Perspective on neuromuscular factors in poststroke fatigue

Disability and Rehabilitation

Volumn 34, Issue 26, 2012, Pages 2291-2299

  Knorr, Svetlana ^a   Rice, Charles L ^a,b   Garland, S Jayne ^c  

^a UNIVERSITY OF WESTERN ONTARIO   (Canada)

^b WESTERN UNIVERSITY   (Canada)

^c UNIVERSITY OF BRITISH COLUMBIA   (Canada)

Author keywords

Central fatigue; Fatigue poststroke; Neuromuscular; Peripheral fatigue; Stroke

Indexed keywords

ARTICLE; CEREBROVASCULAR ACCIDENT; DAILY LIFE ACTIVITY; FATIGUE; HUMAN; MUSCLE FATIGUE; PARESIS; PATHOPHYSIOLOGY; PHYSIOLOGY;

ACTIVITIES OF DAILY LIVING; FATIGUE; HUMANS; MUSCLE FATIGUE; PARESIS; STROKE;

EID: 84867846219     PISSN: 09638288     EISSN: 14645165     Source Type: Journal    
DOI: 10.3109/09638288.2012.683233     Document Type: Review

References (126)

1. Krupp LB, Pollina DA. Mechanisms and management of fatigue in progressive neurological disorders. Curr Opin Neurol 1996;9:456-460.
2. De Groot MH, Phillips SJ, Eskes GA. Fatigue associated with stroke and other neurologic conditions: Implications for stroke rehabilitation. Arch Phys Med Rehabil 2003;84:1714-1720.
3. Colle F, Bonan I, Gellez Leman MC, Bradai N, Yelnik A. Fatigue after stroke. Ann Readapt Med Phys 2006;49:272-6, 361.
4. Michael KM, Allen JK, Macko RF. Fatigue after stroke: Relationship to mobility, fitness, ambulatory activity, social support, and falls efficacy. Rehabil Nurs 2006;31:210-217.
5. Glader EL, Stegmayr B, Asplund K. Poststroke fatigue: A 2-year followup study of stroke patients in Sweden. Stroke 2002;33:1327-1333.
6. Morley W, Jackson K, Mead GE. Post-stroke fatigue: An important yet neglected symptom. Age Ageing 2005;34:313.
7. Sisson RA. Life after a stroke: Coping with change. Rehabil Nurs 1998;23:198-203.
8. Staub F, Bogousslavsky J. Post-stroke depression or fatigue. Eur Neurol 2001;45:3-5.
9. Staub F, Bogousslavsky J. Fatigue after stroke: A major but neglected issue. Cerebrovasc Dis 2001;12:75-81.
10. Ingles JL, Eskes GA, Phillips SJ. Fatigue after stroke. Arch Phys Med Rehabil 1999;80:173-178.
11. Annoni JM, Staub F, Bogousslavsky J, Brioschi A. Frequency, characterisation and therapies of fatigue after stroke. Neurol Sci 2008;29 Suppl 2:S244-S246.
12. Barker-Collo S, Feigin VL, Dudley M. Post stroke fatigue-where is the evidence to guide practice? N Z Med J 2007;120:U2780.
13. McGeough E, Pollock A, Smith LN, Dennis M, Sharpe M, Lewis S, Mead GE. Interventions for post-stroke fatigue. Cochrane Database Syst Rev 2009:CD007030.
14. Enoka RM, Stuart DG. Neurobiology of muscle fatigue. J Appl Physiol 1992;72:1631-1648.
15. Gandevia SC. Spinal and supraspinal factors in human muscle fatigue. Physiol Rev 2001;81:1725-1789.
16. Taylor JL, Todd G, Gandevia SC. Evidence for a supraspinal contribution to human muscle fatigue. Clin Exp Pharmacol Physiol 2006;33:400-405.
17. Gandevia SC, Allen GM, Butler JE, Taylor JL. Supraspinal factors in human muscle fatigue: Evidence for suboptimal output from the motor cortex. J Physiol (Lond 1996;490 (Pt 2):529-536.
18. Sacco P, Thickbroom GW, Byrnes ML, Mastaglia FL. Changes in corticomotor excitability after fatiguing muscle contractions. Muscle Nerve 2000;23:1840-1846.
19. Gandevia SC. Neural control in human muscle fatigue: Changes in muscle afferents, motoneurones and motor cortical drive [corrected]. Acta Physiol Scand 1998;162:275-283.
20. Macefield G, Hagbarth KE, Gorman R, Gandevia SC, Burke D. Decline in spindle support to α-motoneurones during sustained voluntary contractions. J Physiol (Lond 1991;440:497-512.
21. Garland SJ. Role of small diameter afferents in reflex inhibition during human muscle fatigue. J Physiol (Lond 1991;435:547-558.
