Alterations of treatment-naïve pelvis and thigh muscle morphology in children with cerebral palsy

Lower limb (LL) muscle morphology and growth are altered in children with cerebral palsy (CP). Muscle alterations differ with age and with severity of motor impairment, classified according to the gross motor classification system (GMFCS). Muscle alterations differ also with orthopedic intervention, frequently performed at the level of the shank muscles since an early age, such as the gastrocnemius. The aim was to investigate the alterations of treatment-naïve pelvis and thigh muscle lengths and volumes in children with GMFCS levels I and II, of varying ages. 17 children with CP (GMFCS I: N = 9, II: N = 8, age: 11.7 ± 4 years), age-matched to 17 typically developing (TD) children, underwent MRI of the LL. Three-dimensional reconstructions of the muscles were performed bilaterally. Muscle volumes and lengths were calculated in 3D and compared between groups. Linear regression between muscle volumes and age were computed. Adductor-brevis and gracilis lengths, as well as rectus-femoris volume, were decreased in GMFCS I compared to TD (p < 0.05). Almost all the reconstructed muscle volumes and lengths were found to be altered in GMFCS II compared to TD and GMFCS I. All muscle volumes showed significant increase with age in TD and GMFCS I (R2 range: 0.3–0.9, p < 0.05). Rectus-femoris, hamstrings and adductor-longus showed reduced increase in the muscle volume with age in GMFCS II when compared to TD and GMFCS I. Alterations of treatment-naïve pelvis and thigh muscle volumes and lengths, as well as muscle growth, seem to increase with the severity of motor impairment in ambulant children with CP.This study was funded by the research council of the University of Saint-Joseph in Beirut (grant# FM244) and the CEDRE french-lebanese cooperation in academic research (grant# 11SCIF44/L36)

How do 3D skeletal parameters and demographics determine kinematic adaptation from normal to fast speed gait?

The occurrence of falls during gait in elderly people is an important source of morbidity [1]. One of the useful screening tests for falls is the kinematic analysis of fast walking, that identifies subjects with risk of multiple falls [2]. Although the kinematic adaptations from normal to fast speed gait have been studied in asymptomatic adults [3], the demographic and skeletal determinants of these adaptations are still unknown

O 095—How do postural parameters vary during gait in children with cerebral palsy? A 3D subject-specific skeletal segment registration technique

Postural parameters, calculated in static position on frontal and sagittal radiographs, are altered in ambulant children with cerebral palsy (CP) and are known to be related to gait abnormalities [1,2]. Most of these parameters are positional and could vary during gait. Their computation could be performed using gait simulation models that are usually generic or semi-personalized [2,3]. There are currently no studies investigating how subject-specific postural parameters are modified during gait in children with CP

How do postural parameters vary during walking in asymptomatic adults? A registration technique of subject-specific 3D skeletal reconstruction during gait

Postural skeletal alignment is altered with age due to intervertebral disc and joint degeneration, consequently affecting quality of life (QoL) and activities of daily living, such as gait. Postural alignment parameters of the spine, pelvis, hips and lower limbs, measured on static standing radiographs, have been widely studied in asymptomatic subjects and subjects affected by various pathologies. However, while most of these parameters are positional and could vary during gait, there are currently no studies investigating how they are modified during walking

How does the variation of the 3D orientation of the acetabulum during walking influence hip kinematics?

Acetabular cup orientation is crucial for total hip arthroplasty (THA), and its malpositioning could lead to impingement and dislocation [1]. Acetabular cup orientation currently relies on static 3D hip parameters [2] and was shown to be related to changes in pelvic positioning [3]. While pelvic position varies during walking, it is still unknown how dynamic variation of hip orientation during gait could influence hip kinematics

Variation of the sagittal vertical axis during walking and its determinants

Patients with adult spinal deformities (ASD) are known to have altered postural alignment affecting their quality of life and activities of daily living, especially gait. The Sagittal Vertical Axis (SVA), a postural parameter calculated as the distance between the posterior corner of the sacrum and the C7-plumbline on full-body sagittal radiographs [1], has been shown to be highly altered in ASD. Even though this parameter is positional and could vary during gait, no studies have investigated its variation during walking even in asymptomatic subjects

Influence of Spino-Pelvic and Postural Alignment Parameters on Gait Kinematics

Introduction: Postural alignment is altered with spine deformities that might occur with age. Alteration of spino-pelvic and postural alignment parameters are known to affect daily life activities such as gait. It is still unknown how spino-pelvic and postural alignment parameters are related to gait kinematics. Research question: To assess the relationships between spino-pelvic/postural alignment parameters and gait kinematics in asymptomatic adults. Methods: 134 asymptomatic subjects (aged 18-59 years) underwent 3D gait analysis, from which kinematics of the pelvis and lower limbs were extracted in the 3 planes. Subjects then underwent full-body biplanar X-rays, from which skeletal 3D reconstructions and spino-pelvic and postural alignment parameters were obtained such as sagittal vertical axis (SVA), center of auditory meatus to hip axis plumbline (CAM-HA), thoracic kyphosis (TK) and radiologic pelvic tilt (rPT). In order to assess the influence of spino-pelvic and postural alignment parameters on gait kinematics a univariate followed by a multivariate analysis were performed. Results: SVA was related to knee flexion during loading response (β = 0.268); CAM-HA to ROM pelvic obliquity (β = -0.19); rPT to mean pelvic tilt (β = -0.185) and ROM pelvic obliquity (β = -0.297); TK to ROM hip flexion/extension in stance (β = -0.17), mean foot progression in stance (β = -0.329), walking speed (β = -0.19), foot off (β = 0.223) and step length (β = -0.181). Significance: This study showed that increasing SVA, CAM-HA, TK and rPT, which is known to occur in adults with spinal deformities, could alter gait kinematics. Increases in these parameters, even in asymptomatic subjects, were related to a retroverted pelvis during gait, a reduced pelvic obliquity and hip flexion/extension mobility, an increased knee flexion during loading response as well as an increase in external foot progression angle. This was associated with a decrease in the walking pace: reduced speed, step length and longer stance phase

How do skeletal and postural parameters contribute to maintain balance during walking?

