Assessing muscle architecture with ultrasound: implications for spasticity

Submitted: 4 March 2024
Accepted: 21 April 2024
Published: 30 May 2024
Abstract Views: 414
PDF: 231
Supplementary materials: 12
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Botulinum Neurotoxin Type A (BoNT-A) injections using Ultrasound (US) guidance have led to research evaluating changes in muscle architecture. Controversy remains as to what constitutes increased Echo-Intensity (EI) in spastic muscles and whether this may affect outcomes. We aim to provide a narrative review of US muscle architecture changes following Central Nervous System (CNS) lesions and explore their relationship to spasticity. Medline, CINAHL, and Embase databases were searched with keywords: ultrasonography, hypertonia, spasticity, fibrosis, and Heckmatt. Three physicians reviewed the results of the search to select relevant papers. Reviews identified in the search were used as a resource to identify additional studies. A total of 68 papers were included. Four themes were identified, including histopathological changes in spastic muscle, effects of BoNT-A on the muscle structure, available US modalities to assess the muscle, and utility of US assessment in clinical spasticity. Histopathological studies revealed atrophic and fibro-fatty changes after CNS lesions. Several papers described BoNT-A injections contributing to those modifications. These changes translated to increased EI. The exact significance of increased muscle EI remains unclear. The Modified Heckmatt Scale (MHS) is a validated tool for grading muscle EI in spasticity. The use of the US may be an important tool to assess muscle architecture changes in spasticity and improve spasticity management. Treatment algorithms may be developed based on the degree of EI. Further research is needed to determine the incidence and impact of these EI changes in spastic muscles.



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Lance JW. The control of muscle tone, reflexes, and movement: Robert Wartenberg Lecture. Neurology 1980;30:1303-13. DOI:
Li S, Francisco GE, Rymer WZ. A new definition of poststroke spasticity and the interference of spasticity with motor recovery from acute to chronic stages. Neurorehabil Neural Repair 2021;35:601-10. DOI:
Dressler D, Bhidayasiri R, Bohlega S, et al. Defining spasticity: a new approach considering current movement disorders terminology and botulinum toxin therapy. J Neurol 2018;265:856-62. DOI:
Pandyan AD, Gregoric M, Barnes MP, et al. Spasticity: clinical perceptions, neurological realities and meaningful measurement. Disabil Rehabil 2005;27:2-6. DOI:
Gracies J-M. Pathophysiology of spastic paresis. I: Paresis and soft tissue changes. Muscle Nerve 2005;31:535-51. DOI:
Gracies J-M. Pathophysiology of spastic paresis. II: Emergence of muscle overactivity. Muscle Nerve 2005;31:552-71. DOI:
Lieber RL, Steinman S, Barash IA, Chambers H. Structural and functional changes in spastic skeletal muscle. Muscle Nerve 2004;29:615-27. DOI:
Scherbakov N, von Haehling S, Anker SD, et al. Stroke induced Sarcopenia: muscle wasting and disability after stroke. Int J Cardiol 2013;170:89-94. DOI:
Lieber RL, Ward SR. Cellular mechanisms of tissue fibrosis. 4. Structural and functional consequences of skeletal muscle fibrosis. Am J Physiol Cell Physiol 2013;305:C241-52. DOI:
Alter KE, Karp BI. Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures. Toxins (Basel) 2017;10:18. DOI:
Lagnau P, Lo A, Sandarage R, Alter K, et al. Ergonomic Recommendations in Ultrasound-Guided Botulinum Neurotoxin Chemodenervation for Spasticity: An International Expert Group Opinion. Toxins (Basel) 2021;13:249. DOI:
Ozcakar L, Ata AM, Kaymak B, et al. Ultrasound imaging for sarcopenia, spasticity and painful muscle syndromes. Curr Opin Support Palliat Care 2018;12:373-81. DOI:
