James H. Cauraugh

Chronic Motor Dysfunction After Stroke Recovering Wrist and Finger Extension by Electromyography-Triggered Neuromuscular Stimulation

BACKGROUND AND PURPOSE After stroke, many individuals have chronic unilateral motor dysfunction in the upper extremity that severely limits their functional movement control. The purpose of this study was to determine the effect of electromyography-triggered neuromuscular electrical stimulation on the wrist and finger extension muscles in individuals who had a stroke > or = 1 year earlier. METHODS Eleven individuals volunteered to participate and were randomly assigned to either the electromyography-triggered neuromuscular stimulation experimental group (7 subjects) or the control group (4 subjects). After completing a pretest involving 5 motor capability tests, the poststroke subjects completed 12 treatment sessions (30 minutes each) according to group assignments. Once the control subjects completed 12 sessions attempting wrist and finger extension without any external assistance and were posttested, they were then given 12 sessions of the rehabilitation treatment. RESULTS The Box and Block test and the force-generation task (sustained muscular contraction) revealed significant findings (P<0. 05). The experimental group moved significantly more blocks and displayed a higher isometric force impulse after the rehabilitation treatment. CONCLUSIONS Two lines of evidence clearly support the use of the electromyography-triggered neuromuscular electrical stimulation treatment to rehabilitate wrist and finger extension movements of hemiparetic individuals > or =1 year after stroke. The treatment program decreased motor dysfunction and improved the motor capabilities in this group of poststroke individuals.

Maximizing Performance Feedback Effectiveness through Videotape Replay and a Self-Controlled Learning Environment

This study was designed to examine whether participants who could control the schedule of performance feedback (KP) would learn differentially from those who received a rigid feedback schedule while learning a complex task. Participants (N = 48) were randomly assigned to self-controlled KP (SELF), summary KP (SUMMARY), yoked control (YOKE), or knowledge of results only (KR) conditions. Data collection consisted of an acquisition phase and a 4-day retention phase during which right-handed participants performed a left-handed ball throw. Overall, throwing form improved across trial blocks during acquisition, with the SUMMARY, SELF, and YOKE groups showing more improvement than the KR group. During retention, the SELF group retained a higher level of throwing form and accuracy in comparison to the other groups. Results suggest that when given the opportunity to control the feedback environment, learners require relatively less feedback to acquire skills and retain those skills at a level equivalent to or surpassing those who are given more feedback but receive it passively.

Two Coupled Motor Recovery Protocols Are Better Than One Electromyogram-Triggered Neuromuscular Stimulation and Bilateral Movements

Background and Purpose— Overcoming chronic hemiparesis from a cerebrovascular accident (CVA) can be challenging for many patients, especially after the first 12 months after the CVA. With the use of established motor control theories, the present study investigated electromyogram (EMG)-triggered neuromuscular stimulation and bilateral coordination training. Methods— Twenty-five CVA subjects volunteered to participate in this motor recovery protocol study. Subjects were randomly assigned to 1 of 3 groups: (1) coupled protocol of EMG-triggered stimulation and bilateral movement (n=10); (2) EMG-triggered stimulation and unilateral movement (n=10); or (3) control (n=5). All participants completed 6 hours of rehabilitation during a 2-week period according to group assignments. Motor capabilities of the wrist and fingers were evaluated on the basis of 3 categories of motor tasks in a pretest-posttest control group design. Results— Significant findings for the (1) number of blocks moved in a functional task, (2) chronometric reaction times to initiate movements, and (3) sustained muscle contraction capability all favored the coupled bilateral movement training and EMG-triggered neuromuscular stimulation protocol group. In addition, the unilateral movement/stimulation group exceeded the control group in the number of blocks moved and rapid onset of muscle contractions. Conclusions— This new evidence is convincing in that subjects in the coupled protocol group were able to demonstrate enhanced voluntary motor control across 3 categories of tasks. Chronic hemiparesis decreased considerably in the wrist and fingers as CVA patients expanded their motor repertoire.

