Different frequency treadmill running in immobilization‐induced muscle atrophy and ankle joint contracture of rats

Abstract

We investigated the effects of different frequencies of treadmill running on immobilization-induced soleus and gastrocnemius muscle atrophy and ankle joint contracture in rats using morphology and histochemistry. The right ankle joint of rat was immobilized for 2 weeks. Thereafter, the rats were randomly assigned to four groups for 6 weeks of exercise under different conditions: free cage activity and free remobilization (FR), once-a-week treadmill running (lowfrequency running program (LFR)), three-time-a-week running (middle-frequency running program (MFR)), and six-time-a-week running (high-frequency running program (HFR)) groups. Two weeks of immobilization significantly reduced the cross-sectional area of soleus type I (62%, Po0.05) and type II muscle fibers (66%, Po0.05), gastrocnemius type I (78%, Po0.05) and type II muscle fibers (68%, Po0.05), and the range of ankle joint movement (46%, Po0.05). Immobilization also increased the ratio of type II to total fiber numbers in the soleus (Po0.05), and gastrocnemius (Po0.05), and induced pathological changes in muscle fibers. Some of these changes could not be corrected by free remobilization; however, the LFR, MFR, and HFR groups clearly recovered toward normal levels with exercise frequency, the effect on muscle recovery being more beneficial in the MFR and HFR groups. In addition, the range of ankle joint contracture was improved in LFR, MFR, and HFR groups in comparison with that in the FR group. These findings indicate that treadmill running exercise improved the immobilization-induced muscle fiber histochemical alterations and the range of the ankle motion in rats. Running three times and six times a week was more beneficial for recovery of immobilization-induced muscle atrophy and joint contracture compared with no running or once-a-week running.

Avaliação de parâmetros histomorfométricos em sóleos de ratos submetidos à remobilização por salto em meio aquático

“…So, we may state that this study reinforces research findings on muscular tissue recovery after immobilization as Kannus et al 25 who observed that high intensity exercises as walking on treadmill caused beneficial effects on recovery of fiber cross-sectional area of soleus muscle in rats. Sakakima et al 26 also observed that three-week immobilization period and a six-week remobilization period on a treadmill the effects on recovery of fiber cross-sectional area of soleus muscle were enhanced compared to free remobilization. According to Brito et al 27 100 samples of muscle fibers are enough to evaluate properly the medium trophism.…”

Controlling dispersion of axonal regeneration using a multichannel collagen nerve conduit

“…In the second experimental group, for the study of simultaneous retrograde tracing, ankle motion analysis and CMAP recording, 24 rats were randomly assigned to four subgroups: autograft, 1-, 2-and 4-channel conduits. In this latter group, treadmill training (running speed 15m/min, duration 10 minutes [22][23][24]) was performed, one week post operation, and then four times per week for eight weeks in total to prevent formation of contractures.…”

Lower leg muscle atrophy in ankle osteoarthritis

“…2,3 The development of OA is associated with secondary muscular pathologies such as atrophy and weakness. [4][5][6][7][8] Joint immobilization, or restriction of range of motion, is one of the factors causing muscle atrophy, [9][10][11] however, it is likely not the only factor. As early as 1929, Harding 12 described muscle wasting in cats caused by arthritis, which could not be explained simply by immobilization.…”