central cord syndrome, presenting to clinic approximately 1 year post his acute inpatient rehabilitation. He had been compliant with a home-based exercise program including passive range of motion and pulley exercises, weight-bearing activities, and nighttime wear of hand orthoses. His available range of motion had been improving, and his pain was becoming more manageable. He was seeking further therapy to promote neurologic recovery and normalize movement patterns.

At initial evaluation, the patient demonstrated against gravity movements in all muscle groups through partial range of motion (less than 50%) with strong compensatory movements, spasticity throughout, edema in his hands, decreased fine motor coordination utilizing primarily tenodesis-driven gross grasp and lateral pinch. He could ambulate household distances without an assistive device. Functionally, he was requiring moderate assistance with all daily living tasks. Goals for therapy included independence with clothing management, toileting, applying deodorant, return to driving, retraining dissociated movements and isolated joint control, as well as distal coordination and strength.

Given the patient’s impairments across multiple segments of the upper extremity, he was a good candidate for advanced technologies for rehabilitation at the shoulder, elbow and hand.

Upper Limb Exoskeleton

With his upper limb supported in the exoskeleton, the patient focused on functional movement patterns in a three-dimensional workspace. Due to his spasticity, the patient benefitted from tone-reduction strategies, including neuromuscular electrical stimulation, weight-bearing, and high-frequency vibration prior to initiating training with this technology. During initial training, functional electrical stimulation was incorporated to facilitate patterning. As he progressed, the exoskeleton allowed for daily calibration to the patient’s active workspace, level of support at the shoulder and forearm, and task selection to effectively grade the activity for optimal challenge. For additional challenge, incorporation of distal motor function using the grip force sensor and multi-joint demands were possible.

Robotic Orthosis

Using the EMG-driven robotic upper extremity orthosis the patient focused initially on tone modulation, using isolated contraction and relaxation of the targeted muscle in the single modes. He progressed to the dual mode, allowing dissociated elbow movement for coordinating reaching to interact in his environment. Freedom in altering shoulder position allowed for working in both closed-chain weight-bearing positions for bed mobility, transfers and gait training with assistive device, as well as open chain for self care tasks. Adjustability of the EMG sensitivity allowed for amplifying the patient’s muscle activity in the early phases of recovery, while reducing sensitivity as coordination improved.

Sensor-Based Hand Rehab

Complexity of the patient’s neurologically affected hands, including increased tone and trace muscle activity throughout, made him an ideal candidate for the robotic sensor-based rehabilitation device. Training sessions progressed through passive programs, which were utilized for tone modulation and to excite the nervous system. The active-assisted program provided an environment for maximal patient initiation and movement prior to completing the motion. As the patient required less assistance, he was able to utilize active programs using force or movement control, gross or refined, isolated movement in one or two-dimensional planes. Ability to add resistance to finger movements provided the opportunity to increase challenge and target strengthening of functional movement patterns.

Using advanced technologies, the patient learned to modulate his tone and progressed his active range of motion and coordination. He built strength and safety with mobility through protective upper extremity responses. High repetition of movement and retraining dissociated movement patterns resulted in improved reaction time and coordination of multiple limb segments, allowing the patient to return to driving. The patient maintained a high level of engagement and motivation using these technologies.

Future of Advanced Technology

Advanced technology has shifted the focus of upper limb rehabilitation from compensatory to restorative and provides the opportunity for quality movement that was not previously available. Once limited to clinic space due to their large footprint, devices are becoming more portable and accessible to a variety of settings. Combined with the growing augmented and virtual reality platforms, the future of advanced technology seems endless. RM

Heidi Nash, MOT, OTR/L, has been an Occupational Therapist at the International Center for Spinal Cord Injury at Kennedy Krieger Institute, Baltimore, since 2010.

Danielle Wilt, OTR/L, OTD, is a Senior Occupational Therapist at the International Center for Spinal Cord Injury at Kennedy Krieger Institute, Baltimore. For more information, contact RehabEditor@medqor.com.

References

  1. Stats about paralysis. Christopher & Dana Reeve Foundation website. Available at: https://www.christopherreeve.org/living-with-paralysis/stats-about-paralysis. Accessed January 29, 2020.
  2. Stroke. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/stroke/facts.htm. Updated January 31, 2020. Accessed February 5, 2020.
  3. Hatem SM, Saussez G, Della Faille M, et al. Rehabilitation of motor function after stroke: a multiple systematic review focused on techniques to stimulate upper extremity recovery. Front Hum Neurosci. 2016;10:442.
  4. National Spinal Cord Injury Statistical Center, Facts and Figures at a Glance. Birmingham, AL: University of Alabama at Birmingham, 2019.
  5. American Spinal Injury Association: International Standards for Neurological Classification of Spinal Cord Injury, revised 2019; Richmond, VA.
  6. Armeo®Spring. Hocoma website. Available at: https://www.hocoma.com/us/solutions/armeo-spring/. Accessed February 12, 2020.
  7. What is a MyoPro Orthosis? Myomo website. Available at: https://myomo.com/what-is-a-myopro-orthosis/. Accessed February 12, 2020.
  8. Amadeo. Tyromotion website. Available at: https://tyromotion.com/en/products/amadeo/. Accessed February 12, 2020

Backrest Basics for Lightweight Wheelchairs

by Frank Long, Editorial Director

Individuals who use a manual mobility device to get around in their daily lives will likely spend long hours seated in a rigid or folding frame lightweight wheelchair. To make sure the user remains safe and comfortable during such long periods of time, it is crucial to assure the wheelchair’s seating and positioning system offers a personalized fit with adequate support. Seat backs, seat cushions, and positioning hardware are among the components of a complete seating system that contribute to this goal.

Backrest Influence

The position of a manual wheelchair’s backrest, especially, can exert a high level of influence over a wheelchair’s stability and maneuverability.1 The dynamics between a wheelchair backrest and seat can substantially influence stability since adjusting back and seat angles can result in stability changes greater than 20 degrees.1 With this in mind, the function of a backrest that is adjustable and flexible becomes clear.

Stability and Support

Therapists who are working to assemble the optimum seating solution for their clients have a variety of solutions available when it comes to backrests and seating. A backrest made by one manufacturer is built with a lightweight aluminum base and double-layered foam setting that is designed to be ergonomic, provide on-demand adjustable support, and mount to virtually any wheelchair on the market. That manufacturer’s product line also features a backrest made from carbon fiber material that is built to provide superior strength as well as excellent stabilization of trunk during push while reducing loss of energy. In addition to being designed for lightweight strength, this seatback is also designed to distribute forces evenly through the pelvic base of support to ease strain on the lower back.

Flexible Technology

Modular backrests and seats are another type of seating and positioning technology offered by another of the industry’s manufacturers that focus on flexibility. For example, modular custom seating components can allow gradual corrective positioning and are built to adapt to the wheelchair user’s weight fluctuations or changes caused by growth. These custom-contoured backrests are available as a low back kit and standard back kit in three sizes. The modular backrests and seats are designed to be used with any mounting hardware, which enhances to their flexibility. The shell for the backrest can be sized for the appropriate contouring and the width between the lateral supports, and the lumbar curve and upper thoracic region all are designed for quick fit to the wheelchair user. RM

Reference

  1. Thomas L, Sparrey C, Borisoff J. Defining the Stability Limits of a Manual Wheelchair With Adjustable Seat and Backrest. RESNA.org. Accessed April 14, 2020. Available at https://www.resna.org/sites/default/files/conference/2017/pdf_versions/wheeled_mobility/Thomas.pdf.