The effect of assistive force on the agonist and antagonist muscles in elbow flexion

Nursalbiah Nasir, Keisuke Hayashi, Ping Yeap Loh, Satoshi Muraki


This study investigated the responses of the agonist and antagonist muscles against assistive force during isometric muscle contraction. Participants performed isometric elbow flexion at 90º for 30 seconds under two workload conditions (20% and 40% of the maximal voluntary workload) with three levels of assistive force (0%, 50%, and 100% theoretical effectiveness) for 10 seconds. Electromyography (EMG) of the biceps (agonist muscle) and triceps (antagonist muscle) was measured during the task, and perceived exertion was obtained after the task. Assistive force significantly reduced EMG activity in the agonist muscle and the perceived exertion score only at 40% workload. However, the reduction of EMG activity and perceived exertion score were lower than that for the physical estimated effect. In addition, the EMG activity in the antagonist muscle was not influenced, irrespective of workload conditions and the level of assistive force. These results suggested that although the assistive force during isometric muscle contraction relieves the exertion of the agonist muscle that accompanies the decrease in perceived exertion, their assistive effects are influenced by various human physiological and anatomical factors. 


Assistive force, elbow flexion, electromyography, isometric contraction, perceived exertion

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Araullo, J. & Potter, L. E. (2016). Promoting physical activity in seniors: Future opportunities with emerging technologies. Proceedings of the 2016 ACM SIGMIS Conference on Computers and People Research. Washington, DC, USA. 57-64.

Baratta, R., Solomonow, M., Zhou, B. H., Letson, D., Chuinard, R., & D'Ambrosia, R. (1988). Muscular coactivation: The role of the antagonist musculature in maintaining knee stability. The American Journal of Sports Medicine, 16(2), 113-122.

Bazzucchi, I., Sbriccoli, P., Marzattinocci, G., & Felici, F. (2006). Coactivation of the elbow antagonist muscles is not affected by the speed of movement in isokinetic exercise. Muscle & Nerve, 33(2), 191-199.

Bellar, D., LeBlanc, N., & Judge, L. W. (2014). Examination of muscle activity with an elastic hamstring assistance device. Health Research and Reviews, 1(1), 20-24.

Borg, G. A. (1982). Psychophysical bases of perceived exertion. Medicine & Science in Sports & Exercise, 14(5), 377–381.

Buchanan, T. S., Rovai, G. P., & Rymer, W. Z. (1989). Strategies for muscle activation during isometric torque generation at the human elbow. Journal of Neurophysiology, 62(6), 1201-1212.

Clark, B. C., Manini, T. M., Ordway, N. R., & Ploutz-Snyder, L. L. (2004). Leg muscle activity during walking with assistive devices at varying levels of weight bearing. Archives of Physical Medicine and Rehabilitation, 85(9), 1555-1560.

Clarys, J. P. (2000). Electromyography in sports and occupational settings: An update of its limits and possibilities. Ergonomics, 43(10), 1750-1762.

Cram, J. R. (2011). In Criswell E. (Ed.), Cram's introduction to surface electromyography (2nd ed.). United States of America: Jones and Bartlett.

Doheny, E. P., Lowery, M. M., Fitzpatrick, D. P., & O'Malley, M. J. (2008). Effect of elbow joint angle on force-EMG relationships in human elbow flexor and extensor muscles. Journal of Electromyography and Kinesiology: Official Journal of the International Society of Electrophysiological Kinesiology, 18(5), 760-770.

Edlich, R. F., Winters, K. L., Hudson, M. A., Britt, L. D., & Long, W. B. (2004). Prevention of disabling back injuries in nurses by the use of mechanical patient lift systems. Journal of Long-Term Effects of Medical Implants, 14(6), 521-533.

Field, A. (2013). Discovering statistics using IBM SPSS statistics. London: SAGE.

Fujishiro, K., Weaver, J. L., Heaney, C. A., Hamrick, C. A., & Marras, W. S. (2005). The effect of ergonomic interventions in healthcare facilities on musculoskeletal disorders. American Journal of Industrial Medicine, 48(5), 338-347.

Gabriel, D. A., Kamen, G., & Frost, G. (2006). Neural adaptations to resistive exercise: Mechanisms and recommendations for training practices. Sports Medicine, 36(2), 133-149.

Galganski, M. E., Fuglevand, A. J., & Enoka, R. M. (1993). Reduced control of motor output in a human hand muscle of elderly subjects during submaximal contractions. Journal of Neurophysiology, 69(6), 2108-2115.

