Effects of age and sex on shoulder biomechanics and relative effort during functional tasks

Alessio Murgia*, Tibor Hortobágyi, Annet Wijnen, Larissa Bruin, Ron Diercks, Rienk Dekker

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)
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Age-related decline in muscle strength can compromise shoulder function, which could increase the effort needed to perform activities of daily living (ADLs). The purpose of this cross-sectional study was to determine for the first time the relative shoulder effort during ADLs in healthy young and older adults.

Ten healthy young adults and ten healthy older adults were tested for maximal isokinetic torque and on a set of ADL tasks. Using inverse dynamics, the shoulder torques during ADLs were referenced to the maximal isokinetic torque and relative effort was determined.

Older compared to younger adults had >40% lower isokinetic shoulder abduction strength. The ratio of peak joint torque during six ADLs over the maximal isokinetic torque, i.e., relative effort, was higher in old (similar to 52%) compared with young adults (similar to 22%, p <0.05). Relative effort in older adults was over 40% in overhead activities and particularly high in abduction and reaching tasks, over 60%.

Healthy older compared with younger adults perform most ADL tasks involving the shoulder joint with nearly twice the level of relative effort. The concomitant reductions in maximal shoulder isokinetic torque and increases in relative effort may be related to the high prevalence of musculoskeletal pain and shoulder dysfunction in old age reported in epidemiological studies. (C) 2018 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)132-139
Number of pages8
JournalJournal of biomechanics
Publication statusPublished - 16-Nov-2018


  • Ageing
  • ADL
  • Inverse dynamics
  • Relative effort
  • Upper extremity torque

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