- Email: [email protected]
*Poster 82: Are Movement Quality Kinematic Measures Valid Outcomes of Upper-Limb Motor Impairment Poststroke?
2010 ACRM–ASNR JOINT EDUCATIONAL CONFERENCE ABSTRACTS
two 4-week training periods, separated by 2 weeks of rest. A load of 1.5kg was added at the paretic ankle during one of the two 4-week training periods. Training consisted of three 1-hour sessions per week, including 20 minutes of strenuous walking. Main Outcome Measures: Natural and maximal gait speed measured over a 10-m, 6-minute walk test, maximal flexor and extensor strength at the hemiparetic hip. Results: Over the 8-week training period, the natural gait speed increased from 0.66⫾0.19 to 0.79⫾0.29m.s-1 (P⫽.039, effect size ([ES])⫽0.53), and maximal gait speed from 0.85⫾0.35 to 1.05⫾0.46m.s-1 (P⫽0.013, ES⫽0.49), while the six-minute walk test did not improve significantly (from 236.2⫾93.6 to 290.3⫾126.4m, P⫽0.077, ES⫽0.49). Within this 8-week period, effect sizes were slightly larger for the no-load (0.31⬍ES⬍0.41) than the load condition (0.12⬍ES⬍0.18), for gait speeds and endurance. However, hip muscle strength increased more with the load than the no-load condition, both for flexors (ES⫽0.49 vs 0.09) and extensors (ES⫽0.31 vs 0.13). Conclusions: Despite higher gains in strength obtained during treadmill training with a load at the ankle, gait performances did not improve accordingly during this period. A detailed biomechanical gait analysis will be required to further explain these findings. Key Words: Rehabilitation; Stroke.
Poster 80 Optimal Daily Duration of Repetitive Task Specific Training Incorporating Electrical Stimulation in Moderately Impaired Stroke. Stephen Page (University of Cincinnati Academic Health Center, Cincinnati, OH), Kari Dunning, Valerie Hermann, Pierce Boyne, Peter Levine. Disclosure: None declared. Objective: To evaluate and compare the effects of .5 hours, 1 hour, and 2 hour daily training sessions of repetitive task specific training (RTP) incorporating an electrical stimulation neuroprosthesis. Design: Randomized controlled intervention trial with multiple baseline design. Setting: Not applicable. Participants: 36 subjects exhibiting moderate arm hemiparesis secondary to strokes more than 1 year prior to study entry. Interventions: Subjects participated in 30, 60, or 120-minute therapy sessions occurring every weekday for 8 weeks. During the sessions, subjects wore the neuroprosthesis to enable performance of valued activities identified largely by the patients. To assure transfer to their real-world environments, most sessions were home-based, with the subjects coming to the clinic for “tune up” sessions. A fourth group participated in a structured home exercise program. Main Outcome Measures: Action Research Arm Test (ARAT), upper extremity section of the Fugl-Meyer (FM), Arm Motor Ability Test (AMAT), Box and Block Test (BB). Results: The groups were not significantly different in any demographic or motor measure at baseline. After intervention, subjects participating in the 120’ condition exhibited significantly larger changes on the AMAT and FM (P⬍.01); on the BB, 120’ subjects exhibited larger changes, but the differences were nonsignificant. On the ARAT, both the 60’ and 120’ groups showed significant increases after intervention. Subjects in the HEP group showed nominal or no changes on all measures. Conclusions: A longer daily duration of electrical stimulation consistently renders larger motor outcomes in moderately impaired stroke subjects. The study also confirms earlier pilot work suggesting efficacy of this approach in chronic, moderately impaired stroke subjects. Key Words: Electric stimulation; Hemiplegia; Occupational therapy; Rehabilitation.
