Few studies have assessed changes in the time course of the torque and neuromuscular responses during a sustained, isometric task anchored to a constant rating of perceived exertion. The purpose of the present study was to examine the effects of joint angle on the torque and neuromuscular responses during sustained, isometric forearm flexion tasks anchored to RPE = 7 (OMNI-RES scale). Ten college-aged (mean ± SD: age = 21.3 ± 1.8 yrs.) men agreed to participate in this cross-sectional study and performed two, 3s maximal voluntary isometric contractions (MVIC) at elbow joint angles of 75° and 125° before sustained, isometric, forearm flexions anchored to RPE = 7 to task failure at the respective joint angles. The amplitude (AMP) and frequency (MPF) of the electromyographic (EMG) and mechanomyographic (MMG) signals from the biceps brachii were recorded. Repeated measures ANOVAs and Bonferroni corrected dependent t-tests were used to examine differences across time and between joint angles for torque and neuromuscular parameters. There were decreases (p < 0.05) in torque and EMG AMP across time that were not joint angle dependent, but, there were no changes (p > 0.05) for the other neuromuscular parameters. The results indicated three distinct phases for the torque versus time relationships for both joint angles, including 1) An initial rapid decrease in torque; 2) followed by a plateau; and 3) a final decline in torque to task failure. From these responses, we hypothesized that afferent feedback from group III/IV motor neurons and corollary discharge caused decreases in torque to maintain the prescribed RPE.
| [1] | Marcora, S.M. and W. Staiano, The limit to exercise tolerance in humans: mind over muscle? Eur J Appl Physiol, 2010. 109(4): p. 763-70.View Article PubMed |
| [2] | Robertson, R.J. and B.J. Noble, Perception of physical exertion: Methods, mediators, and applications. Exerc Sport Sci Rev, 1997. 25: p. 407-52.View Article |
| [3] | Dias, M.R.C., R. Simão, F.J.F. Saavedra, C.F. Buzzachera, and S. Fleck, Self-Selected Training Load and RPE During Resistance and Aerobic Training Among Recreational Exercisers. Percept Mot Skills, 2018. 125(4): p. 769-787.View Article PubMed |
| [4] | Helms, E.R., K. Kwan, C.A. Sousa, J.B. Cronin, A.G. Storey, and M.C. Zourdos, Methods for Regulating and Monitoring Resistance Training. J Hum Kinet, 2020. 74: p. 23-42.View Article PubMed |
| [5] | Cochrane-Snyman, K.C., T.J. Housh, C.M. Smith, E.C. Hill, and N.D.M. Jenkins, Treadmill running using an RPE-clamp model: mediators of perception and implications for exercise prescription. Eur J Appl Physiol, 2019. 119(9): p. 2083-2094.View Article PubMed |
| [6] | Greenhouse-Tucknott, A., J.B. Butterworth, J.G. Wrightson, N.A. Harrison, and J. Dekerle, Effect of the subjective intensity of fatigue and interoception on perceptual regulation and performance during sustained physical activity. PLoS One, 2022. 17(1): p. e0262303.View Article PubMed |
| [7] | Enoka, R.M. and J. Duchateau, Translating Fatigue to Human Performance. Med Sci Sports Exerc, 2016. 48(11): p. 2228-2238.View Article PubMed |
| [8] | Kluger, B.M., L.B. Krupp, and R.M. Enoka, Fatigue and fatigability in neurologic illnesses: proposal for a unified taxonomy. Neurology, 2013. 80(4): p. 409-16.View Article PubMed |
| [9] | Smith, R.W., et al., Perceptual fatigability and neuromuscular responses during a sustained, isometric forearm flexion muscle action anchored to a constant level of perceived exertion. NeuroSports, 2021. 1(2): p. 1-23. |
| [10] | Pageaux, B., Perception of effort in Exercise Science: Definition, measurement and perspectives. Eur J Sport Sci, 2016. 16(8): p. 885-94.View Article PubMed |
| [11] | Thomas, K., S. Goodall, and G. Howatson, Performance Fatigability Is Not Regulated to A Peripheral Critical Threshold. Exerc Sport Sci Rev, 2018. 46(4): p. 240-246.View Article PubMed |