22. Nordstrom MA, Gorman RB, Laouris Y, Spielmann JM, Stuart DG. Does motoneuron adaptation contribute to muscle fatigue? Muscle Nerve 2007;35:135-158.
23. Kirkendall DT. Mechanisms of peripheral fatigue. Med Sci Sports Exerc 1990;22:444-449.
24. Keyser RE. Peripheral fatigue: High-energy phosphates and hydrogen ions. PM R 2010;2:347-358.
25. Place N, Yamada T, Bruton JD, Westerblad H. Muscle fatigue: From observations in humans to underlying mechanisms studied in intact single muscle fibres. Eur J Appl Physiol 2010;110:1-15.
26. Bigland-Ritchie B, Woods JJ. Changes in muscle contractile properties and neural control during human muscular fatigue. Muscle Nerve 1984;7:691-699.
27. Fitts RH. Cellular mechanisms of muscle fatigue. Physiol Rev 1994;74:49-94.
28. Westerblad H, Allen DG. Recent advances in the understanding of skeletal muscle fatigue. Curr Opin Rheumatol 2002;14:648-652.
29. Enoka RM, Duchateau J. Muscle fatigue: What, why and how it influences muscle function. J Physiol (Lond 2008;586:11-23.
30. Bigland-Ritchie B, Rice CL, Garland SJ, Walsh ML. Task-dependent factors in fatigue of human voluntary contractions. Adv Exp Med Biol 1995;384:361-380.
31. Crenshaw AG, Karlsson S, Gerdle B, Friden J. Differential responses in intramuscular pressure and EMG fatigue indicators during lowvs. high-level isometric contractions to fatigue. Acta Physiol Scand 1997;160:353-361.
32. Sjogaard G, Kiens B, Jorgensen K, Saltin B. Intramuscular pressure, EMG and blood flow during low-level prolonged static contraction in man. Acta Physiol Scand 1986;128:475-484.
33. Tang A, Rymer WZ. Abnormal force-EMG relations in paretic limbs of hemiparetic human subjects. J Neurol Neurosurg Psychiatr 1981;44:690-698.
34. Hu XL, Tong KY, Hung LK. Firing properties of motor units during fatigue in subjects after stroke. J Electromyogr Kinesiol 2006;16:469-476.
35. Riley NA, Bilodeau M. Changes in upper limb joint torque patterns and EMG signals with fatigue following a stroke. Disabil Rehabil 2002;24:961-969.
36. Toffola ED, Sparpaglione D, Pistorio A, Buonocore M. Myoelectric manifestations of muscle changes in stroke patients. Arch Phys Med Rehabil 2001;82:661-665.
37. Young JL, Mayer RF. Physiological alterations of motor units in hemiplegia. J Neurol Sci 1982;54:401-412.
38. Svantesson UM, Sunnerhagen KS, Carlsson US, Grimby G. Development of fatigue during repeated eccentric-concentric muscle contractions of plantar flexors in patients with stroke. Arch Phys Med Rehabil 1999;80:1247-1252.
39. Knorr S, Ivanova TD, Doherty TJ, Campbell JA, Garland SJ. The origins of neuromuscular fatigue post-stroke. Exp Brain Res 2011;214:303-315.
40. Horstman AM, Gerrits KH, Beltman MJ, Koppe PA, Janssen TW, de Haan A. Intrinsic properties of the knee extensor muscles after subacute stroke. Arch Phys Med Rehabil 2010;91:123-128.
41. Gerrits KH, Beltman MJ, Koppe PA, Konijnenbelt H, Elich PD, de Haan A, Janssen TW. Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke. Arch Phys Med Rehabil 2009;90:480-487.
42. Lukacs M, Vecsei L, Beniczky S. Large motor units are selectively affected following a stroke. Clin Neurophysiol 2008;119:2555-2558.
43. Hara Y, Masakado Y, Chino N. The physiological functional loss of single thenar motor units in the stroke patients: When does it occur? Does it progress? Clin Neurophysiol 2004;115:97-103.
44. Dattola R, Girlanda P, Vita G, Santoro M, Roberto ML, Toscano A, Venuto C, et al. Muscle rearrangement in patients with hemiparesis after stroke: An electrophysiological and morphological study. Eur Neurol 1993;33:109-114.
