Abstract
This study was designed to investigate if the relationship between the interpolated twitch-torque (IT) and voluntary torque (VT) is affected by the number of electrical stimuli (single vs. double) and the stimulation site (nerve trunk vs. muscle). The results showed that the IT–VT relationship of the plantar flexors is appropriately described by a composite (linear + curvilinear) model. Indeed, whatever the stimulation method, the IT–VT relationship was linear between approximately 25 and 75% of the maximal voluntary torque (MVT) and curvilinear for higher contraction intensities. The four stimulation conditions are equivalent in assessing the maximal voluntary activation (VA% range 96.2 ± 5.0 to 98.5 ± 3.1%) as well as in determining the true maximal torque expected for total twitch occlusion (MTexp range 171.4 ± 21.2 to 179.0 ± 26.8 Nm). The gap between the MVT and MTexp should be viewed as an index of muscle inactivation. This gap was comparable for the four stimulation methods (2–6%) and close to the deficit in VA% (2–4%). No pulse-number effect was found on the IT–VT relationship when the nerve was stimulated but an effect on the concavity of the composite relationship was observed when the stimulation was applied over the muscle. Even though the four stimulation techniques are equivalent in assessing the maximal activation capacity our results demonstrate that the neural stimulation method is the most consistent as it guarantees the same motor pool recruitment independently from the number of pulses.
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Abbreviations
- DP:
-
Deviation point
- IT:
-
Interpolated twitch torque
- ITT:
-
Interpolated twitch technique
- MVC:
-
Maximal voluntary contraction
- MVT:
-
Maximal voluntary torque
- MTexp :
-
Maximal torque expected for total twitch occlusion
- PFs:
-
Plantar flexors
- PRT:
-
Potentiated rest twitch torque
- RT:
-
Rest twitch torque
- RTexp :
-
Rest twitch torque expected
- VA:
-
Voluntary activation
- VT:
-
Voluntary torque
References
Allen GM, Gandevia SC, McKenzie DK (1995) Reliability of measurements of muscle strength and voluntary activation using twitch interpolation. Muscle Nerve 18:593–600. doi:10.1002/mus.880180605
Allen GM, McKenzie DK, Gandevia SC (1998) Twitch interpolation of the elbow flexor muscles at high forces. Muscle Nerve 21:318–328. doi:10.1002/(SICI)1097-4598(199803)21:3<318::AID-MUS5>3.0.CO;2-D
Behm DG, St-Pierre DM, Perez D (1996) Muscle inactivation: assessment of interpolated twitch technique. J Appl Physiol 81:2267–2273
Behm D, Power K, Drinkwater E (2001) Comparison of interpolation and central activation ratios as measures of muscle inactivation. Muscle Nerve 24:925–934. doi:10.1002/mus.1090
Belanger AY, McComas AJ (1981) Extent of motor unit activation during effort. J Appl Physiol 51:1131–1135
Bulow PM, Norregaard J, Danneskiold-Samsoe B, Mehlsen J (1993) Twitch interpolation technique in testing of maximal muscle strength: influence of potentiation, force level, stimulus intensity and preload. Eur J Appl Physiol Occup Physiol 67:462–466. doi:10.1007/BF00376464
Chapman SJ, Edwards RHT, Greig C, Rutherford O (1985) Practical application of the twitch interpolation technique for the study of voluntary contraction of the quadriceps muscle in man. J Physiol 353:3P
De Serres SJ, Enoka RM (1998) Older adults can maximally activate the biceps brachii muscle by voluntary command. J Appl Physiol 84:29–284. doi:10.1063/1.368025
Dowling JJ, Konert E, Ljucovic P, Andrews DM (1994) Are humans able to voluntarily elicit maximum muscle force? Neurosci Lett 179:25–28. doi:10.1016/0304-3940(94)90926-1