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Poster 81 Rhythmic Training as an Adjunct to Repetitive Task Specific Training in Chronic Stroke. Valerie Hermann (University of Cincinnati Academic Medical Center, Cincinnati, OH), Leah Dunn, Stephen Page. Disclosure: None declared. Objective: To examine efficacy of a combined regimen of rhythmic training (RT) combined with repetitive task specific training (RTP) on affected arm motor impairment in chronic stroke. Design: Randomized, controlled, 2 group, pre-post test design. Setting: Outpatient rehabilitation hospital. Participants: 10 subjects with chronic stroke (⬎1y post ictus) exhibiting moderate, stable, arm hemiparesis. Interventions: Following pretesting, subjects were administered either: (a) RTP only; or (b) RTP augmented by RT (RTP ⫹ RT). Both study conditions lasted 60 minutes, and occurred 3 days per week over a 10-week period. Main Outcome Measures: Upper-extremity section of the Fugl-Meyer Test (primary outcome measure); Canadian Occupational Performance Measure, Stroke Impact Scale, and Arm Motor Ability Test. Results: A total of 10 patients, with 6 in the experiment group and 4 in the control group were studied. There were no significant differences between the groups in terms of demographics or motor impairment before intervention. The RTP ⫹ RT group demonstrated significantly larger decreases in impairment, the primary outcome measure. Both groups exhibited gains in function, perceived physical performance ability and satisfaction and overall recovery. Conclusions: These findings suggest that rhythm and timing training is a feasible intervention that may best fit in the prefunctional arena of treatment as it most impacts the motor impairment domain. Key Words: Hemiplegia; Occupational therapy; Rehabilitation. *Poster 82 Are Movement Quality Kinematic Measures Valid Outcomes of Upper-Limb Motor Impairment Poststroke? Sandeep Subramanian (McGill University, Montreal, QC, Canada), Juri Yamanaka, Geborg Chilingaryan, Mindy Levine. Disclosure: None declared. Objective: To estimate concurrent and discriminant validity of upper-limb movement quality kinematic variables (joint ranges, trunk movement) for pointing and reach-to-grasp tasks. Design: Retrospective analysis of kinematic data collected from individuals with stroke. Setting: Motion analysis laboratory. Participants: Adults (N⫽86) with subacute to chronic poststroke hemiparesis participated. They were divided into 2 datasets according to the task; pointing (n⫽44; 15 women; 58⫾13.9y) and reach-to-grasp (n⫽42; 8 women; 69⫾15.6y). Interventions: Not applicable. Main Outcome Measures: Upperlimb section of the Fugl-Meyer Assessment (FMA) was used as the criterion measure (dependant variable) and movement quality kinematic measures (sagittal trunk displacement, shoulder flexion, shoulder horizontal adduction, elbow extension) were used as predictors (independent variables) for both datasets. Upper-limb and trunk kinematics were recorded with an Optotrak System (6 markers; 100 – 120Hz; 5s). For the pointing dataset, subjects pointed towards a target placed in the contralateral arm workspace at arm’s length with adjustable height. For the reach-to-grasp dataset, subjects reached to and grasped a cylinder placed in the midline at 80% arm’s length. Results: Majority of the variance in FMA scores was explained by a combination of trunk displacement and shoulder flexion (51%) for the pointing task and by trunk displacement alone (52%) for reach-tograsp task. Trunk displacement was the only variable that distinguished between levels of motor impairment severity. Cut-off points were 4.8cm for pointing and 10cm for reach-to-grasp movements. Conclusions: Movement quality kinematic variables are valid measures of upper-limb motor impairment poststroke and can be used to Arch Phys Med Rehabil Vol 91, October 2010
E30
2010 ACRM–ASNR JOINT EDUCATIONAL CONFERENCE ABSTRACTS
assess the effects of clinical interventions. Key Words: Rehabilitation; Stroke.
activities. The effect of repeated exposures and shifting between secondary tasks needs to be studied. Key Word: Rehabilitation.
