[en] The purpose of this study was to investigate the reproducibility of findings derived from a new iso-inertial dynamometer during bench press (BP) and squat (SQ) and to provide descriptive data for recreational athletes. A position transducer and accelerometer were combined to assess velocity and power during free weight lifting exercises. Simulated movement with a pulley system revealed the excellent technical consistency of the dynamometer. Sixteen male subjects participated in the study. Iso-inertial tests consisted of lifting as fast as possible four different relative loads (35, 50, 70, 90% 1RM in BP and 45, 60, 75, 90% 1RM in SQ). The test was repeated one week later. Analysis of variance revealed no significant variation between sessions or trials. Reproducibility was better in velocity than in power, although it remained fairly good in both exercises (coefficients of variation [CV] never exceeding 10%) except for the time to peak power parameter. Descriptive data confirmed the classical force-velocity and force-power relationships for BP and SQ. In conclusion, this study demonstrated reliable measurements in BP and SQ iso-inertial exercises. Monitoring force-velocity and force-power relationships offers an original functional approach in strength training supervision.
Disciplines :
Orthopedics, rehabilitation & sports medicine Laboratory medicine & medical technology
Author, co-author :
Jidovtseff, Boris ; Université de Liège - ULiège > Département des sciences de la motricité > Entraînement
Croisier, Jean-Louis ; Université de Liège - ULiège > Département des sciences de la motricité > Kinésithérapie générale et réadaptation
P. Aagaard, E.B. Simonsen, P. Magnusson et al., A new concept for isokinetic hamstring:quadriceps muscle ratio, Am J Sports Med 26 (1998), 231-236.
P.J. Abernethy, G. Wilson and P. Logan, Strength and power assessment. Issues, controversies and challenges, Sports Med 19 (1995), 401-417.
P.J. Abernethy and J. Jurimae, Cross-sectional and longitudinal uses of isoinertial, isometric, and isokinetic dynamometry, Med Sci Sports Exerc 28 (1996), 1180-1187.
J. Augustsson and R. Thomee, Ability of closed and open kinetic chain tests of muscular strength to assess functional performance, Scand J Med Sci Sports 10 (2000), 164-168.
D. Baker, G. Wilson and B. Carlyon, Generality versus specificity: a comparison of dynamic and isometric measures of strength and speed-strength, Eur J Appl Physiol 68 (1994), 350-355.
M.G. Bemben, J.L. Mayhew, D.M. Rohrs et al., Effect of resistance training on upper body strength, power and performance, J Appl Sports Sci Res 5 (1991), 162.
C. Bosco, A. Belli, M. Astrua et al., A dynamometer for evaluation of dynamic muscle work, Eur J Appl Physiol 70 (1995), 379-386.
U. Carlsson, K. Lind, M. Moller et al., Plantar flexor muscle function in open and closed chain, Clin Physiol 21 (2001), 1-8.
C.E. Clauser, J.T. McConville and J.W. Young, Weight, volume and center of mass of segments of the human body, Aerospace Medical Research Laboratory (TR-69-70) (1969).
J.T. Cramer, T.J. Housh, J.P. Weir et al., Gender, muscle, and velocity comparison of mechanomyographic and electromyographic response during isokinetic muscle actions, Scand J Med Sci Sports 13 (2003), 1-12.
J.L. Croisier and J.M. Crielaard, Exploration isocinétique: analyse des paramètres chiffrés, Ann Réadaptation Méd Phys 42 (1999), 538-545.
J.L. Croisier and J.M. Crielaard, Hamstring muscle tear with recurrent complaints: an isokinetic profile, Isokinetics Exerc Sci 8 (2000), 175-180.
J.L. Croisier, Factors associated with recurrent hamstring injuries, Sports Med 34 (2004), 681-695.
J.B. Cronin, P.J. McNair and R.N. Marshall, The role of maximal strength and load on initial power production, Med Sci Sports Exerc 32 (2000), 1763-1769.
J.B. Cronin, P.J. McNair and R.N. Marshall, Force-velocity analysis of strength-training techniques and load: implications for training strategy and research, J Strength Conditioning Res 17 (2003), 148-155.
D.G. Dolny, M.G. Collins, T. Wilson et al., Validity of lower extremity strength and power utilizing a new closed chain dynamometer, Med Sci Sports Exerc 33 (2001), 171-175.
Z. Dvir, How much is necessary to indicate areal improvement in muscle function? A review of modern methods of reproducibility analysis, Isokinetics Exerc Sci 11 (2003), 49-52.
