1. 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

2. Motivation
Friedland, F., “Physical Therapy,” in Stroke and its Rehabilitation
Limited finger extension is the most common chronic motor impairment following stroke (Trombly, 1989).

3. Rationale Isometric extensor weakness
11 stroke subjects, 5 control subjects

4. Rationale Yet, extensor activity is present
Attempted voluntary isometric extension
Attempted voluntary isometric flexion

5. 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

6. Aim: Develop rehabilitation devices for hand
Criteria
Assist extension only
Externally actuated
Lightweight
Safe
Provide feedback of assistance
Adaptable to assist individuated finger movements

7. Subject population Chronic hemiplegia following stroke (> 9 months)
Stage 2 or 3 for hand on Chedoke-McMaster scale (< 50% full finger extension)
Absence of visuoperceptual disturbance
Absence of fixed contracture
Capacity to provide informed consent

8. Design of development activities
Body-powered orthosis
Cable-driven
Biscapular abduction/ shoulder flexion produce finger extension
Figure 8 harness
Force transducer measures assistance

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

10. Design of development activities
Challenges
Translation of cable housing
Stiffness of PIP joint
leads to hyperextension of DIP and MCP
Cumbersome forearm cuff

11. Design of development activities
Pneumatically-powered hand

12. 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

13. Design of development activities
Efficacy testing
Free movement (CyberGlove®)

14. Design of development activities
Efficacy testing
Isometric and isokinetic (servomotor)