Functional_20Electrical_20Stimulation

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					                              Functional Electrical
                                  Stimulation




            Applications to Stroke and Spinal Cord
                     Injury Rehabilitation
                                              Amy Heitkamp & Jen Mullett
                                              HSS 409 – December 7, 2005

Picture from http://fescenter.case.edu/Resources_Info/fes_guide.htm
                          Main Topics
•   FES overview
•   Stroke overview
•   FES: applications to stroke rehabilitation
•   Current Research: FES & Stroke
•   SCI overview
•   FES: applications to SCI rehabilitation
•   Current Research: FES & SCI
•   Conclusion

Amy Heitkamp & Jennifer       HSS 409            2
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 Functional Electrical Stimulation
              (FES)
• active muscle contraction
• computer or therapist sequenced
  activation
• produces functional movement
• implanted or surface electrodes


                                    (FES Resource Guide, 2004)


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                  Stroke: Overview
• “Brain Attack”
• Damage due to lack of oxygen or blood
• Types of Stroke
    – Hemorrhagic
    – Ischemic
• “Stroke is the leading cause of adult
  disability in the United States” (NSA, 2005)

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      Stroke: Damage & Resulting
               Disability
• Dependent upon location & extent of
  damage
• Examples: (Cleveland Clinic, 2003)
    – Inability to move parts of the body
         • Paralysis (hemiplesia or total)
    – Weakness in parts of the body
    – Persistent gait deficits (Daly, 2001)
         • Swing phase
         • Midsupport phase
         • “Drop foot”
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   Biomechanics in the Gait Cycle
                           Support Phase                          Swing Phase
                |------------------------------------------|-------------------------------|
                 Swing




                        Foot strike      Toe-off                                  Deceleration
                                 Midsupport                               Forward Swing
    (Dhaher, 2005)

    photo: http://www.sportsci.com/adi2001/Adi/services/support/tutorials/gait/chapter1/1.1.asp)


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         Gait Deficits Post-Stroke:
               “Drop-Foot”
• significant weakness of
  ankle and toe dorsiflexion
  muscles.
• These muscles:
   – help the leg clear the
     foot during swing phase
   – control plantar flexion
     of the foot on heel
     strike.
• Causes toes to catch on the
  ground during swing phase
               (Pritchett, 2005)
                                        Figure from: (Kelly, 1981)

Amy Heitkamp & Jennifer       HSS 409                                7
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            Gait Deficits Post-Stroke:
                  Problem Areas
                           Support Phase                          Swing Phase
                |------------------------------------------|-------------------------------|
                 Swing




                        Foot strike      Toe-off                                  Deceleration
                                 Midsupport                               Forward Swing
    (Dhaher, 2005)

    photo: http://www.sportsci.com/adi2001/Adi/services/support/tutorials/gait/chapter1/1.1.asp)


Amy Heitkamp & Jennifer                                  HSS 409                                   8
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      FES: Clinical Applications to
         Stroke Rehabilitation
• Dropped-Foot rehabilitation (ODFS)
• Improve functional mobility (during walking)
  – FNS-IM
•   Others not applicable to this presentation

• Main Goals – Improve coordination the
  different phases of gait
     – Restoration of motor control
     – Prevent debilitating falls

                                                 (Daly, 2003; Daly 2004; “FES
                                                       Resource Guide,” 2004)



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        FES: Odsock Dropped-Foot
            Stimulator (ODFS)




     Figure courtesy of Salisbury District Hospital
                                                           Figure from: www.salisburyfes.com/ infoms.htm
     http://fescenter.case.edu/Start_Here/Patients/
     Stroke/stroke_programs.htm



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            FES: Functional Neuromuscular
    Stimulation – IntraMuscular (FNS-IM)
                                                          • Implanted
                                                            electrodes
                                                          • Individualized
                                                            stimulator on Belt
                                                          • Comfort
                                                          • Better Control

