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
Mullett
HSS 409
2
Functional Electrical Stimulation
(FES)
• active muscle contraction
• computer or therapist sequenced
activation
• produces functional movement
• implanted or surface electrodes
(FES Resource Guide, 2004)
Amy Heitkamp & Jennifer
Mullett
HSS 409
3
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)
Amy Heitkamp & Jennifer
Mullett
HSS 409
4
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”
Amy Heitkamp & Jennifer
Mullett
HSS 409
5
Biomechanics in the Gait Cycle
Support Phase
Swing Phase
|------------------------------------------|-------------------------------|
Swing
Foot strike
Toe-off
Midsupport
Deceleration
Forward Swing
(Dhaher, 2005)
photo: http://www.sportsci.com/adi2001/Adi/services/support/tutorials/gait/chapter1/1.1.asp)
Amy Heitkamp & Jennifer
Mullett
HSS 409
6
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
Mullett
HSS 409
7
Gait Deficits Post-Stroke:
Problem Areas
Support Phase
Swing Phase
|------------------------------------------|-------------------------------|
Swing
Foot strike
Toe-off
Midsupport
Deceleration
Forward Swing
(Dhaher, 2005)
photo: http://www.sportsci.com/adi2001/Adi/services/support/tutorials/gait/chapter1/1.1.asp)
Amy Heitkamp & Jennifer
Mullett
HSS 409
8
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)
Amy Heitkamp & Jennifer
Mullett
HSS 409
9
FES: Odsock Dropped-Foot
Stimulator (ODFS)
Figure courtesy of Salisbury District Hospital
http://fescenter.case.edu/Start_Here/Patients/
Stroke/stroke_programs.htm
Amy Heitkamp & Jennifer
Mullett
Figure from: www.salisburyfes.com/ infoms.htm
HSS 409
10
FES: Functional Neuromuscular
Stimulation – IntraMuscular (FNS-IM)
• Implanted
electrodes
• Individualized
stimulator on Belt
• Comfort
• Better Control
(Daly, 2004)
Figure from www.rehabpub.com/ features/32003/6.asp
Amy Heitkamp & Jennifer
Mullett
HSS 409
11
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
12
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
13
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
Mullett
HSS 409
14
Current Research on FES usage
in Stroke Patients
*** See Attached Summary Table
Amy Heitkamp & Jennifer
Mullett
HSS 409
15
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
16
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
17
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
Mullett
HSS 409
http://www.spinalinjury.net/html/_spinal_cord_101.html
18
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
19
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
20
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
Mullett
HSS 409
http://www.musclepower.com/
21
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
22
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
http://toronto-fes.ibme.utoronto.ca/publications/
Neuroprostheses_Popovic_Thrasher.pdf
23
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
24
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
25
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
Amy Heitkamp & Jennifer
Mullett
HSS 409
26
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)
Amy Heitkamp & Jennifer
Mullett
HSS 409
27
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.
Amy Heitkamp & Jennifer
Mullett
HSS 409
28
Study
Burridg
e et al.
Group
E
N
16
Treatment
Type
FES +
Physiotherapy
FES Type
Measurement
Taken
ODFS
Result
+ 20.5%*
Comments
When ODFS is used
Walking speed
C
16
Daly et
all
[2004]
Physiotherapy
FES + Gait
Training
E
--
+ 5.2%
FNS-IM
8
Kinematics of
Gait Swing
Phase
Gait Training
Yoichi
et al.
C
8
E
3
C
--
FES +
Detector
Peroneal
Stimulator
Detector
--
5
Bolded * = significant improvement
NS=Amy
not significant
Heitkamp & Jennifer
E = experimental group
Mullett
C= control
1- Peak swing
flexion – NS
2- Peak swing
knee flexion – S*
3- Mid-Swing
ankle dorsiflexion
– S*
1- NS
2- NS
3- NS
Difference of
Timing During
Acceleration of
the swing phase
to correct foot
drop
HSS 409
Diff = < 80ms in
acceleration
Diff = < 60 ms in
acceleration
--
- (p < 0.05)
- maintained for 6 months
--
- experimental group = stroke patients
- control group = healthy
- concl. – stimulator effectively controls
FES to regulate gait
- concl. – foot drop effectively corrected
29
Questions?
Amy Heitkamp & Jennifer
Mullett
HSS 409
30