title: Heavy manual work throughout the working lifetime and muscle strength among men at retirement age.
abstract: BACKGROUND
  Reductions in heavy manual work as a consequence of mechanisation might adversely impact muscle strength at older ages. We investigated the association between grip strength at retirement age and lifetime occupational exposure to physically demanding activities. Grip strength is an important predictor of long-term health and physical function in older people.
  
  
  METHODS
  Grip strength (maximum of three readings in each hand) was measured in men from the Hertfordshire Cohort Study at a single examination when their mean age was 65.8 (SD 2.9) years. Associations with lifetime occupational exposure (ascertained by questionnaire) to three activities (standing/walking ≥ 4 h/day; lifting ≥ 25 kg; and energetic work sufficient to induce sweating) were assessed by multivariable linear regression with adjustment for various potential confounders.
  
  
  RESULTS
  Complete data were available from 1418 men who had worked for at least 20 years. After adjustment for age, height and weight, those with longer exposures to walking/standing and heavy lifting had lower grip strength, but the relationship disappeared after further adjustment for confounders. Working at physical intensity sufficient to induce sweating was not significantly associated with grip strength.
  
  
  CONCLUSIONS
  We found no evidence that physically demanding occupational activities increase hand grip strength at normal retirement age. Any advantages of regular physical occupational activity may have been obscured by unmeasured socioeconomic confounders.
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK Arthritis Research UK/MRC Centre for Musculoskeletal Health and Work, University of Southampton, Southampton, UK.
authors.forename: K
authors.initials: K
authors.lastname: Walker-Bone
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: S
authors.initials: S
authors.lastname: D'Angelo
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: H E
authors.initials: HE
authors.lastname: Syddall
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK Arthritis Research UK/MRC Centre for Musculoskeletal Health and Work, University of Southampton, Southampton, UK.
authors.forename: K T
authors.initials: KT
authors.lastname: Palmer
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK Arthritis Research UK/MRC Centre for Musculoskeletal Health and Work, University of Southampton, Southampton, UK NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Southampton, UK.
authors.forename: C
authors.initials: C
authors.lastname: Cooper
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK Arthritis Research UK/MRC Centre for Musculoskeletal Health and Work, University of Southampton, Southampton, UK.
authors.forename: D
authors.initials: D
authors.lastname: Coggon
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK Academic Geriatric Medicine, Faculty of Medicine, University of Southampton, Southampton, UK NIHR Collaboration for Leadership in Applied Health Research and Care, Wessex, UK Newcastle University Institute for Ageing and Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: A A
authors.initials: AA
authors.lastname: Sayer
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018737:Hand Strength; D006801:Humans; D017770:Lifting; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D016273:Occupational Exposure; D009790:Occupations; D005082:Physical Exertion; D011187:Posture; D012179:Retirement; D006113:United Kingdom; D016138:Walking; D014937:Work
keywords: Muscle strength