Gerachshenko, T. & Stinear, J. W. (2007). Suppression of motor evoked potentials in biceps brachii preceding pronator contraction. Experimental Brain Research, 183(4), 531-539.

Graves, A. E., Kornatz, K. W., & Enoka, R. M. (2000). Older adults use a unique strategy to lift inertial loads with the elbow flexor muscles. Journal of Neurophysiology, 83(4), 2030-2039.

Han, J., Waddington, G., Adams, R., Anson, J., & Liu, Y. (2016). Assessing proprioception: A critical review of methods. Journal of Sport and Health Science, 5(1), 80-90.

Holmes, M. W. R. & Keir, P. J. (2012). Posture and hand load alter muscular response to sudden elbow perturbations. Journal of Electromyography and Kinesiology, 22(2), 191-198.

Hunter, S. K., Lepers, R., MacGillis, C. J., & Enoka, R. M. (2003). Activation among the elbow flexor muscles differs when maintaining arm position during a fatiguing contraction. Journal of Applied Physiology, 94(6), 2439-2447.

Hutchinson, H. L., Gloystein, D., & Gillespie, M. (2008). Distal biceps tendon insertion: An anatomic study. Journal of Shoulder and Elbow Surgery, 17(2), 342-346.

Jakobsen, M. D., Sundstrup, E., Andersen, C. H., Aagaard, P., & Andersen, L. L. (2013). Muscle activity during leg strengthening exercise using free weights and elastic resistance: Effects of ballistic vs controlled contractions. Human Movement Science, 32(1), 65-78.

Janssen, I., Heymsfield, S. B., & Ross, R. (2002). Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability. Journal of the American Geriatrics Society, 50(5), 889-896.

Kang, T., Seo, Y., Park, J., Dong, E., Seo, B., & Han, D. (2013). The effects of elbow joint angle change on the elbow flexor muscle activation in pulley with weight exercise. Journal of Physical Therapy Science, 25(9), 1133-1136.

Kirkendall, D. T. & Garrett, W. E. Jr. (1998). The effects of aging and training on skeletal muscle. The American Journal of Sports Medicine, 26(4), 598-602.

Kuriki, H. U., Azevedo, F. M. d., Takahashi, L. S. O., Mello, E. M., Filho, R. d. F. N., & Alves, N. (2012). The relationship between electromyography and muscle force. EMG Methods for Evaluating Muscle and Nerve Function, 31-54.

Lagally, K. M., McCaw, S. T., Young, G. T., Medema, H. C., & Thomas, D. Q. (2004). Ratings of perceived exertion and muscle activity during the bench press exercise in recreational and novice lifters. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 18(2), 359-364.

Lagally, K. M., Robertson, R. J., Gallagher, K. I., Gearhart, R., & Goss, F. L. (2002). Ratings of perceived exertion during low- and high-intensity resistance exercise by young adults. Perceptual and Motor Skills, 94, 723-731.

Levine, M. G. & Kabat, H. (1952). Cocontraction and reciprocal innervation in voluntary movement in man. Science, 116(3005), 115-118.

Li, K. W. & Yu, R. (2011). Assessment of grip force and subjective hand force exertion under handedness and postural conditions. Applied Ergonomics, 42(6), 929-933.

Linnamo, V., Moritani, T., Nicol, C., & Komi, P. V. (2003). Motor unit activation patterns during isometric, concentric and eccentric actions at different force levels. Journal of Electromyography and Kinesiology: Official Journal of the International Society of Electrophysiological Kinesiology, 13(1), 93-101.

Locks, F., Santos, H. Hd., Carvalho, L. C., Stolt, L. R. O. G., & Ferreira, J. Jd. A. (2015). Neural adaptations in isometric contractions with EMG and force biofeedback. Motriz: Revista de Educação Física, 21(1), 15-22.

Mayer, F., Scharhag-Rosenberger, F., Carlsohn, A., Cassel, M., Müller, S., & Scharhag, J. (2011). The intensity and effects of strength training in the elderly. Deutsches Ä rzteblatt International, 108(21), 359-364.

McCreadie, C. & Tinker, A. (2005). The acceptability of assistive technology to older people. Ageing and Society, 25(1), 91-110.

McGuire, J., Green, L. A., & Gabriel, D. A. (2014). Task complexity and maximal isometric strength gains through motor learning. Physiological Reports, 2(11), 1-12.

Miyawaki, K., Sato, T., Iwami, T., Obinata, G., Shimada, Y., & Chida, S. (2009). Evaluation of utility of the "arm-balancer" arm support system. Life support, 21(1), 3-9.

