Upper extremity muscle activation in children with unilateral cerebral palsy during an auditory cued repetitive task: Effects on bimanual coordination.

PURPOSE: The aim of this exploratory study was to investigate mirror muscle activation in the upper limbs of children with unilateral cerebral palsy during an auditory-cued repetitive squeezing task and to compare upper limb muscle activation patterns to typically developing peers engaged in the same task. METHODS: A convenience sample of six children with unilateral cerebral palsy and six typically developing peers (7-17 y) participated in the study. Muscle activity was measured using a 16 channel Zerowire EMG system (Noraxon, USA Inc. Scottsdale, AZ) in the anterior deltoid, biceps brachii, extensor carpi radialis, flexor carpi radialis, and lateral triceps muscles bilaterally as children squeezed a pediatric bulb dynamometer to 3 pounds per square inch (PSI) for a one second duration, 10 times in one minute. Squeezing activity was cued by a computer generated auditory beep. Between hand differences in muscle onset times and onset amplitude for each muscle were determined using paired t-tests. Two group by two hand ANOVA measured between group differences. RESULTS: Results supported increased later muscle onset and lack of significant differences in onset amplitude bilaterally when the dominant hand was working in the CP population. CONCLUSIONS: There are differences in motor control mechanisms of muscle activation between populations.

Bimanual training and constraint-induced movement therapy in children with hemiplegic cerebral palsy: a randomized trial.

BACKGROUND: Constraint-induced movement therapy (CIMT) promotes hand function using intensive unimanual practice along with restraint of the less-affected hand. CIMT has not been compared with a treatment with equivalent dosing frequency and intensity in children with cerebral palsy (CP). OBJECTIVES: The authors report a randomized trial comparing CIMT and a bimanual intervention (hand-arm intensive bimanual therapy; HABIT) that maintains the intensity of practice associated with CIMT but where children are engaged in functional bimanual tasks. METHODS: A total of 42 participants with hemiplegic CP between the ages of 3.5 and 10 years (matched for age and hand function) were randomized to receive 90 hours of CIMT or an equivalent dosage of functional bimanual training (HABIT) conducted in day-camp environments. A physical therapist blinded to treatment allocation tested hand function before and after treatment. The primary outcomes were changes in Jebsen-Taylor Test of Hand Function (JTTHF) and Assisting Hand Assessment (AHA) scores. Secondary measures included the Goal Attainment Scale (GAS). RESULTS: Both the CIMT and HABIT groups demonstrated comparable improvement from the pretest to immediate posttest in the JTTHF and AHA (P < .0001), which were maintained at 6 months. GAS, however, revealed greater progress toward goals for the HABIT group (P < .0001), with continued improvement across test sessions for both groups (P < .0001). CONCLUSIONS: Both CIMT and bimanual training lead to similar improvements in hand function. A potential benefit of bimanual training is that participants may improve more on self-determined goals.

Influence of accuracy constraints on bimanual coordination during a goal-directed task in children with hemiplegic cerebral palsy.

Previously we found that children with hemiplegic cerebral palsy (CP) have impaired bimanual coordination compared to typically developing children during a functional drawer-opening task. However, performance of the task under time constraints (fast-as-possible) facilitated better bimanual coordination for these children. Accuracy is another important task constraint that could influence the coordination of the two hands during such tasks. The effect of accuracy constraints on bimanual coordination in children with hemiplegic CP is not well understood. In the present study, children were asked to reach forward and open a drawer with one hand and then activate a light switch inside the drawer with the contralateral hand. Task accuracy constraints (different handles and switch sizes) were manipulated in order to determine their effect on upper extremity coordination. Eleven children with hemiplegic CP (age 8-16 years) and eleven age-matched typically developing children participated in this study. The results show that higher accuracy constraints prolong the total movement completion time for both groups of children. However, children with hemiplegic CP demonstrated less sequential movement with a higher accuracy constraint (a smaller knob handle) than a lower accuracy constraint (a larger loop handle). Nevertheless, presentation of both higher accuracy constraints (handle and switch) at the same time was detrimental to their performance. These influences of task constraints were similar regardless of which hand was used to open the drawer. The results suggest that performance may not be linearly related to the constraints, and in some cases "more is not better".

Fingertip force control during bimanual object lifting in hemiplegic cerebral palsy.

