Skip to main content
Log in

Reflex Torque Response to Movement of the Spastic Elbow: Theoretical Analyses and Implications for Quantification of Spasticity

  • Published:
Annals of Biomedical Engineering Aims and scope Submit manuscript

Abstract

A parametric model of the human reflex torque response to a large-amplitude, constant angular velocity elbow extension was developed in order to help quantify spasticity in hemiparetic stroke patients, and to better understand its pathophysiology. The model accounted for the routinely observed leveling of torque (i.e., a plateau) at a mean angular increment of 51°±10° s.d. (n=98) after the initial rise. This torque “plateau” was observed in all eight subjects, and in 98 of 125 trials across 25 experimental sessions. The occurrence of this plateau cannot be explained by decreases in elbow flexor moment arms during elbow extension. Rather, the plateau is attributable to a consistent leveling in muscle activation as confirmed both qualitatively from recordings of rectified, smoothed electromyograph (EMG) activity, and quantitatively using an EMG coefficient model. A parametric model was developed in which the pattern of muscle activation in the stretch reflex response of elbow flexors was described as a cumulative normal distribution with respect to joint angle. Two activation functions, one related to biceps and the other to brachioradialis/brachialis, were incorporated into the model in order to account for observations of a bimodal angular stiffness profile. The resulting model yielded biologically plausible parameters of the stretch reflex response which may prove useful for quantifying spasticity. In addition, the model parameters had clear pathophysiological analogs, which may help us understand the nature of the stretch reflex response in spastic muscles. © 1999 Biomedical Engineering Society.

PAC99: 8719Rr, 8719Xx, 8719St, 8719Nn, 8719Ff, 8710+e

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

REFERENCES

  1. An, K. N., E. Y. S. Chao, and K. R. Kaufman. Analysis of muscle and joint loads. In: Basic Orthopaedic Biomechanics, edited by V. C. Mow and W. C. Hayes. New York: Raven, 1991, pp. 1–50.

    Google Scholar 

  2. An, K. N., F. C. Hui, B. F. Morrey, R. L. Linsheid, and E. Y. Chao. Muscles across the elbow joint: A biomechanical analysis. J. Biomech. 14:659–669, 1981.

    Google Scholar 

  3. Ashby, P., and D. Burke. Stretch reflexes in the upper limb of spastic man. J. Neurol., Neurosurg. Psychiatry 34:765–771, 1971.

    Google Scholar 

  4. Ashworth, B. Preliminary trial of carisoprodal in multiple sclerosis. Practitioner 192:540–542, 1964.

    Google Scholar 

  5. Buchanan, T. S., D. P. J. Almdale, J. L. Lewis, and W. Z. Rymer. Characteristics of synergic relations during isometric contractions of human elbow muscles. J. Neurophysiol. 56:1225–1241, 1986.

    Google Scholar 

  6. Buchanan, T. S., M. J. Moniz, J. P. A. Dewald, and W. Z. Rymer. Estimation of muscle forces about the wrist joint during isometric tasks using an EMG coefficient method. J. Biomech. 26:547–560, 1993.

    Google Scholar 

  7. Buchanan, T. S., G. P. Rovai, and W. Z. Rymer. Strategies for muscle activation during isometric torque generation at the human elbow. J. Neurophysiol. 62:1201–1212, 1989.

    Google Scholar 

  8. Burke, D., J. D. Gillies, and J. W. Lance. The quadriceps reflex in human spasticity. J. Neurol., Neurosurg. Psychiatry 33:216–223, 1970.

    Google Scholar 

  9. Burke, D., J. D. Gillies, and J. W. Lance. Hamstrings stretch reflex in human spasticity. J. Neurol., Neurosurg. Psychiatry 34:231–235, 1971.

    Google Scholar 

  10. Burke, D., L. Knowles, C. Andrews, and P. Ashby. Spasticity, decerebrate rigidity and the clasp-knife phenomenon: An experimental study in the cat. Brain 95:31–48, 1972.

    Google Scholar 

  11. Cleland, C. L., L. Hayward, and W. Z. Rymer. Neural mechanisms underlying the clasp-knife reflex in the cat. II. Stretch-sensitive muscular free nerve endings. J. Neurophysiol. 64:1319–1330, 1990.

