European Journal of Applied Physiology

, Volume 110, Issue 6, pp 1251–1257 | Cite as

Sex differences in force steadiness in three positions of the forearm

  • Ruth E. Brown
  • Darl L. Edwards
  • Jennifer M. Jakobi
Original Article

Abstract

The purpose of this study was to examine force steadiness in three positions of the forearm in young men and women across a variety of force levels. Eight young men and eight young women performed three maximum voluntary contractions (MVCs) in the neutral, supinated, and pronated forearm positions. Viewing a target line on a computer screen, subjects performed submaximal isometric contractions relative to their own MVC at 2.5, 5, 10, 25, 50, and 75% in each of the three forearm positions. Force steadiness was determined as the coefficient of variation (standard deviation around the mean force). A repeated-measures three-way ANOVA was used to assess the differences in force steadiness between sex, position, and force level. Men were stronger than women in all three forearm positions. Overall, men were steadier than women across all force levels and forearm positions. The neutral and supinated positions were equally strong and steady, and the pronated position was the weakest and least steady position. The forearm was most steady between 25 and 75% MVC, and least steady at the lower force levels. When correlations were run between MVC and coefficient of variation at all force levels and all forearm positions, a strong negative relationship was found (r = −0.49). In conclusion, men were stronger, as well as steadier, than women. The neutral and supinated forearm positions were both stronger and steadier than the pronated position. Results suggest that one of the primary factors influencing sex differences in force steadiness is absolute strength.

