Linked Life Data

7216678

Source:http://linkedlifedata.com/resource/pubmed/id/7216678

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1981-6-23
pubmed:abstractText
Actively developed horizontal muscle forces and tissue stiffnesses were measured in 29 normal orthophoric volunteer subjects (18 to 33 years old) by means of noninvasive length-tension forceps. Mean active fixation force developed at 50 deg extreme gaze was 26% greater for the medial rectus (74.8 gm) than for the lateral rectus (59.1 gm). The variation of maximum active force among individuals was 2:1 (48 to 103 gm). These muscles developed up to 25% of their maximum active force out of their field of action. Active (counter) hysteresis force differences of over 10 gm were measured between nasal and temporal gaze directions. This study suggests that a muscle which develops a maximum active force of less than 45 gm would be suspect as paretic. Variations from the normal pattern of reciprocal innervation, reflected in the graded active force of individual muscle contraction, may help in understanding some types of oculomotor pathology. The mean tissue stiffness-restraining movement of the globe in the nasal direction (1.05 gm/deg) is 11% greater than in the temporal direction (0.94 gm/deg). This is consistent with a stronger medial rectus balanced by a greater load. Variation of stiffness of 2:1 was observed among individuals; 0.8 to 1.7 gm/deg pulling nasally and 0.77 to 1.2 gm/deg temporally. Passive hysteresis and viscous force differences of over 10 gm were observed between the passive forced pull and normal spring-return of the eye. Large stiffnesses may be normal if balanced by large active forces. Abrupt changes of the length-tension curve indicate the magnitude and location of restrictions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0146-0404
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
652-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Extraocular muscle forces in normal human subjects.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.