    Google Scholar 

  12. Cleland, C. L., and W. Z. Rymer. Neural mechanisms underlying the clasp-knife reflex in the cat I. Characteristics of the reflex. J. Neurophysiol. 64:1303–1318, 1990.

    Google Scholar 

  13. Crago, P. E., J. C. Houk, and Z. Hasan. Regulatory actions of human stretch reflexes. J. Neurophysiol. 39:925–935, 1976.

    Google Scholar 

  14. Feldman, A. G. Functional tuning of the nervous system with control of movement and maintenance of a steady posture II. Controllable parameters of the muscle. Biophysics (Engl. Transl.) 11:565–578, 1966.

    Google Scholar 

  15. Fugl-Meyer, A. R., L. Jaasko, I. Leyman, S. Olsson, and S. Steglind. The post-stroke hemiplegic patient. I. A method for evaluation of physical performance. Scand. J. Rehabil. Med. 7:13–31, 1975.

    Google Scholar 

  16. Given, J. D., J. P. A. Dewald, and W. Z. Rymer. Joint dependent passive stiffness in paretic and contralateral limbs of spastic patients with hemiparetic stroke. J. Neurol., Neurosurg. Psychiatry 59:271–279, 1995.

    Google Scholar 

  17. Grillner, S. The role of muscle stiffness in meeting the changing postural and locomotor requirements for force development by the ankle extensors. Acta Physiol. Scand. 86:92–108, 1972.

    Google Scholar 

  18. Herman, R. The myotactic reflex clinico-physiological aspects of spasticity and contracture. Brain 93:273–312, 1970.

    Google Scholar 

  19. Houk, J. C. Regulation of stiffness by skeletomotor reflexes. Annu. Rev. Physiol. 41:99–114, 1979.

    Google Scholar 

  20. Houk, J. C., P. E. Crago, and W. Z. Rymer. Functional properties of the golgi tendon organs. In: Spinal and Supraspinal Mechanisms of Voluntary Motor Control and Locomotion, edited by J. E. Desmedt. Basel: Karger, 1980, pp. 33–43.

    Google Scholar 

  21. Houk, J., and E. Henneman. Responses of golgi tendon organs to active contractions of the soleus muscle of the cat. J. Neurophysiol. 30:466–481, 1967.

    Google Scholar 

  22. Houk, J. C., W. Z. Rymer, and P. E. Crago. Dependence of dynamic response of spindle receptors on muscle length and velocity. J. Neurophysiol. 46:143–168, 1981.

    Google Scholar 

  23. Houk, J. C., J. J. Singer, and M. R. Goldman. An evaluation of length and force feedback to soleus muscles of decerebrate cats. J. Neurophysiol. 33:784–811, 1970.

    Google Scholar 

  24. Houk, J. C., J. J. Singer, and E. Henneman. Adequate stimulus for tendon organs with observations on mechanics of ankle joint. J. Neurophysiol. 34:1051–1065, 1971.

    Google Scholar 

  25. Ibrahim, I. K., W. Berger, M. Trippel, and V. Dietz. Stretch-induced electromyographic activity and torque in spastic elbow muscles. Brain 116:971–989, 1993.

    Google Scholar 

  26. Iles, J. F., J. J. B. Jack, D. M. Kullmann, and R. C. Roberts. The effects of lesions on autogenetic inhibition in the decerebrate cat. J. Physiol. (London) 419:611–625, 1989.

    Google Scholar 

  27. Jack, J. J. B., D. M. Kullmann, and R. C. Roberts. Autogenetic inhibition from contraction receptors in the decerebrate cat. J. Physiol. (London) 419:589–610, 1989.

    Google Scholar 

  28. Kirsch, R. F., and W. Z. Rymer. Neural compensation for muscular fatigue: Evidence for significant force regulation in man. J. Neurophysiol. 57:1893–1910, 1987.

    Google Scholar 

  29. E. Knutsson. Quantification of spasticity. In: Electromyography and Evoked Potentials, edited by A. Struppler and A. Weindl. Berlin: Springer-Verlag, 1985, pp. 84–91.

    Google Scholar 

  30. Lance, J. W. Pathophysiology of spasticity and clinical experience with baclofen. In: Spasticity: Disordered Motor Control, edited by R. G. Feldman, R. R. Young, and W. P. Koella. Chicago: Year Book, 1980, pp. 185–203.

