Ann-Christin Eliasson

The Manual Ability Classification System (MACS) for children with cerebral palsy: scale development and evidence of validity and reliability

The Manual Ability Classification System (MACS) has been developed to classify how children with cerebral palsy (CP) use their hands when handling objects in daily activities. The classification is designed to reflect the childs typical manual performance, not the childs maximal capacity. It classifies the collaborative use of both hands together. Validation was based on the experience within an expert group, a review of the literature, and thorough analysis of children across a spectrum of function. Discussions continued until consensus was reached, first about the constructs, then about the content of the five levels. Parents and therapists were interviewed about the content and the description of levels. Reliability was tested between pairs of therapists for 168 children (70 females, 98 males; with hemiplegia [n=52], diplegia [n=70], tetraplegia [n=19], ataxia [n=6], dyskinesia [n=19], and unspecified CP [n=2]) between 4 and 18 years and between 25 parents and their childrens therapists. The results demonstrated that MACS has good validity and reliability. The intraclass correlation coefficient between therapists was 0.97 (95% confidence interval 0.96-0.98), and between parents and therapist was 0.96 (0.89-0.98), indicating excellent agreement.

Development of human precision grip I: Basic coordination of force

SummaryThe coordination of manipulative forces was examined while children and adults repeatedly lifted a small object between the thumb and index finger. Grip force, load force (vertical lifting force), grip force rate and the vertical position of the test object were continuously measured. In adults, the force generation was highly automatized and was nearly invariant between trials. After a preload phase in which the grip was established, the grip and load forces increased in parallel under isometric conditions until the load force overcame the force of gravity and the object started to move. During this loading phase, the force rate profiles were essentially bell shaped and single peaked, suggesting that the force increases were programmed as one coordinated event. Children below the age of two exhibited a prolonged preload phase and a loading phase during which the grip and load forces did not increase in parallel. A major increase in grip force preceded the increase in load force, and at the start of the loading phase, the grip force was usually several Newtons (N). The force rate profiles were multi peaked with step-wise force increases most likely allowing peripheral feedback to play an important role in the control of the forces. After the age of two, the grip force increased less during the preload phase. The loading phase was more regularly characterized by a parallel increase of the grip force and load force and the duration of the various phases decreased. The older children programmed the forces in one force rate pulse indicating the emergence of an anticipatory strategy. Yet, the mature coordination of forces was not fully developed until several years later. It was concluded that the development of the precision grip was based upon the formation of a lift synergy coupling grip and load force generating circuits and that it seems to involve a transition from feedback control to feedforward control.

The Assisting Hand Assessment: current evidence of validity, reliability, and responsiveness to change

The Assisting Hand Assessment (AHA) provides a new perspective of hand function evaluation relevant for children with unilateral upper limb disabilities. It measures how effectively the involved hand is actually used for bimanual activity, which, for these children, might be the most important aspect of their hand function. The aim of this paper is to report the conceptual framework and the evidence for validity, reliability, and responsiveness to change for the measures. Previously, the AHA has been evaluated for children aged 18 months to 5 years and excellent inter‐ and intrarater reliability was demonstrated. This paper reports further evidence of construct validity and reliability for the AHA measures involving an extended age range of children with hemiplegic cerebral palsy or obstetric brachial plexus palsy from 18 months to 12 years of age (mean age 4y 11mo [SD 2y 9mo] range 18mo–12y 8mo). A Rasch measurement model was used to analyze 409 assessments from 303 children (170 males, 133 females). The analysis generated a scale demonstrating large capacity to reliably separate and spread personal ability measures, indicating sensitivity to change and a hierarchy of the items ranging them from easy to hard. Aspects of item fit, relationship between age and ability measures, and development of assisting hand function are discussed.

Effects of constraint-induced movement therapy in young children with hemiplegic cerebral palsy: an adapted model.

The aim of this study was to evaluate the effects of a modified version of constraint-induced (CI) movement therapy on bimanual hand-use in children with hemiplegic cerebral palsy (CP; age range 18 mo to 4 y) and to make a comparison with conventional paediatric treatment. Twenty-one children (13 females, eight males) completed the CI therapy programme and 20 children (12 males, eight females) served as a control group. Children in the CI therapy group were expected to wear a restraint glove for 2 hours each day over a period of 2 months. The training was based on principles of motor learning used in play and in motivational settings. To evaluate the effect of treatment, the Assisting Hand Assessment (AHA) was used. Assessments took place on three occasions: at onset, after 2 months, and 6 months after the first assessment. A significant interaction was found between group and AHA measure (ANOVA, F(2,74) = 5.64, p = 0.005). The children who received CI therapy improved their ability to use their hemiplegic hand significantly more than the children in the control group after 2 months, i.e. after treatment. Effect size was high after treatment and remained medium at 6 months. As the treatment was tailored to each childs capacity and interests, little frustration was experienced by the children.

