The Effect of Test Protocol Instructions on the Measurement of Muscle Function in Adult Women

Christ, C. B.; Boileau, R. A.; Slaughter, M. H.; Stillman, R. J.; Cameron, Jo Ann

doi:10.2519/jospt.1993.18.3.502

Cited by 22 publications

(33 citation statements)

References 11 publications

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“…The present data con®rm the results of previous studies (Bemben et al 1990;Christ et al 1993)) which showed the importance of instruction for the measurement of the MRFD. The value of MRFD was higher when measured with a fast instruction instead of the usual hard-and-fast instruction.…”

Section: Discussionsupporting

confidence: 94%

“…On the other hand, it must be mentioned that instruction had opposite eects on MRFD and MVF and that peak force was signi®cantly lower with the fast instruction. Christ et al (1993) have con®rmed these results for dierent small-muscle groups of the upper limbs (®nger exors, thumb extensors, elbow extensors and¯exors) and the lower limbs (ankle dorsi-¯exors and plantar exors). On the other hand, a recent study (Schlumberger et al 1999) which compared four protocols for isometric leg extension (gradual, gradual-and-hard, fast and fast-andhard) found that the dierence in MRFD and MVF between the fast and the fast-and-hard instructions were small and not signi®cant for a leg-press exercise.…”

Section: Introductionsupporting

confidence: 50%

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Maximal voluntary force and rate of force development in humans - importance of instruction

Sahaly¹,

Vandewalle

Driss³

et al. 2001

European Journal of Applied Physiology

158

148

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The present investigation has been designed to confirm the effect of instruction (hard-and-fast instruction compared to fast instruction) upon maximal voluntary isometric force (MVF) and maximal rate of force development (MRFD) in muscle groups which differ with regards to muscle mass and usage. In addition, we took advantage of the force data collected during unilateral and bilateral leg extension, to compare the instruction effects on the indices of the bilateral deficits (BI, the differences between the data collected during bilateral extensions and the sum of the data collected during unilateral left and right extensions) with regard to MVF (BIMVF) and MRFD (BIMRFD). Force-time curves were recorded during maximal isometric contractions of the elbow flexors, the leg extensors of the take-off and lead legs and during bilateral leg extension in 26 healthy young male volunteers from the track-and-field national team of Tunisia. In the first protocol, the subjects were instructed to produce MFV as hard-and-fast as possible (instruction I). In the second protocol (instruction II) the subjects were instructed to provide MFRD, that is the most explosive force, by concentrating on the fastest contraction without concern for achieving maximal force. The present study confirmed the importance of an appropriate instruction for the measurement of MRDF The MRFD (F = 40.8, P < 0.001) were significantly higher when measured after instruction II compared to instruction I. The effect of the instruction upon MRFD were similar for muscle groups with different volumes, cortical representations and uses. The same results (F = 52.1; P < 0.001) were observed when MRFD was related to MVF [MRFD% = (MRFD/MVF) x 100]. On the other hand, MVF was similar following both instructions (ANOVA, F = 0.562; P = 0.454). Moreover, the results of the present study suggested that the effect of instruction was significantly larger for BIMRFD than for BIMVF.

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Section: Discussionsupporting

confidence: 94%

Section: Introductionsupporting

confidence: 50%

Maximal voluntary force and rate of force development in humans - importance of instruction

Sahaly¹,

Vandewalle

Driss³

et al. 2001

European Journal of Applied Physiology

158

148

View full text Add to dashboard Cite

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“…The early deWcit in RFD when the verbal instruction focused on the generation of maximal force might partially explain the large increase in RFD with training. However, the increased RFD by verbal instruction did not have a positive eVect on maximal force, a Wnding consistent with prior research (Christ et al 1993;Sahaly et al 2001). Therefore, the hypothesis of a direct causal relation between RFD and maximal force can be rejected.…”

Section: Direct Causal Relationsupporting

confidence: 81%

“…In addition, the many studies that observed increases in both maximal force and RFD with resistance training (Aagaard et al 2002;Behm and Sale 1993a, b;Häkkinen et al 1985;Häkkinen and Komi 1986;Rich and Cafarelli 2000;Thorstensson et al 1976;Van Cutsem et al 1998) have let several researchers to question whether a direct association between maximal force and RFD exists during resistance training (Andersen and Aagaard 2006;GriYn and Cafarelli 2005;HaV et al 2005). In accordance with this assumption, maximum voluntary contraction with increased RFD has been demonstrated to enhance maximal force generation (Bemben et al 1990), whereas others failed to demonstrate this (Christ et al 1993;Sahaly et al 2001). In addition, the intention to perform an explosive MVC has been suggested to be of major importance to the outcome of resistance training (Behm and Sale 1993a, b).…”

