title: Healthy young and old women differ in their trunk elevation and hip pivot motions when rising from supine to sitting.
abstract: OBJECTIVE
  To describe the differences between healthy young and older women in regards to trunk elevation and hip pivot motions when rising from a supine to a seated position.
  
  
  METHODS
  Cross-sectional comparison.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  Two groups of healthy female volunteers: young adult female controls (n = 22, mean age 23.5 years) and community-dwelling older female adults (n = 17, mean age 73.8 years).
  
  
  METHODS
  Subjects were videotaped as they performed three controlled bed mobility tasks, starting from a supine position: (1) rising to a seated position at the edge of a firm plinth surface (SS); and rising to a seated position without moving to the edge of the bed while either (2) using hands (SUH) or (3) not using hands (SUNH). A series of movements involving the trunk were identified as subjects performed the SS task.
  
  
  RESULTS
  The older women were more likely to rotate and laterally flex their trunks, particularly in the later phases of the SS task. In addition, during the SS task, the older group was more likely to bear weight on their hip/gluteal area, particularly in the later phases, and more likely to use a broad pivot base, consisting of the hip and the elbow. While all young and old performed the SUH task, less than half of the older group could complete the SUNH task. Moreover, the subgroup of older adults who could not complete the SUNH task may have accounted for much of the differences between the young and the old on the SS task.
  
  
  CONCLUSIONS
  Healthy young and older women differ in their ability to rise from a supine to sitting position, primarily in the strategies used to elevate the trunk and facilitate a pivot. Trunk flexion ability likely contributes to the age group differences noted in rising. These data provide the basis for a biomechanical analysis of the critical body segment motions and the strengths required to perform bed mobility tasks.
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, USA.
authors.forename: N B
authors.initials: NB
authors.lastname: Alexander
authors.forename: D K
authors.initials: DK
authors.lastname: Fry-Welch
authors.forename: L M
authors.initials: LM
authors.lastname: Marshall
authors.forename: C C
authors.initials: CC
authors.lastname: Chung
authors.forename: A M
authors.initials: AM
authors.lastname: Kowalski
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D015577:Geriatric Assessment; D006615:Hip / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012399:Rotation; D016683:Supine Position; D013909:Thorax / Q000502:physiology*