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- Cenni, Francesco, et al.
(författare)
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ISB clinical biomechanics award winner 2023 : Medial gastrocnemius muscle and Achilles tendon interplay during gait in cerebral palsy
- 2024
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Ingår i: Clinical Biomechanics. - : Elsevier BV. - 0268-0033 .- 1879-1271. ; 111
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Tidskriftsartikel (refereegranskat)abstract
- Background: The interplay between the medial gastrocnemius muscle and the Achilles tendon is crucial for efficient walking. In cerebral palsy, muscle and tendon remodelling alters the role of contractile and elastic components. The aim was to investigate the length changes of medial gastrocnemius belly and fascicles, and Achilles tendon to understand their interplay to gait propulsion in individuals with cerebral palsy.Methods: Twelve young individuals with cerebral palsy and 12 typically developed peers were assessed during multiple gait cycles using 3D gait analysis combined with a portable ultrasound device. By mapping ultrasound image locations into the shank reference frame, the medial gastrocnemius belly, fascicle, and Achilles tendon lengths were estimated throughout the gait cycle. Participants with cerebral palsy were classified into equinus and non-equinus groups based on their sagittal ankle kinematics.Findings: In typically developed participants, the Achilles tendon undertook most of the muscle-tendon unit lengthening during stance, whereas in individuals with cerebral palsy, this lengthening was shared between the medial gastrocnemius belly and Achilles tendon, which was more evident in the equinus group. The lengthening behaviour of the medial gastrocnemius fascicles resembled that of the Achilles tendon in cerebral palsy. Interpretation: The findings revealed similar length changes of the medial gastrocnemius fascicles and Achilles tendon, highlighting the enhanced role of the muscle in absorbing energy during stance in cerebral palsy. These results, together with the current knowledge of increased intramuscular stiffness, suggest the exploitation of intramuscular passive forces for such energy absorption.
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- Wang, Zhongzheng, 1994-, et al.
(författare)
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In vivo 3D muscle architecture quantification based on 3D freehand ultrasound and magnetic resonance imaging
- 2023
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Ingår i: Journal of Biomechanics. - : Elsevier BV. - 0021-9290 .- 1873-2380. ; 152
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Tidskriftsartikel (refereegranskat)abstract
- Muscle architecture parameters, such as the fascicle length, pennation angle, and volume, are important muscle morphology characteristics. Accurate in vivo quantification of these parameters allows to detect changes due to pathologies, interventions, and rehabilitation trainings, which ultimately impact on muscles' force-producing capacity. In this study, we compared three-dimensional (3D) muscle architecture parameters of the tibialis anterior and gastrocnemius medialis, which were quantified by 3D freehand ultrasound (3DfUS) and a magnetic resonance imaging (MRI) technique, diffusion tensor imaging (DTI), respectively. Sixteen able-bodied subjects were recruited where seven of them received both 3DfUS and MRI measurement, while the rest underwent 3DfUS measurements twice. Good to excellent intra-rater reliability and inter-session repeatability were found in 3DfUS measurements (intra-class correlation coefficient > 0.81). Overall, the two imaging modalities yielded consistent measurements of the fascicle length, pennation angle, and volume with mean differences smaller than 2.9 mm, 1.8 degrees, and 5.7 cm3, respectively. The only significant difference was found in the pennation angle of the tibialis anterior, although the discrepancy was small. Our study demonstrated, for the first time, that 3DfUS measurement had high reliability and repeatability for measurement of muscle architecture in vivo and could be regarded as an alternative to MRI for 3D evaluation of muscle morphology.
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- Wang, Zhongzheng, 1994-
(författare)
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In Vivo Evaluation of Skeletal Muscle Morphological and Mechanical Properties using Medical Imaging
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Skeletal muscles are soft tissues that play an important role in maintaining body posture and enabling movements through force generation. The force-generating capacity is associated with the morphological and mechanical properties of the muscle. Abnormal muscle force-generating capacity may result in or be the outcome of abnormal muscle morphological and mechanical properties. Medical imaging is a widely-used and powerful in vivo measurement technique that could provide valuable information for diagnosis, treatment planning, outcome evaluation, and research of muscle-related pathologies. The overall objectives of this thesis were to quantify skeletal muscle morphological and mechanical properties in vivo using different medical imaging techniques and to evaluate the performance of the proposed medical imaging techniques with respect to different aspects of reliability. This thesis was based on two papers that focused on the morphological and mechanical properties of skeletal muscles, respectively.In the first study, skeletal muscle morphological parameters, i.e., volume, fascicle length, and pennation angle of the tibialis anterior and gastrocnemius medialis, were measured in vivo using three-dimensional freehand ultrasound (3DfUS) and magnetic resonance imaging (MRI), respectively. In total, sixteen able-bodied subjects were recruited in this study. Seven of them received both 3DfUS and MRI measurements, while the remaining subjects received 3DfUS measurements twice at a one-week interval. Good to excellent intra-rater reliability and inter-session repeatability was found in muscle morphological parameters quantified by 3DfUS measurements, as indicated by the high intra-class correlation coefficient values and low standard error of measurement. The only statistically significant difference found between 3DfUS and MRI measurements was the pennation angle of the tibialis anterior, although the actual discrepancy was small. This study suggested that 3DfUS could be considered as an alternative to MRI for measuring 3D skeletal muscle morphological parameters in vivo.In the second study, a direct inversion approach based on magnetic resonance elastography (MRE) and diffusion tensor imaging (DTI) for skeletal muscle’s anisotropic mechanical properties quantification was proposed. DTI was used to identify the muscle fascicle orientation. An incompressible transversely isotropic material model was adopted to describe the material property of the skeletal muscles. The proposed approach was evaluated with a multifrequency MRE setup on gastrocnemius and soleus in five able-bodied subjects. The existence of anisotropy and frequency dependence was observed in all muscle sub-compartments using the proposed inversion approach. The necessity of using DTI to identify muscle fascicle orientation was also illustrated. This study suggested that the proposed direct inversion approach had the potential to quantify the anisotropic mechanical properties of skeletal muscles in both healthy and pathological conditions.
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