A.C. Fry, W.J. Kraemer, C.A. Weseman et al., The effect of an off-season strength and conditioning program on starters and non starters in women's intercollegiate Volleyball, J Appl Sports Sci Res 5 (1991), 174-181.
K. Funato, A. Matsuo and T. Fukunaga, Measurement of specific movement power application: evaluation of weight lifters, Ergonomics 43 (2000), 40-54.
M. Gorassini, J.F. Yang, M. Siu et al., Intrinsic activation of human motorneurons: reduction of motor unit recruitment thresholds by repeated contractions, J Neurophysiol 87 (2002), 1859-1866.
W.G. Hopkins, E.J. Schabort and J.A. Hawley, Reliability of power in physical performance tests, Sports Med 31 (2001), 211-234.
W.G. Hopkins, Measures of reliability in sports medicine and science, Sports Med 30 (2000), 1-15.
T. Hortobagyi and F. Katch, Reliability of muscle mechanical characteristics for isokinetic and isotonic squat and bench press exercise using a multifunction computerized dynamometer, Res Quat Exerc Sports 61 (1990), 191-195.
M. Izquierdo, J. Ibanez, E. Gorostiaga et al., Maximal strength and power characteristics in isometric and dynamic actions of the upper and lower extremities in middle-aged and old men, Acta Physiol Scand 167 (1999), 57-68.
R. Jablonowsky, O. Inbar, A. Rotstein et al., Evaluation of anaerobic performance capacity by the isokinetics ariel computerized exercise system-reliability and validity, J Sports Med Phys Fitness 32 (1992), 262-270.
I. Jacobs and J. Pope, A computerized system for muscle strength evaluation: measurement reproducibility, validity and some normative data, National Strength Conditioning J 8 (1986), 28-33.
B. Jidovtseff and J.M. Crielaard, Musculation fonctionnelle: influence du travail avec ou sans projection, Arch Physiol Biochem 111 (2003), Suppl Sept p45.
P.V. Komi, H. Suominen, E. Heikkinen et al., Effect of heavy resistance training and explosive type strength training methods on mechanical, functional and metabolic aspects of performance, in: Exercise and sport biology, P.V. Komi, ed., Human Kinetics, Champaingn, 1982, pp. 90-102.
W.J. Kraemer and A.C. Fry, Strength testing: development and evaluation of methodology, in: Physiological Assessment of Human Fitness, P.J. Maud and C. Foster, eds, Human Kinetics, Champaign, 1995, pp. 115-138.
P. Logan, D. Fornasiero, P. Abernethy et al., Protocols for the assessment of isoinertiel strength, in: Physiological Tests for Elite Athletes, C.J. Gore, ed., Australian Sports Commission, 2000, pp. 200-220.
J.A. Mastropaolo, A test of the maximum-power stimulus theory for strength, Eur J Appl Physiol 65 (1992), 415-420.
A.J. Murphy, G.J. Wilson and J.F. Pryor, Use of the iso-inertial force mass relationship in the prediction of dynamic human performance, Eur J Appl Physiol 69 (1994), 250-257.
A.J. Murphy and G.J. Wilson, The assessment of human dynamic muscular function: A comparison of isoinertial and isokinetic tests, J Sports Med Phys Fitness 36 (1996), 169-177.
A. Rahmani, G. Dalleau, F. Viale et al., Validity and reliability of a kinematic device for measuring the force developed during squatting, J Appl Biomechanics 16 (2000), 26-35.
D.G. Sale, Testing strength and power, in: Physiological Testing of the High-Performance Athlete, J.D. MacDougall, H.A. Wenger and H.J. Green, eds, Human Kinetics, Champaign, 1991, pp. 21-103.
E.J. Schabort, W.G. Hopkins and J.A. Hawley, Reproducibility of self-paced treadmill performance of trained endurance runners. Int J Sports Med 19 (1998), 48-51.
C.J. Thompson and M.G. Bemben, Reliability and comparability of the accelerometer as a measure of muscular power, Med Sci Sports Exerc 31 (1999), 897-902.
M. Vanderthommen, S. Duteil, C. Wary et al., A comparison of voluntary and electrically induced contractions by interleaved 1H- and 31P-NMRS in humans, J Appl Physiol 94 (2003), 1012-1024.
G.J. Wilson, A.D. Walshe and M.R. Fischer, The development of an isokinetic squat device: reliability and relationship to functional performance, Eur J Appl Physiol 75 (1997), 455-461.
T. Wrigley and G. Strauss, Strength assessment by isokinetics dynamometry, in: Physiological Tests for Elite Athletes, C.J. Gore, ed., Australian Sports Commission, 2000, pp. 155-199.