Introduction: Maintaining balance during gait allows subjects to minimize energy expenditure and avoid falls. Gait balance can be measured by assessing the relationship between the center of mass (COM) and center of pressure (COP) during gait. Demographics, skeletal and postural parameters are known to influence gait balance. Purpose: What are the determinants of dynamic balance during gait in asymptomatic adults among skeletal and demographic parameters? Methods: 115 adults underwent 3D gait analysis and full-body biplanar X-rays. Angles between the COM-COP line and the vertical were calculated in frontal and sagittal planes during gait: maxima, minima, and ROM were evaluated. Full-body 3D reconstructions were obtained; skeletal and postural parameters of the spine (lumbar lordosis, thoracic kyphosis, sagittal vertical axis SVA), pelvis (pelvic tilt and incidence, acetabular orientation in the 3 planes) and lower limbs (neck shaft angle femoral and tibial torsions) were calculated. A univariate followed by a multivariate analysis were computed between the COM-COP parameters and skeletal and demographic parameters. Results: The univariate analysis showed that in the frontal plane, maximum (4.6°) of the COMCOP angle was significantly correlated with weight (r =0.53), age (r =0.28), height (r = 0.35), SVA (r = 0.23), T1T12 (r = 0.24) and pelvic width (r = 0.25).In the sagittal plane, maximum COM-COP (19.7 ± 2.8°) angle was significantly correlated to acetabular tilt (r = 0.25) and acetabular anteversion (r =0.21). The multivariate analysis showed that, in the frontal plane, an increase in the maximum of the COM-COP angle was determined by a decreasing height (β = −0.28), an increasing weight (β = 0.48), being a male (β = −0.42), and an increasing posterior acetabular coverage (β = 0.22). In the sagittal plane, an increasing maximum COMCOP angle was determined by a decreasing height (β = −0.38) and an increasing SVA (β = 0.19). Conclusion: Frontal imbalance appeared to be mainly correlated to demographic parameters. Sagittal imbalance was found to be correlated with weight, height, acetabular parameters and SVA. These results suggest that in addition to demographic parameters, acetabular parameters and SVA are important determinants of balance during gait.This research was funded by the University of Saint-Joseph (grant FM183). The funding source did not intervene in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication

How do 3D skeletal parameters influence kinetics?

Lower limb joints are subject to mechanical load during daily activities, such as gait, which is an important risk factor of osteoarthritis. Moreover, kinetics are known to be influenced by gait alterations in patients with osteoarthritis [1]. While skeletal parameters are known to determine gait kinematics [2], it is still unknown how skeletal parameters influence kinetic parameters

Alterations of 3D acetabular and lower limb parameters in adolescent idiopathic scoliosis

Purpose: To evaluate the 3D deformity of the acetabula and lower limbs in subjects with adolescent idiopathic scoliosis (AIS) and their relationship with spino-pelvic alignment. Methods: Two hundred and seventy-four subjects with AIS (frontal Cobb: 33.5° ± 18° [10°-110°]) and 84 controls were enrolled. All subjects underwent full-body biplanar X-rays with subsequent 3D reconstructions. Classic spino-pelvic and lower limb parameters were collected as well as acetabular parameters: acetabular orientation in the 3 planes (tilt, anteversion and abduction), center-edge angle (CEA) and anterior and posterior sector angles. Subjects with AIS were represented by both lower limb sides and classified by elevated (ES) or lowered (LS), depending on the frontal pelvic obliquity. Parameters were then compared between groups. Determinants of acetabular and lower limb alterations were investigated among spino-pelvic parameters. Results: Acetabular abduction was higher on the ES in AIS (59.2° ± 6°) when compared to both LS (55.6° ± 6°) and controls (57.5° ± 3.9°, p < 0.001). CEA and acetabular anteversion were higher on the LS in AIS (32° ± 6.1°, 20.5° ± 5.7°) when compared to both ES (28.7° ± 5.1°, 19.8° ± 5.1°) and controls (29.8° ± 4.8°, 19.1° ± 4°, respectively, p < 0.001). Anterior sector angle was lower on both ES and LS in AIS when compared to controls. CEA, acetabular abduction and acetabular anteversion were found to be mostly determined (adjusted R2: 0.08-0.32) by pelvic tilt and less by frontal pelvic obliquity, frontal Cobb and T1T12. Conclusions: Subjects with AIS had a more abducted acetabulum at the lowered side, more anteverted acetabulum and a lack of anterior coverage of both acetabula. These alterations were strongly related to pelvic tilt.This study was funded by the University of Saint-Joseph (Grant No. FM300)