AUTHOR=Liang Jing Nong , Bashford Greg , Kulig Kornelia , Ho Kai-Yu 

TITLE=Achilles tendon morphology adaptations in chronic post-stroke hemiparesis: a comparative analysis with neurologically intact controls

JOURNAL=Frontiers in Sports and Active Living

VOLUME=Volume 6 - 2024

YEAR=2025

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2024.1498333

DOI=10.3389/fspor.2024.1498333

ISSN=2624-9367

ABSTRACT=In post-stroke individuals, slow walking speed is a significant concern related to inadequate propulsion of the paretic limb. However, an overlooked factor is this population's altered morphology the Achilles tendon, which may compromise the propulsive forces in the paretic limbs. This study aimed to explore changes in Achilles tendon morphology, including gross thickness and intratendinous collagen fiber bundle organization, following stroke-induced brain lesions. Fifteen individuals with chronic post-stroke hemiparesis (at least 6 months post-stroke) and 19 neurologically intact control participants participated. Ultrasound imaging was used to evaluate Achilles tendon thickness and collagen organization in the paretic and non-paretic limbs of poststroke participants, as well as in the right limb (control limb) of the control group. Compared to control individuals, the paretic limb in individuals post-stroke showed increased tendon thickness at the Achilles tendon insertion and 2 cm above it. The collagen fiber bundle at the Achilles tendon insertion of the paretic limbs showed reduced organization compared to those in the control limbs. Individuals post-stroke also exhibited slower walking speeds, and increased plantarflexor muscle tone in the paretic limb compared to controls. In conclusion, individuals with chronic post-stroke hemiparesis demonstrated tendon thickening and collagen disorganization in the paretic limb, particularly at the insertion site of the Achilles tendon, likely due to an abnormal loading environment influenced by increased plantar flexor tone, co-activation, atrophy, and disuse. These changes may increase tendon compliance, impair force transmission and propulsion, and contribute to slower walking speeds. Addressing Achilles tendon integrity should be incorporated as a component of strategies to improve neuromuscular control in this population.