45. McComas AJ, Sica RE, Upton AR, Aguilera N. Functional changes in motoneurones of hemiparetic patients. J Neurol Neurosurg Psychiatr 1973;36:183-193.
46. Ivey FM, Hafer-Macko CE, Ryan AS, Macko RF. Impaired leg vasodilatory function after stroke: Adaptations with treadmill exercise training. Stroke 2010;41:2913-2917.
47. Ivey FM, Gardner AW, Dobrovolny CL, Macko RF. Unilateral impairment of leg blood flow in chronic stroke patients. Cerebrovasc Dis 2004;18:283-289.
48. Adams WC, Imms FJ. Resting blood flow in the paretic and nonparetic lower legs of hemiplegic persons: Relation to local skin temperature. Arch Phys Med Rehabil 1983;64:423-428.
49. Christie A, Snook EM, Kent-Braun JA. Systematic review and metaanalysis of skeletal muscle fatigue in old age. Med Sci Sports Exerc 2011;43:568-577.
50. Traversa R, Cicinelli P, Oliveri M, Giuseppina Palmieri M, Filippi MM, Pasqualetti P, Rossini PM. Neurophysiological follow-up of motor cortical output in stroke patients. Clin Neurophysiol 2000;111:1695-1703.
51. Liepert J, Restemeyer C, Kucinski T, Zittel S, Weiller C. Motor strokes: The lesion location determines motor excitability changes. Stroke 2005;36:2648-2653.
52. Calautti C, Baron JC. Functional neuroimaging studies of motor recovery after stroke in adults: A review. Stroke 2003;34:1553-1566.
53. Pennisi G, Alagona G, Rapisarda G, Nicoletti F, Costanzo E, Ferri R, Malaguarnera M, Bella R. Transcranial magnetic stimulation after pure motor stroke. Clin Neurophysiol 2002;113:1536-1543.
54. Byrnes ML, Thickbroom GW, Phillips BA, Mastaglia FL. Long-term changes in motor cortical organisation after recovery from subcortical stroke. Brain Res 2001;889:278-287.
55. Luft AR, Waller S, Forrester L, Smith GV, Whitall J, Macko RF, Schulz JB, Hanley DF. Lesion location alters brain activation in chronically impaired stroke survivors. Neuroimage 2004;21:924-935.
56. Luft AR, Forrester L, Macko RF, McCombe-Waller S, Whitall J, Villagra F, Hanley DF. Brain activation of lower extremity movement in chronically impaired stroke survivors. Neuroimage 2005;26:184-194.
57. Liepert J. Motor cortex excitability in stroke before and after constraintinduced movement therapy. Cogn Behav Neurol 2006;19:41-47.
58. Thickbroom GW, Byrnes ML, Archer SA, Mastaglia FL. Motor outcome after subcortical stroke: MEPs correlate with hand strength but not dexterity. Clin Neurophysiol 2002;113:2025-2029.
59. Bashir S, Mizrahi I, Weaver K, Fregni F, Pascual-Leone A. Assessment and modulation of neural plasticity in rehabilitation with transcranial magnetic stimulation. PM R 2010;2:S253-S268.
60. Dimyan MA, Cohen LG. Contribution of transcranial magnetic stimulation to the understanding of functional recovery mechanisms after stroke. Neurorehabil Neural Repair 2010;24:125-135.
61. Perez MA, Cohen LG. The corticospinal system and transcranial magnetic stimulation in stroke. Top Stroke Rehabil 2009;16:254-269.
62. Inghilleri M, Berardelli A, Cruccu G, Manfredi M. Silent period evoked by transcranial stimulation of the human cortex and cervicomedullary junction. J Physiol (Lond 1993;466:521-534.
63. Wilson SA, Lockwood RJ, Thickbroom GW, Mastaglia FL. The muscle silent period following transcranial magnetic cortical stimulation. J Neurol Sci 1993;114:216-222.
64. Classen J, Schnitzler A, Binkofski F, Werhahn KJ, Kim YS, Kessler KR, Benecke R. The motor syndrome associated with exaggerated inhibition within the primary motor cortex of patients with hemiparetic. Brain 1997;120 (Pt 4):605-619.
