Jules G. Becher

Smallest real difference, a link between reproducibility and responsiveness.

The aim of this study is to show the relationship between test-retest reproducibility and responsiveness and to introduce the smallest real difference (SRD) approach, using the sickness impact profile (SIP) in chronic stroke patients as an example. Forty chronic stroke patients were interviewed twice by the same examiner, with a 1-week interval. All patients were interviewed during the qualification period preceding a randomized clinical trial. Test-retest reproducibility has been quantified by the intraclass correlation coefficient (ICC), the standard error of measurement (SEM) and the related smallest real difference (SRD). Responsiveness was defined as the ratio of the clinically relevant change to the SD of the within-stable-subject test-retest differences. The ICC for the total SIP was 0.92, whereas the ICCs for the specified SIP categories varied from 0.63 for the category ‘recreation and pastime’ to 0.88 for the category ‘work’. However, both the SEM and the SRD far more capture the essence of the reproducibility of a measurement instrument. For instance, a total SIP score of an individual patient of 28.3% (which is taken as an example, being the mean score in the study population) should decrease by at least 9.26% or approximately 13 items, before any improvement beyond reproducibility noise can be detected. The responsiveness to change of a health status measurement instrument is closely related to its test-retest reproducibility. This relationship becomes more evident when the SEM and the SRD are used to quantify reproducibility, than when ICC or other correlation coefficients are used.

Clinical assessment of spasticity in children with cerebral palsy: a critical review of available instruments.

This study reviews the instruments used for the clinical assessment of spasticity in children with cerebral palsy, and evaluates their compliance with the concept of spasticity, defined as a velocity‐dependent increase in muscle tone to passive stretch. Searches were performed in Medline, Embase, and Cinahl, including the keywords ‘spasticity’, ‘child’, and‘cerebral palsy’, to identify articles in which a clinical method to measure spasticity was reported. Thirteen clinical spasticity assessment instruments were identified and evaluated using predetermined criteria. This review consists of reports on the standardization applied for assessment at different velocities, testing posture, and quantification of spasticity. Results show that most instruments do not comply with the concept of spasticity; standardization of assessment method is often lacking, and scoring systems of most instruments are ambiguous. Only the Tardieu Scale complies with the concept of spasticity, but this instrument has a comprehensive and time–consuming clinical scoring system.

Anatomical information is needed in ultrasound imaging of muscle to avoid potentially substantial errors in measurement of muscle geometry

This study validates two‐dimensional (2D) ultrasound measurements of muscle geometry of the human medial gastrocnemius (GM) and investigates effects of probe orientation on errors in these measurements. Ultrasound scans of GM muscle belly were made both on human cadavers (n = 4) and on subjects in vivo (n = 5). For half of the cadavers, ultrasound scans obtained according to commonly applied criteria of probe orientation deviated 15° from the true fascicle plane. This resulted in errors of fascicle length and fascicle angle up to 14% and 23%, respectively. Fascicle‐like structures were detectable over a wide range of probe tilt and rotation angles, but they did not always represent true fascicles. Errors of measurement were either linear or quadratic functions of tilt angle. Similar results were found in vivo. Therefore, we conclude that similar errors are likely to occur for in vivo measurements. For all cadavers, at the distal end of GM, the true fascicle plane was shown to be perpendicular to the distal aponeurosis. Using transverse images of GM to detect the curvature of the deep aponeurosis at the distal end of the muscle belly is a simple strategy to help identify the fascicle plane. For subsequent longitudinal imaging, probe alignment within this plane will help minimize measurement errors of fascicle length, fascicle angle, and muscle thickness. Muscle Nerve, 2009

Effectiveness of functional progressive resistance exercise strength training on muscle strength and mobility in children with cerebral palsy: a randomized controlled trial

Aim  To evaluate the effectiveness of functional progressive resistance exercise (PRE) strength training on muscle strength and mobility in children with cerebral palsy (CP).

Activities and participation of 9- to 13-year-old children with cerebral palsy

Objective: To describe the activities and participation of children with cerebral palsy and to examine the relationship with personal factors and disease characteristics. Design: Cross-sectional study. Setting: Department of Rehabilitation Medicine of a University Medical Center in The Netherlands. Subjects: One hundred and ten children: 70 boys, 40 girls, mean (SD) age 11 years and 3 months (20 months). Outcome measures: Activities and participation, described in the domains of mobility, self-care, domestic life, social life and communication, measured with the Gross Motor Function Measure, the Pediatric Evaluation of Disability Inventory and the Vineland Adaptive Behavior Scales. Results: Multiple linear regression models showed that the Gross Motor Function Classification System (GMFCS) was strongly associated with mobility (explained variance 87-92%), self-care and domestic life. Apart from the GMFCS, cognitive impairment and limb distribution were less important but also significantly associated with self-care and domestic life (explained variance 65-81%). Cognitive impairment and epilepsy were the most important factors associated with social life and communication (explained variance 54-75%). Conclusion: Activities and participation can, to a large extent, be explained by only a few associated factors.

