TY - JOUR
T1 - Effort perception during isotonic muscle contractions with superimposed mechanical vibratory stimulation
AU - Liebermann, D. G.
AU - Issurin, V.
PY - 1997
Y1 - 1997
N2 - Forty-one athletes of different expertise levels (Olympic, national, junior and amateurs) evaluated their effort perception immediately after lifting a load (60%, 70%, 90% and 100% of 1RM) during a conventional isotonic contraction (C) and during an isotonic contraction with a superimposed vibratory stimulation (VS) (3 mm nominal amplitude at origin, 0.6 mm at end point, 44 Hz), in random order. We intended to confirm previously reported increases in the load lifted using VS (Issurin, et al., 1994), and to explore whether this effect may be explained exclusively by perceptual factors. We also hypothesized that any VS effect may be related to expertise levels. The results showed a main effect of VS on the maximum lifted weight, confirming previous results. This effect seemed to depend on expertise. All groups presented a gain relative to their mean maximum. This general effect was accompanied by a lower perception of effort during the VS condition which may partially explain the VS force enhancement. Olympic level athletes benefit most (10.5 kg or 8.3% mean gain) and also perceived VS isotonic contractions as being easier than conventional ones (although not significantly different than other groups). VS enhanced performance in the younger subjects (junior high-level athletes), however, their effort perception scores were no different in VS or C conditions. In conclusion, mechanically induced vibrations improved isotonic maximal contractions in adult subjects of different expertise levels. This might also be attributed to cognitive factors (less effort perceived), rather than exclusively to physiological ones. It is worth noting, however, that juniors improved their 1RM, but their effort perception on average showed no differences between conditions. This group might have failed to translate their perception into an objective scale. Eventually, factors such as age and years of experience may be involved. These should be further explored.
AB - Forty-one athletes of different expertise levels (Olympic, national, junior and amateurs) evaluated their effort perception immediately after lifting a load (60%, 70%, 90% and 100% of 1RM) during a conventional isotonic contraction (C) and during an isotonic contraction with a superimposed vibratory stimulation (VS) (3 mm nominal amplitude at origin, 0.6 mm at end point, 44 Hz), in random order. We intended to confirm previously reported increases in the load lifted using VS (Issurin, et al., 1994), and to explore whether this effect may be explained exclusively by perceptual factors. We also hypothesized that any VS effect may be related to expertise levels. The results showed a main effect of VS on the maximum lifted weight, confirming previous results. This effect seemed to depend on expertise. All groups presented a gain relative to their mean maximum. This general effect was accompanied by a lower perception of effort during the VS condition which may partially explain the VS force enhancement. Olympic level athletes benefit most (10.5 kg or 8.3% mean gain) and also perceived VS isotonic contractions as being easier than conventional ones (although not significantly different than other groups). VS enhanced performance in the younger subjects (junior high-level athletes), however, their effort perception scores were no different in VS or C conditions. In conclusion, mechanically induced vibrations improved isotonic maximal contractions in adult subjects of different expertise levels. This might also be attributed to cognitive factors (less effort perceived), rather than exclusively to physiological ones. It is worth noting, however, that juniors improved their 1RM, but their effort perception on average showed no differences between conditions. This group might have failed to translate their perception into an objective scale. Eventually, factors such as age and years of experience may be involved. These should be further explored.
KW - Effort perception
KW - Muscle force
KW - Vibration
UR - http://www.scopus.com/inward/record.url?scp=21944439544&partnerID=8YFLogxK
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AN - SCOPUS:21944439544
SN - 0306-7297
VL - 32
SP - 171
EP - 186
JO - Journal of Human Movement Studies
JF - Journal of Human Movement Studies
IS - 4
ER -