In vivo estimation of the short-range stiffness of cross-bridges from joint rotation.

Abstract Short-range stiffness (SRS) is a mechanical property of muscles that is characterized by a disproportionally high stiffness within a short length range during both lengthening and shortening movements. SRS is attributed to the cross-bridges and is beneficial for stabilizing a joint during, e.g., postural conditions. Thus far, SRS has been estimated mainly on isolated mammalian muscles. In this study we presented a method to estimate SRS in vivo in the human wrist joint. SRS was estimated at joint level in the angular domain (N m/rad) for both flexion and extension rotations of the human wrist in nine healthy subjects. Wrist rotations of 0.15 rad at 3 rad/s were imposed at eight levels of voluntary contraction ranging from 0 to 2.1 N m by means of a single axis manipulator. Flexion and extension SRS of the wrist joint was estimated consistently and accurately using a dynamic nonlinear model that was fitted onto the recorded wrist torque. SRS increased monotonically with torque in a way consistent with previous studies on isolated muscles. It is concluded that in vivo measurement of joint SRS represents the population of coupled cross-bridges in wrist flexor and extensor muscles. In its current form, the presented technique can be used for clinical applications in many neurological and muscular diseases where altered joint torque and (dissociated) joint stiffness are important clinical parameters.

[1]  J. P. Paul,et al.  In vivo human tendon mechanical properties , 1999, The Journal of physiology.

[2]  R. Lieber,et al.  Architecture of selected muscles of the arm and forearm: anatomy and implications for tendon transfer. , 1992, The Journal of hand surgery.

[3]  M. Lakie,et al.  Resonance at the wrist demonstrated by the use of a torque motor: an instrumental analysis of muscle tone in man. , 1984, The Journal of physiology.

[4]  C. Oomens,et al.  The non-linear mechanical properties of soft engineered biological tissues determined by finite spherical indentation , 2008, Computer methods in biomechanics and biomedical engineering.

[5]  K H Mauritz,et al.  Chronic transformation of muscle in spasticity: a peripheral contribution to increased tone. , 1985, Journal of neurology, neurosurgery, and psychiatry.

[6]  E. Perreault,et al.  Modeling short-range stiffness of feline lower hindlimb muscles. , 2008, Journal of biomechanics.

[7]  G. Elzinga,et al.  Mechanical properties of skinned rabbit psoas and soleus muscle fibres during lengthening: effects of phosphate and Ca2+. , 1992, The Journal of physiology.

[8]  Eric J Perreault,et al.  Motor unit composition has little effect on the short-range stiffness of feline medial gastrocnemius muscle. , 2007, Journal of applied physiology.

[9]  W. Rymer,et al.  Mechanical properties of cat soleus muscle elicited by sequential ramp stretches: implications for control of muscle. , 1993, Journal of neurophysiology.

[10]  T. Nichols,et al.  Intrinsic properties and reflex compensation in reinnervated triceps surae muscles of the cat: effect of activation level. , 2003, Journal of neurophysiology.

[11]  Richard L Lieber,et al.  Mechanical considerations in the design of surgical reconstructive procedures. , 2002, Journal of biomechanics.

[12]  Betsy V. Hunter,et al.  Muscle moment arm and normalized moment contributions as reference data for musculoskeletal elbow and wrist joint models. , 2009, Journal of biomechanics.

[13]  S. Lehman,et al.  Phase transition in force during ramp stretches of skeletal muscle. , 1998, Biophysical journal.

[14]  M. Noble,et al.  Enhancement of mechanical performance by stretch during tetanic contractions of vertebrate skeletal muscle fibres. , 1978, The Journal of physiology.

[15]  D. Morgan Separation of active and passive components of short-range stiffness of muscle. , 1977, The American journal of physiology.

[16]  R. Lieber,et al.  Architecture of selected wrist flexor and extensor muscles. , 1990, The Journal of hand surgery.

[17]  F. W. Flitney,et al.  Cross‐bridge detachment and sarcomere 'give' during stretch of active frog's muscle. , 1978, The Journal of physiology.

[18]  S. Delp,et al.  The isometric functional capacity of muscles that cross the elbow. , 2000, Journal of biomechanics.

[19]  M. Lakie,et al.  A cross‐bridge mechanism can explain the thixotropic short‐range elastic component of relaxed frog skeletal muscle , 1998, The Journal of physiology.

[20]  Alexandre Delalleau,et al.  Characterization of the mechanical properties of skin by inverse analysis combined with the indentation test. , 2006, Journal of biomechanics.

[21]  W. Rymer,et al.  Muscle stiffness during transient and continuous movements of cat muscle: perturbation characteristics and physiological relevance , 1994, IEEE Transactions on Biomedical Engineering.

[22]  P. Rack,et al.  The short range stiffness of active mammalian muscle and its effect on mechanical properties , 1974, The Journal of physiology.

[23]  G. Piazzesi,et al.  The contractile response during steady lengthening of stimulated frog muscle fibres. , 1990, The Journal of physiology.

[24]  Frans C. T. van der Helm,et al.  Design of a torque-controlled manipulator to analyse the admittance of the wrist joint , 2006, Journal of Neuroscience Methods.

[25]  R. Gorman,et al.  Passive mechanical properties of human gastrocnemius muscle–tendon units, muscle fascicles and tendons in vivo , 2007, Journal of Experimental Biology.

[26]  B. Walmsley,et al.  Comparison of stiffness of soleus and medial gastrocnemius muscles in cats. , 1981, Journal of neurophysiology.