G. Bollini

Gait initiation reflects the adaptive biomechanical strategies of adolescents with idiopathic scoliosis

BACKGROUNDnThe dynamics behavior of patients with idiopathic scoliosis obviously requires some biomechanical compensatory strategies. Our objective is to analyze the ground reaction forces (GRF) exerted during gait initiation in order to determine the dynamic consequences of idiopathic scoliosis.nnnMETHODSnTen adolescent girls suffering from idiopathic scoliosis with a right thoracic curvature (Cobb>15°) and 15 healthy adolescents participated in this study. Two force plates were used to record the ground force evolution for the right and left limbs tested during gait initiation.nnnRESULTSnWhichever limb was used to initiate gait, gait initiation duration was found to be significantly longer in persons with scoliosis than in healthy subjects. In the scoliosis group (SG), the impulses, occurrences and forces values were also greater than in healthy subjects. Under the stance foot, the anteroposterior and vertical forces were always increased. Under the swing foot, the SG showed the same characteristics associated to decreased mediolateral impulses parameters. Even greater differences were observed between these two groups in terms of peak occurrences during left-limb gait initiation. The intragroup comparisons only unveiled very few differences between the two limbs for the control group (CG), whereas significantly higher values were recorded for the group of scoliosis patients when gait was initiated with the left limb rather than with the right one.nnnCONCLUSIONnFor patients with scoliosis specific dynamic behavior adjustment are made during gait initiation patterns, for both limbs in order to maintain balance during gait to compensate for their spine deformation. Patients with scoliosis always showed slower dynamic patterns than healthy controls. These results show the importance of including specific evaluation and dynamic physical rehabilitation for patients with idiopathic scoliosis.

Lateral steps reveal adaptive biomechanical strategies in adolescent idiopathic scoliosis

INTRODUCTIONnAdolescent idiopathic scoliosis (characterized by a morphological deformation of the trunk) prompts the development of new postural control strategies. This adaptation has an influence on the dynamics of motor behaviour. The present study analysed ground reaction forces during lateral stepping in order to highlight the dynamic consequences of idiopathic scoliosis.nnnMATERIAL AND METHODSnTen adolescents suffering from idiopathic scoliosis with right thoracic curvature (Cobb angle>or=15 degrees) and 15 healthy adolescents participated in the study. We used two force platforms to record ground reaction forces for the right and left legs during large and small lateral steps (LSs).nnnRESULTSnOur results revealed intergroup and interlimb differences for both types of step. For small LSs, right-side (i.e. convexity side) initiation induced a significant increase in the ground reaction force impulse during the postural phase for the scoliotic group, when compared with the control group. For large LSs, left-side (i.e. concavity side) initiation induced a significant increase in ground reaction force impulse during the landing phase only. Patients always displayed slower dynamic behaviour than healthy controls. For both stepping sides, the asymmetry index (AI) was higher in the scoliotic group than in the control group (0.2<or=AI>or=85 in the scoliotic group versus 0.124.4 in the control group). Furthermore, the scoliotic group showed a significant increase in the variability of the dynamic parameters (>8%).nnnCONCLUSIONnIn scoliotic subjects, lateral stepping prompts specific dynamic behaviour affecting both limbs, in order to maintain balance during movement despite spinal deformation. This stepping task could be used in future studies to identify specific motor strategies.

The influence of adolescent idiopathic scoliosis on the dynamic adaptive behaviour

The idiopathic scoliosis is characterized by a three-dimensional spinal deformity involving new dynamical strategies to regulate the posture. The aim is to analyze the centre of pressure (CP) behaviour in forward stepping (FS) and lateral stepping (LS) to determine the dynamical consequences of scoliosis. Ten adolescents suffering from right thoracic scoliosis (Cobb>or=18 degrees ) and 15 healthy adolescents participated in this study. Two forceplates recorded the CP evolution in medio-lateral and antero-posterior axes resulting from FS and, LS with the dominant (D) and with the non-dominant (nD) limbs. Our results showed between groups and within groups differences respect to axis of motion. The comparison between groups in the LS showed the increase of the CP total displacement only when stepping with nD limb. Conversely no major evidence emerges from the FS analysis. Whatever the axis was, the CP total displacement of the D limb did not differ between groups. The comparison between lower limbs for healthy subjects was always different for FS whereas this comparison became non-significant for LS. For patients the same analysis showed results less systematically different. The correlation analysis, only when LS is initiated with nD limb, revealed opposite CP dynamical strategies between groups. These results may be explained by the influence of the spinal deformation on internal mass distribution and the asymmetrical neurophysiological factors previously described. Therefore, to perform LS the patients develop an asymmetry between both limbs to guarantee the balance despite scoliosis. Thus LS reveals the differences between groups and between initiation limbs.

