TY - JOUR
T1 - The force-length curves of the human rectus femoris and gastrocnemius muscles in vivo.
AU - Winter, Samantha. L.
AU - Challis, John H.
N1 - This work is the third of a series of three and compares the section of the force-length curve used by 28 individual subjects for both the rectus femoris and the gastrocnemius in the same individuals. These muscles have very different ratios of tendon slack length to muscle fibre optimum length. The study tested the hypothesis for the first time that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method validated in the previous paper by the same authors. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. This finding has implications for the modelling of muscle and for motor control and the rehabilitation and training of muscle.
PY - 2010/2
Y1 - 2010/2
N2 - For a physiologically realistic joint range of motion and therefore range of muscle fiber lengths, only part of the whole muscle force-length curve can be used in vivo; that is, only a section of the force-length curve is expressed. Previous work has determined that the expressed section of the force-length curve for individual muscles can vary between subjects; however, the degree of intersubject variability is different for different muscles. This study determined the expressed section of both the rectus femoris and gastrocnemius—muscles with very different ratios of tendon slack length to muscle fiber optimum length—for 28 nonspecifically trained subjects to test the hypothesis that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method of Herzog & ter Keurs (1988). There was no relationship between the expressed sections of the force-length curve for the two muscles. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. The lack of relationship between the expressed sections of the two muscles has implications for motor control and for training muscle for rehabilitation.
AB - For a physiologically realistic joint range of motion and therefore range of muscle fiber lengths, only part of the whole muscle force-length curve can be used in vivo; that is, only a section of the force-length curve is expressed. Previous work has determined that the expressed section of the force-length curve for individual muscles can vary between subjects; however, the degree of intersubject variability is different for different muscles. This study determined the expressed section of both the rectus femoris and gastrocnemius—muscles with very different ratios of tendon slack length to muscle fiber optimum length—for 28 nonspecifically trained subjects to test the hypothesis that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method of Herzog & ter Keurs (1988). There was no relationship between the expressed sections of the force-length curve for the two muscles. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. The lack of relationship between the expressed sections of the two muscles has implications for motor control and for training muscle for rehabilitation.
UR - http://hdl.handle.net/2160/8449
M3 - Article
SN - 1543-2688
VL - 26
SP - 45
EP - 51
JO - Journal of Applied Biomechanics
JF - Journal of Applied Biomechanics
IS - 1
ER -