Muscle force is determined also by muscle relative position: isolated effects.

Effects on force of changes of the position of extensor digitorum longus muscle (EDL) relative to surrounding tissues were investigated in rat. Connective tissue at the muscle bellies of tibialis anterior (TA), extensor hallucis longus (EHL) and EDL was left intact, to allow myofascial force transmission. The position of EDL muscle was altered, without changing EDL muscle-tendon complex length, and force exerted at proximal and distal tendons of EDL as well as summed force exerted at the distal tendons of TA and EHL muscles (TA+EHL) were measured. Proximal and distal EDL forces as well as distal TA+EHL force changed significantly on repositioning EDL muscle. These muscle position-force characteristics were assessed at two EDL lengths and two TA+EHL lengths. It was shown that changes of muscle force with length changes of a muscle is the result of the length changes per se, as well as of changes of relative position of parts of the muscle. It is concluded that in addition to length, muscle position relative to its surroundings co-determines isometric muscle force.

[1]  G J van Ingen Schenau,et al.  Effects of prestretch at the onset of stimulation on mechanical work output of rat medial gastrocnemius muscle-tendon complex. , 1990, The Journal of experimental biology.

[2]  M. Bobbert,et al.  The unique action of bi-articular muscles in complex movements. , 1987, Journal of anatomy.

[3]  P A Huijing,et al.  Intermuscular interaction via myofascial force transmission: effects of tibialis anterior and extensor hallucis longus length on force transmission from rat extensor digitorum longus muscle. , 2001, Journal of biomechanics.

[4]  P Huijing,et al.  Muscular force transmission: a unified, dual or multiple system? A review and some explorative experimental results. , 1999, Archives of physiology and biochemistry.

[5]  P A Huijing,et al.  Acute effects of intramuscular aponeurotomy on rat gastrocnemius medialis: force transmission, muscle force and sarcomere length. , 1999, Journal of biomechanics.

[6]  P A Huijing,et al.  Extramuscular myofascial force transmission within the rat anterior tibial compartment: proximo-distal differences in muscle force. , 2001, Acta physiologica Scandinavica.

[7]  R. Close.  Dynamic properties of fast and slow skeletal muscles of the rat during development , 1964, The Journal of physiology.

[8]  P A Huijing,et al.  Muscle as a collagen fiber reinforced composite: a review of force transmission in muscle and whole limb. , 1999, Journal of biomechanics.

[9]  G. J. van Ingen Schenau,et al.  Role of Mono- and Biarticular Muscles in Explosive Movements , 1984, International journal of sports medicine.

[10]  R. Kretchmar.  Exercise and Sport Science , 1989 .

[11]  V. Edgerton,et al.  Role of motor unit structure in defining function , 2001, Muscle & nerve.

[12]  R L Lieber,et al.  Muscle fiber length and moment arm coordination during dorsi- and plantarflexion in the mouse hindlimb. , 1997, Acta anatomica.

[13]  M. Bobbert,et al.  Length and moment arm of human leg muscles as a function of knee and hip-joint angles , 2004, European Journal of Applied Physiology and Occupational Physiology.

[14]  C. Berthier,et al.  Supramolecular organization of the subsarcolemmal cytoskeleton of adult skeletal muscle fibers. A review , 1997, Biology of the cell.

[15]  R. Ramsey,et al.  Sarcolemma: Transmitter of Active Tension in Frog Skeletal Muscle , 1965, Science.

[16]  B Roszek,et al.  Decreasing stimulation frequency-dependent length-force characteristics of rat muscle. , 1994, Journal of applied physiology.

[17]  J. Altman,et al.  Effects of arrested cerebellar development on locomotion in the rat , 1980, Experimental Brain Research.

[18]  A. de Haan,et al.  Changes in velocity of shortening, power output and relaxation rate during fatigue of rat medial gastrocnemius muscle , 1989, Pflügers Archiv.

[19]  W. Lierse,et al.  Functional construction of the superficial and deep fascia system of the lower limb in man. , 1990, Acta anatomica.

[20]  Caroline M. Pond,et al.  The importance of connective tissue within and between muscles , 1982, Behavioral and Brain Sciences.

[21]  D. Denny-Brown,et al.  The Histological Features of Striped Muscle in Relation to Its Functional Activity , 1929 .

[22]  S. Delp,et al.  The action of the rectus femoris muscle following distal tendon transfer: does it generate knee flexion moment? , 1997, Developmental medicine and child neurology.