In the present study we examined unimanual and bimanual fingertip force control during grasping in children with hemiplegic cerebral palsy (CP). Participants lifted, transported and released an object with one hand or both hands together in order to examine the effect on fingertip force control for each hand separately and to determine whether any benefit exists for the affected hand when it performed the task concurrently with the less-affected hand. Seven children with hemiplegic CP performed the task while their movement and fingertip force control were measured. In the bimanual conditions, the weight of the instrumented objects was equal or unequal. The durations of the all temporal phases for the less-affected hand were prolonged during bimanual control compared to unimanual control. We observed close synchrony of both hands when the task was performed with both hands, despite large differences in duration between both hands when they performed separately. There was a marginal benefit for two of the five force related variables for the affected hand (grip force at onset of load force, and peak grip force) when it transported the object simultaneously with the less-affected hand. Collectively, these results corroborate earlier findings of reaching studies that showed slowing down of the less-affected hand when it moved together with the affected hand. A new finding that extends these studies is that bimanual tasks may have the potential to facilitate force control of the affected hand. The implications of these findings for recent rehabilitative therapies in children with CP that make use of bimanual training are discussed.

Efficacy of a hand-arm bimanual intensive therapy (HABIT) in children with hemiplegic cerebral palsy: a randomized control trial.

Children with hemiplegic cerebral palsy (CP) have impairments in bimanual coordination above and beyond their unilateral impairments. Recently we developed hand-arm bimanual intensive therapy (HABIT), using the principles of motor learning, and neuroplasticity, to address these bimanual impairments. A single-blinded randomized control study of HABIT was performed to examine its efficacy in children with hemiplegic CP with mild to moderate hand involvement. Twenty children (age range 3 y 6 mo-15 y 6 mo) were randomized to either an intervention (n=10: seven males, three females; mean age 8 y 7 mo, SD 4 y) or a delayed treatment control group (n=10: seven males, three females; mean age 6 y 10 mo, SD 2 y 4 mo). Children were engaged in play and functional activities that provided structured bimanual practice 6 hours per day for 10 days. Each child was evaluated immediately before and after the intervention, and again at 1-month post-intervention. Children in the intervention group demonstrated improved scores on the Assisting Hand Assessment, increased involved extremity use measured using accelerometry and a caregiver survey, bimanual items of the Bruininks-Oseretsky Test of Motor Proficiency, and the simultaneity of completing a draw-opening task with two hands (p<0.05 in all cases). The results suggest that for this carefully selected subgroup of children with hemiplegic CP, HABIT appears to be efficacious in improving bimanual hand use.

A repeated course of constraint-induced movement therapy results in further improvement.

A recent therapeutic intervention, constraint-induced movement therapy (CIMT), has been shown to improve movement efficiency and quality of movement in the involved hand of children with hemiplegic cerebral palsy (CP). In the present study, we investigate the long-term effects of CIMT and the effect of a second course on involved limb function using an ABABA design. Eight children with mild to moderate hemiplegic CP (six males, two females; mean age 8y 7mo [SD 2y 6mo]; range 5-11y), who had received a CI therapy intervention 12 months before this study, participated in a second intervention. In both interventions, the children wore a sling on their non-involved upper extremity for 6 hours per day during 10 out of 12 consecutive days and were engaged in play and functional activities that provided structured practice using the involved upper extremity. The results indicated initial improvements in movement efficiency, as measured by the Jebsen-Taylor Test of Hand Function, the Speed and Dexterity subtest (no. 8) of the Bruininks-Oseretsky Test of Motor Proficiency, and caregivers' perceptions of amount of use and quality of movement of the involved limb, were retained 12 months after the first intervention. The second intervention resulted in further improvement on these measures. Results indicate that intensive practice associated with CIMT may be retained long term, and that continued improvements may occur after a second intervention dose.

Development of hand-arm bimanual intensive training (HABIT) for improving bimanual coordination in children with hemiplegic cerebral palsy.

Constraint-induced (CI) movement therapy is a physical intervention that has been receiving increasing attention in pediatric rehabilitation. So far, the evidence suggests that practice associated with CI therapy may improve impaired unimanual hand function in some children with hemiplegic cerebral palsy (CP). However, CI therapy has several important limitations. Most importantly, children with hemiplegia have impairments in bimanual coordination beyond their unilateral impairments. Thus, an intervention approach to increase functional independence during activities of daily living by using both hands in cooperation is needed. Here we briefly review the etiology of hemiplegic CP, describe studies of pediatric CI therapy efficacy in relation to the etiology, discuss the conceptual and practical limitations of CI therapy for this population, and describe bimanual coordination impairments in children with hemiplegia. Finally, we introduce a new intervention for children with hemiplegia, hand-arm bimanual intensive training (HABIT), to address the limitations of CI therapy and to improve bimanual coordination. HABIT retains the two major elements of pediatric CI therapy (intensive structured practice and child-friendliness). The proposed methodology demonstrates that extensive targeted practice can be provided in a child-friendly manner without using a physical restraint, although the efficacy of such an approach remains to be determined.