| [12] | Keller, J.L., T.J. Housh, J.P.V. Anders, T.J. Neltner, R.J. Schmidt, and G.O. Johnson, Anchor scheme, intensity, and time to task failure do not influence performance fatigability or changes in neuromuscular responses following bilateral leg extensions. JEPonline, 2020. 23(4): p. 119-134. |
| [13] | Tucker, R., The anticipatory regulation of performance: the physiological basis for pacing strategies and the development of a perception-based model for exercise performance. Br J Sports Med, 2009. 43(6): p. 392-400.View Article PubMed |
| [14] | Robertson, R.J., et al., Concurrent validation of the OMNI perceived exertion scale for resistance exercise. Med Sci Sports Exerc, 2003. 35(2): p. 333-41.View Article PubMed |
| [15] | Arendt-Nielsen, L., K.R. Mills, and A. Forster, Changes in muscle fiber conduction velocity, mean power frequency, and mean EMG voltage during prolonged submaximal contractions. Muscle & nerve, 1989. 12(6): p. 493-7.View Article PubMed |
| [16] | De Luca, C.J., Myoelectrical manifestations of localized muscular fatigue in humans. Crit Rev Biomed Eng, 1984. 11(4): p. 251-79. |
| [17] | Beck, T.W., T.J. Housh, G.O. Johnson, J.P. Weir, J.T. Cramer, J.W. Coburn, and M.H. Malek, Mechanomyographic amplitude and mean power frequency versus torque relationships during isokinetic and isometric muscle actions of the biceps brachii. J Electromyogr Kinesiol, 2004. 14(5): p. 555-64.View Article PubMed |
| [18] | Beck, T.W., T.J. Housh, G.O. Johnson, J.T. Cramer, J.P. Weir, J.W. Coburn, and M.H. Malek, Does the frequency content of the surface mechanomyographic signal reflect motor unit firing rates? A brief review. J Electromyogr Kinesiol, 2007. 17(1): p. 1-13.View Article PubMed |
| [19] | Doheny, E.P., M.M. Lowery, D.P. Fitzpatrick, and M.J. O'Malley, Effect of elbow joint angle on force-EMG relationships in human elbow flexor and extensor muscles. J Electromyogr Kinesiol, 2008. 18(5): p. 760-70.View Article PubMed |
| [20] | Weir, J.P., K.M. Ayers, J.F. Lacefield, and K.L. Walsh, Mechanomyographic and electromyographic responses during fatigue in humans: influence of muscle length. Eur J Appl Physiol, 2000. 81(4): p. 352-9.View Article PubMed |
| [21] | Kulig, K., J.G. Andrews, and J.G. Hay, Human strength curves. Exerc Sport Sci Rev, 1984. 12(1): p. 417-466.View Article PubMed |
| [22] | Keller, J.L., T.J. Housh, E.C. Hill, C.M. Smith, R.J. Schmidt, and G.O. Johnson, Neuromuscular responses of recreationally active women during a sustained, submaximal isometric leg extension muscle action at a constant perception of effort. Eur J Appl Physiol, 2018. 118(12): p. 2499-2508.View Article PubMed |
| [23] | Keller, J.L., T.J. Housh, E.C. Hill, C.M. Smith, R.J. Schmidt, and G.O. Johnson, Self-regulated force and neuromuscular responses during fatiguing isometric leg extensions anchored to a rating of perceived exertion. Appl Psychophysiol Biofeedback, 2019. 44(4): p. 343-350.View Article PubMed |
| [24] | Linnamo, V., V. Strojnik, and P.V. Komi, Maximal force during eccentric and isometric actions at different elbow angles. Eur J Appl Physiol, 2006. 96(6): p. 672-8.View Article PubMed |
| [25] | Zajac, F.E., Muscle and tendon: properties, models, scaling, and application to biomechanics and motor control. Crit Rev Biomed Eng, 1989. 17(4): p. 359-411. |
| [26] | Smith, R.W., T.J. Housh, J.P.V. Anders, T.J. Neltner, J.E. Arnett, R.J. Schmidt, and G.O. and Johnson, Application of the ratings of perceived exertion-clamp model to examine the effects of joint angle on the time course of torque and neuromuscular responses during a sustained, isometric forearm flexion task to failure. J Strength Cond Res, Accepted. |
| [27] | Albertus, Y., R. Tucker, A. St Clair Gibson, E.V. Lambert, D.B. Hampson, and T.D. Noakes, Effect of distance feedback on pacing strategy and perceived exertion during cycling. Med Sci Sports Exerc, 2005. 37(3): p. 461-8.View Article PubMed |