65. von Giesen HJ, Roick H, Benecke R. Inhibitory actions of motor cortex following unilateral brain lesions as studied by magnetic brain stimulation. Exp Brain Res 1994;99:84-96.
66. Wheaton LA, Villagra F, Hanley DF, Macko RF, Forrester LW. Reliability of TMS motor evoked potentials in quadriceps of subjects with chronic hemiparesis after stroke. J Neurol Sci 2009;276:115-117.
67. Berardelli A, Inghilleri M, Cruccu G, Mercuri B, Manfredi M. Electrical and magnetic transcranial stimulation in patients with corticospinal damage due to stroke or motor neurone disease. Electroencephalogr Clin Neurophysiol 1991;81:389-396.
68. Homberg V, Stephan KM, Netz J. Transcranial stimulation of motor cortex in upper motor neurone syndrome: Its relation to the motor deficit. Electroencephalogr Clin Neurophysiol 1991;81:377-388.
69. Nelles G, Spiekermann G, Jueptner M, Leonhardt G, Muller S, Gerhard H, Diener HC. Reorganization of sensory and motor systems in hemiplegic stroke patients. A positron emission tomography study. Stroke 1999;30:1510-1516.
70. Thickbroom GW, Sacco P, Kermode AG, Archer SA, Byrnes ML, Guilfoyle A, Mastaglia FL. Central motor drive and perception of effort during fatigue in multiple sclerosis. J Neurol 2006;253:1048-1053.
71. Solomon NP, Robin DA. Perceptions of effort during handgrip and tongue elevation in Parkinson's disease. Parkinsonism Relat Disord 2005;11:353-361.
72. Jones LA. The senses of effort and force during fatiguing contractions. Adv Exp Med Biol 1995;384:305-313.
73. Arasaki K, Igarashi O, Ichikawa Y, Machida T, Shirozu I, Hyodo A, Ushijima R. Reduction in the motor unit number estimate (MUNE) after cerebral infarction. J Neurol Sci 2006;250:27-32.
74. Brown WF, Snow R. Denervation in hemiplegic muscles. Stroke 1990;21:1700-1704.
75. Gemperline JJ, Allen S, Walk D, Rymer WZ. Characteristics of motor unit discharge in subjects with hemiparesis. Muscle Nerve 1995;18:1101-1114.
76. Hara Y, Akaboshi K, Masakado Y, Chino N. Physiologic decrease of single thenar motor units in the F-response in stroke patients. Arch Phys Med Rehabil 2000;81:418-423.
77. Lukacs M. Electrophysiological signs of changes in motor units after ischaemic stroke. Clin Neurophysiol 2005;116:1566-1570.
78. Linssen WH, Stegeman DF, Joosten EM, Binkhorst RA, Merks MJ, ter Laak HJ, Notermans SL. Fatigue in type I fiber predominance: A muscle force and surface EMG study on the relative role of type I and type II muscle fibers. Muscle Nerve 1991;14:829-837.
79. Johnson MA, Polgar J, Weightman D, Appleton D. Data on the distribution of fibre types in thirty-six human muscles. An autopsy study. J Neurol Sci 1973;18:111-129.
80. De Deyne PG, Hafer-Macko CE, Ivey FM, Ryan AS, Macko RF. Muscle molecular phenotype after stroke is associated with gait speed. Muscle Nerve 2004;30:209-215.
81. Jakobsson F, Edstrom L, Grimby L, Thornell LE. Disuse of anterior tibial muscle during locomotion and increased proportion of type II fibres in hemiplegia. J Neurol Sci 1991;105:49-56.
82. Edstrom L. Selective changes in the sizes of red and white muscle fibres in upper motor lesions and Parkinsonism. J Neurol Sci 1970;11:537-550.
83. Slager UT, Hsu JD, Jordan C. Histochemical and morphometric changes in muscles of stroke patients. Clin Orthop Relat Res 1985;199:159-168.
84. Hachisuka K, Umezu Y, Ogata H. Disuse muscle atrophy of lower limbs in hemiplegic patients. Arch Phys Med Rehabil 1997;78:13-18.
85. Sunnerhagen KS, Svantesson U, Lonn L, Krotkiewski M, Grimby G. Upper motor neuron lesions: Their effect on muscle performance and appearance in stroke patients with minor motor impairment. Arch Phys Med Rehabil 1999;80:155-161.