Miyawaki, K., Sato, T., Iwami, T., Matsunaga, T., Chida, S., Shimada, Y., & Obinata, G. (2010). Evaluation of utility of the “Arm-Balancer” arm support system. 2010 International Symposium on Micro-Nano Mechatronics and Human Science, Nagoya, 208-213.

Morishita, S, Yamauchi, S, Fujisawa, C., & Domen, K. (2013) Rating of perceived exertion for quantification of the intensity of resistance exercise. International Journal of Physical Medicine & Rehabilitation, 1(9)172, 1-4.

Mottram, C. J., Maluf, K. S., Stephenson, J. L., Anderson, M. K., & Enoka, R. M. (2006). Prolonged vibration of the biceps brachii tendon reduces time to failure when maintaining arm position with a submaximal load. Journal of Neurophysiology, 95(2), 1185-1193.

Murray, W. R. (1988). Maintenance of elbow equilibrium through co-contraction. Proceedings of the 1988 Fourteenth Annual Northeast Bioengineering Conference, 29-32.

Oldfield, R. C. (1971). The assessment and analysis of handedness: The Edinburgh inventory. Neuropsychologia, 9(1), 97-113.

Pincivero, D. M., Coelho, A. J., & Erikson, W. H. (2000). Perceived exertion during isometric quadriceps contraction: A comparison between men and women. Journal of Sports Medicine and Physical Fitness, 40(4), 319-26.

Pincivero, D. M., Coelho, A. J., Campy, R. M., Salfetnikov, Y., & Bright, A. (2001). The effects of voluntary contraction intensity and gender on perceived exertion during isokinetic quadriceps exercise. European Journal of Applied Physiology, 84(3), 221-226.

Pincivero, D. M., Coelho, A. J., Campy, R. M., Salfetnikov, Y., & Bright, A. (2002). The effects of voluntary contraction effort on quadriceps femoris electromyogram median frequency in humans: A muscle and sex comparison. European Journal of Applied Physiology, 87(4-5), 448-455.

Proske, U. & Gandevia, S. C. (2012). The proprioceptive senses: Their roles in signaling body shape, body position and movement, and muscle force. Physiological Reviews, 92(4), 1651-1697.

Rasch, P. J., Pierson, W. R., & Logan, G. A. (1961). The effect of isometric exercise upon the strength of antagonistic muscles. Internationale Zeitschrift Fur Angewandte Physiologie, Einschliesslich Arbeitsphysiologie, 19, 18-22.

Riemann, B. L. & Lephart, S. M. (2002). The sensorimotor system, part II: The role of proprioception in motor control and functional joint stability. Journal of Athletic Training, 37(1), 80-84.

Rikli, R. E. (2005). Movement and mobility influence on successful aging: Addressing the issue of low physical activity. Quest, 57(1), 46-66.

Robertson, D. G. E., Caldwell, G. E., Hamill, J., Kamen, G. & Whittlesey, S. N. (2004). Research methods in biomechanics. United States of America: Human Kinetics.

Rochette, L., Hunter, S. K., Place, N., & Lepers, R. (2003). Activation varies among the knee extensor muscles during a submaximal fatiguing contraction in the seated and supine postures. Journal of Applied Physiology, 95(4), 1515-1522.

Shibata, K., Takizawa, K., & Mizuno, M. (2015). Comparison between twelve and six sets of high load leg extension on muscle strength. Movement, Health & Exercise, 4(1), 51-59.

St Clair Gibson, A., Lambert, M. L., & Noakes, T. D. (2001). Neural control of force output during maximal and submaximal exercise. Sports Medicine, 31(9), 637-650.

Tilney, F. & Pike, F. H. (1925). Muscular coordination experimentally studied in its relation to the cerebellum. Archives Neuropsychiatry, 13(3), 289-334.

Troiano, A., Naddeo, F., Sosso, E., Camarota, G., Merletti, R., & Mesin, L. (2008). Assessment of force and fatigue in isometric contractions of the upper trapezius muscle by surface EMG signal and perceived exertion scale. Gait & Posture, 28(2), 179-186.

Yusif, S., Soar, J., & Hafeez-Baig, A. (2016). Older people, assistive technologies, and the barriers to adoption: A systematic review. International Journal of Medical Informatics, 94, 112-116.

Zhuang, Z., Stobbe, T. J., Hsiao, H., Collins, J. W., & Hobbs, G. R. (1999). Biomechanical evaluation of assistive devices for transferring residents. Applied Ergonomics, 30(4), 285-294.