PhD Scientific Days 2025

Budapest, 7-9 July 2025

Poster Session I. - N: Health Sciences

Assessment of Muscle Function and stretch-shortening cycle Performance in Older Adults: A Foundation for Eccentric Overload Resistance Training - A Pilot Study

Előadó neve

Mr. Emam Mohamed

Neptun code

BNV9I4

Előadó munkahelye

Semmelweis University

Előadó telefonszáma

0036300946773

Előadó e-mail címe

drmohamedelshenawy17@gmail.com

Az előadás címe

Assessment of Muscle Function and stretch-shortening cycle Performance in Older Adults: A Foundation for Eccentric Overload Resistance Training - A Pilot Study

Szerző(k) neve és munkahelye

Mohamed Abdelaziz Emam MOHAMED, PhD1, András Horváth1, Bálint Kovács2, Akman Mehmet2, Beáta Csizmadia2, Jingyi Ye2, Linjie Zhang2, János Négyesi2, Tibor Hortobágyi2

1: Semmelweis University
2: Hungarian University of Sports Science

Bemutatás módja

Poszter

Szekció

Poster Session I. - N: Health Sciences

Language of the presentation

English

Preferred session

Health Sciences

Összefoglaló szövege

Introduction: Age-related decline is not uniform in measures of neuromuscular function. There is a relative maintenance in maximal voluntary eccentric vs. concentric and isometric force (MVC). It is unclear how age effects measures that are even more closely related to daily function such as stretch-shortening cycle (SSC) efficiency tested during dynamometry and vertical jumps. Identifying age-differences in neuromuscular outcomes could inform prescription of resistance training especially with an eccentric overload to target age-typical deficiencies at the start of a resistance training program.

Methods: We compared healthy, active young adults (32.4 ± 5.59 years, n=4) and older adults (73.75 ± 2.75 years, n=4) in selected neuromuscular outcomes of the knee extensor muscles. Participants performed MVC knee extension and SSC contractions on a dynamometer and peak strength, the rate of torque development and mechanical efficiency was calculated. In addition, squat and counter-movement jumps were also performed where jump height and related parameters calculated. All measurements were conducted twice to establish test-retest reliability.

Results: Mechanical efficiency and SSC effect during SSC contractions were similar between Young (Y: 45.09 ± 2.06%) vs. Old (O: 44.92 ± 1.13%) and (Y: 1.10 ± 0.10 vs. O: 1.08 ± 0.17) respectively. However, younger adults demonstrated knee extensor higher torque and rate of torque development during the isometric contractions (Y:0.78 ± 0.24 vs. O: 0.25 ± 0.17 Nm/ms, p = 0.01, d = 2.50). There also were no age-differences in MVC (Y: 130.45 ± 15.91 vs. O: 122.87 ± 23.26 Nm, p = 0.60, d = 0.39). Squat jump height (Y: 0.27 ± 0.05 vs. O: 0.13 ± 0.02 m, p < 0.01, d = 3.17), and countermovement jump height (Y: 0.34 ± 0.06 vs. O: 0.15 ± 0.03 m, p < 0.01, d = 3.87). All measurements demonstrated excellent test-retest reliability (ICC > 0.85).

Conclusion: While mechanical efficiency and SSC effect remain preserved with aging, explosive strength and jump performance show significant age-related declines. The lack of significant difference in MVC despite age differences suggests it may not be a sensitive indicator of age-related muscle function changes. Such data inform our subsequent eccentric overload training intervention to improve older adults’ neuromuscular function especially affected by aging.

University

Semmelweis University

Supervisor

András Horváth

Publication of my abstract

I give consent to the publication of my abstract on the website of the congress.

phd.section.field

in doctoral studies before complex exam (PhD)

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

7920

Start

16:36

End

16:42