[23]  B. Koopman,et al.  Three-dimensional finite element modeling of skeletal muscle using a two-domain approach: linked fiber-matrix mesh model. , 2001, Journal of biomechanics.

[24]  F. Zajac,et al.  The effect of activation history on tension production by individual muscle units , 1976, Brain Research.

[25]  S. J. Goldberg,et al.  Summation of extraocular motor unit tensions in the lateral rectus muscle of the cat , 1997, Muscle & nerve.

[26]  P. Huijing,et al.  Progressive surgical dissection for tendon transposition affects length‐force characteristics of rat flexor carpi ulnaris muscle , 2002, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[27]  W. Herzog,et al.  A method for the determination of the force-length relation of selected in-vivo human skeletal muscles , 1988, Pflügers Archiv.

[28]  W. Buford,et al.  Muscle balance at the knee--moment arms for the normal knee and the ACL-minus knee. , 1997, IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[29]  C. Maganaris,et al.  In vivo measurements of the triceps surae complex architecture in man: implications for muscle function , 1998, The Journal of physiology.

[30]  G. H. Rose,et al.  Magnetic resonance elastography of skeletal muscle , 2001, Journal of magnetic resonance imaging : JMRI.

[31]  W. Herzog,et al.  Force-length relation of in-vivo human rectus femoris muscles , 1988, Pflügers Archiv.

[32]  P. Huijing,et al.  IMPLICATIONS OF MUSCLE RELATIVE POSITION AS A CO-DETERMINANT OF ISOMETRIC MUSCLE FORCE: A REVIEW AND SOME EXPERIMENTAL RESULTS , 2003 .

[33]  R L Lieber,et al.  12 Force Transmission in Skeletal Muscle: from Actomyosin to External Tendons , 1997, Exercise and sport sciences reviews.

[34]  J. Altman,et al.  Swimming in the rat: Analysis of locomotor performance in comparison to stepping , 2004, Experimental Brain Research.

[35]  R. D'ambrosia,et al.  The isometric length-force models of nine different skeletal muscles. , 1992, Journal of biomechanics.

[36]  S. Woo,et al.  Role of fascia in maintenance of muscle tension and pressure. , 1981, Journal of applied physiology: respiratory, environmental and exercise physiology.

[37]  V R Edgerton,et al.  Transmission of forces within mammalian skeletal muscles. , 1999, Journal of biomechanics.

[38]  T. Fukunaga,et al.  Determination of fascicle length and pennation in a contracting human muscle in vivo. , 1997, Journal of applied physiology.

[39]  Huijing.  Non-myotendinous force transmission in rat extensor digitorum longus muscle , 1998, The Journal of experimental biology.

[40]  Peter A Huijing,et al.  Myofascial force transmission: muscle relative position and length determine agonist and synergist muscle force. , 2003, Journal of applied physiology.

[41]  P. Huijing,et al.  Acute effects of intramuscular aponeurotomy and tenotomy on multitendoned rat EDL: Indications for local adaptation of intramuscular connective tissue , 2002, The Anatomical record.

[42]  Peter A. Huijing,et al.  of the 23 rd Annual EMBS International Conference , October 25-28 , Istanbul , Turkey FINITE ELEMENT MODELING OF INTERMUSCULAR INTERACTIONS AND MYOFASCIAL FORCE TRANSMISSION , 2004 .

[43]  P. Rack,et al.  The effects of length and stimulus rate on tension in the isometric cat soleus muscle , 1969, The Journal of physiology.

[44]  Thomas Stretch Dowse,et al.  MUSCLE AND NERVE , 1903 .

[45]  S. Delp,et al.  In vivo motion of the rectus femoris muscle after tendon transfer surgery. , 2002, Journal of biomechanics.

[46]  P. Huijing,et al.  Myofascial Force Transmission Causes Interaction between Adjacent Muscles and Connective Tissue: Effects of Blunt Dissection and Compartmental Fasciotomy on Length Force Characteristics of Rat Extensor Digitorum Longus Muscle , 2001, Archives of physiology and biochemistry.

[47]  J. C. van der Wal,et al.  The organization of the substrate of proprioception in the elbow region of the rat , 1988 .

[48]  S. Street,et al.  Lateral transmission of tension in frog myofibers: A myofibrillar network and transverse cytoskeletal connections are possible transmitters , 1983, Journal of cellular physiology.

[49]  H. Grootenboer,et al.  A Hill type model of rat medial gastrocnemius muscle that accounts for shortening history effects. , 1998, Journal of biomechanics.