Powered Orthosis for Post-Stroke Gait Improvement


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Class presentation on the need for affordable post-stroke assistive gait rehabilitation devices in addition to gait retraining devices.

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  • Stroke affects gait by resulting in diminished strength and inappropriately timed or graded activity
  • Exercise therapy by therapist produced statistically significant increase in speed in most cases functional walking capacity was “restricted” before and after treatment. Strength training increasing strength of muscles by providing resistance to contraction didn’t really find favor because of concerns of increasing spasticity and not enough motivation to move from the conventional therapy. Mentally stimulating a person into more intensive during regular training has shown promise. The review indicates a cautious indication of positive effects in case of electrical stimulation. More impact on sub acute patients than chronic patients. Although positive outcome on walking speed is seen the AHA clinical practice guidelines point to insufficient evidence for benefits of FES and recommend to apply FES only for a limited time post-stroke. Biofeedback did not show significant improvement For individuals who could walk independently, treadmill training and more specifically treadmill training with body support showed speed improvement As far as the robotic devices are concerned, the Lokomat driven gait orthosis and Mechanized gait trainer are 2 commercially available devices which improve the repeatability of training, and enable an increase in the extent of training. Despite reported benefits for gait performance, treatment effects on gait speed and especially on functional community walking capacity have not yet been substantiated. A 2008 paper review paper compares Intervention Approaches for gait rehabilitation. Right from simple exercise therapy,
  • Not much research into follow up after initial training although I found a paper that used robot (MIT-Manus) experience to provide additional goal-directed sensorimotor activity to standard rehabilitation treatments but for the upper limb. On reevaluating the impaired limb 3 years later, they found further significant decreases in impairment measures. However, there is increasing evidence that the major part of the improvement in motor functions occurs during the first three months, after which it may continue slowly for up to six months.2~ Physiotherapists may still treat some stroke patients for long periods, even after one year, in spite of the fact that the patients make no measurable progress. Considering that no method of gait retraining has shown significant improvement in functional community walking capacity, there is a need to shift focus to assistance during walking to improve gait than retraining.
  • Devices which support or correct the function of a limb or torso. There is another class of powered orthoses that are intended to increase human motor abilities over and above normal levels
  • University of Tsukuba in Japan
  • The idea of using assistance for walking is promising Apart from the drawbacks of electrical stimulation as a method of gait improvement the other drawbacks include Focuses just on ankle dorsiflexsion whereas knee flexion is an important requirement Study conducted only on one person Do not compare walking speed but use motion analysis using the camera and marker method. Cannot be used with water or while driving Costs $5000.
  • Powered Orthosis for Post-Stroke Gait Improvement

