A1 Journal article (refereed)
ISB clinical biomechanics award winner 2023 : Medial gastrocnemius muscle and Achilles tendon interplay during gait in cerebral palsy (2024)

Cenni, F., Alexander, N., Sukanen, M., Mustafaoglu, A., Wang, Z., Wang, R., & Finni, T. (2024). ISB clinical biomechanics award winner 2023 : Medial gastrocnemius muscle and Achilles tendon interplay during gait in cerebral palsy. Clinical Biomechanics, 111, Article 106158. https://doi.org/10.1016/j.clinbiomech.2023.106158

JYU authors or editors

Publication details

All authors or editorsCenni, Francesco; Alexander, Nathalie; Sukanen, Maria; Mustafaoglu, Afet; Wang, Zhongzheng; Wang, Ruoli; Finni, Taija

Journal or seriesClinical Biomechanics



Publication year2024


Article number106158


Publication countryUnited Kingdom

Publication languageEnglish


Publication open accessOpenly available

Publication channel open accessPartially open access channel

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/92515


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.

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.

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.

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.

Keywordsmusclestendonskinematicscalcaneal tendonphysical training

Free keywordsmuscle and tendon length; fascicle length; muscle and tendon strain; pennation angle; joint kinematics; stance phase

Contributing organizations

Related projects

Ministry reportingYes

Reporting Year2024

Preliminary JUFO rating1

Last updated on 2024-02-07 at 23:26