Pillen S, Arts IMP, Zwarts MJ. Muscle ultrasound in neuromuscular disorders. Muscle Nerve 2008;37:679-93. DOI:
Heckmatt JZ, Dubowitz V. Ultrasound imaging and directed needle biopsy in the diagnosis of selective involvement in muscle disease. J Child Neurol 1987;2:205-13. DOI:
Ketchum N, Carda S, O’Dell MW, et al. Module 4: Optimizing Outcomes in Spasticity Treatment. J Int Soc Physical Rehabil Med 2022;5:S50-60. DOI:
Reebye R, Balbert A, Bensmail D, et al. Module 2: Nonsurgical Management of Spasticity. J Int Soc Physical Rehabil Med 2022;5:S23-37. DOI:
Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part IV. Muscle pathology. N Z Vet J 1986;34:186-90. DOI:
Harrison GD, Duncan ID, Clayton MK. Determination of the early age of onset of equine recurrent laryngeal neuropathy. 1. Muscle pathology. Acta Neuropathol 1992;84:307-15. DOI:
Slocombe RF, Huntington PJ, Friend SC, et al. Pathological aspects of Australian Stringhalt. Equine Vet J 1992;24:174-83. DOI:
Chalmers HJ, Viel L, Caswell JL, Ducharme N. Ultrasonographic detection of early atrophy of the intrinsic laryngeal muscles of horses. Am J Vet Res 2015;76:426-36. DOI:
Pillen S, Tak RO, Zwarts MJ, et al. Skeletal muscle ultrasound: correlation between fibrous tissue and echo intensity. Ultrasound Med Biol 2009;35:443-6. DOI:
Lieber RL, Johansson CB, Vahlsing HL, et al. Long-term effects of spinal cord transection on fast and slow rat skeletal muscle. I. Contractile properties. Exp Neurol. 1986;91(3):423-34. DOI:
Lieber RL. Skeletal muscle adaptability. II: Muscle properties following spinal-cord injury. Dev Med Child Neurol 1986;28:533-42. DOI:
Lieber RL, Fridén JO, Hargens AR, Feringa ER. Long-term effects of spinal cord transection on fast and slow rat skeletal muscle. II. Morphometric properties. Exp Neurol 1986;91:435-48. DOI:
Booth CM, Cortina-Borja MJ, Theologis TN. Collagen accumulation in muscles of children with cerebral palsy and correlation with severity of spasticity. Dev Med Child Neurol 2001;43:314-20. DOI:
Smith LR, Lee KS, Ward SR, et al. Hamstring contractures in children with spastic cerebral palsy result from a stiffer extracellular matrix and increased in vivo sarcomere length. J Physiol 2011;589:2625-39. DOI:
Fridén J, Lieber RL. Spastic muscle cells are shorter and stiffer than normal cells. Muscle Nerve 2003;27:157-64. DOI:
Lieber RL, Runesson E, Einarsson F, Fridén J. Inferior mechanical properties of spastic muscle bundles due to hypertrophic but compromised extracellular matrix material. Muscle Nerve 2003;28:464-71. DOI:
Pingel J, Bartels EM, Nielsen JB. New perspectives on the development of muscle contractures following central motor lesions. J Physiol 2017;595:1027-38. DOI:
Gillies AR, Lieber RL. Structure and function of the skeletal muscle extracellular matrix. Muscle Nerve 2011;44:318-31. DOI:
Amir A, Kim S, Stecco A, et al. Hyaluronan homeostasis and its role in pain and muscle stiffness. PM R 2022;14:1490-6. DOI:
Lieber RL, Roberts TJ, Blemker SS, et al. Skeletal muscle mechanics, energetics and plasticity. J Neuroeng Rehabil 2017;14:108. DOI:
Mathevon L, Michel F, Decavel P, et al. Muscle structure and stiffness assessment after botulinum toxin type A injection. A systematic review. Ann Phys Rehabil Med 2015;58:343-50. DOI:
Schroeder AS, Ertl-Wagner B, Britsch S, et al. Muscle biopsy substantiates long-term MRI alterations one year after a single dose of botulinum toxin injected into the lateral gastrocnemius muscle of healthy volunteers. Mov Disord 2009;24:1494-503. DOI:
Valentine J, Stannage K, Fabian V, et al. Muscle histopathology in children with spastic cerebral palsy receiving botulinum toxin type A. Muscle Nerve 2016;53:407-14. DOI:
Picelli A, Filippetti M, Melotti C, et al. Does botulinum toxin treatment affect the ultrasonographic characteristics of post-stroke spastic equinus? A retrospective pilot Study. Toxins (Basel) 2020;12:797. DOI:
