TY - JOUR
T1 - On the relevance of residual force enhancement for everyday human movement
AU - Seiberl, Wolfgang
AU - Paternoster, Florian
AU - Achatz, Florian
AU - Schwirtz, Ansgar
AU - Hahn, Daniel
PY - 2013/8/9
Y1 - 2013/8/9
N2 - Although residual force enhancement (RFE), i.e. enhanced force after active muscle stretch, is shown to be present in voluntarily activated human muscles, its relevance for everyday human movement is still elusive. Natural human motion is mainly composed of voluntarily submaximally activated muscle contractions driving coordinated multi-joint movements. Up to now there has been no study that directly investigated the presence of RFE following stretch when performing a submaximal multi-joint movement. For this purpose, n=13 subjects performed feedback controlled bilateral leg extensions at the level of 30% maximum voluntary activation in a motor-driven leg press dynamometer. Isometric-eccentric-isometric and purely isometric contractions were arranged in a randomized experimental protocol. Kinematics, forces and muscular activity were measured using optical motion tracking, 3d force plates and EMG of 9 lower extremity muscles. ANOVA identified significant RFE of external reaction force, and knee extension and plantar flexion torque (calculated by inverse dynamics). Enhanced force and torque ranged between 3% and 22% and was present for up to 22. s post-stretch. In spite of motor redundancy for solving a given task, no differences between contraction conditions were observed for any of the analyzed muscles, except for tibialis anterior. On the basis of our results, RFE is present in everyday alike human movement and might be an evolutionary optimization mechanism to enhance muscular performance at a given amount of energetic effort.
AB - Although residual force enhancement (RFE), i.e. enhanced force after active muscle stretch, is shown to be present in voluntarily activated human muscles, its relevance for everyday human movement is still elusive. Natural human motion is mainly composed of voluntarily submaximally activated muscle contractions driving coordinated multi-joint movements. Up to now there has been no study that directly investigated the presence of RFE following stretch when performing a submaximal multi-joint movement. For this purpose, n=13 subjects performed feedback controlled bilateral leg extensions at the level of 30% maximum voluntary activation in a motor-driven leg press dynamometer. Isometric-eccentric-isometric and purely isometric contractions were arranged in a randomized experimental protocol. Kinematics, forces and muscular activity were measured using optical motion tracking, 3d force plates and EMG of 9 lower extremity muscles. ANOVA identified significant RFE of external reaction force, and knee extension and plantar flexion torque (calculated by inverse dynamics). Enhanced force and torque ranged between 3% and 22% and was present for up to 22. s post-stretch. In spite of motor redundancy for solving a given task, no differences between contraction conditions were observed for any of the analyzed muscles, except for tibialis anterior. On the basis of our results, RFE is present in everyday alike human movement and might be an evolutionary optimization mechanism to enhance muscular performance at a given amount of energetic effort.
KW - EMG
KW - Energetic effort
KW - Feedback control
KW - Inverse dynamics
KW - Motor redundancy
KW - Multi-joint
KW - Muscle contraction
KW - Submaximal muscle action
UR - http://www.scopus.com/inward/record.url?scp=84880698388&partnerID=8YFLogxK
U2 - 10.1016/j.jbiomech.2013.06.014
DO - 10.1016/j.jbiomech.2013.06.014
M3 - Article
C2 - 23845729
AN - SCOPUS:84880698388
SN - 0021-9290
VL - 46
SP - 1996
EP - 2001
JO - Journal of Biomechanics
JF - Journal of Biomechanics
IS - 12
ER -