Standing in children with bilateral spastic cerebral palsy : aspects of muscle strength, vision and motor function

The movement and posture disorder of cerebral palsy (CP) is presumed to mainly be a consequence of the motor disorder, but accompanying disturbances with sensations and perception have also been suggested to influence motor function. The aim was to investigate factors influencing standing posture in children with bilateral spastic CP (BSCP) with varying standing abilities. Three-dimensional motion analysis with surface electromyography was recorded to describe posture during three standing tasks: in a habitual standing position, while blindfolded, and during an attention-demanding task. Muscle strength in the lower limbs was measured with a hand-held dynamometer. Motor function was measured with the Gross Motor Function Measure. The children also underwent a neuro-ophthalmological examination. Almost half of the participants required hand-held support to stand. Investigation of standing posture verified a crouched body position during standing which was more obvious in the children who required hand-held support. Muscle strength measurements indicated that the children in both groups were equally strong in the lower limb muscles despite their variation in standing abilities. The children who stood with support were as capable to perform motor activities in lying, sitting and kneeling positions as the children who stood unsupported. Vision influenced posture differently depending on the children's standing ability. During the attention demanding task, the children who stood unsupported stood more still and with less lower limb muscle activity. While blindfolded, they adapted their posture to the environmental change by activating muscles around the ankle with no changes in overall body position. In contrast, the children who required hand-held support to stand used another strategy; the already flexed body position became even more flexed, and muscle activity increased in the knee extensors while blindfolded, despite the use of external support. Motor disorders could not explain the support for standing or the crouched body position during standing. The children were equally strong in the lower limb muscles and had reasonably similar abilities to perform motor activities in positions with no requirement of standing on the feet opposing gravity. The crouched body position and the reduced ability to maintain posture while blindfolded indicate proprioception deficits in the children who required support. The increased quadriceps muscle activity could be an indication of compensatory co-contraction caused by perceptual impairments. That motor function difficulty arises in a standing position opposing gravity indicates that standing difficulties may be attributable to sensory and/or perceptual disturbances

Evaluation of Knee Position Sense in Children with Motor Disabilities and Children with Typical Development: A Cross-Sectional Study

Background: In children with motor disabilities, knee position during walking is often of concern in rehabilitation. This study aimed to investigate knee joint position sense. Thirty-seven children with Cerebral Palsy (CP), 21 with Myelomeningocele (MMC), 19 with Arthrogryposis (AMC), and 42 TD children participated in the study. Knee joint position sense, i.e., the difference between the criterion angle and the reproduced angle (JPS-error), was assessed in sitting while 3D motion capture was recorded at flexed knee 70 (Knee70), 45 (Knee45), and 20 (Knee20) degrees, and after three seconds at maintained criterion angle (CAM) and maintained reproduced angle (RAM). No differences were found between the groups in JPS-error, CAM, and RAM. At Knee70, CAM differed between the right and left legs in the TD group (p = 0.014) and RAM in the MMC group (p = 0.021). In the CP group, CAM was greater than RAM at Knee70 in the left leg (p = 0.002), at Knee45 in both legs (p = 0.004, p = 0.025), and at Knee20 in the right leg (p = 0.038). Difficulties in maintaining the knee position at CAM in the CP group sheds light on the need for complementary judgments of limb proprioception in space to explore the potential influence on knee position during walking

Reliability and Validity of the Dyskinesia Impairment Scale in Children and Young Adults with Inherited or Idiopathic Dystonia

Background: The Dyskinesia Impairment Scale (DIS) is a new assessment scale for dystonia and choreoathetosis in children and youth with dyskinetic cerebral palsy. Today, the Burke–Fahn–Marsden Dystonia Rating Scale (BFM) is mostly used to assess dystonia in children with inherited dystonia. The aim of this study was to assess reliability and validity of the DIS in children and youth with inherited or idiopathic dystonia. Methods: Reliability was measured by (1) the intraclass correlation coefficients (ICCs) for inter-rater and test-retest reliability, as well as (2) standard error of measurement (SEM) and minimal detectable difference (MDD). For concurrent validity of the DIS-dystonia subscale, the BFM was administered. Results: In total, 11 males and 9 females (median age 16 years and 7 months, range 6 to 24 years) were included. For inter-rater reliability, the ICCs for the DIS total score and the dystonia and choreoathetosis subscale scores were 0.83, 0.87, and 0.71, respectively. For test-retest reliability, the ICCs for the DIS total score and the dystonia and choreoathetosis subscale scores were 0.95, 0.88, and 0.93, respectively. The SEM and MDD for the total DIS were 3.98% and 11.04%, respectively. The Spearman correlation coefficient between the dystonia subscale and the BFM was 0.88 (p < 0.01). Conclusions: Good to excellent inter-rater, test-retest reliability, and validity were found for the total DIS and the dystonia subscale. The choreoathetosis subscale showed moderate inter-rater reliability and excellent test-retest reliability. The DIS may be a promising tool to assess dystonia and choreoathetosis in children and young adults with inherited or idiopathic dystonia

European consensus on the concepts and measurement of the pathophysiological neuromuscular responses to passive muscle stretch

Background and purpose To support clinical decision-making in central neurological disorders, a physical examination is used to assess responses to passive muscle stretch. However, what exactly is being assessed is expressed and interpreted in different ways. A clear diagnostic framework is lacking. Therefore, the aim was to arrive at unambiguous terminology about the concepts and measurement around pathophysiological neuromuscular response to passive muscle stretch. Methods During two consensus meetings, 37 experts from 12 European countries filled online questionnaires based on a Delphi approach, followed by plenary discussion after rounds. Consensus was reached for agreement ≥75%. Results The term hyper-resistance should be used to describe the phenomenon of impaired neuromuscular response during passive stretch, instead of for example ‘spasticity’ or ‘hypertonia’. From there, it is essential to distinguish non-neural (tissue-related) from neural (central nervous system related) contributions to hyper-resistance. Tissue contributions are elasticity, viscosity and muscle shortening. Neural contributions are velocity dependent stretch hyperreflexia and non-velocity dependent involuntary background activation. The term ‘spasticity’ should only be used next to stretch hyperreflexia, and ‘stiffness’ next to passive tissue contributions. When joint angle, moment and electromyography are recorded, components of hyper-resistance within the framework can be quantitatively assessed. Conclusions A conceptual framework of pathophysiological responses to passive muscle stretch is defined. This framework can be used in clinical assessment of hyper-resistance and will improve communication between clinicians. Components within the framework are defined by objective parameters from instrumented assessment. These parameters need experimental validation in order to develop treatment algorithms based on the aetiology of the clinical phenomena