View Full Version : Re: Summary of joint cracking

David Clarke
04-06-1997, 08:53 AM
Dear Biomch-l readers:

A short while ago, I posted a question inquiring about the cracking of
joints and what causes it. Thanks to all that replied!

Three publications were mentioned as good sources of information:

[1] "The audible release associated with joint manipulation". Journal
of Manipulative and Physiological Therapeutics. 18(3):155-64,
1995 Mar-Apr.

[2] Castellanos J., Axelrod D., "Effect of habitual knuckle cracking on
hand function". Ann Rheum Dis 1990; 49:308-309.

[3] Unsworth, Dowson, & Wright, 1971, "Cracking Joints: A Bioengineering
Study of Cavitation in the Metacarpophalangeal Joint," Ann. Rheum.
Dis., 30:348-358.

Reference [1] states that "The audible release is caused by a cavitation
process whereby a sudden decrease in intracapsular pressure causes
dissolved gasses in the synovial fluid to be released into the joint
cavity. Habitual joint cracking does not correlate with arthritic
changes. The cavitation process is generated by an elastic recoil of the
synovial capsule as it "snaps back" from the capsule/synovial fluid

Simply put, cavitation causes the sound and it won't give me arthritis.

One response stated that the cracking of a joint can cause short term
relief, but that after a short while (hours, days, weeks), the previous
symptoms reappear. This can lead to an "addiction" of joint cracking and
is probably the reason why I crack my knees and fingers so much.

Once again, thanks to all that responded. You've been most helpful.

David Clarke
Engineering Student
Memorial University of Newfoundland
St. John's, NF