title: Age-related reduction and independent predictors of toe flexor strength in middle-aged men.
abstract: BACKGROUND
  Toe flexor muscles play an important role in posture and locomotion, and poor toe flexor strength is a risk factor for falls. In this cross-sectional study, we estimated the age-related change in toe flexor strength and compared it with that of handgrip strength. Independent factors predicting toe flexor and handgrip strength were also determined.
  
  
  METHODS
  A total of 1401 male (aged 35-59 years) study participants were divided into five groups according to their chronological age; 35-39, 40-44, 45-49, 50-54, and 55-59 years. Toe flexor and handgrip strength, anthropometry, and resting blood pressure were measured. Fasting blood samples were collected to measure blood glucose, triglycerides, high- and low-density lipoprotein-cholesterols, and albumin. A self-administered lifestyle questionnaire was conducted.
  
  
  RESULTS
  Decline in absolute toe flexor and handgrip strength began in the age groups 50-55 and 55-59 years, respectively. In comparison to the mean values of the youngest group, relative toe flexor strength (87.0 ± 26.6%) was significantly lower than handgrip strength (94.4 ± 13.1%) for the oldest group. Multiple regression analyses showed that independent factors predicting both toe flexor and handgrip strength were lean body mass, age, serum albumin, drinking habit, and fat mass. Additionally, fasting blood glucose, diastolic blood pressure, sleeping time and exercise habit were predicting factors of toe flexor strength but not of handgrip strength.
  
  
  CONCLUSIONS
  Age-related reduction in toe flexor strength was earlier and greater than handgrip strength, and toe flexor strength reflects body composition and metabolic status.
authors.affiliation: Health Support Center WELPO, Toyota Motor Corporation, 1-1, Ipponmatsu, Iwakura-cho, Toyota, Aichi 444-2225 Japan.
authors.forename: Masataka
authors.identifier: 0000-0002-1169-5448
authors.initials: M
authors.lastname: Suwa
authors.affiliation: Health Support Center WELPO, Toyota Motor Corporation, 1-1, Ipponmatsu, Iwakura-cho, Toyota, Aichi 444-2225 Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Imoto
authors.affiliation: Health Support Center WELPO, Toyota Motor Corporation, 1-1, Ipponmatsu, Iwakura-cho, Toyota, Aichi 444-2225 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kida
authors.affiliation: Toyota Memorial Hospital, 1-1, Heiwa-cho, Toyota, Aichi 471-8513 Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Iwase
authors.affiliation: Health Support Center WELPO, Toyota Motor Corporation, 1-1, Ipponmatsu, Iwakura-cho, Toyota, Aichi 444-2225 Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokochi
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D000886:Anthropometry; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014034:Toes / Q000502:physiology*
keywords: Aging; Blood pressure; Handgrip; Hyperglycemia; Skeletal muscle; Toe flexion