| [28] | Hermens, H.J., B. Freriks, C. Disselhorst-Klug, and G. Rau, Development of recommendations for SEMG sensors and sensor placement procedures. J Electromyogr Kinesiol, 2000. 10(5): p. 361-74.View Article |
| [29] | Kwatny, E., D.H. Thomas, and H.G. Kwatny, An application of signal processing techniques to the study of myoelectric signals. IEEE Trans Biomed Eng, 1970. 17(4): p. 303-13.View Article PubMed |
| [30] | Komi, P.V., Strength and Power in Sport. The Encyclopedia of Sports Medicine. 1992, Boston, MA: Blackwell Scientific Publications. 404. |
| [31] | Philippou, A., G.C. Bogdanis, A.M. Nevill, and M. Maridaki, Changes in the angle-force curve of human elbow flexors following eccentric and isometric exercise. Eur J Appl Physiol, 2004. 93(1-2): p. 237-44.View Article PubMed |
| [32] | Keller, J.L., T.J. Housh, C.M. Smith, E.C. Hill, R.J. Schmidt, and G.O. Johnson, Sex-Related Differences in the Accuracy of Estimating Target Force Using Percentages of Maximal Voluntary Isometric Contractions vs. Ratings of Perceived Exertion During Isometric Muscle Actions. J Strength Cond Res, 2018. 32(11): p. 3294-3300.View Article PubMed |
| [33] | Pincivero, D.M., A.J. Coelho, R.M. Campy, Y. Salfetnikov, and E. Suter, Knee extensor torque and quadriceps femoris EMG during perceptually-guided isometric contractions. J Electromyogr Kinesiol, 2003. 13(2): p. 159-67.View Article |
| [34] | West, S.J., L. Smith, E.V. Lambert, T.D. Noakes, and A. St Clair Gibson, Submaximal force production during perceptually guided isometric exercise. Eur J Appl Physiol, 2005. 95(5-6): p. 537-42.View Article PubMed |
| [35] | Flood, T.R., M. Waldron, and O. Jeffries, Oral L-menthol reduces thermal sensation, increases work-rate and extends time to exhaustion, in the heat at a fixed rating of perceived exertion. Eur J Appl Physiol, 2017. 117(7): p. 1501-1512.View Article PubMed |
| [36] | Amann, M., H.Y. Wan, T.S. Thurston, V.P. Georgescu, and J.C. Weavil, On the influence of group III/IV muscle afferent feedback on endurance exercise performance. Exerc Sport Sci Rev, 2020. 48(4): p. 209-216.View Article PubMed |
| [37] | Zénon, A., M. Sidibé, and E. Olivier, Disrupting the supplementary motor area makes physical effort appear less effortful. J Neurosci, 2015. 35(23): p. 8737-44.View Article PubMed |
| [38] | Marcora, S., Perception of effort during exercise is independent of afferent feedback from skeletal muscles, heart, and lungs. J Appl Physiol, 2009. 106(6): p. 2060-2.View Article PubMed |
| [39] | Allen, D.G., G.D. Lamb, and H. Westerblad, Skeletal muscle fatigue: cellular mechanisms. Physiol Rev, 2008. 88(1): p. 287-332.View Article PubMed |
| [40] | Broxterman, R.M., et al., Influence of group III/IV muscle afferents on small muscle mass exercise performance: a bioenergetics perspective. J Physiol, 2018. 596(12): p. 2301-2314.View Article PubMed |
| [41] | Bonde-Petersen, F., A.L. Mork, and E. Nielsen, Local muscle blood flow and sustained contractions of human arm and back muscles. Eur J Appl Physiol Occup Physiol, 1975. 34(1): p. 43-50.View Article PubMed |
| [42] | Maclaren, D.P., H. Gibson, M. Parry-Billings, and R.H. Edwards, A review of metabolic and physiological factors in fatigue. Exerc Sport Sci Rev, 1989. 17: p. 29-66.View Article PubMed |
| [43] | Jones, A.A., G.A. Power, and W. Herzog, History dependence of the electromyogram: Implications for isometric steady-state EMG parameters following a lengthening or shortening contraction. J Electromyogr Kinesiol, 2016. 27: p. 30-8.View Article PubMed |
| [44] | Hureau, T.J., L.M. Romer, and M. Amann, The 'sensory tolerance limit': A hypothetical construct determining exercise performance? Eur J Sport Sci, 2018. 18(1): p. 13-24.View Article PubMed |
| [45] | Robertson, C.V. and F.E. Marino, A role for the prefrontal cortex in exercise tolerance and termination. J Appl Physiol, 2016. 120(4): p. 464-6.View Article PubMed |
