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The following is a list of some published studies
proving the
connection between ligament atrophy and limb immobilization.
In other words, these scientific studies show that if
you prevent an arm or a leg from moving and force it to
be in total rest for a long time, then the ligaments in
it grow weak and thin. There is no reason to
believe that the same wouldn't happen to breast tissue
when it is forced to 'sit still' in bras without any
movement, and that would explain why bras would actually
cause your breasts to sag more.
Enzymatic adaptation in ligaments during immobilization.
by: Gamble JG, Edwards CC, Max SR. Am J Sports Med. 1984 May-Jun;12(3):221-8.
"Like muscle and bone, ligaments are dynamic, undergoing hypertrophy with exercise and atrophy with immobilization. This paper reviews the structure and composition of ligaments and discusses the cellular events responsible for atrophy of ligaments with immobilization. As an experimental model, one knee of New Zealand White rabbits was immobilized with a pin. ... The cells switch from an anabolic synthetic state to a catabolic, degradative state during immobility."
Inframammary crease ligament.
Bayati S, Seckel BR. Plast Reconstr Surg. 1995 Mar;95(3):501-8.
"This study was designed to clarify and define the anatomic components of the inframammary crease in the female breast. ... The horizontal position of this ligament determines the medial versus lateral fall of the ptotic breast."
Differential metabolic responses of periarticular ligaments and tendon to joint immobilization
Harwood FL, Amiel D. J Appl Physiol. 1992 May;72(5):1687-91.
"After 12 weeks (of immobilization), all three tissues
experienced significant losses of collagen mass, which resulted in
tissue atrophy. ...
These results taken together have demonstrated that the ligamentous tissues are more susceptible to the effects of stress deprivation secondary to joint immobilization than the PT (patellar tendon)."
Effects of immobilization on joints
Akeson WH, Amiel D, Abel MF, Garfin SR, Woo SL. Clin Orthop. 1987 Jun;(219):28-37. "Stress deprivation alters the morphologic, biochemical
and biomechanical characteristics of various components of synovial
joints. ... Reduced load-to-failure and reduced energy-absorbing capacity of the bone-ligament complex progresses to about one-third that of controls."
Weakening of ligament insertion sites and disorganization of cellular and
fibrallar ligament alignment were found. Collagen decreased 10%;
atrophy of cartilage was seen.
Stress deprivation effect on metabolic turnover of the medial collateral ligament collagen. A comparison between nine- and 12-week immobilization.
Amiel D, Akeson WH, Harwood FL, Frank CB. Clin Orthop. 1983 Jan-Feb;(172):265-70.
"Immobilization causes atrophy with reduction of collagen mass and increased collagen degradation. The matrix composition, as reflected by collagen turnover, changed dramatically as the period of immobilization was increased from 9 to 12 weeks. A large decrease in total collagen mass (-27%) is observed at the end of 12 weeks.
Exponential degradation has occurred as immobilization has continued, and ligament
regenerative capacity apparently has failed."
Isotopic evidence for resorption of soft tissues and bone in immobilized dogs.
Klein L, Player JS, Heiple KG, Bahniuk E, Goldberg VM. J Bone Joint Surg Am. 1982 Feb;64(2):225-30.
"We have demonstrated significant atrophy of soft tissue (lateral meniscus and ant. curc. ligament) as well as of bone in immobilized joints of dogs."
Prevention of ligament and meniscus atrophy by active joint motion in a non-weight-bearing model
Klein L, Heiple KG, Torzilli PA, Goldberg VM, Burstein AH. J Orthop Res. 1989;7(1):80-5.
"This study describes the effect of active joint motion on the maintenance of ligament and meniscus mass in a non-weight-bearing model of disuse. ... The absence of weight bearing for 8 weeks resulted in marked bone atrophy without resorption or atrophy of soft tissues." In other words, in dogs, this model showed bone loss, but the active joint motion protected ligaments and tendons.
[Immobilization damage]
Diekstall P, Schulze W, Noack W. Sportverletz Sportschaden. 1995 Jun;9(2):35-43.
"Prolonged immobilization can threaten the surgical results.
The reduction in muscle diameter is reported to be 10 to 60 %
after 4 weeks of immobilization depending on the different muscle groups. The result of immobilization is shortening of all fibrous tissues.
The loss of ligament-specific orientation of fibrils leads to
significant reduction in tensile strength."
007 Breasts wants to thank Ralph L. Reed for providing the references.
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