*Poster 83 Deficits in Coordination Between Grip Force and Arm Movement in Stroke. Juri Yamanaka (McGill University, Montreal, QC, Canada), Anatol G. Feldman, Mindy F. Levin. Disclosure: None declared. Objective: Studies have shown that people with stroke can produce anticipatory control during static pinch-grip tasks; however, it is unknown whether this ability is preserved during functional object transport tasks. Design: Controlled matched-pairs design. Setting: Pinchlift-transfer task on a single axis manipulandum. Participants: 10 chronic stroke patients and 10 age-matched healthy controls. Intervention: Cross-sectional observation study. Main Outcome Measures: The delay between grip force (GF) onset and arm movement onset; kinematic data (GF and acceleration) and EMG data of 2 thumb flexor/extensor muscles and 2 arm flexor/extensor muscles. Results: People with stroke showed higher initial GF, more muscle coactivation, less force modulation and abnormal grasp-and-transfer strategies, despite the presence of anticipatory control of GF. Abnormal flexor muscle activation was also observed in the brachioradialis in stroke subjects, which may contribute to discoordination between finger and arm movements during this task. Conclusions: People with stroke do not have as much flexibility in coordination between arm movement and GF compared to healthy controls. This may be due to abnormal flexor activation in the arm during movement. The decreased GF regulation during arm movement may contribute to impaired dexterity in people with good sensorimotor recovery of the hand poststroke. Key Words: Hand strength; Rehabilitation; Stroke.
Poster 85 Influence of Spontaneous Physical Activity on Muscle Plasticity Poststroke. LeAnn Snow (University of Minnesota, Minneapolis, MN), Zhenhong Nan, Walter Low, LeDora Thompson. Disclosure: None declared. Objective: To determine the contribution of spontaneous poststroke activity to neurologic dysfunction and skeletal muscle plasticity. Design: Randomized, controlled study. Setting: Basic science laboratory. Animals: 24 male Sprague Dawley rats, randomly divided into 3 groups: control (C, n⫽8), hemorrhagic stroke (S, n⫽8), and sham controls (SC, n⫽8). Interventions: Hemorrhagic stroke was induced by collagenase injection into the right striatum. Sham controls had either striatal saline injections (n⫽4), or anesthesia only (n⫽4). Rats in the C group had no surgery. Neurologic testing was performed before, and 2 weeks poststroke. Spontaneous physical activity was monitored 5 nights/week, 8 hours/night, for 1 week preoperatively, and 2 weeks postoperatively. Animals were sacrificed 2 weeks after stroke, and left soleus (SOL) and tibialis anterior (TA) muscles were harvested. Muscles were immunolabeled for myosin heavy chains to determine fiber types. Main Outcome Measures: Behavioral test scores for limb placement, total activity and ambulatory activity (counts/time interval), muscle fiber type composition, and muscle fiber cross-sectional areas were determined (blinded evaluations). Results: The S rats demonstrated lower behavioral test scores for left hindlimbs compared to C and SC groups (C⫽6, SC⫽6, S⫽4; normal function⫽ 6). There was no difference in amount of total or ambulatory spontaneous physical activity between groups within each of the week-long study intervals. There was no significant difference in fiber types or crosssectional areas in SOL of controls versus stroke groups. TA however, showed a smaller cross-sectional area of type 2a2b fibers in stroke versus control groups (C⫽3591⫾353m2, S⫽2474⫾161m2, P⫽.005). Conclusions: Early skeletal muscle plasticity 2 weeks poststroke was evident in the TA muscle, and occurred even though there was no difference in amount of spontaneous physical activity between stroke and control groups. Key Words: Muscle, skeletal; Rehabilitation; Stroke.