Keywords

Strength Sex differences Force steadiness Neutral Supinated Pronated 

References

  1. Barry BK, Riley ZA, Pascoe MA, Enoka RM (2008) A spinal pathway between synergists can modulate activity in human elbow flexor muscles. Exp Brain Res 190(3):347–359CrossRefPubMedGoogle Scholar
  2. Bazzucchi I, Felici F, Macaluso A, De Vito G (2004) Differences between young and older women in maximal force, force fluctuations, and surface EMG during isometric knee extension and elbow flexion. Muscle Nerve 30:626–635CrossRefPubMedGoogle Scholar
  3. Brown RE, Bruce SH, Jakobi JM (2009a) Is the ability to maximally activate the dorsiflexors in adult men and women affected by indwelling EMG needles? Arch Phys Med Rehabil 54:2135–2140CrossRefGoogle Scholar
  4. Brown RE, Edwards DL, Kenno KA, Jakobi JM (2009b) Effect of tendon vibration on elbow flexor force steadiness and motor unit activity in men and women. Med Sci Sports Exer 41(S5):S21Google Scholar
  5. Carville SF, Rutherford OM, Newham DJ (2006) Power output, isometric strength and steadiness in the leg muscles of pre- and postmenopausal women; the effects of hormone replacement therapy. Eur J Appl Physiol 96:292–298CrossRefPubMedGoogle Scholar
  6. Carville SF, Perry MC, Rutherford OM, Smith CH, Newham DJ (2007) Steadiness of quadriceps contractions in young and older adults with and without a history of falling. Eur J Appl Physiol 100:527–533CrossRefPubMedGoogle Scholar
  7. Christou EA, Jakobi JM, Critchlow A, Fleshner M, Enoka RM (2004) The 1- to 2-Hz oscillations in muscle force are exacerbated by stress, especially in older adults. J Appl Physiol 97:225–235CrossRefPubMedGoogle Scholar
  8. Clark BC, Collier SR, Manini TM, Ploutz-Snyder LL (2005) Sex differences in muscle fatigability and activation patterns of the human quadriceps femoris. Eur J Appl Physiol 94:196–206CrossRefPubMedGoogle Scholar
  9. Danion F, Gallea C (2004) The relation between force magnitude, force steadiness, and muscle co-contraction in the thumb during precision grip. Neurosci Lett 368:176–180CrossRefPubMedGoogle Scholar
  10. Dewhurst S, Graven-Nielsen T, De Vito G, Farina D (2007) Muscle temperature has a different effect on force fluctuations in young and older women. Clin Neurophysiol 118:762–769CrossRefPubMedGoogle Scholar
  11. Enoka RM, Christou EA, Hunter SK, Kornatz KW, Semmler JG, Taylor AM, Tracy BL (2003) Mechanisms that contribute to differences in motor performance between young and old adults. J Electromyogr Kinesiol 13:1–12CrossRefPubMedGoogle Scholar
  12. Graves AE, Kornatz KW, Enoka RM (2000) Older adults use a unique strategy to lift inertial loads with the elbow flexor muscles. J Neurophysiol 83:2030–2039PubMedGoogle Scholar
  13. Hart CEF, Tracy BL (2008) Yoga as steadiness training: effects on motor variability in young adults. J Strength Cond Res 22:1659–1669CrossRefPubMedGoogle Scholar
  14. Harwood B, Edwards DL, Jakobi JM (2008) Age- and sex-related differences in muscle activation for a discrete functional task. Eur J Appl Physiol 103(6):677–686Google Scholar
  15. Harwood B, Edwards DL, Jakobi JM (2010) Age independent and position dependent alterations in motor unit activity of the biceps brachii. Eur J Appl Physiol. doi:10.1007/s00421-010-1438-2
  16. Hortobagyi T, Tunnel D, Moody J, Beam S, De Vita P (2001) Low- or high-intensity strength and training partially restores impaired quadriceps force accuracy and steadiness in aged adults. J Gerontol 56A:38–47Google Scholar
  17. Hunter SK, Enoka RM (2001) Sex differences in the fatigability of arm muscles depends on absolute force during isometric contractions. J Appl Physiol 91:2686–2694PubMedGoogle Scholar
  18. Jongen HA, Denier van der Gon JJ, Gielen CC (1989) Inhomogeneous activation of motoneurone pools as revealed by co-contraction of antagonistic human arm muscles. Exp Brain Res 75(3):555–562Google Scholar
  19. Kanehisa H, Ikegawa S, Fukunaga T (1994) Comparison of muscle cross-sectional area and strength between untrained women and men. Eur J Appl Physiol Occup Physiol 68:148–154CrossRefPubMedGoogle Scholar
  20. Laidlaw DH, Bilodeau M, Enoka RM (2000) Steadiness is reduced and motor unit discharge is more variable in old adults. Muscle Nerve 23:600–612CrossRefPubMedGoogle Scholar
  21. Matsuoka J, Berger RA, Berglund LJ, An K (2006) An analysis of symmetry of torque strength of the forearm under resisted forearm rotation in normal subjects. J Hand Surg 31A:801–805Google Scholar
  22. Miller AEJ, MacDougall JD, Tarnopolsky MA, Sale DG (1993) Gender differences in strength and muscle fiber characteristics. Eur J Appl Physiol 66:254–262CrossRefGoogle Scholar
  23. Mogk JPM, Keir PJ (2003) The effects of posture on forearm muscle loading during gripping. Ergonomics 46:956–975CrossRefPubMedGoogle Scholar
  24. Moritz CT, Barry BK, Pascoe MA, Enoka RM (2005) Discharge rate variability influences the variation in force fluctuations across the working range of a hand muscle. J Neurophysiol 93:2449–2459CrossRefPubMedGoogle Scholar
  25. Murray WM, Delp SL, Buchanan TS (1995) Variation of muscle moment arms with and forearm position. J Biomech 28:513–525CrossRefPubMedGoogle Scholar
  26. Nonaka H, Mita K, Akataki K, Watakabe M, Itoh Y (2006) Sex differences in mechanomyographic responses to voluntary isometric contractions. Med Sci Sports Exerc 38(7):1311–1316Google Scholar
  27. Paquet B, Carpentier A, Duchateau J (2005) Change in muscle fascicle length influences the recruitment and discharge rate of motor units during isometric contractions. J Neurophysiol 94:3126–3133CrossRefGoogle Scholar
  28. Paquet B, Carpentier A, Duchateau J (2006) Specific modulation of motor unit discharge for a similar change in fascicle length during shortening and lengthening contractions in humans. J Physiol 1:753–765CrossRefGoogle Scholar
  29. Sarwar R, Niclos BB, Rutherford OM (1996) Changes in muscle strength, relaxation rate and fatiguability during the human menstrual cycle. J Physiol 493( Pt 1):267–272Google Scholar
  30. Seynnes O, Hue OA, Garrandes F, Colson SS, Bernard PL, Legros P, Fiatarone Singh MA (2005) Force steadiness in the lower extremities as an independent predictor of functional performance in older women. J Aging Phys Act 13:395–408PubMedGoogle Scholar
  31. Slifkin AB, Newell KM (1999) Noise, information transmission, and force variability. J Exp Psychol Hum Percept Perform 25:837–851CrossRefPubMedGoogle Scholar
  32. Solomonow M, Baratta R, Zhou BH, D'Ambrosia R (1988) Electromyogram coactivation patterns of the elbow antagonist muscles during slow isokinetic movement. Exp Neurol 100(3):470–477Google Scholar
  33. Sosnoff JJ, Newell KM (2006) Are age-related increases in force variability due to decrements in strength? Exp Brain Res 174:86–94CrossRefPubMedGoogle Scholar
  34. ter Haar Romeny BM, van der Gon JJ, Gielen CC (1984) Relation between location of a motor unit in the human biceps brachii and its critical firing levels for different tasks. Exp Neurol 85(3):631–650Google Scholar
  35. Tracy BL, Enoka RM (2002) Older adults are less steady during submaximal isometric contractions with the knee extensor muscles. J Appl Physiol 92:1004–1012PubMedGoogle Scholar
  36. Tracy BL, Mehoudar PD, Ortega JD (2007) The amplitude of force variability is correlated in the knee extensor and elbow flexor muscles. Exp Brain Res 176:448–464CrossRefPubMedGoogle Scholar
  37. Turner TS, Tucker KJ, Rogasch NC, Semmler JG (2008) Impaired neuromuscular function during isometric, shortening, and lengthening contractions after exercise induced damage to elbow flexor muscles. J Appl Physiol 105:502–509CrossRefPubMedGoogle Scholar
  38. van Zuylen EJ, Gielen CC, Denier van der Gon JJ (1988) Coordination and inhomogeneous activation of human arm muscles during isometric torques. J Neurophysiol 60:1523–1548Google Scholar
  39. Zhang L, Butler J, Nishida T, Nuber G, Huang H, Rymer WZ (1998) In vivo determination of the direction of rotation and moment-angle relationship of individual elbow muscles. J Biomech Eng 120:625–633CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Ruth E. Brown
    • 1
  • Darl L. Edwards
    • 2
  • Jennifer M. Jakobi
    • 1
  1. 1.University of British Columbia OkanaganKelownaCanada
  2. 2.University of WindsorWindsorCanada

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