Fingertip force planning during grasp is disrupted by impaired sensorimotor integration in children with hemiplegic cerebral palsy.

In the present study we examine the ability of children with hemiplegic cerebral palsy (CP) to use anticipatory control of fingertip forces during grasping, and whether anticipatory control is facilitated by lifts with the contralateral hand. Eight children with CP (age 4-13) were asked to perform several lifts of either a 250-g or 500-g object instrumented with force transducers with one hand, followed immediately by several lifts with the contralateral hand. This was repeated for each combination of weight and starting (involved or non-involved) hand. Similar to previous studies, the rate of load force development showed impaired anticipatory control during lifts with the involved hand, intact anticipatory control in the non-involved hand, and transfer of anticipatory control from the non-involved to the involved hand. Surprisingly, however, we also found a transfer from the involved hand to the non-involved hand. The results suggest that the impaired anticipatory control in the involved hand is not purely a sensory or motor problem, and instead is due to an inability to appropriately integrate sensory information with subsequent motor output of the same hand. These results provide important information about the mechanisms underlying impaired anticipatory control, and may have important clinical implications.

Efficacy of a child-friendly form of constraint-induced movement therapy in hemiplegic cerebral palsy: a randomized control trial.

Constraint-induced (CI) movement therapy is a promising therapy for improving upper limb function in adults after stroke. It involves restraint of the non-involved limb and extensive movement practice with the involved limb. In this study, a single-blinded, randomized, control study was performed to examine the efficacy of CI therapy, modified to be child friendly, in children with hemiplegic cerebral palsy (CP). Twenty-two children (8 females, 14 males; mean age 6 y 8 mo [SD 1 y 4 mo]; range 4-8 y) were randomized to either an intervention group (n=11) or a delayed treatment control group (n=11). Children wore a sling on their non-involved upper limb for 6 hours per day for 10 out of 12 consecutive days and were engaged in play and functional activities. Children in the treatment group demonstrated improved movement efficiency and dexterity of the involved upper extremity, which were sustained through the 6-month evaluation period, as measured by the Jebsen-Taylor Test of Hand Function and fine motor-subtests of the Bruininks-Oseretsky Test of Motor Proficiency (p<0.05 in both cases). Initial severity of hand impairment and testing compliance were strong predictors of improvement. Caregivers reported significant increases in involved limb frequency of use and quality of movement. However, there was no change in strength, sensibility, or muscle tone (p>0.05 in all cases). Results suggest that for a carefully selected subgroup of children with hemiplegic CP, CI therapy modified to be child-friendly, appears to be efficacious in improving movement efficiency of the involved upper extremity.

Efficacy of constraint-induced movement therapy on involved upper-extremity use in children with hemiplegic cerebral palsy is not age-dependent.

OBJECTIVES: Constraint-induced (CI) movement therapy has been shown recently to be promising for improving upper-limb function in children with cerebral palsy (CP). Because little is known about patient characteristics predicting treatment efficacy, not all children may benefit from this intervention. Here we examine the relationship between efficacy of a child-friendly form of CI therapy and age on involved upper-extremity function. DESIGN: Twenty children with hemiplegic CP age 4 to 13 years received CI therapy and completed evaluations. Based on established functional and neuromaturational changes in hand skill development, the children were divided into a "younger group" (age 4-8 years, n = 12) and "older group" (age 9-13 years, n = 8). Children wore a sling on their noninvolved upper extremity for 6 hours per day for 10 of 12 consecutive days, during which time they were engaged in play and functional activities. Each child was evaluated by trained evaluators who were blinded to the fact that the children received treatment. The evaluations took place once before the intervention and at 1 week, 1 month, and 6 months after the intervention. Efficacy was examined at the movement efficiency (Jebsen-Taylor Test of Hand Function, subtest 8 of the Bruininks-Oseretsky Test of Motor Proficiency), environmental (caregiver frequency and quality of involved upper-limb use), and impairment (strength, tactile sensitivity, and muscle tone) levels. RESULTS: Children in both age groups had significant improvements in involved hand-movement efficiency and environmental functional limitations, which were retained through the 6-month posttest. However, there were no differences in efficacy between younger and older children. Both hand severity and the children's behavior during testing (number of redirections), with the latter serving as a reasonable correlate for attention during the intervention, were related to changes in performance in the younger group but not in the older group. CONCLUSIONS: The results suggest that the intensive practice associated with CI therapy can improve movement efficiency and environmental functional limitations among a carefully selected subgroup of children with hemiplegic CP of varying ages and that this efficacy is not age-dependent.