86. Adam A, De Luca CJ. Firing rates of motor units in human vastus lateralis muscle during fatiguing isometric contractions. J Appl Physiol 2005;99:268-280.
87. Frontera WR, Grimby L, Larsson L. Firing rate of the lower motoneuron and contractile properties of its muscle fibers after upper motoneuron lesion in man. Muscle Nerve 1997;20:938-947.
88. Rosenfalck A, Andreassen S. Impaired regulation of force and firing pattern of single motor units in patients with spasticity. J Neurol Neurosurg Psychiatr 1980;43:907-916.
89. Kernell D. The limits of firing frequency in cat lumbosacral motoneurones possessing different time course of afterhyperpolarization. Acta Physiol Scand 1965;65:87-100.
90. Kernell D, Bakels R, Copray JC. Discharge properties of motoneurones: How are they matched to the properties and use of their muscle units? J Physiol Paris 1999;93:87-96.
91. Sawczuk A, Powers RK, Binder MD. Intrinsic properties of motoneurons. Implications for muscle fatigue. Adv Exp Med Biol 1995;384:123-134.
92. Liang L, Chen J, Wang Y, Jakubiec M, Mierzejewska J, Piotrkiewicz M. Changes in spinal motoneuron "Fastness" in post-stroke spastic patients. J Med Biol Eng 2010;30:17-22.
93. Newham DJ, Hsiao SF. Knee muscle isometric strength, voluntary activation and antagonist co-contraction in the first six months after stroke. Disabil Rehabil 2001;23:379-386.
94. Garland SJ, Gray VL, Knorr S. Muscle activation patterns and postural control following stroke. Motor Control 2009;13:387-411.
95. Dewald JP, Pope PS, Given JD, Buchanan TS, Rymer WZ. Abnormal muscle coactivation patterns during isometric torque generation at the elbow and shoulder in hemiparetic subjects. Brain 1995;118 (Pt 2):495-510.
96. Dewald JP, Beer RF. Abnormal joint torque patterns in the paretic upper limb of subjects with hemiparesis. Muscle Nerve 2001;24:273-283.
97. Gandevia SC. The perception of motor commands or effort during muscular paralysis. Brain 1982;105:151-159.
98. Milot MH, Nadeau S, Gravel D, Requiao LF. Bilateral level of effort of the plantar flexors, hip flexors, and extensors during gait in hemiparetic and healthy individuals. Stroke 2006;37:2070-2075.
99. Gersten JW, Orr W. External work of walking in hemiparetic patients. Scand J Rehabil Med 1971;3:85-88.
100. Taub E, Morris DM. Constraint-induced movement therapy to enhance recovery after stroke. Curr Atheroscler Rep 2001;3:279-286.
101. Sirtori V, Corbetta D, Moja L, Gatti R. Constraint-induced movement therapy for upper extremities in stroke patients. Cochrane Database Syst Rev 2009:CD004433.
102. Mark VW, Taub E, Morris DM. Neuroplasticity and constraint-induced movement therapy. Eura Medicophys 2006;42:269-284.
103. Blanton S, Wilsey H, Wolf SL. Constraint-induced movement therapy in stroke rehabilitation: Perspectives on future clinical applications. NeuroRehabilitation 2008;23:15-28.
104. Liepert J, Graef S, Uhde I, Leidner O, Weiller C. Training-induced changes of motor cortex representations in stroke patients. Acta Neurol Scand 2000;101:321-326.
105. Liepert J, Miltner WH, Bauder H, Sommer M, Dettmers C, Taub E, Weiller C. Motor cortex plasticity during constraint-induced movement therapy in stroke patients. Neurosci Lett 1998;250:5-8.
106. Brown JA. Recovery of motor function after stroke. Prog Brain Res 2006;157:223-228.
107. Edwards D, Fregni F. Modulating the healthy and affected motor cortex with repetitive transcranial magnetic stimulation in stroke: Development of new strategies for neurorehabilitation. NeuroRehabilitation 2008;23:3-14.
108. Lefaucheur JP. Stroke recovery can be enhanced by using repetitive transcranial magnetic stimulation (rTMS). Neurophysiol Clin 2006;36:105-115.