Passive stiffness characteristics of ankle plantar flexors in hemiplegia

OBJECTIVE To assess the feasibility and reliability of ankle plantar flexor stiffness measurements in hemiplegia. DESIGN Repeated measurements in five consecutive weeks. BACKGROUND In hemiplegia, an equinovarus positioning of the foot might be caused by an increased stiffness of the m. triceps surae. METHODS In eight hemiplegic patients the net joint torque of passive muscle stretch was measured as a function of ankle-angle by a dynamometer, at both sides. Ankle-stiffness was characterised and also a biomechanical model of the passive muscle was fitted. RESULTS In the vast majority of measurements it was possible to obtain measurements that were not distorted by involuntary muscle contraction. These measurements showed for the angle at which a passive plantar moment of 10 N m was reached a standard error of measurement of less than 2.7 degrees. The muscle model showed the increased stiffness as a shortening of the muscle-fibre-length. CONCLUSION The feasibility of this method to measure muscle stiffness was fair to good in hemiplegic patients. Provided the abandoning of involuntary muscle activity, the reproducibility warrants application in clinical practice at an individual level. The use of the model relates this changes to a shortened m. soleus and/or m. gastrocnemius. RelevanceEffective clinical decisions for treatment of equinovarus positioning of the foot in the hemiplegic individual, should consider excessive involuntary contractions of the m. triceps surae complex (i.e., spasticity), as well as shortened muscle tissue resulting in high stiffness. Despite the importance of increased stiffness there have been no validated methods of measurement.

The effect of botulinum toxin type A treatment of the lower extremity on the level of functional abilities in children with cerebral palsy: evaluation with goal attainment scaling:

Objective: To measure the effect of botulinum toxin type A (BTX-A) treatment in children with cerebral palsy with regard to individual goals concerning functional abilities, using goal attainment scaling. Design: A single-blind randomized multiple baseline/treatment phase design across subjects. Setting: The paediatric department of a rehabilitation centre. Subjects: Eleven children with cerebral palsy participated. Intervention: BTX-A treatment of the lower extremity. Main measures: A six-point goal attainment scaling of three individual treatment goals at the level of functional abilities. Standardized video-tapes of each goal were recorded weekly for a period of 14 weeks. Rating on the predetermined goal attainment scaling was blinded. Results: Nine of the 11 subjects showed significant improvement in 18 out of 33 goals. Seven subjects showed clinically relevant improvement (at least 2 points on the goal attainment scaling) in 11 goals. Testing the difference between all medians of baseline measurements (after correction for improvement during baseline) and the medians of the treatment phase measurements for all goal attainment scaling scores (n < 33) resulted in significant improvement (p < 0.001). Tested at subject level (medians of the three goal attainment scaling scores per assessment, n < 11), a significant improvement was also found (p < 0.005). The change in goal attainment scaling score was related to the moment of treatment with BTX-A. Conclusion: Clinically relevant improvement in individual rehabilitation goals at ability level, achieved with the treatment of BTX-A in children with cerebral palsy, were demonstrated using the goal attainment scaling method.

Parents' reactions to the diagnosis of cerebral palsy: associations between resolution, age and severity of disability

BACKGROUND For parents, receiving a diagnosis, typically in early childhood, that their child has cerebral palsy may conjure up high distress and anxiety. Resolution of these initial reactions may help parents to focus on the challenges and needs of their children. AIMS of the study were to test whether parents of older children displayed resolution more often than parents of younger children, and whether parents of children with less severe cerebral palsy also showed more resolution. METHOD Resolution of reactions to diagnosis was assessed with the Reaction to Diagnosis Interview, in a clinic-based sample of 255 parents of children with cerebral palsy aged between 1.4 and 17.3 years. Physicians rated motor ability using the Gross Motor Function Classification System. RESULTS Overall, the responses of 81.6% of the parents were predominantly indicative of resolution. Unresolved reactions were significantly more often found among parents of younger children and parents of children with more severe motor disabilities. Among parents of teenage children, resolution was more often apparent from a focus on action to better the lives of their children, whereas in parents of younger children, it was more apparent from their focus on constructive thoughts and information seeking. CONCLUSIONS Given time, the large majority of parents may resolve their reactions to the diagnosis that their child has cerebral palsy. Parents of the most severely affected children may need specific support which, given the age trends, might be aimed at different resolution processes for parents of younger and older children.

Effectiveness of functional progressive resistance exercise training on walking ability in children with cerebral palsy: A randomized controlled trial

The objective of the study was to evaluate the effectiveness of functional progressive resistance exercise (PRE) training on walking ability in children with cerebral palsy (CP). Fifty-one ambulant children with spastic CP (mean age 10 years 5 months, 29 boys) were randomized to an intervention (n=26) or control group (n=25, receiving usual care). The intervention consisted of 12 weeks functional PRE circuit training, for 3 times a week. Main outcome measures were walking ability and participation. Secondary outcomes were muscle strength and anaerobic muscle power. Possible adverse outcomes were spasticity and passive range of motion (ROM). Muscle strength increased significantly in the training group compared to the control group, but walking ability, participation and anaerobic muscle power did not change. Spasticity and ROM remained unchanged, except for a significant decrease in rectus femoris length in the intervention group. It is concluded that twelve weeks of functional PRE-training does not improve walking ability, despite improved muscle strength.

Social Functioning and Communication in Children with Cerebral Palsy: Association with Disease Characteristics and Personal and Environmental Factors.

Aim  The objective of this longitudinal study was to describe the course of social functioning and communication in children with cerebral palsy (CP) over a 3‐year period, its difference with the normative course, and its relationship with disease characteristics and personal and environmental factors.