Prolonged occupational activity and 6-year changes in postural sway in elderly women.
OBJECTIVE
Prolonged occupational work such as farm work has been reported to adversely affect mobility in elderly women. The purpose of this study was to investigate possible relationships between prolonged occupational work and 6-year changes in postural sway in elderly women.


METHODS
Subjects were 392 women aged ≥ 69 years who participated in a 6-year follow-up examination of the Muramatsu Cohort Study. Handgrip strength and postural sway, measured as gravity-center velocity (cm/s), were evaluated at baseline and 6-year follow-up. Interviews were conducted to determine the time spent on moderate occupational activity (3-5 metabolic equivalents) such as farm work. Activity levels were defined as: 1, no-activity; 2, 'short' (>0, ≤ 17.75 h/wk); and 3, 'long' ( ≥ 17.75 h/wk).


RESULTS
At baseline, mean values for age, handgrip strength, and postural sway were 73.3 years (SD 3.7), 20.3 kg (SD 4.1), and 2.0 cm/s (SD 0.8), respectively, and 32.5% of participants engaged in occupational activity. The change in postural sway was significantly greater in the long-activity group (median, 35.0 h/wk) than the no-activity group (0.56 vs. 0.27 cm/s, P=0.021).


CONCLUSIONS
Prolonged occupational work may be detrimental to the control of body balance. Accordingly, elderly individuals are not recommended to engage in prolonged occupational activity.
Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City 951-8510, Japan.
K
K
Nakamura
K
K
Kitamura
R
R
Oshiki
R
R
Kobayashi
T
T
Saito
T
T
Nishiwaki
D000368:Aged; D000383:Agriculture; D005260:Female; D005500:Follow-Up Studies; D018737:Hand Strength; D006801:Humans; D007564:Japan; D007899:Leisure Activities; D009784:Occupational Diseases; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*