0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Letters |

Engineering Terms in Joint Disease

Roy E. Brackin, MD
JAMA. 1964;190(4):401. doi:10.1001/jama.1964.03070170142031.
Text Size: A A A
Published online

ABSTRACT

To the Editor:—  Pentecost, Murray, and Brindley are correct in their explanation of the mechanisms of "stress" fractures ("Fatigue, Insufficiency, and Pathologic Fractures," JAMA187:1001 [March 28] 1964).Engineering terms can also be used to describe subaudible musculoskeletal sound. The knee joint, while in passive motion, generates compound wave forms, as is shown when this acoustic energy is converted to electric energy and recorded. Under certain circumstances, the knee joint at rest generates a wave motion as a pure sinusoidal wave of simple harmonic motion of 28 or 29 cycles per second. These vibrations are recovered from normal knees as periodic vibrations of the menisci vibrating as a system. Under conditions of injury or disease of the menisci this sine wave is absent or distorted because the meniscus vibrates in parts. The natural frequencies of the menisci are 28 cps medially and 29 cps laterally. Their voltage output varies

Topics

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview

Figures

Tables

References

CME
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

1 Views
0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
×
brightcove.createExperiences();