Which functional impairments are the main contributors to pelvic anterior tilt during gait in individuals with cerebral palsy?

While past investigations focused on describing pelvic motion patterns in the frontal and transversal plane, the sagittal plane "double bump" pattern commonly found in children with cerebral palsy was only rarely investigated, especially concerning the underlying pathology. 375 ambulatory (GMFCS I-III) patients with bilateral spastic cerebral palsy were included in this study. Gait and clinical data (ROM, strength, spasticity) were classified in two different ways: (a) into two groups of normal and enhanced mean anterior pelvic tilt and (b) into two groups of moderate and excessive ROM in pelvic tilt. The results reveal that increased mean pelvic tilt is mainly associated with gait features of reduced hip extension and increased pelvic and trunk obliquity ROM but with increased knee ROM. In the clinical exam this corresponds to a smaller passive knee extension deficit and reduced knee flexor strength. It seems that flexors to extensors strength imbalance at the knee is a major feature why mean pelvic position is tilted anterior whereas maximum passive hip extension is of minor importance. Contrarily, excessive sagittal pelvic ROM is associated with increased knee flexion at initial contact and reduced knee ROM. Furthermore, Duncan-Ely- and Tardieu-tests show both increased values in this group with excessive pelvic range of motion indicating for spastic rectus femoris activation. The results of our study indicate that the two gait variables are influenced by different specific mechanisms which are now described for the first time. Since the pelvis plays a central role during gait, these findings should be considered when planning single event multilevel surgery in patients with cerebral palsy.

Wolf SI ，Mikut R ，Kranzl A ，Dreher T ... -  《-》

The influence of hip abductor weakness on frontal plane motion of the trunk and pelvis in patients with cerebral palsy.

Trendelenburg walking pattern is a common finding in various disorders, including cerebral palsy (CP), where it is seen in children and adults. Clinically, this deviation is viewed as a consequence of hip abductor weakness resulting in pelvic obliquity. Trunk lean to the ipsilateral side is a common compensatory mechanism to counteract pelvic obliquity and to maintain gait stability. However, no published investigations objectively address pelvic and trunk motions in the frontal plane or examine the correlation with hip abductor weakness in patients with CP. We selected 375 ambulatory (GMFCS I-III) patients with spastic bilateral CP and 24 healthy controls from our gait laboratory database. They had all undergone a standardized three-dimensional analysis of gait, including trunk motion, and a clinical examination including hip abductor strength testing. Selected frontal plane kinematic and kinetic parameters were investigated and statistically tested for correlation (Spearman rank) with hip abductor strength. Only a weak (r=0.278) yet highly significant correlation between trunk lean and hip abductor strength was found. Hip abductor weakness was accompanied by decreased hip abduction moment. However, no significant differences in pelvic position were found between the different strength groups, indicating that the pelvis remained stable regardless of the patients' strength. Our findings indicate that weak hip abductors in patients with CP are accompanied by increased trunk lean to the ipsilateral side while pelvic position is preserved by this compensatory mechanism. However, since this correlation is weak, other factors influencing lateral trunk lean should be considered. In patients with severe weakness of the hip abductors compensatory trunk lean is no longer fully able to stabilize the pelvis, and frontal pelvic kinematics differs from normal during loading response. The results indicate that the stable pelvic position seems to be of greater importance than trunk position for patients with CP. Further studies are needed to investigate other factors influencing lateral trunk lean.

Krautwurst BK ，Wolf SI ，Heitzmann DW ，Gantz S ，Braatz F ，Dreher T ... -  《-》

Three-dimensional head and trunk movement characteristics during gait in children with spastic diplegia.