109. Khedr EM, Fetoh NA. Short- And long-term effect of rTMS on motor function recovery after ischemic stroke. Restor Neurol Neurosci 2010;28:545-559.
110. Platz T, Rothwell JC. Brain stimulation and brain repair-rTMS: From animal experiment to clinical trials-what do we know? Restor Neurol Neurosci 2010;28:387-398.
111. Mansur CG, Fregni F, Boggio PS, Riberto M, Gallucci-Neto J, Santos CM, Wagner T, et al. A sham stimulation-controlled trial of rTMS of the unaffected hemisphere in stroke patients. Neurology 2005;64:1802-1804.
112. Takeuchi N, Chuma T, Matsuo Y, Watanabe I, Ikoma K. Repetitive transcranial magnetic stimulation of contralesional primary motor cortex improves hand function after stroke. Stroke 2005;36:2681-2686.
113. Mally J, Dinya E. Recovery of motor disability and spasticity in poststroke after repetitive transcranial magnetic stimulation (rTMS). Brain Res Bull 2008;76:388-395.
114. Yozbatiran N, Alonso-Alonso M, See J, Demirtas-Tatlidede A, Luu D, Motiwala RR, Pascual-Leone A, Cramer SC. Safety and behavioral effects of high-frequency repetitive transcranial magnetic stimulation in stroke. Stroke 2009;40:309-312.
115. Kim YH, You SH, Ko MH, Park JW, Lee KH, Jang SH, Yoo WK, Hallett M. Repetitive transcranial magnetic stimulation-induced corticomotor excitability and associated motor skill acquisition in chronic stroke. Stroke 2006;37:1471-1476.
116. Badics E, Wittmann A, Rupp M, Stabauer B, Zifko UA. Systematic muscle building exercises in the rehabilitation of stroke patients. NeuroRehabilitation 2002;17:211-214.
117. Flansbjer UB, Miller M, Downham D, Lexell J. Progressive resistance training after stroke: Effects on muscle strength, muscle tone, gait performance and perceived participation. J Rehabil Med 2008;40:42-48.
118. Kim CM, Eng JJ, MacIntyre DL, Dawson AS. Effects of isokinetic strength training on walking in persons with stroke: A double-blind controlled pilot study. J Stroke Cerebrovasc Dis 2001;10:265-273.
119. Ouellette MM, LeBrasseur NK, Bean JF, Phillips E, Stein J, Frontera WR, Fielding RA. High-intensity resistance training improves muscle strength, self-reported function, and disability in long-term stroke survivors. Stroke 2004;35:1404-1409.
120. Weiss A, Suzuki T, Bean J, Fielding RA. High intensity strength training improves strength and functional performance after stroke. Am J Phys Med Rehabil 2000;79:369-76.
121. Barreca S, Sigouin CS, Lambert C, Ansley B. Effects of extra training on the ability of stroke survivors to perform an independent sit-to-stand: A randomized controlled trial. J Geriatr Phys Ther 2004;27:59-64.
122. Monger C, Carr JH, Fowler V. Evaluation of a home-based exercise and training programme to improve sit-to-stand in patients with chronic stroke. Clin Rehabil 2002;16:361-367.
123. Bohannon RW. Muscle strength and muscle training after stroke. J Rehabil Med 2007;39:14-20.
124. Dodd KJ, Taylor NF, Shields N, Prasad D, McDonald E, Gillon A. Progressive resistance training did not improve walking but can improve muscle performance, quality of life and fatigue in adults with multiple sclerosis: A randomized controlled trial. Mult Scler 2011;17:1362-1374.
125. Dalgas U, Stenager E, Jakobsen J, Petersen T, Hansen HJ, Knudsen C, Overgaard K, Ingemann-Hansen T. Fatigue, mood and quality of life improve in MS patients after progressive resistance training. Mult Scler 2010;16:480-490.
126. Chang YJ, Hsu MJ, Chen SM, Lin CH, Wong AM. Decreased central fatigue in multiple sclerosis patients after 8 weeks of surface functional electrical stimulation. J Rehabil Res Dev 2011;48:555-564.