Rehabilitation of Finger Extension in Chronic Hemiplegia

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Rehabilitation of Finger Extension in Chronic
Hemiplegia

• Derek G. Kamper1,2
• Robert V. Kenyon1,3
• William Z. Rymer1,2

Erik Cruz1 Xun Luo3 Heidi Waldinger1
1Sensory Motor Performance Program 2Northwestern
University 3University of Illinois at Chicago
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Motivation
Friedland, F., Physical Therapy, in Stroke and
its Rehabilitation
Limited finger extension is the most common
chronic motor impairment following stroke
(Trombly, 1989).
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Rationale
Isometric extensor weakness
11 stroke subjects, 5 control subjects
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Rationale
Yet, extensor activity is present
Attempted voluntary isometric extension
Attempted voluntary isometric flexion
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Rationale
Suggestion that treatment can alter cortical and
peripheral activation
Constraint-induced use (Liepert et al., 1998
2000)
Voluntary wrist extension in CP subject prior to
NMES therapy
Voluntary wrist extension in CP subject after
NMES therapy
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Aim Develop rehabilitation devices for hand
Criteria

• Assist extension only
• Externally actuated
• Lightweight
• Safe
• Provide feedback of assistance
• Adaptable to assist individuated finger movements

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Subject population

• Chronic hemiplegia following stroke (gt 9 months)
• Stage 2 or 3 for hand on Chedoke-McMaster scale
  (lt 50 full finger extension)
• Absence of visuoperceptual disturbance
• Absence of fixed contracture
• Capacity to provide informed consent

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Design of development activities
Body-powered orthosis

• Cable-driven
• Biscapular abduction/ shoulder flexion produce
  finger extension
• Figure 8 harness
• Force transducer measures assistance

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Design of development activities
Current glove design
Zipper across palm for ease of donning
Cable housing sewn into dorsal side
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Design of development activities
Challenges

• Translation of cable housing
• Stiffness of PIP joint
• leads to hyperextension of DIP and MCP
• Cumbersome forearm cuff

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Design of development activities
Pneumatically-powered hand
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Design of development activities
Training

• Thrice weekly for 8 weeks
• Virtual targets
• Feedback of assistance level

• Glasstron head-mounted display
• CAVElibrary
• Use see-through VR to visualize object and hand
• GUI for therapist select object type and size

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Design of development activities
Efficacy testing
Free movement (CyberGlove)
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Design of development activities
Efficacy testing
Isometric and isokinetic (servomotor)