title: Effects of short duration stretching on disuse muscle atrophy in immobilized rat soleus muscles.
abstract: The purpose of this study was to determine whether short duration stretching is ameliorating for disuse muscle atrophy in immobilized rat soleus muscles. Eighteen male Wistar rats (age, 8 weeks; weight, 311.0 ± 35.6 g) were divided randomly into control (n=3) and experimental (n=15) groups. Bilateral ankles of each rat in the experimental group were fixed in full planter flexion with a plaster cast. After the experimental groups rats were immobilized for 4 weeks, animals were divided into three groups: immobilization alone (group I, n=3), stretch training for 30 min/day for 1 or 3 weeks after remobilization (group S, n=6), and spontaneous recovery (non stretch training) for 1 or 3 weeks after remobilization (group NS, n=6). At the end of the experimental periods, the soleus muscle was extracted from hindlimb, and the frozen sections were stained with myofibrillar adenosine triphosphatase. After 1 week of remobilization, the means of the muscle fiber diameters for type I fibers in group S had increased significantly compared with group NS, but those for type II fibers in group S did not significantly differ from that for group NS. After 3 weeks of remobilization, the means of the muscle fiber diameters for types I and II fibers in group S had increased significantly compared with group NS. No difference in the fiber type distribution were observed between the experimental group. Our findings suggest that short duration stretching induces recovery from disuse muscle atrophy after joint fixation.
authors: School of Allied Medical Sciences, Nagasaki University, Nagasaki 852-8520, Japan.
authors: M
authors: M
authors: Okita
authors: School of Allied Medical Sciences, Nagasaki University, Nagasaki 852-8520, Japan.
authors: T
authors: T
authors: Yoshimura
authors: Department of Health Science, Graduate School of Medical Science, Hiroshima University, Hiroshima 734-8551, Japan.
authors: J
authors: J
authors: Nakano
authors: Nagasaki Yurino Hospital, Nagasaki 851-2103, Japan.
authors: A
authors: A
authors: Saeki
authors: Seiai Rehabilitation Hospital, Fukuoka 816-0955, Japan.
authors: A
authors: A
authors: Uehara
authors: Komonji Hospital, Fukuoka 802-0026, Japan.
authors: A
authors: A
authors: Mineshita
authors: The First Department of Internal Medicine, Nagasaki University School of Medicine, Nagasaki 852-8501, Japan.
authors: K
authors: K
authors: Eguchi
keywords: disuse muscle atrophy; immobilization; stretching