Poster 84 Stroke Affects the Ability to Adapt to Different Cognitive Demands During Walking. Rachel Kizony (University of Haifa, Haifa, Israel), Mindy F. Levin, Lucinda Hughey, Claire Perez, Joyce Fung. Disclosure: None declared. Objective: To examine gait speed changes between repetitive performance of a functional cognitive-locomotor dual-task and a novel dual-task in people with stroke as compared to control subjects. Design: Quasi-experimental, mixed model design. Setting: A virtual reality gait lab in a research hospital. Participants: A convenience sample of 7 individuals with stroke (65.6⫾5.1y) and 10 healthy persons (69.7⫾7.6y) with no cognitive deficits (MMSE scoreⱖ25). Interventions: After habituating to the self-paced treadmill while viewing a virtual grocery aisle, an auditory “shopping list” was given to the participant who would then “reach for” remembered items after walking to the end of the aisle. This dual-task was repeated 10 to 20 times with varying lists. The session ended with the novel dual-task of backwards counting while walking. Main Outcome Measure: Selfpaced treadmill speed. Results: When first presented with a functional dual-task, healthy subjects (7/10) decreased gait speed, whereas stroke individuals showed no change (3/7), decreased gait speed (2/7), or even increased gait speed by more than 0.1m/s (2/7). Most subjects continuously increased gait speed throughout repetition such that both groups walked 0.1 to 0.2m/s faster than the first dual-task or baseline walking trial. On switching to the novel dual-task, healthy subjects significantly (P⬍.05) decreased their gait speed, whereas stroke individuals demonstrated responses that were as variable as when a cognitive load was first added. Conclusions: These results suggest that people poststroke have difficulty shifting between cognitive-motor dual tasks. Such inflexibility may affect their performance in daily Arch Phys Med Rehabil Vol 91, October 2010
*Poster 86 Haptic Forces Applied Through an Instrumented Cane During Self-Paced Treadmill Walking Poststroke. Kata Patterson (School of Physical and Occupational Therapy, McGill University, Montre´al, QC, Canada), Claire Perez, Alison Oates, Joyce Fung. Disclosure: None declared. Objective: To describe and compare the 3-dimensional (3D) forces exerted through an instrumented cane: (1) between individuals poststroke and age-matched healthy controls and (2) during self-paced treadmill walking at different inclines. Design: Quasi-experimental, mixed model design. Setting: Rehabilitation hospital, multidisciplinary research center site. Participants: Community-dwelling individuals with chronic stroke (n⫽9, 48.5⫾17.1mo poststroke) and healthy age-matched adults (n⫽9). 4 of the individuals with stroke were regular cane users. Interventions: Participants walked on a self-paced treadmill (mounted on a large platform capable of movement in 6 degrees of freedom) and immersed in a virtual environment. The physical and virtual environments were changed from level to 5° upslope and 5° downslope while the participant walked with and without an instrumented cane capable of measuring 3D forces. Main Outcome Measure: Loading forces exerted through an instrumented cane normalized to the gait cycle. Results: A 2-way analysis of
two 4-week training periods, separated by 2 weeks of rest. A load of 1.5kg was added at the paretic ankle during one of the two 4-week training periods. Training consisted of three 1-hour sessions per week, including 20 minutes of strenuous walking. Main Outcome Measures: Natural and maximal gait speed measured over a 10-m, 6-minute walk test, maximal flexor and extensor strength at the hemiparetic hip. Results: Over the 8-week training period, the natural gait speed increased from 0.66⫾0.19 to 0.79⫾0.29m.s-1 (P⫽.039, effect size ([ES])⫽0.53), and maximal gait speed from 0.85⫾0.35 to 1.05⫾0.46m.s-1 (P⫽0.013, ES⫽0.49), while the six-minute walk test did not improve significantly (from 236.2⫾93.6 to 290.3⫾126.4m, P⫽0.077, ES⫽0.49). Within this 8-week period, effect sizes were slightly larger for the no-load (0.31⬍ES⬍0.41) than the load condition (0.12⬍ES⬍0.18), for gait speeds and endurance. However, hip muscle strength increased more with the load than the no-load condition, both for flexors (ES⫽0.49 vs 0.09) and extensors (ES⫽0.31 vs 0.13). Conclusions: Despite higher gains in strength obtained during treadmill training with a load at the ankle, gait performances did not improve accordingly during this period. A detailed biomechanical gait analysis will be required to further explain these findings. Key Words: Rehabilitation; Stroke.
