Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women: Effects of unilateral long-term disuse due to hip-osteoarthritis
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Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women : Effects of unilateral long-term disuse due to hip-osteoarthritis. / Suetta, C.; Aagaard, P.; Magnusson, S. P.; Andersen, L. L.; Sipilä, S.; Rosted, A.; Jakobsen, A. K.; Duus, B.; Kjaer, M.
In: Journal of Applied Physiology, Vol. 102, No. 3, 03.2007, p. 942-948.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women
T2 - Effects of unilateral long-term disuse due to hip-osteoarthritis
AU - Suetta, C.
AU - Aagaard, P.
AU - Magnusson, S. P.
AU - Andersen, L. L.
AU - Sipilä, S.
AU - Rosted, A.
AU - Jakobsen, A. K.
AU - Duus, B.
AU - Kjaer, M.
PY - 2007/3
Y1 - 2007/3
N2 - 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, Δforce/Δtime), 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 = 19) and women (W: 60-86 yr; n = 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 (-18%) 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.
AB - 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, Δforce/Δtime), 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 = 19) and women (W: 60-86 yr; n = 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 (-18%) 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.
KW - Aging
KW - Muscle activation
KW - Neural activity
KW - Rate of force development
UR - http://www.scopus.com/inward/record.url?scp=33847712518&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00067.2006
DO - 10.1152/japplphysiol.00067.2006
M3 - Journal article
C2 - 17122381
AN - SCOPUS:33847712518
VL - 102
SP - 942
EP - 948
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 3
ER -
ID: 388031302