A behavioral mechanism of how increases in leg strength improve old adults' gait speed

Azusa Uematsu; Kazushi Tsuchiya; Norio Kadono; Hirofumi Kobayashi; Takamasa Kaetsu; Tibor Hortobágyi; Shuji Suzuki

doi:10.1371/journal.pone.0110350

A behavioral mechanism of how increases in leg strength improve old adults' gait speed

PLoS One. 2014 Oct 13;9(10):e110350. doi: 10.1371/journal.pone.0110350. eCollection 2014.

Authors

Azusa Uematsu¹, Kazushi Tsuchiya², Norio Kadono³, Hirofumi Kobayashi⁴, Takamasa Kaetsu⁵, Tibor Hortobágyi⁶, Shuji Suzuki¹

Affiliations

¹ Faculty of Human Sciences, Waseda University, Tokorozawa, Japan.
² Graduate School of Human Sciences, Waseda University, Tokorozawa, Japan.
³ Advanced Research Center for Human Sciences, Waseda University, Tokorozawa, Japan.
⁴ Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan.
⁵ School of Human Sciences, Waseda University, Tokorozawa, Japan.
⁶ University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne, United Kingdom.

Abstract

We examined a behavioral mechanism of how increases in leg strength improve healthy old adults' gait speed. Leg press strength training improved maximal leg press load 40% (p = 0.001) and isometric strength in 5 group of leg muscles 32% (p = 0.001) in a randomly allocated intervention group of healthy old adults (age 74, n = 15) but not in no-exercise control group (age 74, n = 8). Gait speed increased similarly in the training (9.9%) and control (8.6%) groups (time main effect, p = 0.001). However, in the training group only, in line with the concept of biomechanical plasticity of aging gait, hip extensors and ankle plantarflexors became the only significant predictors of self-selected and maximal gait speed. The study provides the first behavioral evidence regarding a mechanism of how increases in leg strength improve healthy old adults' gait speed.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Age Factors
Aged
Aged, 80 and over
Female
Gait*
Humans
Leg*
Male
Muscle Strength*
Resistance Training
Walking

Grants and funding

This study was supported in part by Waseda University Grant for Special Research Projects (2013A-943 and 2013B-224) (http://www.waseda.jp/rps/en/index.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.