title: Biomechanical gait alterations independent of speed in the healthy elderly: evidence for specific limiting impairments.
abstract: OBJECTIVE
  It is not known whether changes in the biomechanics of elderly gait are related to aging per se, or to reduced walking speed in this population. The goals of the present study were to identify specific biomechanical changes, independent of speed, that might impair gait performance in healthy older people by identifying age-associated changes in the biomechanics of gait, and to determine which of these changes persist at increased walking speed.
  
  
  METHODS
  Stereophotogrammetric and force platform data were collected. Differences in peak joint motion (kinematic) and joint moment and power (kinetic) values between healthy young and elderly subjects at comfortable and increased walking speed were measured.
  
  
  METHODS
  A gait laboratory.
  
  
  METHODS
  Thirty-one healthy elderly (age 65 to 84 years) and 31 healthy young adult subjects (age 18 to 36 years), all without known neurologic, musculoskeletal, cardiac, or pulmonary problems.
  
  
  METHODS
  All major peak kinematic and kinetic variables during the gait cycle.
  
  
  RESULTS
  Several kinematic and kinetic differences between young and elderly adults were found that did not persist when walking speed was increased. Differences that persisted at both comfortable and fast walking speeds were reduced peak hip extension, increased anterior pelvic tilt, and reduced ankle plantarflexion and ankle power generation.
  
  
  CONCLUSIONS
  Gait performance in the elderly may be limited by both subtle hip flexion contracture and ankle plantarflexor concentric weakness. Results of the current study should motivate future experimental trials of specific hip flexor stretching and ankle plantarflexor concentric strengthening exercises to preserve and potentially improve walking performance in the elderly.
authors.affiliation: Harvard Medical School Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Boston, MA 02114, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Kerrigan
authors.forename: M K
authors.initials: MK
authors.lastname: Todd
authors.forename: U
authors.initials: U
authors.lastname: Della Croce
authors.forename: L A
authors.initials: LA
authors.lastname: Lipsitz
authors.forename: J J
authors.initials: JJ
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male