Table 1 Summary of MRCP studies for acute and chronic effect on strength
Author (year) | Sample | Muscle(s) | Strength exercise protocol | Experimental design | MRCP Behavior | Electrodes used |
|---|---|---|---|---|---|---|
Freude et al. [22] | Flexor digitorum superficialis, flexor digitorum profundus | 20%, 50% and 80% of MVIC in the handgrip, with and without intentional fatigue | Acute | The highest strength levels were well correlated with RP. With 80% of CVM in fatiguing situation and 20% without fatigue, there have been increases in RP, which did not occur with 50% of CVM. | C3, Cz, C4 | |
Oda and Moritani [8] | 11 right-handed men | First dorsal interosseous, flexor digitorum profundus, flexor digitorum superficialis | 50% and 10% MVIC handgrip | Acute | Increase in amplitude of negative slope (NS) in Fz, with 50% CVM > 10% CVM. | C3 and C4 |
Shibata et al. [10] | 10 right-handed men | Biceps brachialis | 3 tasks: 1st - autodynamic “shots” with 20% of MVIC; 2nd - keep 2 seconds with 20% of MVIC; 3rd - the same as the 2nd task with arterial occlusion | Acute | The mean amplitude of MRCP was higher in tasks 2 and 3 and in the respective electrodes | C3, Cz, C4 |
Siemionow et al. [12] | 6 men and 2 women, both right-handers | Biceps brachialis and brachioradialis | 10, 35, 60 and 85% of elbow flexion MVIC; 3 Rates of strength development (slow, moderate and fast) with 30% MVIC of elbow flexion | Acute | High correlation between MRCP and strength levels with r = 0.84 (SMA) and r = 0.85 (sensory-motor). | C3, Cz, C4 |
Fang et al. [25] | 6 men and 2 women, both right-handers | Biceps brachialis, brachioradialis, triceps brachialis and deltoid | 50 eccentric voluntary contractions and 50 concentric voluntary contractions with 10% load of the body weight | Acute | Increase in amplitude of the negative slope (NS), being higher for eccentric action than concentric action | C3, Cz, C4 and Fz |
Siemionow et al. [11] | 8 patients with chronic fatigue syndrome (SFC) (5 men and 3 women) and 8 healthy individuals (5 men and 3 women) | First dorsal interosseous, flexor digitorum profundus, flexor digitorum superficialis and finger extensors | 50% of MVIC handgrip in two situations: fatiguing task (FT) and non-fatiguing task (NFT) | Acute | Increase in amplitude of the negative slope (NS) the SFC group was significantly higher than the control group, both in FT and NFT. In the SFC group, the amplitude of NS was higher in FT than in NFT. | C3, Cz, C4 |
Fang et al. [24] | 6 men and 2 women, both right-handers | Biceps brachialis, brachioradialis, triceps brachialis and deltoid | 40 maximal eccentric voluntary contractions and 40 maximal concentric voluntary contractions, both in an isokinetic dynamometer | Acute | Increase in negative slope in the eccentric compared to concentric phase | C3, C4, C6, F4, FC4 and FC6 |
Liu et al. [23] | 8 men and 1 woman | Flexor digitorum superficialis, flexor digitorum profundus and biceps brachialis | 200 intermittent MVIC on handgrip | Acute | Without significant difference | C3, Cz, C4, Fz and Pz |
Do Nascimento et al. [7] | 14 men and 1 woman, both right-handers | Soleus and anterior tibial | Plantar flexion, isometric plantar flexion (real or imaginary) in two different rates of force development (“rapid” and “ballistics”), ending at two different levels of torque | Acute | Both RP and MP showed similarity with real and imaginary movements, independent of the strength development rate and torque amplitude. | FC1, FC2, CF13, CF1, CFZ1, CFZ2, CF2, CF24, C3, C13, C1, CZ1, CZ, CZ2, C2, C24, C4, CP3, CP1, CPZ1, CPZ, CPZ2, CP2 and CP4 |
Schillings et al. [9] | 14 women | Flexors and extensors of right hand fingers | 30 minutes of repetitive contractions with 70% of MVIC in handgrip with a 7 second interval between each grip | Acute | During repetitive contractions the beginning of RP changed from 1.5 second to 1.9 s before the strength start in Cz, and from 1.0 second to 1.6 and 1.7 second before the strength start in C3 and C4, respectively. | C3, Cz, C4 |
Falvo et al. [26] | 9 women and 2 men | Vastus lateralis muscle of the quadriceps | 3 times per week (total of 9 sessions); sessions 1 and 3–3 x 10–12 repetitions with 70-75% of 1RM; sessions 6 and 4–4 x 8–10 repetitions with 75-80% of 1RM; sessions 9 and 7–5 x 6–8 repetitions with 80-85% of 1 RM | Chronic | Amplitude attenuation of MP in Cz, C1 and C2 (p < 0.05) in post-workout. RP was started in advance at 28% to the Cz electrode in the post-workout | C1, Cz, C2 |