Immobilization effects in young and older adults

Urso, Maria L.; Clarkson, Priscilla M.; Price, Thomas B.

doi:10.1007/s00421-005-0109-1

Cited by 52 publications

(49 citation statements)

References 18 publications

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“…Studies on immobilization and unloading have underlined the fact that skeletal muscle tissue responds quickly to unloading with a lowering of muscle strength by approximately 10-22% after 2 weeks (Alfredson et al 1998;Berg and Tesch 1996;Urso et al 2006), and that longer periods of unloading decrease the muscle strength and cross-sectional area (CSA) even further (Christensen et al 2008;Stevens et al 2006). In addition to the muscle strength, neuromuscular functions have also shown impairment by immobilization (Clark et al 2006).…”

Section: Introductionmentioning

confidence: 96%

The influence of training status on the drop in muscle strength after acute exercise

et al. 2009

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Skeletal muscles fatigue after exercise, and reductions in maximal force appear. A difference in training status between the legs was introduced by unilateral immobilization of the calf muscles for 2 weeks in young men, who were randomly assigned to two groups, either a RUN group (n = 8) that was exposed to prolonged exercise (1-h running: individual pace) or a REST group (n = 12) that did no exercise after immobilization. Cross-sectional area (CSA) of the triceps-surae muscles was calculated by magnetic resonance imaging (MRI), and maximal voluntary contraction (MVC) force of the plantar flexors was measured before and after immobilization and after the running protocol. The CSA of triceps-surae muscles decreased significantly with a 7% reduction in both groups. A significant drop in the MVC of the triceps-surae muscle (10%; P < 0.05) was observed in response to immobilization. When subjected to running exercise immediately after immobilization, the muscle strength of the triceps-surae muscles dropped even further, but just in the immobilized leg (41%; P < 0.05). The present study highlights the importance of determining the muscle endurance when evaluating the effect of immobilization on muscle parameters.

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Section: Introductionmentioning

confidence: 96%

The influence of training status on the drop in muscle strength after acute exercise

et al. 2009

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“…This is contrasted by the fact that the elderly population more often undergoes periods of immobilization and disuse, not only due to joint pain, but also due to a higher degree of comorbidity and hospitalization (32). Studies in healthy young adults have demonstrated that immobilization leads to rapid decreases in maximal muscle strength, muscle mass, and neural activation (4,19); however, recent studies indicate that skeletal muscle in aged animals and humans is more vulnerable to muscle unloading than that in young individuals (8,41). Furthermore, recent data from Yasuda et al (43) show that there might be a gender-specific response to unloading, as evidenced by a more pronounced decrease in specific strength in young women compared with young men after 14 days of unilateral limb immobilization.…”

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confidence: 99%

Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women: effects of unilateral long-term disuse due to hip-osteoarthritis

Suetta¹,

Aagaard²,

Magnusson³

et al. 2007

Journal of Applied Physiology

135

128

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Suetta C, Aagaard P, Magnusson SP, Andersen LL, Sipilä S, Rosted A, Jakobsen AK, Duus B, Kjaer M. Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women: effects of unilateral long-term disuse due to hip-osteoarthritis. J Appl Physiol 102: [942][943][944][945][946][947][948] 2007. First published November 22, 2006; doi:10.1152/japplphysiol.00067.2006.-Substantial evidence exists for the age-related decline in muscle strength and neural function, but the effect of long-term disuse in the elderly is largely unexplored. The present study examined the effect of unilateral long-term limb disuse on maximal voluntary quadriceps contraction (MVC), lean quadriceps muscle cross-sectional area (LCSA), contractile rate of force development (RFD, ⌬force/⌬time), impulse (͐force dt), muscle activation deficit (interpolated twitch technique), maximal neuromuscular activity [electromyogram (EMG)], and antagonist muscle coactivation in elderly men (M: 60 -86 yr; n ϭ 19) and women (W: 60 -86 yr; n ϭ 20) with unilateral chronic hip-osteoarthritis. Both sides were examined to compare the effect of long-term decreased activity on the affected (AF) leg with the unaffected (UN) side. AF had a significant lower MVC (W: 20%; M: 20%), LCSA (W: 8%; M: 10%), contractile RFD (W: 17-26%; M: 15-24%), impulse (W: 10 -19%, M: 19 -20%), maximal EMG amplitude (W: 22-25%, M: 22-28%), and an increased muscle activation deficit (Ϫ18%) compared with UN. Furthermore, women were less strong (AF: 40%; UN: 39%), had less muscle mass (AF: 33%; UN: 34%), and had a lower RFD (AF: 38 -50%; UN: 41-48%) compared with men. Similarly, maximum EMG amplitude was smaller for both agonists (AF: 51-63%; UN: 35-61%) and antagonist (AF: 49 -64%; UN: 36 -56%) muscles in women compared with men. However, when MVC and RFD were normalized to LCSA, there were no differences between genders. The present data demonstrate that disuse leads to a marked loss of muscle strength and muscle mass in elderly individuals. Furthermore, the data indicate that neuromuscular activation and contractile RFD are more affected by long-term disuse than maximal muscle strength, which may increase the future risk for falls.aging; rate of force development; neural activity; muscle activation IT IS WELL KNOWN FROM ANIMAL and human studies that a chronic reduction in neuromuscular activity results in marked muscle atrophy (4, 28), reduced muscle strength (2, 33), and diminished neural drive to muscle fibers (9). For people older than 45 yr of age, Ͼ33% suffer from joint pain, and osteoarthritis (OA) has been shown to be the most common cause of inactivity and long-term disability in people aged Ն65 yr (12). However, most of the current knowledge with respect to the effects of inactivity and immobilization on neuromuscular function is based on animal data (2, 8) or on studies performed on healthy young individuals (4, 28). This is contrasted by the fact that the elderly population more often undergoes periods of immobilization and disuse, not only due to join...

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“…Fleck e Kraemer (1997) relatam que ocorre um decréscimo nos valores de repouso dos hormônios anabólicos como testosterona, hormônio do crescimento e insulina, bem como a resposta destes ao treinamento de força. Em estudo comparando idosos e jovens, Urso et al (2006) observaram perda da massa muscular do adutor do polegar significativa somente em idosos quando submetidos à imobilização dessa musculatura, sendo que no mesmo estudo os autores puderam constatar redução da força muscular de forma semelhante nos dois grupos, atribuindo desta forma a compensação da atrofia aos fatores neurais. Somado a isso, o processo de perda de força tem sido atribuído em grande parte ao declínio de MM característico do envelhecimento.…”

Section: Discussionunclassified