This study uses a recently developed trunk model to determine which head and trunk kinematic parameters differentiate children with spastic diplegia from typically developing (TD) children while walking. Differences in head and trunk parameters in relation to the severity of the motor involvement (GMFCS levels) were additionally examined. The trunk model consisted of five segments (pelvis, thorax, head, shoulder line, spine). Discrete kinematic parameters (ROM, mean position) and angular waveforms were compared between 20 children with spastic diplegia (age 9.8 years±2.9 years; GMFCS I: n=10, GMFCS II: n=10) and 20 individually age-matched TD children (9.7 years±3 years). A new measure for overall trunk pathology, the trunk profile score (TPS), was proposed and included in the comparative analysis. Compared to TD children, children with GMFCS II showed a significantly higher TPS and increased ROM for pelvis tilt, for thorax and head in nearly all planes, and the angle of kyphosis. In children with GMFCS I, only ROM of thorax lateral bending was significantly increased. Sagittal ROM differentiated best between GMFCS levels, with higher ROM found in children with GMFCS II. Current results provide new insights into head and trunk kinematics during gait in children with spastic diplegia.

Heyrman L ，Feys H ，Molenaers G ，Jaspers E ，Monari D ，Meyns P ，Desloovere K ... -  《-》

The relationship between clinical measurements and gait analysis data in children with cerebral palsy.

Spasticity is a common impairment that interferes with motor function (particularly gait pattern) in children with cerebral palsy (CP). Gait analysis and clinical measurements are equally important in evaluating and treating gait disorders in children with CP. This study aimed to explore the relationship between the spasticity of lower extremity muscles and deviations from the normal gait pattern in children with CP. Thirty-six children with spastic CP (18 with spastic hemiplegia [HS] and 18 with spastic diplegia [DS]), ranging in age from 7 to 12 years, participated in the study. The children were classified as level I (n=24) or level II (n=12) according to the Gross Motor Function Classification System. Spasticity levels were evaluated with the Dynamic Evaluation of Range of Motion (DAROM) using the accelerometer-based system, and gait patterns were evaluated with a three dimensional gait analysis using the Zebris system (Isny, Germany). The Gillette Gait Index (GGI) was calculated from the gait data. The results show that gait pathology in children with CP does not depend on the static and dynamic contractures of hip and knee flexors. Although significant correlations were observed for a few clinical measures with the gait data (GGI), the correlation coefficients were low. Only the spasticity of rectus femoris showed a fair to moderate correlation with GGI. In conclusion, the results indicate the independence of the clinical evaluation and gait pattern and support the view that both factors provide important information about the functional problems of children with CP.

Domagalska M ，Szopa A ，Syczewska M ，Pietraszek S ，Kidoń Z ，Onik G ... -  《-》

Predictors of pelvic retraction in children with cerebral palsy derived from gait parameters and clinical testing.

Excessive pelvic rotation in the transverse plane is common in patients with cerebral palsy. Knowing the underlying reasons is important for clinical decision making, since changes in pelvic retraction might have an effect on internally rotated gait. We hypothesized that the contralateral leg contributes considerably to pelvic rotation on the retracted side. Therefore the aim of this study is to calculate predictors for pelvic retraction using both, parameters from the retracted and from the contralateral protracted side. Thirty-two children with diplegia and 18 children with hemiplegia were examined by three-dimensional gait analysis followed by a clinical examination protocol. Stepwise multilinear regression of the response value mean pelvic retraction during stance phase was performed on 10 potential predictors of dynamic gait data and 10 corresponding predictors of clinical data of the retracted and the contralateral protracted side. Gait analysis revealed ankle push-off energy on the protracted side as the best predictors in hemiplegic patients explaining 59% of the variance in pelvic retraction. In diplegic patients external hip rotation of the protracted side was most accurate in predicting pelvic retraction (27%). Best clinical predictors for hemiplegic patients were ankle dorsiflexion on the retracted side (46%) and for diplegic patients it was the knee extension strength on the protracted side together with hip rotation on the retracted side (36%). In hemiplegic patients ankle push-off energy of the contralateral side is a significant compensation mechanism that might cause increased pelvic retraction to compensate for the weakness of the involved side. In diplegic patients prediction of pelvic retraction was only moderate and requires further investigation.

Böhm H ，Stief F ，Dussa CU ，Döderlein L ... -  《-》