Abstract
Electrical stimulation has been used to prevent muscle atrophy, but this method is different in many previous studies, appropriate stimulation protocol is still not decided. Although resistance exercise has also been shown to be an effective countermeasure on muscle atrophy, almost previous studies carried out an electrical stimulation without resistance. It was hypothesized that electrical stimulation without resistance is insufficient to contract skeletal muscle forcefully, and the combination of electrical stimulation and forceful resistance contraction is more effective than electrical stimulation without resistance to attenuate muscle atrophy. This study investigated the combined effects of electrical stimulation and resistance isometric contraction on muscle atrophy in the rat tibialis anterior muscle. The animals were divided into control, hindlimb unloading (HU), hindlimb unloading plus electrical stimulation (ES), and hindlimb unloading plus the combination of electrical stimulation and resistance isometric contraction (ES+IC). Electrical stimulation was applied to the tibialis anterior muscle percutaneously for total 240 sec per day. In the ES+IC group, the ankle joint was fixed to produce resistance isometric contraction during electrical stimulation. After 7 days, the cross-sectional areas of each muscle fiber type in the HU group decreased. Those were prevented in the ES+IC group rather than the ES group. The expression of heat shock protein 72 was enhanced in the ES and ES+IC groups. These results indicated that although electrical stimulation is effective to prevent muscle atrophy, the combination of electrical stimulation and isometric contraction have further effect.
Highlights
Skeletal muscle atrophy results from variety conditions, including unloading [, ], joint immobilization [, ], denervation [ - ], and spinal cord injury [ - ]
The novel findings of the present study include the combination of electrical stimulation and forceful isometric contraction sufficiently prevented a decrease of the muscle mass in unloading muscle, and the cross-sectional areas in all fiber types were maintained at Cont levels in the electrical stimulation plus forceful isometric contraction group
An isotonic contraction was occurred in the tibialis anterior muscles by electrical stimulation in the ES group, whereas resistance isometric contraction was occurred by joint fixation in the electrical stimulation and resistance isometric contraction (ES+IC) group
Summary
Skeletal muscle atrophy results from variety conditions, including unloading [ , ], joint immobilization [ , ], denervation [ - ], and spinal cord injury [ - ]. Whereas other studies have indicated that electrical stimulation could not prevent muscle atrophy [ , ]. Some studies have reported that the effect of electrical stimulation on muscle atrophy was influenced by stimulation intensity [ ] and frequency [ , ], chronaxie [ ], number of contraction [ , ], number of therapeutic session in a day [ ], types of contraction [ ], and electrode differences between surface [ , , ] and implantation [ - , , , , ]. Resistance exercise has been shown to be an effective countermeasure on muscle atrophy [ , ]. Some studies showed the preventive effect on muscle atrophy [ , ] in response to resistance exercise. We hypothesized that the combination of electrical stimulation and forceful resistance contraction is more effective than electrical stimulation without resistance to prevent muscle atrophy. For the prevention of skeletal muscle atrophy, it has been demonstrated that heat shock protein (HSP) is associated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
