This Article
Right arrow Full Text (PDF)
Right arrow Letters to the Editor: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when Letters to the Editor are posted
Right arrow Alert me if a correction is posted
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrowReprints and Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gebhard, J. S.
Right arrow Articles by Meals, R. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gebhard, J. S.
Right arrow Articles by Meals, R. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Technorati  
What's this?

The Journal of Bone and Joint Surgery, Vol 75, Issue 11 1636-1647, Copyright © 1993 by Journal of Bone and Joint Surgery, Inc

JOURNAL CONTENTS

Passive motion: the dose effects on joint stiffness, muscle mass, bone density, and regional swelling. A study in an experimental model following intra-articular injury

JS Gebhard, JM Kabo and RA Meals
Wadsworth Veterans Administration Medical Center, Los Angeles, California.

We studied the effects of passive motion on joint stiffness, muscle mass, bone density, and regional swelling after an intra-articular injury. Instrumentation was applied to the hindlimbs of thirty adolescent New Zealand White rabbits to allow either passive motion or immobilization of the ankle. The knee was immobilized by the locking together of Steinmann pins that had been placed within the medullary canals of the tibia and femur. An intra-articular injury was produced by drilling of the tibial pin through the ankle joint into the talus and subsequent withdrawal of the pin from the ankle joint. The rabbits were divided into five groups, and they received four, eight, twelve, sixteen, or twenty-four hours of passive motion each day during the three-week period of study. One ankle of each rabbit was moved through an arc of 90 to 170 degrees of dorsiflexion at one cycle per minute, while the contralateral ankle was immobilized in 100 degrees of dorsiflexion with an aluminum splint, which was fixed to the aluminum block that was used to stabilize the knee joint. We found that sixteen and twenty-four hours of passive motion prevented stiffness of the joint. Passive motion for shorter periods was ineffective, even harmful, and resulted in stiffness ratios that were as much as four times higher than those of the control limbs (those treated with immobilization). Swelling of the limb decreased only in the group that received twenty-four hours of passive motion. Muscle mass increased by an average of 13 per cent (range, 4 to 34 per cent), in comparison with that of the immobilized limbs in every group that was treated with passive motion. Bone density was maintained only in the limbs in which the ankle became stiff (ankles that had been treated with passive motion for twelve hours or less). An inverse relationship was noted between the duration of passive motion and the radiographic density of the distal tibial metaphysis; this relationship was statistically significant (p < 0.01). The limbs treated for twelve, eight, or four hours each day showed progressively greater bone density in comparison with those treated with immobilization or with sixteen or twenty-four hours of passive motion.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Technorati Technorati    What's this?