Section: Introductionmentioning

confidence: 80%

The effect of rate of force development on maximal force production: acute and training-related aspects

et al. 2007

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The force generated during a maximal voluntary contraction (MVC) is known to increase by resistance training. Although this increase cannot be solely attributed to changes in the muscle itself, many studies examining muscle activation at peak force failed to detect neural adaptations with resistance training. However, the activation prior to peak force can have an impact on maximal force generation. This study aims at investigating the role of rate of force development (RFD) on maximal force during resistance training. Fourteen subjects carried out 5 days of isometric resistance training with dorsiflexion of the ankle with the instruction to generate maximal force. In a second experiment, 18 subjects performed the same task with the verbal instruction to generate maximal force (instruction I) and to generate force as fast and forcefully as possible (instruction II). The main findings were that RFD increased twice as much as the 16% increase in maximal force with training, with a positive association between RFD and force within the last session of training and between training sessions. Instruction II generated a higher RFD than instruction I, with no difference in maximal force. These findings suggest that the positive association between RFD and maximal force is not causal, but is mediated by a third factor. In the discussion, we argue for the third factor to be physiological changes affecting both aspects of a MVC or different processes affecting RFD and maximal force separately, rather than a voluntary strategic change of both aspects of MVC.

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“…The maximal rate of force development (MRFD) was significantly slower when the subjects were instructed to produce their maximal peak force as fast as possible (hard-and-fast instructions) than when they were instructed to focus on the MRFD without any concern for the peak force (fast instruction). Christ et al (1993) confirmed these results for different small-muscle groups of the upper limbs (finger flexors, thumb extensors, elbow extensors and flexors) and the lower limbs (ankle dorsi-flexors and plantar flexors). A recent study (Sahaly et al 2001) indicates that the effect of the instruction upon MRFD is similar for muscle groups with different volumes (elbow flexors, one or both legs), cortical representations (arms and legs) and uses (take-off and lead legs, unilateral and bilateral leg extension).…”

Section: Introductionsupporting

confidence: 84%

Surface electromyograms of agonist and antagonist muscles during force development of maximal isometric exercises—effects of instruction

et al. 2003

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Surface integrated electromyograms (iEMG) of agonist and antagonist muscles were studied during the rising phase of maximal isometric efforts (elbow flexion, unilateral and bilateral leg extension) to explain the difference in maximal rate of force development (MRFD) with a hard-and-fast instruction (instruction I) and a fast instruction (instruction II ). Force and EMG were simultaneously recorded in 24 athletes and iEMG were computed at MRFD and during different phases of force development (P(0-25), P(25-50), P(50-75), P(75-90) and P(90-100)). A two-way ANOVA for repeated measures (muscle x instruction) showed that the value of iEMG at MRFD was significantly higher with instruction II for elbow flexion, unilateral and bilateral leg press exercises (F>4.9; P<0.04). The effect of instruction upon iEMG of the agonist muscles corresponding to the different phases of the force development was significant for elbow flexion (F=4.2; P<0.05 ) unilateral (F>6.4; P<0.02) and bilateral leg extension (F>9 and P<0.006 for soleus and vastus lateralis; but F=3.2 and P=0.08 for vastus medialis). There was a significant interaction between instruction and phase of force development (F>2.6; P<0.05 ): iEMG was significantly higher with instruction II at the beginning of force development (P(0-25)) for all the muscles (except the soleus muscle during the bilateral leg exercise) but not at higher force (P(75-90) and P(90-100)). The steeper force development with instruction II can be explained by the better activation of the agonist muscles at the beginning of force development. A lower co-activation of the antagonist muscles does not explain the improvement in MRFD as the iEMG of the antagonist muscles was not lower with instruction II but was proportional to the activation level of the agonist muscle.

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The Effect of Test Protocol Instructions on the Measurement of Muscle Function in Adult Women

Cited by 22 publications

References 11 publications

Maximal voluntary force and rate of force development in humans - importance of instruction

Maximal voluntary force and rate of force development in humans - importance of instruction

The effect of rate of force development on maximal force production: acute and training-related aspects

Surface electromyograms of agonist and antagonist muscles during force development of maximal isometric exercises—effects of instruction

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