Rehabilitation of Finger Rehabilitation of Finger Extension in Chronic Extension in Chronic
HemiplegiaHemiplegiaDerek G. KamperDerek G. Kamper1,21,2
Robert V. KenyonRobert V. Kenyon1,31,3
William Z. RymerWilliam Z. Rymer1,21,2
Erik CruzErik Cruz11
Xun LuoXun Luo33
Heidi WaldingerHeidi Waldinger11
1Sensory Motor Performance Program1Sensory Motor Performance Program2Northwestern University2Northwestern University3University of Illinois at Chicago3University of Illinois at Chicago
MotivationMotivation
Limited finger extension is the most common chronic motor impairment following stroke (Trombly, 1989).
Friedland, F., “Physical Therapy,” in Stroke and its Rehabilitation
RationaleRationaleIsometric extensor weakness
11 stroke subjects, 5 control subjects
RationaleRationaleYet, extensor activity is present
Attempted voluntary isometric extensionAttempted voluntary isometric flexion
RationaleRationaleSuggestion that treatment can alter cortical and peripheral activation
Voluntary wrist extension in CP subject prior to NMES therapy
Voluntary wrist extension in CP subject after NMES therapy
Constraint-induced use (Liepert et al., 1998; 2000)
Aim: Develop rehabilitation Aim: Develop rehabilitation devices devices for handfor hand
• Assist extension onlyAssist extension only
• Externally actuatedExternally actuated
• LightweightLightweight
• SafeSafe
• Provide feedback of assistanceProvide feedback of assistance
• Adaptable to assist individuated Adaptable to assist individuated finger movementsfinger movements
Criteria
Subject populationSubject population
• Chronic hemiplegia following stroke (> 9 Chronic hemiplegia following stroke (> 9 months)months)
• Stage 2 or 3 for hand on Chedoke-McMaster Stage 2 or 3 for hand on Chedoke-McMaster scale (< 50% full finger extension)scale (< 50% full finger extension)
• Absence of visuoperceptual disturbanceAbsence of visuoperceptual disturbance• Absence of fixed contractureAbsence of fixed contracture• Capacity to provide informed consentCapacity to provide informed consent
Design of development Design of development activitiesactivitiesBody-powered orthosis
• Cable-driven• Biscapular abduction/
shoulder flexion produce finger extension
• Figure 8 harness• Force transducer
measures assistance
Design of development Design of development activitiesactivitiesCurrent glove design
Zipper across palm for ease of donning Cable housing sewn into dorsal side
Design of development Design of development activitiesactivitiesChallenges
• Translation of cable housing• Stiffness of PIP joint
• leads to hyperextension of DIP and MCP• Cumbersome forearm cuff
Design of development Design of development activitiesactivitiesPneumatically-powered hand
Design of development Design of development activitiesactivities
• Thrice weekly for 8 Thrice weekly for 8 weeksweeks
• Virtual targetsVirtual targets
• Feedback of Feedback of assistance levelassistance level
Training
• Glasstron head-mounted display
• CAVElibrary
• Use see-through VR to visualize object and hand
• GUI for therapist: select object type and size
Design of development Design of development activitiesactivities
Efficacy testing
Free movement (CyberGlove®)
Design of development Design of development activitiesactivities
Motor Shaft
Air Bladder
Channel
VacuumPump Tube
Efficacy testing
Isometric and isokinetic (servomotor)