A critical review of constraint-induced movement therapy and forced use in children with hemiplegia.

Hemiplegia is a physical impairment that can occur in childhood following head trauma, cerebral vascular accident or transient ischemic attack (stroke), brain tumor, or congenital or perinatal injury. One of the most disabling symptoms of hemiplegia is unilaterally impaired hand and arm function. Sensory and motor impairments in children with hemiplegia compromise movement efficiency. Such children often tend not to use the affected extremity, which may further exacerbate the impairments, resulting in a developmentally learned non-use of the involved upper extremity, termed 'developmental disuse'. Recent studies suggest that children with hemiplegia benefit from intensive practice. Forced use and Constraint-Induced Movement Therapy (CI therapy) are recent therapeutic interventions involving the restraint of the non-involved upper extremity and intensive practice with the involved upper extremity. These approaches were designed for adults with hemiplegia, and increasing evidence suggests that they are efficacious in this population. Recently, forced use and constraint-induced therapy have been applied to children with hemiplegia. In this review, we provide a brief description of forced use and CI therapy and their historical basis, provide a summary of studies of these interventions in children, and discuss a number of important theoretical considerations, as well as implications for postural control. We will show that whereas the studies to date suggest that both forced use and CI therapy appear to be promising for improving hand function in children with hemiplegia, the data are limited. Substantially more work must be performed before this approach can be advocated for general clinical use.

Methods of constraint-induced movement therapy for children with hemiplegic cerebral palsy: development of a child-friendly intervention for improving upper-extremity function.

We delineate the methodology for constraint-induced movement therapy (CIMT) modified for children with hemiplegic cerebral palsy (CP) and describe important considerations that need to be made when testing this intervention in children. The resulting intervention evolved from piloting and testing it with 38 children with hemiplegic CP who were between the ages of 4 and 14 years. Thirty-seven successfully completed the treatment protocol. The intervention retains the 2 major elements of the adult CIMT (repetitive practice, shaping) and was constructed to be as child-friendly as possible. It involves restraining the noninvolved extremity with a sling and having the child engage in unimanual activities with the involved extremity 6 hours a day for 10 days (60 h). Specific activities are selected by considering joint movements with pronounced deficits and improvement of which interventionists believe have greatest potential. The activities are chosen to elicit repetitive practice and shaping. The intervention is conducted in groups of 2 to 3 children to provide social interaction, modeling, and encouragement. Each child is assigned to an interventionist to maintain at least a 1:1 ratio. CIMT can be modified to be child-friendly while maintaining all practice elements of the adult CIMT. The modified therapy is tolerated by most children. Further modifications will likely be required to hone in on the specific components of the intervention that are most effective before applying them to children who are most likely to benefit.

Bimanual coordination during a goal-directed task in children with hemiplegic cerebral palsy.

Most studies of impaired hand function in children with hemiplegic cerebral palsy (CP) have focused on either the involved or the non-involved extremity in isolation. Coordination of the involved and non-involved hand during bimanual tasks in these children is not well understood. The present study examined bimanual coordination using a drawer-opening task under speed and hand constraints in 10 children with hemiplegic CP (5 males and 5 females, mean age 13y 5mo, range 8y to 16y) and 10 age-matched right-handed developing typically children (6 males and 4 females, mean age 13y 1mo). Children were asked to reach forward and open a drawer with one hand and then activate a light switch inside the drawer with the contralateral hand. The role of the two hands (open drawer and activate switch) and speed (self-paced vs fast-as-possible) were varied. The children with hemiplegic CP were slower (p<0.001) and less coordinated in this task, with reduced movement overlap of the two hands (p<0.001) and sequential completion of the two movement objectives (p<0.001). Moreover, the hand used for each task subcomponent affected task performance for the children with hemiplegic CP (p<0.05). Interestingly, faster speed facilitated better bimanual coordination for the children with hemiplegic CP (p<0.001). Results highlight the importance of movement constraints on task performance and suggest that movement speed might facilitate better bimanual coordination.