Changes in passive mechanical properties of the gastrocnemius muscle at the muscle fascicle and joint levels in stroke survivors.

OBJECTIVES To investigate the ankle joint-level and muscle fascicle-level changes and their correlations in stroke survivors with spasticity, contracture, and/or muscle weakness at the ankle. DESIGN To investigate the fascicular changes of the medial gastrocnemius muscle using ultrasonography and the biomechanical changes at the ankle joint across 0 degrees, 30 degrees, 60 degrees, and 90 degrees knee flexion in a case-control manner. SETTING Research laboratory in a rehabilitation hospital. PARTICIPANTS Stroke survivors (n=10) with ankle spasticity/contracture and healthy control subjects (n=10). INTERVENTIONS Not applicable. MAIN OUTCOME MEASUREMENTS At the muscle fascicle level, medial gastrocnemius muscle architecture including the fascicular length, pennation angle, and thickness were evaluated in vivo with the knee and ankle flexion changed systematically. At the joint level, the ankle range of motion (ROM) and stiffness were determined across the range of 0 degrees to 90 degrees knee flexion. RESULTS At comparable joint positions, stroke survivors showed reduced muscle fascicle length, especially in ankle dorsiflexion (P< or =.048) and smaller pennation angle, especially for more extended knee positions (P< or =.049) than those of healthy control subjects. At comparable passive gastrocnemius force, stroke survivors showed higher fascicular stiffness (P< or =.044) and shorter fascicle length (P< or =.025) than controls. The fascicle-level changes of decreased muscle fascicle length and pennation angle and increased medial gastrocnemius fascicle stiffness in stroke were correlated with the joint level changes of increased joint stiffness and decreased ROM (P<.05). CONCLUSIONS This study evaluated specific muscle fascicular changes as mechanisms underlying spasticity, contracture, and joint-level impairments, which may help improve stroke rehabilitation and outcome evaluation.

[1]  T. Fukunaga,et al.  The length-force characteristcs of human gastrocnemius and soleus muscles in vivo , 2000 .

[2]  L. Ada,et al.  Contribution of thixotropy, spasticity, and contracture to ankle stiffness after stroke , 2000, Journal of neurology, neurosurgery, and psychiatry.

[3]  Adam P Shortland.  In vivo gastrocnemius muscle fascicle length in children with and without diplegic cerebral palsy. , 2008, Developmental medicine and child neurology.

[4]  Adamantios Arampatzis,et al.  Effect of different ankle- and knee-joint positions on gastrocnemius medialis fascicle length and EMG activity during isometric plantar flexion. , 2006, Journal of biomechanics.

[5]  G. Loeb,et al.  Mechanics of feline soleus: I. Effect of fascicle length and velocity on force output , 1996, Journal of Muscle Research and Cell Motility.

[6]  Adamantios Arampatzis,et al.  Mechanical and morphological properties of different muscle–tendon units in the lower extremity and running mechanics: effect of aging and physical activity , 2005, Journal of Experimental Biology.

[7]  M Gough,et al.  Architecture of the medial gastrocnemius in children with spastic diplegia , 2001, Developmental medicine and child neurology.

[8]  David A. Winter,et al.  Biomechanics and Motor Control of Human Movement , 1990 .

[9]  C. Gans,et al.  Functional bases of fiber length and angulation in muscle , 1987, Journal of morphology.

[10]  R L Lieber,et al.  Skeletal muscle mechanics: implications for rehabilitation. , 1993, Physical therapy.

[11]  Tetsuro Muraoka,et al.  In vivo passive mechanical properties of the human gastrocnemius muscle belly. , 2005, Journal of biomechanics.

[12]  P A Huijing,et al.  Architecture of the human gastrocnemius muscle and some functional consequences. , 1985, Acta anatomica.

[13]  G. Allison,et al.  Evaluation of triceps surae muscle length and resistance to passive lengthening in patients with acquired brain injury. , 2002, Clinical biomechanics.

[14]  W. Herzog.  Skeletal muscle mechanics: from mechanisms to function , 2001 .

[15]  Jae Hyun Kim,et al.  US extended-field-of-view imaging technology. , 1997, Radiology.

[16]  Vasilios Baltzopoulos,et al.  Differences in gastrocnemius muscle architecture between the paretic and non-paretic legs in children with hemiplegic cerebral palsy. , 2007, Clinical biomechanics.

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

[18]  S. Gandevia,et al.  Change in length of relaxed muscle fascicles and tendons with knee and ankle movement in humans , 2002, The Journal of physiology.

[19]  M. Kjaer,et al.  Load‐displacement properties of the human triceps surae aponeurosis in vivo , 2001, The Journal of physiology.

[20]  W Z Rymer,et al.  Hyperactive tendon reflexes in spastic multiple sclerosis: measures and mechanisms of action. , 2000, Archives of physical medicine and rehabilitation.

[21]  W. Rymer,et al.  Spastic hypertonia: mechanisms and measurement. , 1989, Archives of physical medicine and rehabilitation.

[22]  J. Tabary,et al.  Functional adaptation of sarcomere number of normal cat muscle. , 1976, Journal de physiologie.

[23]  V. Edgerton,et al.  Muscle architecture of the human lower limb. , 1983, Clinical orthopaedics and related research.

[24]  Richard W. Bohannon,et al.  Interrater reliability of a modified Ashworth scale of muscle spasticity. , 1987, Physical therapy.

[25]  Richard L Lieber,et al.  Spastic muscle cells are shorter and stiffer than normal cells , 2003, Muscle & nerve.

[26]  R. Brand,et al.  Muscle fiber architecture in the human lower limb. , 1990, Journal of biomechanics.

[27]  V. Edgerton,et al.  Physiological cross‐sectional area of human leg muscles based on magnetic resonance imaging , 1992, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[28]  G. Allison,et al.  Reflex and non-reflex elements of hypertonia in triceps surae muscles following acquired brain injury: implications for rehabilitation. , 2001, Disability and rehabilitation.

[29]  G. Goldspink,et al.  Changes in sarcomere length and physiological properties in immobilized muscle. , 1978, Journal of anatomy.

[30]  E. Roth,et al.  Biomechanic changes in passive properties of hemiplegic ankles with spastic hypertonia. , 2004, Archives of physical medicine and rehabilitation.

[31]  Akinori Nagano,et al.  Simulation of Muscle-Tendon Complex During Human Movements , 2005 .

[32]  P. Cerretelli,et al.  In vivo human gastrocnemius architecture with changing joint angle at rest and during graded isometric contraction. , 1996, The Journal of physiology.

[33]  K. Tong,et al.  The effect of poststroke impairments on brachialis muscle architecture as measured by ultrasound. , 2007, Archives of physical medicine and rehabilitation.

[34]  T. Fukunaga,et al.  Muscle-fiber pennation angles are greater in hypertrophied than in normal muscles. , 1993, Journal of applied physiology.

[35]  S W Herring,et al.  Regulation of sarcomere number in skeletal muscle: A comparison of hypotheses , 1984, Muscle & nerve.

[36]  C. Maganaris.  Force‐length characteristics of the in vivo human gastrocnemius muscle , 2003, Clinical anatomy.

[37]  Anna Danielsson,et al.  Muscle and tendon stiffness in patients with upper motor neuron lesion following a stroke , 2000, European Journal of Applied Physiology.

[38]  J. Harlaar,et al.  Passive stiffness characteristics of ankle plantar flexors in hemiplegia. , 2000, Clinical biomechanics.