    Google Scholar 

  31. Lee, W. A., A. Boughton, and W. Z. Rymer. Absence of stretch reflex gain enhancement in voluntarily activated spastic muscle. Exp. Neurol. 98:317–335, 1987.

    Google Scholar 

  32. Levin, M. F., and A. G. Feldman. The role of stretch reflex threshold regulation in normal and impaired motor control. Brain Res. 657:23–30, 1994.

    Google Scholar 

  33. Matthews, P. B. C. The dependence of tension upon extension in the stretch reflex of the soleus muscle of the decerebrate cat. J. Physiol. (London) 147:521–546, 1959.

    Google Scholar 

  34. Matthews, P. B. C. A study of certain factors influencing the stretch reflex of the decerebrate cat. J. Physiol. (London) 47:547–564, 1959.

    Google Scholar 

  35. Mense, S., and H. Meyer. Different types of slowly conducting afferent units in cat skeletal muscle and tendon. J. Physiol. (London) 363:403–417, 1985.

    Google Scholar 

  36. Messier, R. H., J. Duffy, H. M. Litchman, P. R. Paslay, J. F. Soechting, and P. A. Stewart. The electromyogram as a measure of tension in the human biceps and triceps muscles. Int. J. Mech. Sci. 13:585–598, 1971.

    Google Scholar 

  37. Murray, W. M., S. L. Delp, and T. S. Buchanan. Variation of muscle moment arms with elbow and forearm positions. J. Biomech. 28:513–525, 1995.

    Google Scholar 

  38. Nichols, T. R., and J. C. Houk. Improvement in linearity and regulation of stiffness that results from actions of stretch reflex. J. Neurophysiol. 39:119–142, 1976.

    Google Scholar 

  39. Powers, R. K., D. L. Campbell, and W. Z. Rymer. Stretch reflex dynamics in spastic elbow flexor muscles. Ann. Neurol. 25:32–42, 1989.

    Google Scholar 

  40. Powers, R. K., J. Marder-Meyer, and W. Z. Rymer. Quantitative relations between hypertonia and stretch reflex threshold in spastic hemiparesis. Ann. Neurol. 23:115–124, 1988.

    Google Scholar 

  41. Rack, P. M. H., and D. R. Westbury. Elastic properties of the cat soleus tendon and their functional importance. J. Physiol. (London) 347:479–495, 1984.

    Google Scholar 

  42. Rymer, W. Z., and Z. Hasan. Absence of force-feedback regulation in soleus muscle of the decerebrate cat. Brain Res. 184:203–209, 1980.

    Google Scholar 

  43. Rymer, W. Z., J. C. Houk, and P. E. Crago. Mechanisms of the clasp-knife reflex studied in an animal model. Exp. Brain Res. 37:93–113, 1979.

    Google Scholar 

  44. Schmit, B. D., J. P. A. Dewald, and W. Z. Rymer. Stretch reflex adaptation in elbow flexors during repeated passive movements in unilateral brain-injured patients. Arch. Phys. Med. Rehabil., 1999.

  45. Stephens, J. A., R. M. Reinking, and D. G. Stuart. Tendon organs of cat medial gastrocnemius: responses to active and passive forces as a function of muscle length. J. Neurophysiol. 38:1217–1231, 1975.

    Google Scholar 

  46. Thilmann, A. F., S. J. Fellows, and E. Garms. The mechanism of spastic muscle hypertonus: Variation in reflex gain over the time course of spasticity. Brain 114:233–244, 1991.

    Google Scholar 

  47. Wolf, S. L., R. L. Segal, P. A. Catlin, J. Tschorn, T. Raleigh, H. Kontos, and P. Pate. Determining consistency of elbow joint threshold angle in elbow flexor muscles with spastic hypertonia. Phys. Ther. 76:586–600, 1996.

    Google Scholar 

  48. Woods, J. J., and B. Bigland-Ritchie. Linear and nonlinear surface EMG/force relationships in human muscles. Am. J. Phys. Med. 62:287–299, 1983.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Schmit, B.D., Dhaher, Y., Dewald, J.P.A. et al. Reflex Torque Response to Movement of the Spastic Elbow: Theoretical Analyses and Implications for Quantification of Spasticity. Annals of Biomedical Engineering 27, 815–829 (1999). https://doi.org/10.1114/1.234

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1114/1.234

Navigation