Poster 80 Optimal Daily Duration of Repetitive Task Specific Training Incorporating Electrical Stimulation in Moderately Impaired Stroke. Stephen Page (University of Cincinnati Academic Health Center, Cincinnati, OH), Kari Dunning, Valerie Hermann, Pierce Boyne, Peter Levine. Disclosure: None declared. Objective: To evaluate and compare the effects of .5 hours, 1 hour, and 2 hour daily training sessions of repetitive task specific training (RTP) incorporating an electrical stimulation neuroprosthesis. Design: Randomized controlled intervention trial with multiple baseline design. Setting: Not applicable. Participants: 36 subjects exhibiting moderate arm hemiparesis secondary to strokes more than 1 year prior to study entry. Interventions: Subjects participated in 30, 60, or 120-minute therapy sessions occurring every weekday for 8 weeks. During the sessions, subjects wore the neuroprosthesis to enable performance of valued activities identified largely by the patients. To assure transfer to their real-world environments, most sessions were home-based, with the subjects coming to the clinic for “tune up” sessions. A fourth group participated in a structured home exercise program. Main Outcome Measures: Action Research Arm Test (ARAT), upper extremity section of the Fugl-Meyer (FM), Arm Motor Ability Test (AMAT), Box and Block Test (BB). Results: The groups were not significantly different in any demographic or motor measure at baseline. After intervention, subjects participating in the 120’ condition exhibited significantly larger changes on the AMAT and FM (P⬍.01); on the BB, 120’ subjects exhibited larger changes, but the differences were nonsignificant. On the ARAT, both the 60’ and 120’ groups showed significant increases after intervention. Subjects in the HEP group showed nominal or no changes on all measures. Conclusions: A longer daily duration of electrical stimulation consistently renders larger motor outcomes in moderately impaired stroke subjects. The study also confirms earlier pilot work suggesting efficacy of this approach in chronic, moderately impaired stroke subjects. Key Words: Electric stimulation; Hemiplegia; Occupational therapy; Rehabilitation.
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Poster 81 Rhythmic Training as an Adjunct to Repetitive Task Specific Training in Chronic Stroke. Valerie Hermann (University of Cincinnati Academic Medical Center, Cincinnati, OH), Leah Dunn, Stephen Page. Disclosure: None declared. Objective: To examine efficacy of a combined regimen of rhythmic training (RT) combined with repetitive task specific training (RTP) on affected arm motor impairment in chronic stroke. Design: Randomized, controlled, 2 group, pre-post test design. Setting: Outpatient rehabilitation hospital. Participants: 10 subjects with chronic stroke (⬎1y post ictus) exhibiting moderate, stable, arm hemiparesis. Interventions: Following pretesting, subjects were administered either: (a) RTP only; or (b) RTP augmented by RT (RTP ⫹ RT). Both study conditions lasted 60 minutes, and occurred 3 days per week over a 10-week period. Main Outcome Measures: Upper-extremity section of the Fugl-Meyer Test (primary outcome measure); Canadian Occupational Performance Measure, Stroke Impact Scale, and Arm Motor Ability Test. Results: A total of 10 patients, with 6 in the experiment group and 4 in the control group were studied. There were no significant differences between the groups in terms of demographics or motor impairment before intervention. The RTP ⫹ RT group demonstrated significantly larger decreases in impairment, the primary outcome measure. Both groups exhibited gains in function, perceived physical performance ability and satisfaction and overall recovery. Conclusions: These findings suggest that rhythm and timing training is a feasible intervention that may best fit in the prefunctional arena of treatment as it most impacts the motor impairment domain. Key Words: Hemiplegia; Occupational therapy; Rehabilitation. *Poster 82 Are Movement Quality Kinematic Measures Valid Outcomes of Upper-Limb Motor Impairment Poststroke? Sandeep Subramanian (McGill University, Montreal, QC, Canada), Juri Yamanaka, Geborg Chilingaryan, Mindy Levine. Disclosure: None declared. Objective: To estimate concurrent and discriminant validity of upper-limb movement quality kinematic variables (joint ranges, trunk movement) for pointing and reach-to-grasp tasks. Design: Retrospective analysis of kinematic data collected from individuals with stroke. Setting: Motion analysis laboratory. Participants: Adults (N⫽86) with subacute to chronic poststroke hemiparesis participated. They were divided into 2 datasets according to the task; pointing (n⫽44; 15 women; 58⫾13.9y) and reach-to-grasp (n⫽42; 8 women; 69⫾15.6y). Interventions: Not applicable. Main Outcome Measures: Upperlimb section of the Fugl-Meyer Assessment (FMA) was used as the criterion measure (dependant variable) and movement quality kinematic measures (sagittal trunk displacement, shoulder flexion, shoulder horizontal adduction, elbow extension) were used as predictors (independent variables) for both datasets. Upper-limb and trunk kinematics were recorded with an Optotrak System (6 markers; 100 – 120Hz; 5s). For the pointing dataset, subjects pointed towards a target placed in the contralateral arm workspace at arm’s length with adjustable height. For the reach-to-grasp dataset, subjects reached to and grasped a cylinder placed in the midline at 80% arm’s length. Results: Majority of the variance in FMA scores was explained by a combination of trunk displacement and shoulder flexion (51%) for the pointing task and by trunk displacement alone (52%) for reach-tograsp task. Trunk displacement was the only variable that distinguished between levels of motor impairment severity. Cut-off points were 4.8cm for pointing and 10cm for reach-to-grasp movements. Conclusions: Movement quality kinematic variables are valid measures of upper-limb motor impairment poststroke and can be used to Arch Phys Med Rehabil Vol 91, October 2010
E30
2010 ACRM–ASNR JOINT EDUCATIONAL CONFERENCE ABSTRACTS
assess the effects of clinical interventions. Key Words: Rehabilitation; Stroke.
activities. The effect of repeated exposures and shifting between secondary tasks needs to be studied. Key Word: Rehabilitation.
*Poster 83 Deficits in Coordination Between Grip Force and Arm Movement in Stroke. Juri Yamanaka (McGill University, Montreal, QC, Canada), Anatol G. Feldman, Mindy F. Levin. Disclosure: None declared. Objective: Studies have shown that people with stroke can produce anticipatory control during static pinch-grip tasks; however, it is unknown whether this ability is preserved during functional object transport tasks. Design: Controlled matched-pairs design. Setting: Pinchlift-transfer task on a single axis manipulandum. Participants: 10 chronic stroke patients and 10 age-matched healthy controls. Intervention: Cross-sectional observation study. Main Outcome Measures: The delay between grip force (GF) onset and arm movement onset; kinematic data (GF and acceleration) and EMG data of 2 thumb flexor/extensor muscles and 2 arm flexor/extensor muscles. Results: People with stroke showed higher initial GF, more muscle coactivation, less force modulation and abnormal grasp-and-transfer strategies, despite the presence of anticipatory control of GF. Abnormal flexor muscle activation was also observed in the brachioradialis in stroke subjects, which may contribute to discoordination between finger and arm movements during this task. Conclusions: People with stroke do not have as much flexibility in coordination between arm movement and GF compared to healthy controls. This may be due to abnormal flexor activation in the arm during movement. The decreased GF regulation during arm movement may contribute to impaired dexterity in people with good sensorimotor recovery of the hand poststroke. Key Words: Hand strength; Rehabilitation; Stroke.
Poster 85 Influence of Spontaneous Physical Activity on Muscle Plasticity Poststroke. LeAnn Snow (University of Minnesota, Minneapolis, MN), Zhenhong Nan, Walter Low, LeDora Thompson. Disclosure: None declared. Objective: To determine the contribution of spontaneous poststroke activity to neurologic dysfunction and skeletal muscle plasticity. Design: Randomized, controlled study. Setting: Basic science laboratory. Animals: 24 male Sprague Dawley rats, randomly divided into 3 groups: control (C, n⫽8), hemorrhagic stroke (S, n⫽8), and sham controls (SC, n⫽8). Interventions: Hemorrhagic stroke was induced by collagenase injection into the right striatum. Sham controls had either striatal saline injections (n⫽4), or anesthesia only (n⫽4). Rats in the C group had no surgery. Neurologic testing was performed before, and 2 weeks poststroke. Spontaneous physical activity was monitored 5 nights/week, 8 hours/night, for 1 week preoperatively, and 2 weeks postoperatively. Animals were sacrificed 2 weeks after stroke, and left soleus (SOL) and tibialis anterior (TA) muscles were harvested. Muscles were immunolabeled for myosin heavy chains to determine fiber types. Main Outcome Measures: Behavioral test scores for limb placement, total activity and ambulatory activity (counts/time interval), muscle fiber type composition, and muscle fiber cross-sectional areas were determined (blinded evaluations). Results: The S rats demonstrated lower behavioral test scores for left hindlimbs compared to C and SC groups (C⫽6, SC⫽6, S⫽4; normal function⫽ 6). There was no difference in amount of total or ambulatory spontaneous physical activity between groups within each of the week-long study intervals. There was no significant difference in fiber types or crosssectional areas in SOL of controls versus stroke groups. TA however, showed a smaller cross-sectional area of type 2a2b fibers in stroke versus control groups (C⫽3591⫾353m2, S⫽2474⫾161m2, P⫽.005). Conclusions: Early skeletal muscle plasticity 2 weeks poststroke was evident in the TA muscle, and occurred even though there was no difference in amount of spontaneous physical activity between stroke and control groups. Key Words: Muscle, skeletal; Rehabilitation; Stroke.
