Research

Low-volume muscular endurance and strength training during 3-week forearm immobilization was effective in preventing functional deterioration

Mika Matsumura^1,2 , Chihoko Ueda³ , Kiyoshi Shiroishi^1,4 , Kazuki Esaki¹ , Fumiko Ohmori⁵ , Kuniko Yamaguchi⁶ , Shiro Ichimura⁷ , Yuko Kurosawa⁸ , Ryotaro Kime¹ , Takuya Osada¹ , Norio Murase¹ , Toshihito Katsumura¹ , Akinori Hoshika² and Takafumi Hamaoka^1,5

¹Department of Sports Medicine for Health Promotion, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan

²Department of Pediatrics, Tokyo Medical University, 6-7-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan

³Research Institute of Physical Fitness, Japan Women's College of Physical Education, 8-19-1 Kita-Karasuyama, Setagaya-ku, Tokyo, 157-8565, Japan

⁴Department of Judotherapy and Sports Medicine, Faculty of Health Science, Ryotokuji University, 5-8-1 Akemi, Urayasu-City, Chiba, 279-8567, Japan

⁵Department of Sports Medicine and Science, National Institute of Fitness and Sports in Kanoya, Shiromizu-cho 1, Kanoya, Kagoshima, 891-2393, Japan

⁶Department of Food and Nutrition, Yamanashi Gakuin Junior College, 2-4-5 Sakaori, Kofu City, Yamanashi, 400-8575, Japan

⁷Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki Noda City, Chiba, 278-8510, Japan

⁸Department of Neurology, University of Cincinnati, 3125 Eden Ave, 2327 Vontz Center for Molecular Studies PO Box 670536 Cincinnati, OH, 45267-0536, USA

author email corresponding author email

Dynamic Medicine 2008, 7:1doi:10.1186/1476-5918-7-1

Published:	15 January 2008

Abstract

Purpose

The purpose of this study was to determine whether endurance and strength hand grip exercises during 3-week upper limb immobilization preserve muscle oxidative capacity, endurance performance and strength.

Methods

Ten healthy adult men underwent non-dominant forearm immobilization by plaster cast for 21 days. Five healthy adult subjects were designated as the immobilization (IMM) group and five were designated as the immobilization + training (IMM+TRN) group. Grip strength, forearm circumference, dynamic handgrip endurance and muscle oxygenation response were measured before and after the 21 day immobilization period. Using near-infrared spectroscopy (NIRS), muscle oxygen consumption recovery (VO₂mus) was recorded after a submaximal exercise and the recovery time constant (TcVO₂mus) was calculated. Reactive hyperemic oxygenation recovery was evaluated after 5 minutes ischemia. Two training programs were performed by the IMM+TRN group twice a week. One exercise involved a handgrip exercise at 30% maximum voluntary contraction (MVC) at a rate of 1 repetition per 1 second until exhaustion (about 60 seconds). The other involved a handgrip exercise at 70% MVC for 2 seconds with a 2 second rest interval, repeated 10 times (40 seconds).

Results

There was a significant group-by-time interaction between the IMM and IMM+TRN groups in the TcVO₂mus (p = 0.032, F = 6.711). A significant group-by-time interaction was observed between the IMM and IMM+TRN groups in the MVC (p = 0.001, F = 30.415) and in grip endurance (p = 0.014, F = 9.791). No significant group-by-time interaction was seen in forearm circumference and reactive hyperemic oxygenation response either in IMM or IMM+TRN group.

Conclusion

The training programs during immobilization period used in this experiment were effective in preventing a decline in muscle oxidative function, endurance and strength.