 Figure from www.rehabpub.com/ features/32003/6.asp
                                                                      (Daly, 2004)

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  Current Research on FES usage
        in Stroke Patients
• Daly, JJ. et al. (2004)

    – Purpose: preclude post-stroke outcomes of
      gait deficits using FES during rehabilitation
    – Methods:
       • (E) Experimental group – therapy & FES
         (FNS-IM)
       • (C) Control group - therapy
    – Subjects: 16 stroke patients

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  Current Research on FES usage
        in Stroke Patients
• Daly, JJ. et al. (2004)
    – Results:
       • Peak swing flexion – no significant difference
       • Peak swing knee flexion – significant gains in E group
       • Mid-Swing ankle dorsiflexion – significant gains in E
         group
    – Conclusions:
       • Improvements were maintained for 6 months post-study
       • FES (FNS-IM) is an effective tool for stroke
         rehabilitation



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  Current Research on FES usage
        in Stroke Patients
• Burridge, J.H. et al (1997)
    – Improvements shown in walking speed
      with FES


• Yoichi, S. et al (2005)
    – Improvements shown in acceleration
      phase of walking with acceleration sensor
      + FES

Amy Heitkamp & Jennifer   HSS 409             14
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  Current Research on FES usage
        in Stroke Patients



*** See Attached Summary Table




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           Spinal Cord Injury (SCI):
                   Overview
• What is Spinal Cord Injury?
    – Damage to the spinal cord that results in a loss of function
• Frequent Causes of SCI include:
    – Trauma: car accident, gunshot, falls
    – Disease: polio, spina bifida, ataxia
• The spinal cord does not have to be
  severed for loss of function to occur
• The higher in the spinal column
  injury occurs, the more dysfunction
  a person will experience




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           Spinal Cord Injury (SCI):
                   Overview
• Two types of injuries
    – Complete injury means that there is no function
      below the level of injury; no sensation and no
      voluntary movement
         • Both sides are equally affected


    – Incomplete injury means that there is some
      functioning below the primary level of the injury
         • May be able to use one limb more than another, may
           feel parts of the body that cannot be moved, or may
           have more function in one side of the body than the
           other
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                          SCI
• Cervical injuries usually
  result in quadriplegia
• Injuries above C-4 may
  require a ventilator
• Injuries at or below the
  thoracic level result in
  paraplegia


Amy Heitkamp & Jennifer   HSS 409   http://www.spinalinjury.net/html/_spinal_cord_101.html   18
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            Prevalence and Death
• Approx. 450,000 people live with SCI in the US
• About 10,000 new cases every year
    – 82% involve males between ages 16-30
       • motor vehicle accidents
       • violence
       • from falls
• Quadriplegia is slightly more common than
  paraplegia
• 85% of SCI patients who survive the first 24 hrs are
  alive after 10 years
    – Most common cause of death is diseases of the respiratory system such
      as pneumonia
    – Second leading cause is nonischemic heart disease
    – Third leading cause is suicides and/or homicides

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              Christopher Reeves
• SCI recovery is thought to occur in the first
  6 months-2 years
• Reeves’ recovery came 5-7 years after his
  injury
    – began an intense exercise program under Dr.
      John McDonald
• Exercise program included:
    –   Daily electric stimulation
    –   FES bicycle
    –   Spontaneous breathing training
    –   Aquatherapy
    –   Treadmill training
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                          FES Bicycle
• Allows a person with little or no
  voluntary leg movement to pedal a
  stationary leg-cycle (ergometer)
• Cost approximately $15,000
• Some health clinics have
  the bikes
• Increase muscle mass and
  cardiopulmonary function
Amy Heitkamp & Jennifer       HSS 409   http://www.musclepower.com/   21
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                          Physiology
• Normally, electric signals travel from
  the brain down through the spinal cord
  to the corresponding muscles or
  organs
• When damage occurs to the spinal
  cord, these signals cannot reach there
  intended destination
• Applying a small electrical current to
  the nerve or muscle, the desired
  function can be triggered
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   FES: Clinical Applications to
        SCI Rehabilitation
• Standing and Transfer FES System
    – Jen
         • C6-C7 incomplete injury in 1998
• FES Walking System
    – Don
         • Incomplete paraplegic since 1983
• FES System for Gripping and
  Releasing
    – Annette
         • Incomplete C5-C6 Quadriplegic due to
           car accident in 2002
    – Jim
         • Activities of Daily Living             http://toronto-fes.ibme.utoronto.ca/publications/
                                                  Neuroprostheses_Popovic_Thrasher.pdf

