Faculty Collaboration Database

Age and sex differences in steadiness of elbow flexor muscles with imposed cognitive demand. Eur J Appl Physiol 2015 Jun;115(6):1367-79

Date

01/31/2015

Pubmed ID

25633070

Pubmed Central ID

PMC4431934

DOI

10.1007/s00421-015-3113-0

Scopus ID

2-s2.0-84939994592 (requires institutional sign-in at Scopus site)   38 Citations

Abstract

PURPOSE: These studies determined (1) age- and sex-related differences in steadiness of isometric contractions when high cognitive demand was imposed across a range of forces with the elbow flexor muscles (study 1) and; (2) sex differences in steadiness among older adults when low cognitive demand was imposed (study 2).

METHODS: 36 young adults (18-25 years; 18 women) and 30 older adults (60-82 years; 17 women) performed isometric contractions at 5, 30 and 40 % of maximum voluntary contraction (MVC). Study 1 involved a high-cognitive demand session (serial subtractions by 13 during the contraction) and a control session (no mental math). Study 2 (older adults only) involved a low-cognitive demand session (subtracting by 1s).

RESULTS: Older individuals exhibited greater increases in force fluctuations (coefficient of variation of force, CV) with high cognitive demand than young adults, with the largest age difference at 5 % MVC (P = 0.01). Older adults had greater agonist EMG activity with high-cognitive demand and women had greater coactivation than men (P < 0.05). In study 2, CV of force increased with low cognitive demand for the older women but not for the older men (P = 0.03).

CONCLUSION: Older adults had reduced steadiness and increased muscle activation when high cognitive demand was imposed while low cognitive demand induced increased force fluctuations in older women but not older men. These findings have implications for daily and work-related tasks that involve cognitive demand performed simultaneously during submaximal isometric contractions in an aging workforce.

Author List

Pereira HM, Spears VC, Schlinder-Delap B, Yoon T, Nielson KA, Hunter SK

Author

Kristy Nielson PhD Professor in the Psychology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Age Factors
Aged
Aged, 80 and over
Anxiety
Cognition
Elbow
Female
Humans
Isometric Contraction
Male
Middle Aged
Muscle Strength
Muscle, Skeletal
Sex Factors