Bilateral movement training and stroke rehabilitation: A systematic review and meta-analysis

OBJECTIVE AND DESIGN Bilateral movement training is being increasingly used as a post-stroke motor rehabilitation protocol. The contemporary emphasis on evidence-based medicine warrants a prospective meta-analysis to determine the overall effectiveness of rehabilitating with bilateral movements. METHODS After searching reference lists of bilateral motor recovery articles as well as PubMed and Cochrane databases, 11 stroke rehabilitation studies qualified for this systematic review. An essential requirement for inclusion was that the bilateral training protocols involved either functional tasks or repetitive arm movements. Each study had one of three common arm and hand functional outcome measures: Fugl-Meyer, Box and Block, and kinematic performance. RESULTS The fixed effects model primary meta-analysis revealed an overall effect size (ES=0.732, S.D.=0.13). These findings indicate that bilateral movement training was beneficial for improving motor recovery post-stroke. Moreover, a fail-safe analysis indicated that 48 null effects would be necessary to lower the mean effect size to an insignificant level. CONCLUSION These meta-analysis findings indicate that bilateral movements alone or in combination with auxiliary sensory feedback are effective stroke rehabilitation protocols during the sub-acute and chronic phases of recovery.

Bilateral and unilateral movement training on upper limb function in chronic stroke patients: A TMS study

The use of activity-dependent interventions has shown some success in promoting recovery of upper limb function in chronic stroke patients. This study compared the neurophysiological and behavioural changes associated with two such rehabilitation protocols: unilateral and bilateral movement training. Twelve chronic stroke patients were randomly assigned to the two training protocols involving six daily practice sessions. Each session consisted of 50 trials of a dowel placement task performed either with both impaired and unimpaired arm moving synchronously (bilateral training group) or with only the impaired arm moving (unilateral training). Kinematic measurements of upper limb movements were made in four unilateral test trials performed prior to and following each practice session. Functional assessments of the impaired upper limb and neurophysiological assessments, using transcranial magnetic stimulation (TMS), of the affected and non-affected cortical hemispheres were made prior to and following the intervention sessions. Individuals receiving bilateral training showed a reduction in movement time of the impaired limb and increased upper limb functional ability compared to individuals receiving unilateral training. In some patients changes to upper limb function were associated with changes to the cortical representation of a target muscle in the non-affected hemisphere. Overall, these findings suggest that a short-term bilateral training intervention may be effective in facilitating upper limb motor function in chronic stroke patients.

Visual search, anticipation, and reactive comparisons between highly-skilled and beginning tennis players

Abstract Simulated tennis playing situations were created for the laboratory testing of visual search patterns, anticipation, reactions, and movements to compare male and female high-level and beginning players. Of particular interest was the degree to which each measure would differentiate the groups. Participants were highly-rated university players (N-30) and students enrolled in a beginning tennis class (N = 30). Under one testing condition, visual search patterns were recorded as they viewed filmed opponents serve (60 trials) and hit ground strokes (60 trials). Also recorded was anticipation accuracy and speed of the intended type and location of serves and the intended placement of ground strokes. In other testing, execution of a split step was followed by moving rapidly to the comet location for a simulated stroke in response to a series of light cues. Reaction and movement times were recorded. Discrimination analysis revealed that experts and beginners were most differentiated due to fixations on ...

Bilateral movement training and stroke motor recovery progress: a structured review and meta-analysis.