Les biphosphonates chez l’enfant : présent et avenir

Resume Les biphosphonates sont des analogues synthetiques du pyrophosphate naturel qui ont ete introduits initialement en therapeutique humaine pour le traitement de la maladie de Paget. Leur mecanisme d’action qui passe principalement par une inhibition de l’activite osteoclastique, constitue une reference pour le traitement d’affections comportant une augmentation de la resorption osseuse. En pediatrie les osteoporoses (notamment l’osteogenese imparfaite), les hypercalcemies, et les calcifications ectopiques, sont les trois situations principales au cours desquelles ils ont ete utilises avec succes, mais pour l’instant avec un faible recul et sans etude controlee. L’evolution de ces molecules avec generation de produits de plus en plus actifs, utilisables par voie orale, devrait permettre l’extension de leur utilisation. Des etudes multicentriques sont maintenant necessaires pour preciser au mieux leur efficacite et leur mode d’emploi chez l’enfant.

Mesure de la qualité de vie chez l'enfant atteint de paralysie cérébrale

Objectives. – To identify and describe available health-related quality of life (HRQL) markers in walking paediatric cerebral palsy (CP) patients. Methods. – A Medline literature review (1980–2007); content, application field, and metrologic properties of the scales were specified. Results. – Seventeen scales were identified and classified into three categories: scales developed for cerebral palsy patients or developed for neuromotor pathologies and used mostly in cerebral palsy patients; generic scales developed for the general population; generic scales developed for chronic, non-specific diseases. Discussion and Conclusion. – Documentation of metrologic properties in available HRQL scales is unequal. Information about ‘‘sensitivity to change’’ of the scales is necessary for their use in therapeutic outcome or cohort follow-up studies in CP patients. To include an analysis of the patient’s opinion is important, thus most of the questionnaires are based on the experimenter’s experience and synthesis of the literature. CP children’s auto-evaluation of their quality of life using a questionnaire developed based on the patients’ and families’ opinions, in association with a participation questionnaire, seems to be the most informative method to include in outcome studies. # 2008 Elsevier Masson SAS. All rights reserved.

Dynamic EMG of peroneus longus in hemiplegic children with equinovarus.

OBJECTIVEnIn hemiplegic children the appearance of equinovarus is correlated with premature electromyography (EMG) activity of the gastrocnemius medialis (GM) prior to initial contact. The goal was to analyze the onset of EMG activation in the GM and, more particularly, the peroneus longus (PL) in cases of equinovarus: is PL activity likewise premature?nnnMATERIAL AND METHODSnAs 15 hemiplegic children (age 5 years±1.5) with equinovarus walked, their PL and GM EMG activity was being recorded. The latter was normalized in terms of gait cycle percentage (0-100%) and detected through semi-automatic selection with activation threshold set at 20μV. A paired t-test compared activation onset of the PL versus the GM muscles.nnnRESULTSnAs regards the healthy limb, activity onset of the GM (+14.55%) and the PL (+19.2%) muscles occurred only during the ST. In cases of equinovarus, activation of the GM (-5.2%) and the PL (-6.1%) occurred during the SW and was premature. For each muscle, comparison between the healthy and the hemiplegic side was highly significant (P<0.001).nnnCONCLUSIONnPremature PL and GM EMG activity preceding initial contact corresponds not to a disorder secondary to imbalance but rather, more probably, to motor command dysfunction. While the PL consequently contributes to equinus deformity, its possible role in varus genesis is less evident. EMG study needs to be completed by comparing PL and tibialis posterior strength while taking foot bone morphology into full account.

SOFOP-04 – Chirurgie orthopédique – Etude de la fiabilité des mesures d’incidence pelvienne en pratique quotidienne

Introduction L’incidence pelvienne est un parametre anatomique independant de la position du bassin dans l’espace. Il s’agit d’un parametre etablit a partir d’une construction radiologique. L’imperfection des incidences radiographiques ne permet pas toujours d’avoir des conditions de mesure correctes. Les remaniements anatomiques du plateau sacre sont egalement un obstacle a la mesure rigoureuse de cette valeur. L’objectif de cette etude est de determiner la fiabilite de ce parametre en pratique quotidienne. Materiel et methodes Dans cette etude prospective, nous avons mesure l’incidence pelvienne et sa variante chez 50 patients. Les mesures ont ete effectuees sur des images scannographiques permettant de realiser 3 series de mesures, une en profil strict, une avec les tetes femorales decalees dans le plan horizontal et une avec les tetes femorales decalees dans le plan vertical. Resultats Les resultats n’ont pas mis en evidence de difference significative en ce qui concerne l’incidence pelvienne, quelle que soit la position des tetes femorales sur les radiographies, avec des coefficients de correlations tous superieurs a 0,98 (p L’analyse de la variante d’incidence pelvienne montrait en revanche une difference significative entre la position theorique ideale et le decalage horizontal des tetes femorales sur les radiographies (p Les mesures moyennes de l’incidence pelvienne (IP) et de sa variante (VIP) etaient statistiquement differentes pour chaque individu (p Discussion La mesure de l’incidence pelvienne est donc fiable meme si la qualite de realisation de la radiographie n’est pas parfaite. En revanche, la variante utilisant la face posterieure du sacrum est tres dependante de la position du bassin dans l’espace avec des differences significatives. Enfin il n’est pas retrouve de relation entre l’incidence pelvienne (IP) et sa variante (VIP). Sur le plan pratique il parait licite d’assimiler le centre des tetes femorales au milieu de la droite joignant les deux tetes femorales. Par contre la variante a l’incidence prenant comme repere la face posterieure du sacrum nous semble un repere non fiable en pratique.