Amy Heitkamp & Jennifer            HSS 409                                                  23
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  Current Research on FES usage
          in SCI Patients
HAND (Peckham, 2001)
    – 51 quadriplegic adults with C5 or C6 SCI
    – Assessed participants:

         1) ability to grasp, move, and release standardized objects

         2) degree of assistance required to perform ADLs

         3) user satisfaction


• Results: became more independent in ADLs and high user
  satisfaction

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  Current Research on FES usage
          in SCI Patients
RESPIRATION (Lin, 2001)
    – 8 men with quadriplegia
    – Measured values were evaluated after a 4 week
      period of using FMS

• Results
    – Expiratory Lung Volumes and Lung Capacities
      greatly increased
    – 4 week protocol of FMS, improved voluntary
      expiratory muscles significantly

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  Current Research on FES usage
          in SCI Patients
• Standing (Hesse, 1998)
    – 17 patients with SCI
       • 4 quadriplegic patients
       • 10 paraplegic patients
       • 3 patients with incomplete cervical lesion, able
         to walk short distances before treatment

• Results: standing duration and walking distances
  were dependent on the severity of SCI


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                     Future Outlook
• Researchers at Sweden’s Karolinska
  Institute snipped the spinal cords of
  laboratory rats
• Bridged the gap using transplanted nerves
• The graft restored function to the rats
  previously motionless hindlimbs
• After a few months, they could flex their
  joints and partially support their body weight

•   (US News and World Report, 1996)
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                          Conclusions
Applications of FES seems to be an
 effective addition to stroke and SCI
 rehabilitation; however, further
 research is needed and encouraged,
 especially with intramuscular FES
 systems.



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 Study     Group   N      Treatment     FES Type      Measurement               Result                        Comments
                            Type                        Taken

Burridg                 FES +           ODFS                            + 20.5%*             When ODFS is used
e et al.    E      16   Physiotherapy

                                                     Walking speed
                        Physiotherapy       --                          + 5.2%                                     --
            C      16

Daly et                 FES + Gait      FNS-IM                          1- Peak swing        - (p < 0.05)
all                     Training                                        flexion – NS         - maintained for 6 months
[2004]                                                                  2- Peak swing
                                                                        knee flexion – S*
            E      8                                                    3- Mid-Swing
                                                     Kinematics of      ankle dorsiflexion
                                                      Gait Swing        – S*
                                                         Phase

                        Gait Training       --                          1- NS                                      --
            C      8                                                    2- NS
                                                                        3- NS

Yoichi                  FES +           Peroneal                        Diff = < 80ms in     - experimental group = stroke patients
et al.      E      3    Detector        Stimulator                      acceleration         - control group = healthy
                                                       Difference of
                                                      Timing During                          - concl. – stimulator effectively controls
                        Detector            --       Acceleration of    Diff = < 60 ms in    FES to regulate gait
                                                     the swing phase    acceleration         - concl. – foot drop effectively corrected
            C      5                                  to correct foot
                                                            drop


 Bolded * = significant improvement
 NS= not significant
    Amy Heitkamp & Jennifer                               HSS 409                                                              29
 E = experimental group
    Mullett
 C= control
                          Questions?




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