    1. 1. Saanika Pillai 06/01/2010 Powered Orthosis for Post-Stroke Gait Improvement
    2. 2. Gait <ul><li>Pattern of movement of the limbs of animals </li></ul><ul><li>Balance movement and speed </li></ul>Stroke <ul><li>Damage to Motor cells and pathways of the CNS </li></ul><ul><li>Decreased walking velocity, cadence, and stride length, and an increased gait cycle in order to compensate for poorer motor control. </li></ul>
    3. 3. The Problem <ul><li>Diminished Strength or inability to generate voluntary muscle contractions of normal magnitude </li></ul><ul><li>Inappropriately timed or inappropriately graded muscle activity </li></ul>
    4. 4. Current Solution <ul><li>Exercise Therapy </li></ul><ul><ul><li>Strength Training </li></ul></ul><ul><ul><li>Motor Imagery Practice </li></ul></ul><ul><li>Electrical Stimulation </li></ul><ul><li>Biofeedback </li></ul><ul><li>Treadmill Gait Training with/without BWS </li></ul><ul><li>Robotic Machines </li></ul><ul><ul><li>Lokomat </li></ul></ul><ul><ul><li>Mechanized Gait Trainer </li></ul></ul>
    5. 5. Observation <ul><li>‘ statistically significant speed gains were demonstrated by most of the interventions, with the magnitude being comparable across different treatments.’ </li></ul><ul><li>‘ Common factors repeatability, intensity seem more essential for functional outcomes than the particular treatment mode.’ </li></ul>
    6. 6. Common Drawbacks <ul><li>Short-term improvement </li></ul><ul><li>Gait maintenance not measured </li></ul><ul><li>Not easily accessible </li></ul><ul><li>Expensive </li></ul><ul><li>Potential for improvement decreases with time </li></ul>
    7. 7. Powered Orthoses <ul><li>Biomechatronics Laboratory at the MIT Media Laboratory </li></ul><ul><ul><li>Prosthetics for amputees </li></ul></ul><ul><li>Cybernics Laboratory at the University of Tsukuba in Japan </li></ul><ul><ul><li>Hybrid Assistive Limb </li></ul></ul><ul><li>Yobotics, Inc. </li></ul><ul><ul><li>Augment or replace muscular functions of the lower extremities. </li></ul></ul><ul><ul><li>MIT Leg Laboratory </li></ul></ul><ul><ul><li>Not commercially available  </li></ul></ul><ul><li>Division of Kinesiology (University of Michigan, Ann Arbor, Michigan) </li></ul><ul><ul><li>Pneumatically powered lower limb orthoses for locomotor training </li></ul></ul><ul><li>Robotic Exoskeletons </li></ul><ul><ul><li>Superhuman ability </li></ul></ul><ul><li>WalkAide2 </li></ul><ul><ul><li>battery-operated, single channel electrical stimulator </li></ul></ul>
    8. 8. HAL – Hybrid Assistive Limb
    9. 9. Yobotics, Inc - RoboWalker
    10. 10. WalkAide2 <ul><li>The WalkAide 2 (WA2) is a battery-operated, single channel electrical stimulator </li></ul><ul><li>Programmable tilt sensor, such that stimulation begins at toe-off, and ends at heel strike. </li></ul><ul><li>Surface electrodes, </li></ul><ul><li>Balanced contraction of the Tibialis Anterior and Peroneal muscles </li></ul><ul><li>Active dorsiflexion of the ankle during the swing phase of gait </li></ul>
    11. 11. Hypothesis <ul><li>Using a leg splint/brace which provides timely and graded knee flexion and ankle dorsiflexsion force controlled by the gait of the unaffected limb is more effective in gait improvement in hemiparetic patients compared to electrical stimulation. </li></ul>
    12. 12. Method <ul><li>20 Stroke survivors </li></ul><ul><li>1 year after stroke </li></ul><ul><li>Divided into 2 equal groups </li></ul><ul><li>1 week of training </li></ul><ul><li>6 weeks of using the device </li></ul><ul><li>Compare gait speed after 6 weeks. </li></ul><ul><li>Limitations </li></ul><ul><li>Device itself! </li></ul><ul><li>Tracking use of device </li></ul><ul><li>Only on patients who can walk independently </li></ul><ul><li>Turning, Sidestepping </li></ul>
    13. 13. References <ul><li>Preuss R, Stein RB, Fung J, Gait kinematics after forty weeks of use of the Walkaide 2: a case study, 10th Annual Conference of the International FES Society ( July 2005) – Montreal, Canada </li></ul><ul><li>H. P. von Schroeder, R.D. Coutts, P. D. Lyden, E. Billings Jr., V. L. Nickel, Gait parameters following stroke : A practical assessment, Journal of Rehabilitation Research and Development (February 1995), 32,1, pp. 25-31 </li></ul><ul><li>N S Ward, Mechanisms underlying recovery of motor function after stroke, Postgrad Med J (2005), 81, pp. 510-514 </li></ul><ul><li>F. B. van de Weg, D. J. Kuik and G. J. Lankhorst, Post-stroke depression and functional outcome: a cohort study investigating the influence of depression on functional recovery from stroke, Clinical Rehabiitationl (1999), 13, pp. 268 </li></ul><ul><li>J.J. Daly, K. Roenigk, J. Holcomb, J. M. Rogers, K. Butler, J. Gansen, J. McCabe, E. Fredrickson, E. B. Marsolais and R. L. Ruff, A Randomized Controlled Trial of Functional Neuromuscular Stimulation in Chronic Stroke Subjects, Stroke (2006),37, pp. 172-178; </li></ul><ul><li>M. Visintin, H. Barbeau, N. Korner-Bitensky and N. E. Mayo, A New Approach to Retrain Gait in Stroke Patients Through Body Weight Support and Treadmill Stimulation, Stroke (1998),29, pp. 1122-1128 </li></ul><ul><li>U. Bogataj, N. Gros, M. Kljajlc,R. Aclmovlc, M. Malezic, The Rehabilitation of Gait in Patients With Hemiplegia:A Comparison Between Conventional Therapy and multichannel Functional Electrical Stimulation Therapy, Physical Therapy (June 1995), 75, 6 </li></ul><ul><li>J. Mehrholz, C. Werner, J. Kugler, M. Pohl, Electromechanical-assisted training for walking after stroke (Review), The Cochrane Library (2007), 4 </li></ul><ul><li>R. Dickstein, Rehabilitation of Gait Speed After Stroke: A Critical Review of Intervention Approaches, Neurorehabilitation and Neural Repair (2008), 22, 649 </li></ul><ul><li>R.W. Teasell, S. K. Bhogal, N. C. Foley, and M. R. Speechley, Gait Retraining Post Stroke, Topics in Stroke Rehabilitation (2003),10(2), pp. 34–65 </li></ul><ul><li>B. T. Volpe, H. I. Krebs, N. Hogan, L. Edelsteinn, C. M. Diels and M. L. Aisen, Robot training enhanced motor outcome in patients with stroke maintained over 3 years, Neurology (1999),53,1874 </li></ul><ul><li>J. Green, A. Forster, S. Bogle and J. Young, Physiotherapy for patients with mobility problems more than 1 year after stroke: a randomised controlled trial, Lancet (2002), 359, pp. 199–203 </li></ul><ul><li>Ferris D.P. ,Sawicki S.G., and Domingo A.R. Powered Lower Limb Orthoses for Gait Rehabilitation, Top Spinal Cord Inj Rehabil 2005;11(2):34–49 </li></ul>
    14. 14. Questions