The purpose of this study was to investigate middle-age effects on Achilles displacement patterns under passive stretch and eccentric loading. Healthy young (24.1 ± 1.4 years, n = 9) and middle-aged (49.0 ± 3.1 years, n = 9) adults were positioned prone and the ankle was cyclically dorsiflexed (0.5 Hz, 25° range) during passive stretch and active lengthening. Achilles displacements were tracked in cine ultrasound using 2D speckle tracking. Displacements were found to be non-uniform, with mid and deep portions of the tendon displacing more than superficial portions. However, the degree of non-uniformity was significantly reduced in middle-aged adults, suggesting a potential age-related reduction in inter-fascicle sliding or a shift in loading sharing between plantarflexors. Eccentric loading reduced displacement magnitudes, likely reflecting distal tendon stretch induced via active muscle contractions. Changes in tendon displacement with active loading were greater in middle-aged adults, which could reflect greater tendon compliance. The observed age-related changes in Achilles tendon behavior may have implications for both plantarflexor performance and injury risk.
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http://dx.doi.org/10.1016/j.medengphy.2015.04.004 | DOI Listing |
Rehabilitacion (Madr)
January 2025
University of Health Sciences, Şişli Hamidiye Etfal Training and Research Hospital, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey.
Objective: Spasticity developing in the upper extremity in stroke patients causes disability by limiting movement and causing pain. This study investigates the effects of botulinum toxin injections on pain, functionality, spasticity, and range of motion in hemiplegic patients with post-stroke spasticity.
Materials And Methods: The study involved a double-blind, prospective, randomized controlled trial with thirty-one stroke patients aged 35-80 who developed upper extremity spasticity.
Circ Res
January 2025
Department of Integrative Pathophysiology, Medical Faculty Mannheim, DZHK Partnersite Mannheim-Heidelberg, University of Heidelberg, Germany (S.L.).
This review examines the giant elastic protein titin and its critical roles in heart function, both in health and disease, as discovered since its identification nearly 50 years ago. Encoded by the TTN (titin gene), titin has emerged as a major disease locus for cardiac disorders. Functionally, titin acts as a third myofilament type, connecting sarcomeric Z-disks and M-bands, and regulating myocardial passive stiffness and stretch sensing.
View Article and Find Full Text PDFTop Stroke Rehabil
January 2025
Department of Physical Therapy, Graduate School, Kyungnam University, Changwon, Republic of Korea.
Objectives: The plantar fascia stretching intervention can correct balance ability and induces a change spatiotemporal parameter doing gait ability. Our objective is to compare the effects of a 4-week program of plantar fascia stretching with those of calf stretching exercise on ankle dorsiflexion passive range of motion (DF-PROM), open and closed eyes static balance ability, gait parameters, and foot and ankle disability index in chronic post-stroke condition.
Methods: Participants were randomized to either the plantar fascia stretching ( = 10) or calf stretching ( = 10) group.
J Funct Morphol Kinesiol
December 2024
Faculty of Rehabilitation Sciences, Nishi Kyushu University, Kanzaki-shi 842-0015, Saga, Japan.
: the purpose of this study was to determine the contributions of mechanical, neural, morphological, and muscle quality factors on individual differences in the maximal ankle dorsiflexion range of motion (ROM). : A sample of 41 university students performed passive-dorsiflexion and morphological measurements. In the passive-dorsiflexion measurement, while the ankle was passively dorsiflexed, maximal dorsiflexion ROM was measured in addition to passive torque at a given angle and muscle-tendon junction (MTJ) displacement during the last 13° as mechanical factors, and stretch tolerance and muscle activation were measured as neural factors.
View Article and Find Full Text PDFFront Neurosci
December 2024
Department of Psychology and Communication, University of Idaho, Moscow, ID, United States.
Muscle tone represents a foundational property of the motor system with the potential to impact musculoskeletal pain and motor performance. Muscle tone is involuntary, dynamically adaptive, interconnected across the body, sensitive to postural demands, and distinct from voluntary control. Research has historically focused on pathological tone, peripheral regulation, and contributions from passive tissues, without consideration of the neural regulation of active tone and its consequences, particularly for neurologically healthy individuals.
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