PMID- 2055867
OWN - NLM
STAT- MEDLINE
DCOM- 19910801
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 70
IP  - 4
DP  - 1991 Apr
TI  - Effects of lower limb unloading on skeletal muscle mass and function in humans.
PG  - 1882-5
AB  - A model to simulate effects of microgravity on skeletal muscle mass and function 
      in humans has been developed. Unilateral lower limb unloading that allowed ankle, 
      knee, and hip joint mobility was conducted in six healthy men by suspending one 
      lower limb and having the subjects walk on crutches. They performed maximal 
      unilateral concentric or eccentric quadriceps actions at different angular 
      velocities before and after 4 wk of suspension and after 4 days and after 7 wk of 
      uncontrolled recovery. Peak torque (PT) and angle-specific torque (AST) were 
      measured. Muscle cross-sectional area (CSA) and radiological density (RD) of the 
      thigh were assessed by means of computerized tomography. Concentric and eccentric 
      PT and AST across speeds decreased (P less than 0.05) by 22 and 16%, 
      respectively, in response to unloading. At 4 days of recovery PT (-11%) and AST 
      (-7%) were still lower (P less than 0.05) than before. Muscle CSA and RD 
      decreased (P less than 0.05) by 7 and 6%, respectively. After 7 wk of recovery 
      PT, AST, CSA, and RD had returned to normal. The control limb showed no changes 
      over the experimental period except for a 6% decrease (P less than 0.05) in RD. 
      It is suggested that this human model of unloading could serve to simulate 
      effects of microgravity on skeletal muscle mass and function because reductions 
      in muscle mass and strength were of similar magnitude to those produced by bed 
      rest.
FAU - Berg, H E
AU  - Berg HE
AD  - Department of Physiology, Karolinska Institute, Stockholm, Sweden.
FAU - Dudley, G A
AU  - Dudley GA
FAU - Haggmark, T
AU  - Haggmark T
FAU - Ohlsen, H
AU  - Ohlsen H
FAU - Tesch, P A
AU  - Tesch PA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
SB  - IM
MH  - Adult
MH  - Bed Rest/adverse effects
MH  - Humans
MH  - Immobilization/*adverse effects/physiology
MH  - Male
MH  - Models, Biological
MH  - Muscles/*pathology/physiopathology
MH  - Muscular Atrophy/*etiology/pathology/physiopathology
MH  - Weightlessness/*adverse effects
OID - NASA: 91276908
OTO - NASA
OT  - NASA Center KSC
OT  - NASA Discipline Musculoskeletal
FIR - Dudley, G A
IR  - Dudley GA
IRAD- KSC
EDAT- 1991/04/01 00:00
MHDA- 1991/04/01 00:01
CRDT- 1991/04/01 00:00
PHST- 1991/04/01 00:00 [pubmed]
PHST- 1991/04/01 00:01 [medline]
PHST- 1991/04/01 00:00 [entrez]
AID - 10.1152/jappl.1991.70.4.1882 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1991 Apr;70(4):1882-5. doi: 10.1152/jappl.1991.70.4.1882.