Journal of Neurophysiology, Vol 44, Issue 5 951-960, Copyright © 1980 by APS

ARTICLES

Muscle architecture and force-velocity characteristics of cat soleus and medial gastrocnemius: implications for motor control

S. A. Spector, P. F. Gardiner, R. F. Zernicke, R. R. Roy and V. R. Edgerton

1. Isometric and isotonic contractile parameters of the soleus (SOL) and medial gastrocnemius (MG) muscles of seven adult cats were studied. In addition, architectural characteristics of six contralateral pairs of these ankle extensors were determined. 2. The in situ peak isometric tetanic tension developed by the MG at the Achilles tendon is nearly 5 times (9,846 vs 2,125 g) that of the SOL muscle. However, when differences between the MG and SOL in fiber length (2.01 vs 3.66 cm), muscle mass (9.80 vs. 3.31 g), and angle of pinnation (21.4 vs. 6.4 degrees) are considered, the specific tensions of these muscles are similar (approximately 2.3 kg x cm-2). 3. When the effects of muscle architecture are eliminated, the nearly threefold greater maximum isotonic shortening velocity (Vmax) of sarcomeres of the MG (38.2 micron/s) relative to the SOL (13.4 micron/s) is presumably due to intrinsic differences in the biochemical properties of these muscle. However, the Vmax developed by the MG at the Achilles tendon (258.6 mm/s) during a shortening contraction is only 1.5 times that of the SOL (176.3 mm/s) due to the influence of these muscles' specific architectures. 4. Variations in geometrical characteristics of the SOL and MG are consonant with the relative amounts of participation of these muscles during posture, locomotion, and jumping. Posture requires the development of low forces for prolonged periods for which the SOL seems best suited both architecturally and physiologically. The MG, relatively inactive during quiet standing, becomes responsible for a greater percentage of tension and shortening speed during plantar flexion (E3) as gait speeds increase, which is consistent with this muscle's greater tension- and velocity-generating capacity. 5. At high speeds of locomotion (3.0 m/s) and jumping, the shortening velocities developed at the end of E3 (approximately 20-40 ms before paw off) exceed Vmax of the SOL. Consequently, the SOL, although electrically active, cannot contribute to the tensions required to generate the shortening velocities dictated by these movements. 6. These data demonstrate the influence of the differing geometries of the SOL and MG on the roles of these muscles in generating forces at varying velocities, as demanded by the dynamics of the movement.

This article has been cited by other articles:

				S. S. M. Lee and S. J. Piazza Built for speed: musculoskeletal structure and sprinting ability J. Exp. Biol., November 15, 2009; 212(22): 3700 - 3707. [Abstract] [Full Text] [PDF]

				H. Maas, R. J. Gregor, E. F. Hodson-Tole, B. J. Farrell, and B. I. Prilutsky Distinct muscle fascicle length changes in feline medial gastrocnemius and soleus muscles during slope walking J Appl Physiol, April 1, 2009; 106(4): 1169 - 1180. [Abstract] [Full Text] [PDF]

				M. Kaya, T. R Leonard, and W. Herzog Premature deactivation of soleus during the propulsive phase of cat jumping J R Soc Interface, April 6, 2008; 5(21): 415 - 426. [Abstract] [Full Text] [PDF]

				N. D. Reeves, M. V. Narici, and C. N. Maganaris Effect of resistance training on skeletal muscle-specific force in elderly humans J Appl Physiol, March 1, 2004; 96(3): 885 - 892. [Abstract] [Full Text] [PDF]

				M. Kaya, T. Leonard, and W. Herzog Coordination of medial gastrocnemius and soleus forces during cat locomotion J. Exp. Biol., October 15, 2003; 206(20): 3645 - 3655. [Abstract] [Full Text] [PDF]

				J. M. Wakeling, M. Kaya, G. K. Temple, I. A. Johnston, and W. Herzog Determining patterns of motor recruitment during locomotion J. Exp. Biol., February 1, 2002; 205(3): 359 - 369. [Abstract] [Full Text] [PDF]

				P. J. Keir and R. P. Wells The Effect of Typing Posture on Wrist Extensor Muscle Loading Human Factors: The Journal of the Human Factors and Ergonomics Society, January 1, 2002; 44(3): 392 - 403. [Abstract] [PDF]

				T. J. Burkholder Age does not influence muscle fiber length adaptation to increased excursion J Appl Physiol, December 1, 2001; 91(6): 2466 - 2470. [Abstract] [Full Text] [PDF]

				K. Kumagai, T. Abe, W. F. Brechue, T. Ryushi, S. Takano, and M. Mizuno Sprint performance is related to muscle fascicle length in male 100-m sprinters J Appl Physiol, March 1, 2000; 88(3): 811 - 816. [Abstract] [Full Text] [PDF]

				S. Peters and D. Aulner Sexual dimorphism in forelimb muscles of the bullfrog, Rana catesbeiana: a functional analysis of isometric contractile properties J. Exp. Biol., January 12, 2000; 203(23): 3639 - 3654. [Abstract] [PDF]

				A Seyfarth, R Blickhan, and J. Van Leeuwen Optimum take-off techniques and muscle design for long jump J. Exp. Biol., January 2, 2000; 203(4): 741 - 750. [Abstract] [PDF]

				T. J Koh and J. G Tidball Nitric oxide synthase inhibitors reduce sarcomere addition in rat skeletal muscle J. Physiol., August 15, 1999; 519(1): 189 - 196. [Abstract] [Full Text] [PDF]

				Y. Kawakami, Y. Ichinose, and T. Fukunaga Architectural and functional features of human triceps surae muscles during contraction J Appl Physiol, August 1, 1998; 85(2): 398 - 404. [Abstract] [Full Text] [PDF]

				T. J Koh and W. Herzog Excursion is important in regulating sarcomere number in the growing rabbit tibialis anterior J. Physiol., April 1, 1998; 508(1): 267 - 280. [Abstract] [Full Text] [PDF]