Academic Journal
Altered plantarflexor muscle-tendon mechanics and gearing during stretch-shortening contractions in older adults.
| Τίτλος: | Altered plantarflexor muscle-tendon mechanics and gearing during stretch-shortening contractions in older adults. |
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| Συγγραφείς: | Monte A; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy. Electronic address: andrea.monte@univr.it., Maganaris CN; Liverpool John Moores University, Research Institute for Sport and Exercise Sciences (RISES), Liverpool, United Kingdom. |
| Πηγή: | Experimental gerontology [Exp Gerontol] 2026 Oct 15; Vol. 224, pp. 113298. Date of Electronic Publication: 2026 Aug 22. |
| Τύπος έκδοσης: | Journal Article |
| Γλώσσα: | English |
| Στοιχεία περιοδικού: | Publisher: Elsevier Science Country of Publication: England NLM ID: 0047061 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1873-6815 (Electronic) Linking ISSN: 05315565 NLM ISO Abbreviation: Exp Gerontol Subsets: MEDLINE |
| Imprint Name(s): | Publication: Tarrytown Ny : Elsevier Science Original Publication: Oxford. |
| Ιατρικοί όροι (MeSH): | Muscle, Skeletal*/physiology , Muscle, Skeletal*/diagnostic imaging , Aging*/physiology , Achilles Tendon*/physiology , Achilles Tendon*/diagnostic imaging , Muscle Contraction*/physiology , Tendons*/physiology, Ankle Joint/physiology ; Humans ; Aged ; Biomechanical Phenomena ; Male ; Female ; Torque ; Adult ; Ultrasonography ; Young Adult |
| Περίληψη: | Ageing is associated with impairments in muscle force-generating capacity and tendon mechanical properties, yet its effects on stretch-shortening cycle (SSC) function remain unclear. We combined in vivo ultrasonography with dynamometric and kinematic measurements to investigate the muscle-tendon mechanisms underpinning SSC performance in older adults. Fourteen young (28 ± 5 years) and fifteen older adults (67 ± 3 years) performed electrically evoked plantarflexion contractions on an isokinetic dynamometer. Pure shortening and stretch-shortening (SSC) contractions were performed at angular velocities of 60 and 150°·s-1. Ankle torque, muscle-tendon unit (MTU) force, fascicle force, fascicle and Achilles tendon (AT) length changes, muscle belly gearing, tendon gearing, and mechanical work were quantified. Older adults exhibited lower maximal plantarflexor force and AT stiffness than young participants (both P < 0.001). SSCs increased ankle torque, MTU force, and fascicle force in both groups, with a greater enhancement at the higher shortening velocity. The magnitude of SSC-induced force enhancement was similar between groups, with no significant age×SSC interactions for force-related variables. Older adults exhibited greater AT elongation and tendon gearing, but less fascicle shortening, smaller changes in pennation angle, and lower muscle belly gearing. AT mechanical work increased during SSCs in both groups, whereas fascicle work was reduced only in the young participants. These findings demonstrate no significant age-related differences in SSC-effect between populations despite marked reductions in maximal force-generating capacity. The comparable SSC-effect could be achieved through altered muscle-tendon interaction strategies characterised by greater AT compliance and modified fascicle behaviour. Ageing, therefore, seems to preserve SSC function while altering the distribution of mechanical work within the MTU. (Copyright © 2026 The Authors. Published by Elsevier Inc. All rights reserved.) |
| Competing Interests: | Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. |
| Entry Date(s): | Date Created: 20260822 Date Completed: 20260924 Latest Revision: 20260924 |
| Update Code: | 20260925 |
| DOI: | 10.1016/j.exger.2026.113298 |
| PMID: | 42632432 |
| Βάση Δεδομένων: | MEDLINE |
| ISSN: | 1873-6815 |
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| DOI: | 10.1016/j.exger.2026.113298 |