The purpose was to conduct a structured review and meta-analysis to determine the cumulative effect of bilateral arm training on motor capabilities post stroke. Forty-eight stroke studies were selected from three databases with 25 comparisons qualifying for inclusion in our meta-analysis. We identified and coded four types of bilateral arm interventions with 366 stroke patients. A random effects model using the standardized mean difference technique determined a large and significant effect size (0.734; SE=0.125), high fail-safe N (532), and medium variability in the studies (I(2)=63%). Moderator variable analysis on the type of bilateral training revealed two large and significant effects: (a) BATRAC (0.842; SE=0.155) and (b) coupled bilateral and EMG-triggered neuromuscular stimulation (1.142; SE=0.176). These novel findings provide strong evidence supporting bilateral arm training with the caveat that two coupled protocols, rhythmic alternating movements and active stimulation, are most effective.

Electromyogram-triggered neuromuscular stimulation and stroke motor recovery of arm/hand functions: a meta-analysis

Debate persists about the effectiveness of poststroke behavioral interventions for progress toward motor recovery. The current meta-analysis assessed the effect of electromyogram (EMG)-triggered neuromuscular stimulation on arm and hand functions. Computer searches of PubMed and Cochran databases, as well as hand searches of reference lists identified seven EMG-triggered neuromuscular stimulation studies. Outcome measures focused on arm and hand motor capability functions. In addition, the quality of each study was rated on three guidelines: randomization, double blind, and dropouts. After adjusting data for consistency in the arm/hand outcome measures and to avoid bias, five active stimulation studies were included in the analysis. Rehabilitation treatment in each study focused on wrist extension. The total number of individuals in the treatment groups was 47 whereas the control groups had 39 subjects. The meta-analysis revealed a significant overall mean effect size (delta=0.82, S.D.=0.59). A homogeneity test indicated that the pooled standardized effect sizes estimated the same treatment effect. A fail-safe test for null effect findings revealed that 15 studies were required to reduce the large effect (0.82) to a small effect (0.20). These improved wrist extension motor capabilities findings support EMG-triggered neuromuscular stimulation as an effective poststroke protocol.

Verbal instructional sets to normalise the temporal and spatial gait variables in Parkinson’s disease

Gait in Parkinson’s disease is characterised by slowed velocity; shuffling, small steps; and absent arm swing. Drug therapy intervention is beneficial in improving mobility, though with prolonged use its effects may diminish. The purpose of this study was to examine whether Parkinsonian patients could improve their gait patterns in response to five instructional sets: natural walking; walking while deliberately swinging the arms; walking with large steps; fast walking; and walking while counting aloud. Eight subjects with idiopathic Parkinson’s disease and eight age matched control subjects were tested using motion analysis. The findings indicated that parkinsonian patients followed the instructions which immediately altered a series of single walking variables. Simultaneously, automatically activated changes occurred in other gait variables producing more normal gait. The instructional set is a strategy which can aid normalisation of Parkinsonian gait although its benefits may depend on the stage of disease progression and the degree of attention to the instructions.

Dynamic postural control but not mechanical stability differs among those with and without chronic ankle instability

The purpose of this investigation was to compare dynamic postural control and mechanical ankle stability among patients with and without chronic ankle instability (CAI) and controls. Seventy‐two subjects were divided equally into three groups: uninjured controls, people with previous ankle injury but without CAI, and people with CAI. Subjects completed a single‐leg hop‐stabilization task, and then had an anterior drawer test and lateral ankle radiograph performed bilaterally. The dynamic postural stability index was calculated from the ground reaction forces of the single‐leg hop‐stabilization task. Ankle joint stiffness (N/m) was measured with an instrumented arthrometer during the anterior drawer test, and fibula position was assessed from the radiographic image. Patients with previous ankle injuries but without CAI demonstrated higher frontal plane dynamic postural stability scores than both the uninjured control and CAI groups (P<0.01). Patients with and without CAI had significantly higher sagittal plane dynamic postural stability scores (P<0.01) and increased ankle joint stiffness (P=0.045) relative to the control group. The increased frontal plane dynamic postural control may represent a component of a coping mechanism that limits recurrent sprains and the development of CAI. Mechanical stability alterations are speculated to result from the initial ankle trauma.