PMID- 8808994
OWN - NLM
STAT- MEDLINE
DCOM- 19961024
LR  - 20220316
IS  - 1079-5006 (Print)
IS  - 1079-5006 (Linking)
VI  - 51
IP  - 5
DP  - 1996 Sep
TI  - Effects of age on rapid ankle torque development.
PG  - M226-32
AB  - BACKGROUND: When balance is disturbed, often only fractions of a second are 
      available in which to make the initial responses needed for its restoration. 
      Abilities to develop joint torques rapidly may be critical to such responses. We 
      undertook this study to quantify age effects among healthy adults in abilities to 
      develop ankle joint torques rapidly. METHODS: Ankle dorsiflexion (DF) and 
      plantarflexion (PF) torque development during rapid isometric and during 
      isokinetic (30, 60, 120, 180, and 240 deg/sec) exertions was assessed in 24 
      healthy young (mean age 23 years) and 24 healthy old adults (mean age 72 years). 
      The effects of age, gender, and torque direction on the times needed to reach 
      given torque magnitudes, maximum rates of isometric torque development (MRTD), 
      and maximum isokinetic torques were examined. RESULTS: The old adults required 
      substantially more time to reach given torque magnitudes than the young adults. 
      For example, the young and old females needed approximately 236 and 337 msec to 
      develop 15 Nm of DF torque, of which 141 and 164 msec were reaction times. 
      Isometric MRTD were 25 to 36% lower in the old than in the young adults. The age 
      declines in isometric torque development time were associated with losses in 
      maximum isometric strength. Maximum isokinetic torques developed by the old were 
      20 to 40% lower than those of young adults. The percent losses in isokinetic 
      torques with age were independent of joint angular velocity for PF, but increased 
      with velocity for DF. CONCLUSIONS: We found substantial age declines in abilities 
      of healthy old adults to rapidly develop ankle joint torques. The capacities of 
      even healthy old adults to recover balance or to carry out other time-critical 
      actions that require moderate-to-substantial strengths may be considerably 
      degraded by these declines.
FAU - Thelen, D G
AU  - Thelen DG
AD  - Department of Mechanical Engineering and Applied Mechanics, University of 
      Michigan, Ann Arbor, USA.
FAU - Schultz, A B
AU  - Schultz AB
FAU - Alexander, N B
AU  - Alexander NB
FAU - Ashton-Miller, J A
AU  - Ashton-Miller JA
LA  - eng
GR  - AG-06621/AG/NIA NIH HHS/United States
GR  - AG-08808/AG/NIA NIH HHS/United States
GR  - AG-10542/AG/NIA NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Gerontol A Biol Sci Med Sci
JT  - The journals of gerontology. Series A, Biological sciences and medical sciences
JID - 9502837
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Aging/*physiology
MH  - Ankle Joint/*physiology
MH  - Female
MH  - Humans
MH  - Male
MH  - Movement
MH  - Reaction Time
MH  - Reference Values
EDAT- 1996/09/01 00:00
MHDA- 1996/09/01 00:01
CRDT- 1996/09/01 00:00
PHST- 1996/09/01 00:00 [pubmed]
PHST- 1996/09/01 00:01 [medline]
PHST- 1996/09/01 00:00 [entrez]
AID - 10.1093/gerona/51a.5.m226 [doi]
PST - ppublish
SO  - J Gerontol A Biol Sci Med Sci. 1996 Sep;51(5):M226-32. doi: 
      10.1093/gerona/51a.5.m226.