Battaglia M, Cosenza L, Scotti L, et al. Triceps surae muscle characteristics in spastic hemiparetic stroke survivors treated with botulinum toxin type a: clinical implications from ultrasonographic evaluation. Toxins (Basel) 2021;13:889. DOI:
Cosenza L, Picelli A, Azzolina D, et al. Rectus femoris characteristics in post stroke spasticity: clinical implications from ultrasonographic evaluation. Toxins (Basel) 2020;12:497. DOI:
Thielman G, Yourey L. Ultrasound imaging of upper extremity spastic muscle post-stroke and the correlation with function: A pilot study. NeuroRehabilitation 2019;45:213-20. DOI:
Lee CH, Lee SH, Yoo JI, Lee SU. Ultrasonographic evaluation for the effect of extracorporeal shock wave therapy on gastrocnemius muscle spasticity in patients with chronic stroke. PM R 2019;11:363-71. DOI:
Calvo-Lobo C, Useros-Olmo AI, Almazán-Polo J, et al. Quantitative ultrasound imaging pixel analysis of the intrinsic plantar muscle tissue between hemiparesis and contralateral feet in post-stroke patients. Int J Environ Res Public Health 2018;15:2591. DOI:
Hadi S, Khadijeh O, Hadian M, et al. The effect of dry needling on spasticity, gait and muscle architecture in patients with chronic stroke: A case series study. Top Stroke Rehabil 2018;25:326-32. DOI:
Mathevon L, Michel F, Aubry S, et al. Two-dimensional and shear wave elastography ultrasound: A reliable method to analyse spastic muscles? Muscle Nerve 2018;57:222-8. DOI:
Picelli A, Vallies G, Chemello E, et al. Is spasticity always the same? An observational study comparing the features of spastic equinus foot in patients with chronic stroke and multiple sclerosis. J Neurol Sci 2017;380:132-6. DOI:
Jakubowski KL, Terman A, Santana RVC, Lee SSM. Passive material properties of stroke-impaired plantarflexor and dorsiflexor muscles. Clin Biomech (Bristol, Avon) 2017;49:48-55. DOI:
Dias CP, Freire B, Goulart NB, et al. Muscle architecture and torque production in stroke survivors: an observational study. Top Stroke Rehabil 2017;24:206-13. DOI:
Kesikburun S, Yaşar E, Adıgüzel E, et al. Assessment of spasticity with sonoelastography following stroke: a feasibility study. PM&R 2015;7:1254-60. DOI:
Fröhlich-Zwahlen AK, Casartelli NC, Item-Glatthorn JF, Maffiuletti NA. Validity of resting myotonometric assessment of lower extremity muscles in chronic stroke patients with limited hypertonia: A preliminary study. J Electrom Kinesiol 2014;24:762-9. DOI:
Picelli A, Tamburin S, Cavazza S, et al. Relationship between ultrasonographic, electromyographic, and clinical parameters in adult stroke patients with spastic equinus: an observational study. Arch Phys Med Rehabil 2014;95:1564-70. DOI:
Yang Y-B, Zhang J, Leng Z-P, et al. Evaluation of spasticity after stroke by using ultrasound to measure the muscle architecture parameters: a clinical study. Int J Clin Experim Med 2014;7:2712-7.
Hong MJ, Park JB, Lee YJ, et al. Quantitative evaluation of post-stroke spasticity using neurophysiological and radiological tools: a pilot study. Ann Rehabil Med 2018;42:384-95. DOI:
Kim JM, Tay MRJ, Rajeswaran DK, et al. Changes in muscle architecture on ultrasound in patients early after stroke. NeuroRehabilitation. 2021;49(4):565-72. DOI:
Yoldaş Aslan Ş, Kutlay S, Düsünceli Atman E, et al. Does extracorporeal shock wave therapy decrease spasticity of ankle plantar flexor muscles in patients with stroke: A randomized controlled trial. Clinical Rehabil 2021:02692155211011320. DOI:
Gao J, Rubin JM, Chen J, O'Dell M. Ultrasound elastography to assess botulinum toxin a treatment for post-stroke spasticity: a feasibility study. Ultrasound Med Biol 2019;45:1094-102. DOI:
Gao J, Chen J, O'Dell M, et al. Ultrasound strain imaging to assess the biceps brachii muscle in chronic poststroke spasticity. J Ultrasound Med 2018;37:2043-52. DOI:
Aşkın A, Kalaycı Ö T, Bayram KB, et al. Strain sonoelastographic evaluation of biceps muscle intrinsic stiffness after botulinum toxin-A injection. Top Stroke Rehabil 2017;24:12-7. DOI:
Yasar E, Adiguzel E, Kesikburun S, et al. Assessment of forearm muscle spasticity with sonoelastography in patients with stroke. Br J Radiol 2016;89:20160603. DOI:
Liu J, Pan H, Bao Y, et al. The value of real-time shear wave elastography before and after rehabilitation of upper limb spasm in stroke patients. BioMed Res Int 2020;2020:6472456. DOI:
Lee SSM, Jakubowski KL, Spear SC, Rymer WZ. Muscle material properties in passive and active stroke-impaired muscle. J Biomech 2019;83:197-204. DOI:
Leng Y, Wang Z, Bian R, et al. Alterations of elastic property of spastic muscle with its joint resistance evaluated from shear wave elastography and biomechanical model. Front Neurol 2019;10:736. DOI:
Gao J, He W, Du LJ, et al. Quantitative ultrasound imaging to assess the biceps brachii muscle in chronic post-stroke spasticity: preliminary observation. Ultrasound Med Biol 2018;44:1931-40. DOI:
Wu C-H, Ho Y-C, Hsiao M-Y, et al. Evaluation of post-stroke spastic muscle stiffness using shear wave ultrasound elastography. Ultrasound Med Biol 2017;43:1105-11. DOI:
Eby S, Zhao H, Song P, et al. Quantitative evaluation of passive muscle stiffness in chronic stroke. Am J Phys Med Rehabil 2016;95:899-910. DOI:
Eby SF, Zhao H, Song P, et al. Quantifying spasticity in individual muscles using shear wave elastography. Radiol Case Rep 2017;12:348-52. DOI:
Rasool G, Wang AB, Rymer WZ, Lee SS. Altered viscoelastic properties of stroke-affected muscles estimated using ultrasound shear waves - Preliminary data. Annu Int Conf IEEE Eng Med Biol Soc 2016;2016:2869-72. DOI:
Moreta MC, Fleet A, Reebye R, et al. Reliability and validity of the modified heckmatt scale in evaluating muscle changes with ultrasound in spasticity. Arch Rehabil Res Clin Transl 2020;2:100071. DOI:
Hara T, Abo M, Hara H, et al. Effects of botulinum toxin A therapy and multidisciplinary rehabilitation on lower limb spasticity classified by spastic muscle echo intensity in post-stroke patients. Int J Neurosci 2018;128:412-20. DOI:
Picelli A, Bonetti P, Fontana C, et al. Is spastic muscle echo intensity related to the response to botulinum toxin type A in patients with stroke? A cohort study. Arch Phys Med Rehabil 2012;93:1253-8. DOI:
Kenis-Coskun O, Giray E, Gencer-Atalay ZK, et al. Reliability of quantitative ultrasound measurement of flexor digitorum superficialis and profundus muscles in stroke. J Comp Eff Res 2020;9:1293-300. DOI:
Santamato A, Micello MF, Panza F, et al. Extracorporeal shock wave therapy for the treatment of poststroke plantar-flexor muscles spasticity: a prospective open-label study. Top Stroke Rehabil 2014;21:S17-24. DOI:
Filippetti M, Di Censo R, Varalta V, et al. Is the outcome of diagnostic nerve block related to spastic muscle echo intensity? A retrospective observational study on patients with spastic equinovarus foot. J Rehabil Med 2022;54:jrm00275. DOI:
Schillebeeckx F, De Groef A, De Beukelaer N, et al. Muscle and tendon properties of the spastic lower leg after stroke defined by ultrasonography: a systematic review. Eur J Phys Rehabil Med 2020;57:495-510. DOI:
Tran A, Gao J. Quantitative ultrasound to assess skeletal muscles in post stroke spasticity. J Cent Nerv Syst Dis 2021;13:1179573521996141. DOI:
Miller T, Ying M, Sau Lan Tsang C, et al. Reliability and validity of ultrasound elastography for evaluating muscle stiffness in neurological populations: a systematic review and meta-analysis. Phys Ther 2021;101:pzaa188. DOI:
Lee SS, Spear S, Rymer WZ. Quantifying changes in material properties of stroke-impaired muscle. Clin Biomech (Bristol, Avon) 2015;30:269-75. DOI:
Battisti N, Milletti D, Miceli M, et al. Usefulness of a qualitative ultrasound evaluation of the gastrocnemius-soleus complex with the heckmatt scale for clinical practice in cerebral palsy. Ultrasound Med Biol 2018;44:2548-55. DOI:
Arts IM, Pillen S, Schelhaas HJ, et al. Normal values for quantitative muscle ultrasonography in adults. Muscle Nerve 2010;41:32-41. DOI:
Strasser EM, Draskovits T, Praschak M, et al. Association between ultrasound measurements of muscle thickness, pennation angle, echogenicity and skeletal muscle strength in the elderly. Age (Dordr) 2013;35:2377-88. DOI:
Fukumoto Y, Ikezoe T, Yamada Y, et al. Skeletal muscle quality assessed from echo intensity is associated with muscle strength of middle-aged and elderly persons. Eur J Appl Physiol 2012;112:1519-25. DOI:
Coletta G, Phillips SM. An elusive consensus definition of sarcopenia impedes research and clinical treatment: A narrative review. Ageing Res Rev 2023;86:101883. DOI:
Loizou CP, Pattichis CS, Pantziaris M, et al. Quality evaluation of ultrasound imaging in the carotid artery based on normalization and speckle reduction filtering. Med Biol Eng Comput 2006;44:414-26. DOI:
Michailovich OV, Tannenbaum A. Despeckling of medical ultrasound images. IEEE Trans Ultrason Ferroelectr Freq Control 2006;53:64-78. DOI:
Wu S, Zhu Q, Xie Y. Evaluation of various speckle reduction filters on medical ultrasound images. Annu Int Conf IEEE Eng Med Biol Soc 2013;2013:1148-51.
Pillen S, Van Keimpema M, Nievelstein RAJ, et al. Skeletal muscle ultrasonography: Visual versus quantitative evaluation. Ultrasound Med Biol 2006;32:1315-21. DOI:
Pillen S, van Dijk JP, Weijers G, et al. Quantitative gray-scale analysis in skeletal muscle ultrasound: a comparison study of two ultrasound devices. Muscle Nerve 2009;39:781-6. DOI:
Pillen S, van Alfen N. Skeletal muscle ultrasound. Neurol Res 2011;33:1016-24. DOI:
Shen J, Cartwright MS. Neuromuscular ultrasound in the assessment of polyneuropathies and motor neuron disease. J Clin Neurophysiol 2016;33:86-93. DOI:
Pillen S, Boon A, Van Alfen N. Muscle ultrasound. Handb Clin Neurol 2016;136:843-53. DOI:
Heckmatt JZ, Leeman S, Dubowitz V. Ultrasound imaging in the diagnosis of muscle disease. J Pediatr 1982;101:656-60. DOI:
Picelli A, Baricich A, Chemello E, et al. Ultrasonographic evaluation of botulinum toxin injection site for the medial approach to tibialis posterior muscle in chronic stroke patients with spastic equinovarus foot: an observational study. Toxins (Basel) 2017;9:375. DOI:
Stecco A, Stecco C, Raghavan P. Peripheral mechanisms contributing to spasticity and implications for treatment. Curr Phys Med Rehabil Rep 2014;2:121-7. DOI:
Yamada M, Kimura Y, Ishiyama D, et al. Differential characteristics of skeletal muscle in community-dwelling older adults. J Am Med Dir Assoc 2017;18:807e9-e16. DOI:
Rehabilitation AAoPMa. STEP Interventional Spasticity Certificate Program 2023 [Available from:
Koçer DS. Toxin Academy Courses: Swiss Neurological Society; 2023.
Howard JJ, Huntley JS, Graham HK, Herzog WL. Intramuscular injection of collagenase clostridium histolyticum may decrease spastic muscle contracture for children with cerebral palsy. Med Hypotheses 2019;122:126-8. DOI:
Raghavan P. Emerging therapies for spastic movement disorders. Phys Med Rehabil Clin N Am 2018;29:633-44. DOI:
Raghavan P, Lu Y, Mirchandani M, Stecco A. Human recombinant hyaluronidase injections for upper limb muscle stiffness in individuals with cerebral injury: a case series. EBioMedicine 2016;9:306-13. DOI:
Winston P, Mills PB, Reebye R, Vincent D. Cryoneurotomy as a percutaneous mini-invasive therapy for the treatment of the spastic limb: case presentation, review of the literature, and proposed approach for use. Arch Rehabil Res Clin Transl 2019;1:100030. DOI:

How to Cite

Boissonnault, Ève, Jeon, A., Munin, M. C., Filippetti, M., Picelli, A., Haldane, C., & Reebye, R. (2024). Assessing muscle architecture with ultrasound: implications for spasticity. European Journal of Translational Myology, 34(2).