title: Walking-Induced Fatigue Leads to Increased Falls Risk in Older Adults.
abstract: For older adults, falls are a serious health problem, with more than 30% of people older than 65 suffering a fall at least once a year. One element often overlooked in the assessment of falls is whether a person's balance, walking ability, and overall falls risk is affected by performing activities of daily living such as walking.
  
  
  
  This study assessed the immediate impact of incline walking at a moderate pace on falls risk, leg strength, reaction time, gait, and balance in 75 healthy adults from 30 to 79 years of age. Subjects were subdivided into 5 equal groups based on their age (group 1, 30-39 years; group 2, 40-49 years; group 3, 50-59 years; group 4, 60-69 years; group 5, 70-79 years).
  
  
  
  Each person's falls risk (using the Physiological Profile Assessment), simple reaction time, leg strength, walking ability, and standing balance were assessed before and after a period of incline walking on an automated treadmill. The walking task consisted of three 5-minute trials at a faster than preferred pace. Fatigue during walking was elicited by increasing the treadmill incline in increments of 2° (from level) every minute to a maximum of 8°.
  
  
  
  As predicted, significant age-related differences were observed before the walking activity. In general, increasing age was associated with declines in gait speed, lower limb strength, slower reaction times, and increases in overall falls risk. Following the treadmill task, older adults exhibited increased sway (path length 60-69 years; 10.2 ± 0.7 to 12.1 ± 0.7 cm: 70-79 years; 12.8 ± 1.1 to 15.1 ± 0.8 cm), slower reaction times (70-79 years; 256 ± 6 to 287 ± 8 ms), and declines in lower limb strength (60-69 years; 36 ± 2 to 31 ± 1 kg: 70-79 years; 32.3 ± 2 to 27 ± 1 kg). However, a significant increase in overall falls risk (pre; 0.51 ± 0.17: post; 1.01 ± 0.18) was only seen in the oldest group (70-79 years). For all other persons (30-69 years), changes resulting from the treadmill-walking task did not lead to a significant increase in falls risk.
  
  
  
  As most falls occur when an individual is moving and/or fatigued, assessing functional properties related to balance, gait, strength, and falls risk in older adults both at rest and following activity may provide additional insight.
authors.affiliation: School of Physical Therapy and Athletic Training, Old Dominion University, Norfolk, VA. Electronic address: smorriso@odu.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Morrison
authors.affiliation: Human Movement Sciences Department, Old Dominion University, Norfolk, VA.
authors.forename: Sheri R
authors.initials: SR
authors.lastname: Colberg
authors.affiliation: Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Henri K
authors.initials: HK
authors.lastname: Parson
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Serina
authors.initials: S
authors.lastname: Neumann
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Richard
authors.initials: R
authors.lastname: Handel
authors.affiliation: Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Etta J
authors.initials: EJ
authors.lastname: Vinik
authors.affiliation: Psychology Sciences Department, Old Dominion University, Norfolk, VA.
authors.forename: James
authors.initials: J
authors.lastname: Paulson
authors.affiliation: Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Arthur I
authors.initials: AI
authors.lastname: Vinik
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D005080:Exercise Test; D005221:Fatigue; D006801:Humans; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology; D011930:Reaction Time; D018570:Risk Assessment; D016138:Walking / Q000502:physiology*
keywords: Fatigue; age; balance; falls; gait
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