Poster 84 Stroke Affects the Ability to Adapt to Different Cognitive Demands During Walking. Rachel Kizony (University of Haifa, Haifa, Israel), Mindy F. Levin, Lucinda Hughey, Claire Perez, Joyce Fung. Disclosure: None declared. Objective: To examine gait speed changes between repetitive performance of a functional cognitive-locomotor dual-task and a novel dual-task in people with stroke as compared to control subjects. Design: Quasi-experimental, mixed model design. Setting: A virtual reality gait lab in a research hospital. Participants: A convenience sample of 7 individuals with stroke (65.6⫾5.1y) and 10 healthy persons (69.7⫾7.6y) with no cognitive deficits (MMSE scoreⱖ25). Interventions: After habituating to the self-paced treadmill while viewing a virtual grocery aisle, an auditory “shopping list” was given to the participant who would then “reach for” remembered items after walking to the end of the aisle. This dual-task was repeated 10 to 20 times with varying lists. The session ended with the novel dual-task of backwards counting while walking. Main Outcome Measure: Selfpaced treadmill speed. Results: When first presented with a functional dual-task, healthy subjects (7/10) decreased gait speed, whereas stroke individuals showed no change (3/7), decreased gait speed (2/7), or even increased gait speed by more than 0.1m/s (2/7). Most subjects continuously increased gait speed throughout repetition such that both groups walked 0.1 to 0.2m/s faster than the first dual-task or baseline walking trial. On switching to the novel dual-task, healthy subjects significantly (P⬍.05) decreased their gait speed, whereas stroke individuals demonstrated responses that were as variable as when a cognitive load was first added. Conclusions: These results suggest that people poststroke have difficulty shifting between cognitive-motor dual tasks. Such inflexibility may affect their performance in daily Arch Phys Med Rehabil Vol 91, October 2010
*Poster 86 Haptic Forces Applied Through an Instrumented Cane During Self-Paced Treadmill Walking Poststroke. Kata Patterson (School of Physical and Occupational Therapy, McGill University, Montre´al, QC, Canada), Claire Perez, Alison Oates, Joyce Fung. Disclosure: None declared. Objective: To describe and compare the 3-dimensional (3D) forces exerted through an instrumented cane: (1) between individuals poststroke and age-matched healthy controls and (2) during self-paced treadmill walking at different inclines. Design: Quasi-experimental, mixed model design. Setting: Rehabilitation hospital, multidisciplinary research center site. Participants: Community-dwelling individuals with chronic stroke (n⫽9, 48.5⫾17.1mo poststroke) and healthy age-matched adults (n⫽9). 4 of the individuals with stroke were regular cane users. Interventions: Participants walked on a self-paced treadmill (mounted on a large platform capable of movement in 6 degrees of freedom) and immersed in a virtual environment. The physical and virtual environments were changed from level to 5° upslope and 5° downslope while the participant walked with and without an instrumented cane capable of measuring 3D forces. Main Outcome Measure: Loading forces exerted through an instrumented cane normalized to the gait cycle. Results: A 2-way analysis of