Relative phase measures of intersegmental coordination describe motor control impairments in children with cerebral palsy who exhibit stiff-knee gait.

BACKGROUND: The purpose of this retrospective study was to explore lower limb intersegmental coordination as a clinically important indicator of motor control mechanisms in individuals with cerebral palsy exhibiting stiff-knee gait. We used the relative phase of thigh and foot segments around foot-off to describe motor control, given the relevance of the pre-swing phase of gait to the existence of stiff-knee gait. METHODS: Traditional gait parameters and thigh/foot intersegmental coordination were calculated using pre-and postoperative kinematic data from a cohort of 54 subjects (92 legs) with spastic cerebral palsy. All participants had stiff-knee gait, walked without assistive devices, and underwent rectus femoris transfer surgery to improve swing period knee flexion. Analyses included correlations between a) preoperative intersegmental coordination and gait variables (knee flexion range, rate and gait performance) and b) pre-to-postoperative intersegmental coordination change and change in gait variables. FINDINGS: Thigh/foot intersegmental coordination significantly (P < 0.001) correlated with knee flexion range, rate and walking speed. Postoperative intersegmental coordination was significantly more uncoupled than preoperative. Pre-to-postoperative intersegmental coordination improvement also significantly correlated with improvements in knee flexion range, rate and walking speed. Pre-to-postoperative changes in intersegmental coordination accounted for 43% and 36% of variance in knee flexion range change and knee flexion rate change respectively. INTERPRETATION: Intersegmental coordination is a clinically important factor in knee flexion limitations associated with stiff-knee gait for individuals with cerebral palsy. These findings are a foundation for further study of intersegmental coordination measures as complements to traditional instrumented gait analysis.

Analysis of Reach-to-Grasp by School-Aged Children with Down Syndrome Elucidates Limitations in Upper Extremity Motor Control.

AIMS: To identify limitations in preparatory planning (PP) and movement execution that constrain performance of reach-to-grasp (RTG) movements in school-aged children with Down syndrome (DS) and examine the effect of chronological age (CA) on performance. METHODS: Nine children with DS ages 6 to 12 years and nine with typical development (TD) participated in this pilot descriptive study. Three-dimensional kinematic analysis was applied to RTG movements performed in the context of two functional tasks. RESULTS: PP variables focused on the coordination of reach and grasp. Compared to the group with TD, the group with DS demonstrated significant limitations in anticipatory slowing down of hand transport and orientation of the hand in preparation for object contact. There was also relatively late onset of preparatory grip formation in the group with DS. In regard to movement execution, reach trajectories of the group with DS showed significantly greater deviation from the straight path. Correlations of study variables with CA were low and insignificant in both groups. CONCLUSIONS: Motor control mechanisms that mediate both PP and execution of the fundamental RTG movement are potential factors limiting upper extremity activity in school-aged children with DS. They should be addressed in future intervention-based research.

Sagittal plane coordination dynamics of typically developing gait.

BACKGROUND: Individuals who undergo an instrumented gait analysis often have an aberrant gait pattern due to neuromuscular impairments that adversely affect their coordination. Conventional instrumented gait analysis descriptors fail to capture the complex coordination dynamics of gait. This paper presents a straightforward methodology for generating descriptors of coordination dynamics based on dynamical systems theory and provides the largest reported dataset of sagittal plane coordination measures, including adjacent and non-adjacent segment pairings, from individuals free of gait pathology walking over-ground. METHODS: Tri-planar marker trajectories from 104 unimpaired subjects between the ages of 8 and 66 years were collected as they walked at a self-selected speed on a level surface. Phase portraits for the pelvis, thigh, shank, and foot and continuous relative phase diagrams for the segment pairs of pelvis-thigh, thigh-shank, shank-foot, and thigh-foot were calculated. FINDINGS: The low coefficients of variation for each coordination curve are comparable to inter-subject coefficients of variation for kinematic curves, narrow confidence intervals for relative phase angles at four essential footfall conditions, and small standard deviation bands of the continuous relative phase diagrams are evidence that these curves characterize the coordination dynamics of normal gait. INTERPRETATION: These findings support the use of this normative dataset as a reference for coordination studies in the clinic or research laboratory. Improving our understanding of gait strategies from the level of coordination and characterizing the natural variability in gait patterns offer a means to enhance our understanding of atypical gait patterns.

Physical therapy clinical management recommendations for children with cerebral palsy - spastic diplegia: achieving functional mobility outcomes.

The purpose of this special report is to present recommendations for the clinical management of children with cerebral palsy, spastic diplegia when increased functional mobility is the identified outcome. These recommendations provide a framework that allows physical therapists to increase their accountability and promote effective interventions for improved patient outcomes. The key components of this special report on clinical management are: a) the Major Recommendations that provide the background and evidence for clinical management; b) a flow chart to assist in clinical decision-making; and c) a Table of Tests and Measures for information on useful tools in the management of children with spastic diplegia. These recommendations are suggestions for clinical management, not an all-inclusive document on physical therapy for children with cerebral palsy. These recommendations may help therapists develop systematic approaches to service delivery and documentation.

Activity-focused motor interventions for children with neurological conditions.

This article presents a model to guide activity-focused physical therapy and occupational therapy interventions for children with neurological conditions. Activity-focused interventions involve structured practice and repetition of functional actions and are directed toward the learning of motor tasks that will increase independence and participation in daily routines. According to this model, the pediatric therapist: (1) develops activity-related goals in collaboration with the child and the family; (2) plans activity-focused interventions by adapting knowledge of motor learning to the child's individual learning strengths and needs; and (3) integrates impairment-focused intervention with activity-focused intervention.

The effects of knowledge of performance and cognitive strategies on motor skill learning in children with cerebral palsy.

PURPOSE: The purpose of this research was to examine the effects of presenting augmented information to children with cerebral palsy during practice of a novel motor skill. METHODS: Single-subject designs with nonconcurrent baselines were used to study improvements in performance. Thirteen children with cerebral palsy were randomly assigned to one of three practice protocols and performed 36 ten-second trials to learn to move a Pedalo, a therapeutic exercise vehicle, backward. Each protocol involved a variable mix of practice under the following conditions: no augmented information, knowledge of performance, and knowledge of performance enhanced by a cognitive strategy. Performance was measured by changes in backward displacement (cm) of the Pedalo across trials. RESULTS: All 13 subjects demonstrated improvement in performance across phases. However, only eight subjects (62%) demonstrated a significant improvement in performance when the baseline and retention phases were compared. Of these eight subjects, one demonstrated significant improvement in performance with practice alone, two when provided with knowledge of performance, and five when provided with knowledge of performance and a cognitive strategy. CONCLUSIONS: This study suggests that children with cerebral palsy benefit greatly from practice of motor tasks and that some of these children may benefit from the use of cognitive strategies to enhance the role of knowledge of performance during practice of motor skills. However, sufficient time is required to successfully integrate the feedback into performance.