Development of the Assisting Hand Assessment: A Rasch-built Measure intended for Children with Unilateral Upper Limb Impairments

The purpose of this paper was to report on the first step in the development of a new instrument, the Assisting Hand Assessment (AHA), that measure the effectiveness with which a child with unilateral impairment makes use of his/her affected hand in bimanual activity performance. The assessment is intended for children with hemiplegic cerebral palsy or obstetric brachial plexus palsy, from age 18 months to 5 years. The AHA is conducted through observations of performance skills exposed during play where toys requiring bimanual handling are used. The validity and reliability of the measures were explored using a Rasch measurement model for analysis. In the AHA, 22 items consisting of observable actions are scored on a 4-point rating scale evaluating the quality of the performance. The Rasch analysis suggests that the test rationale, the usefulness of the assisting hand, does form a unidimensional construct and that the items represent the tested phenomenon well. The results show potential for the AHA to become a useful tool for both clinical practice and research.

BASIC CO-ORDINATION OF MANIPULATIVE FORCES OF CHILDREN WITH CEREBRAL PALSY

The co‐ordination of manipulatory forces during prehension was studied in 12 children with cerebral palsy (CP) and compared with that of controls. The results indicated that coupling of grip force and load force does not develop in children with CP. These childrens force development increased in stages, with an early onset of excessive grip force. They did not use anticipatory control of the isometric force development during the load phase. Prolonged delays between successive phases indicated inefficient sensory feedback during the movement. The early onset of grip force and the over‐all high force employment may compensate for the lack of anticipatory control and inefficient sensorimotor integration.

Development of human precision grip

When an object held by a precision grip is subjected to an abrupt vertical load perturbation, somatosensory input from the digits triggers an increase in grip force to restore an adequate safety margin, preventing frictional slips. In adults the response occurs after a latency of 60–80 ms. In the present study, children from 2 years old upward and adults grasped and lifted an object using a precision grip. Sudden, unpredicted increases in load force (tangential to the grip surfaces) were induced by the experimenter by dropping a small disc on to a receptacle attached to the object. The impact elicited a grip force response which in young children had a longer latency and a smaller amplitude than was seen in adults. The grip response latency gradually become shorter and its amplitude increased with increasing age, reaching adult values at 6–10 years. The muscle activity underlying the response could have several bursts. The adults showed one brisk response, appearing 40–50 ms after impact, in extrinsic and intrinsic hand muscles, while younger children also exhibited a short-latency burst, appearing about 20 ms after impact. It is suggested that the short-latency response was mediated via spinal pathways, and that these pathways are disengaged by supraspinal centers during development. In a predictable loading situation, when subjects dropped the disc themselves into the receptacle using the contralateral hand, they changed strategy. Adults induced a well-timed anticipatory grip force increase prior to the impact that was scaled to the weight of the object. The youngest children did not time the force increase properly in relation to the impact. Yet, they could scale their anticipatory grip force increase with respect to the weight of the dropped disc. This suggests a well-developed capacity to use information about the weight of objects held by one hand to parameterize a programmed force output to the other hand.

IMPAIRED ANTICIPATORY CONTROL OF ISOMETRIC FORCES DURING GRASPING BY CHILDREN WITH CEREBRAL PALSY

The authors examined the force regulation during prehension of 12 children with cerebral palsy (CP) and an age‐matched control group. The control group appropriately scaled the isometric force output in one force‐rate pulse toward the weight of the previously lifted object, but children with CP exhibited stepwise increases in force in which the force amplitudes were not influenced by the objects weight. When the object was held in the air, most children with CP were able to modify their force output according to the objects weight, using sensory feedback, but their forces were more variable than those of the control group and less influenced by the objects weight. Although children with CP have disturbed sensory feedback—likely to lead to an indistinct internal representation of an objects physical properties—their main disability stems from impaired central co‐ordination of motor activity.

Hand function in relation to brain lesions and corticomotor-projection pattern in children with unilateral cerebral palsy

Aim  To investigate relationships between hand function, brain lesions, and corticomotor projections in children with unilateral cerebral palsy (CP).

Quantitative assessment of mirror movements in children and adolescents with hemiplegic cerebral palsy

Mirror movements in individuals with hemiplegic cerebral palsy (CP) may result from a reorganization of the central sensorimotor system. Motor performances of both hands were measured to characterize mirror activity (or mirroring) and hand functions in 22 participants (6 to 18 years) with hemiplegic CP and in 17 control participants. During a unimanual repetitive squeezing task, contractions of the active hand and fingertip forces of the opposite hand were recorded simultaneously. In the control group, slight mirror activity (or mirroring) was found that decreased with age. In participants with CP, mirror activity was 15 times stronger than in the control group, and was found at all age levels. Mirroring was more prominent in the unaffected hand of the CP group. The amount of mirror activity was not related to the degree of hemiplegia, which was assessed with measures of spasticity, strength, and dexterity. Mirror movements disturbed functional bimanual skills, although to some extent they could be suppressed by voluntary effort.