Abstract
Gripping force is produced by co-contraction of forearm flexors and extensors. Activation of extensors is important for stabilizing the wrist during gripping. However, forearm muscle function is complicated and the neurophysiological mechanism responsible for the gain in gripping force is unclear. Therefore, the purpose of this study was to investigate whether increasing forearm extensor activation with isometric wrist extension training has an effect on gripping force. Thirteen healthy subjects participated in this study. Maximal voluntary contraction of gripping was measured using a piezosensor (MVCgrip) and EMG of forearm muscles at every wrist angle (from 70° flexion to 80° extension with 10° intervals) were measured simultaneously at baseline, 4 weeks, and 8 weeks after training. Training consisted of 30 repetitions equal to 70% MVC of isometric wrist extension for 8 weeks (5/week) on the right side. Gripping force was measured on both sides using a grip dynamometer without wrist angle restriction. Gripping force, EMG, maximal wrist extension force, and wrist angle-gripping force curve were investigated after training. After training, maximal wrist extension force increased significantly. Gripping force on the trained side also increased significantly. The training changed wrist angle at peak of MVCgrip. EMG activation of forearm extensors increased and that of flexors decreased during gripping. These results suggest that wrist extension training leads to an increase in gripping force and changes the balance of EMG activation between forearm flexors and extensors during gripping. Therefore, this training method should be useful as a therapeutic strategy for increasing grip strength.
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References
Aagaard P (2003) Training-induced changes in neural function. Exerc Sport Sci Rev 31:61–67
Aagaard P, Simonsen EB, Andersen JL, Magnusson SP, Halkjaer-Kristensen J, Dyhre-Poulsen P (2000) Neural inhibition during maximal eccentric and concentric quadriceps contraction: effects of resistance training. J Appl Physiol 89:2249–2257
Alizadehkhaiyat O, Fisher AC, Kemp GJ, Frostick SP (2007a) Strength and fatigability of selected muscles in upper limb: assessing muscle imbalance relevant to tennis elbow. J Electromyogr Kinesiol 17:428–436
Alizadehkhaiyat O, Fisher AC, Kemp GJ, Vishwanathan K, Frostick SP (2007b) Upper limb muscle imbalance in tennis elbow: a functional and electromyographic assessment. J Orthop Res 25:1651–1657
Blackwell JR, Kornatz KW, Heath EM (1999) Effect of grip span on maximal grip force and fatigue of flexor digitorum superficialis. Appl Ergon 30:401–405
Blazevich AJ, Cannavan D, Coleman DR, Horne S (2007) Influence of concentric and eccentric resistance training on architectural adaptation in human quadriceps muscles. J Appl Physiol 103:1565–1575
Carolan B, Cafarelli E (1992) Adaptations in coactivation after isometric resistance training. J Appl Physiol 73:911–917
Carroll TJ, Riek S, Carson RG (2002) The sites of neural adaptation induced by resistance training in humans. J Physiol 544:641–652
Claudon L (1998) Evaluation of grip force using electromyograms in isometric isotonic conditions. Int J Occup Saf Ergon 4:169–184
Claudon L (2003) Relevance of the EMG/grip relationship in isometric anisotonic conditions. Int J Occup Saf Ergon 9:121–134
De Luca CJ, Erim Z (2002) Common drive in motor units of a synergistic muscle pair. J Neurophysiol 87:2200–2204
Delp SL, Grierson AE, Buchanan TS (1996) Maximum isometric moments generated by the wrist muscles in flexion–extension and radial–ulnar deviation. J Biomech 29:1371–1375
Duque J, Masset D, Malchaire J (1995) Evaluation of handgrip force from EMG measurements. Appl Ergon 26:61–66
Farina D, Merletti R, Enoka RM (2004) The extraction of neural strategies from the surface EMG. J Appl Physiol 96:1486–1495
Gabriel DA, Kamen G, Frost G (2006) Neural adaptations to resistive exercise: mechanisms and recommendations for training practices. Sports Med 36:133–149
Gonzalez RV, Buchanan TS, Delp SL (1997) How muscle architecture and moment arms affect wrist flexion–extension moments. J Biomech 30:705–712
Johnston JA, Winges SA, Santello M (2005) Periodic modulation of motor-unit activity in extrinsic hand muscles during multidigit grasping. J Neurophysiol 94:206–218
Kilgallon M, Donnelly AE, Shafat A (2007) Progressive resistance training temporarily alters hamstring torque–angle relationship. Scand J Med Sci Sports 17:18–24
Li ZM (2002) The influence of wrist position on individual finger forces during forceful grip. J Hand Surg [Am] 27: 886–896
Lieber RL, Friden J (1998) Musculoskeletal balance of the human wrist elucidated using intraoperative laser diffraction. J Electromyogr Kinesiol 8:93–100
Loren GJ, Shoemaker SD, Burkholder TJ, Jacobson MD, Friden J, Lieber RL (1996) Human wrist motors: biomechanical design and application to tendon transfers. J Biomech 29:331–342
Mogk JP, Keir PJ (2003a) Crosstalk in surface electromyography of the proximal forearm during gripping tasks. J Electromyogr Kinesiol 13:63–71
Mogk JP, Keir PJ (2003b) The effects of posture on forearm muscle loading during gripping. Ergonomics 46:956–975
Moritani T (1993) Neuromuscular adaptations during the acquisition of muscle strength, power and motor tasks. J Biomech 26(Suppl 1): 95–107
Moritani T, deVries HA (1979) Neural factors versus hypertrophy in the time course of muscle strength gain. Am J Phys Med 58:115–130
Moritani T, Muro M (1987) Motor unit activity and surface electromyogram power spectrum during increasing force of contraction. Eur J Appl Physiol Occup Physiol 56:260–265
O’Driscoll SW, Horii E, Ness R, Cahalan TD, Richards RR, An KN (1992) The relationship between wrist position, grasp size, and grip strength. J Hand Surg [Am] 17:169–177
Pienimaki TT, Siira PT, Vanharanta H (2002) Chronic medial and lateral epicondylitis: a comparison of pain, disability, and function. Arch Phys Med Rehabil 83:317–321
Reeves ND, Maganaris CN, Longo S, Narici MV (2009) Differential adaptations to eccentric versus conventional resistance training in older humans. Exp Physiol 94:825–833
Snijders CJ, Volkers AC, Mechelse K, Vleeming A (1987) Provocation of epicondylalgia lateralis (tennis elbow) by power grip or pinching. Med Sci Sports Exerc 19:518–523
Staron RS, Karapondo DL, Kraemer WJ, Fry AC, Gordon SE, Falkel JE, Hagerman FC, Hikida RS (1994) Skeletal muscle adaptations during early phase of heavy-resistance training in men and women. J Appl Physiol 76:1247–1255
Volz RG, Lieb M, Benjamin J (1980) Biomechanics of the wrist. Clin Orthop Relat Res 149:112–117
Winges SA, Santello M (2004) Common input to motor units of digit flexors during multi-digit grasping. J Neurophysiol 92:3210–3220
Acknowledgments
The authors would like to thank Dr. Tadano, Dr. Yona, Dr. Naito, Mr. Seki and Ms. Tajima for their support and the participants who took part in this study. We received no funding for this study.
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The authors declare that they have no conflict of interest.
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Communicated by Toshio Moritani.
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Shimose, R., Matsunaga, A. & Muro, M. Effect of submaximal isometric wrist extension training on grip strength. Eur J Appl Physiol 111, 557–565 (2011). https://doi.org/10.1007/s00421-010-1675-4
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DOI: https://doi.org/10.1007/s00421-010-1675-4