Folland JP, Williams AG (2007) Methodological issues with the interpolated twitch technique. J Electromyogr Kinesiol 17(3):317–327. doi:10.1016/j.jelekin.2006.04.008
Gandevia SC (2001) Spinal and supraspinal factors in human muscle fatigue. Physiol Rev 81(4):1725–1789
Herbert RD, Gandevia SC (1999) Twitch interpolation in human muscles: mechanisms and implications for measurement of voluntary activation. J Neurophysiol 82:2271–2283
Kent-Braun JA, Ng AV (1999) Specific strength and voluntary muscle activation in young and elderly women and men. J Appl Physiol 87:22–29
Loring SH, Hershenson MB (1992) Effects of series compliance on twitches superimposed on voluntary contractions. J Appl Physiol 73:516–521
Merton PA (1954) Voluntary strength and fatigue. J Physiol 123:553–564
Miller M, Downham D, Lexell J (1999) Superimposed single impulse and pulse train electrical stimulation: a quantitative assessment during submaximal isometric knee extension in young, healthy men. Muscle Nerve 22:1038–1046. doi:10.1002/(SICI)1097-4598(199908)22:8<1038::AID-MUS5>3.0.CO;2-R
Norregaard J, Lykkegaard JJ, Bulow PM, Danneskiold-Samsoe B (1997) The twitch interpolation technique for the estimation of true quadriceps muscle strength. Clin Physiol 17:523–532. doi:10.1046/j.1365-2281.1997.05555.x
Phillips SK, Bruce SA, Newton D, Woledge RC (1992) The weakness of old age is not due to failure of muscle activation. J Gerontol 47:M45–M49
Rutherford OM, Jones DA, Newham DJ (1986) Clinical and experimental application of the percutaneous twitch superimposition technique for the study of human muscle activation. J Neurol Neurosurg Psychiatry 49:1288–1291. doi:10.1136/jnnp.49.11.1288
Scaglioni G, Ferri A, Minetti AE, Martin A, Van Hoecke J, Capodaglio P, Sartorio A, Narici MV (2002) Plantar flexor activation capacity and H reflex in older adults: adaptations to strength training. J Appl Physiol 92:2292–2302
Shield A, Zhou S (2004) Assessing voluntary muscle activation with the twitch interpolation technique. Sports Med 34:253–267. doi:10.2165/00007256-200434040-00005
Stackhouse SK, Dean JC, Lee SC, Binder-MacLeod SA (2000) Measurement of central activation failure of the quadriceps femoris in healthy adults. Muscle Nerve 23:1706–1712. doi:10.1002/1097-4598(200011)23:11<1706::AID-MUS6>3.0.CO;2-B
Stackhouse SK, Stevens JE, Johnson CD, Snyder-Mackler L, Binder-Macleod SA (2003) Predictability of maximum voluntary isometric knee extension force from submaximal contractions in older adults. Muscle Nerve 27:40–45. doi:10.1002/mus.10278
Suter E, Herzog W (2001) Effect of number of stimuli and timing of twitch application on variability in interpolated twitch torque. J Appl Physiol 90:1036–1040
Todd G, Gorman RB, Gandevia SC (2004) Measurement and reproducibility of strength and voluntary activation of lower-limb muscles. Muscle Nerve 29:834–842. doi:10.1002/mus.20027
Yue GH, Ranganathan VK, Siemionow V, Liu JZ, Sahgal V (2000) Evidence of inability to fully activate human limb muscle. Muscle Nerve 23:376–384. doi:10.1002/(SICI)1097-4598(200003)23:3<376::AID-MUS9>3.0.CO;2-2
Acknowledgments
This work was supported by European Commission Framework V funding (‘Better Ageing’ Project, No. QLRT-2001-00323).
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Scaglioni, G., Martin, A. Assessment of plantar flexors activation capacity: nerve versus muscle stimulation by single versus double pulse. Eur J Appl Physiol 106, 563–572 (2009). https://doi.org/10.1007/s00421-009-1049-y
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DOI: https://doi.org/10.1007/s00421-009-1049-y