35 research outputs found
Muscle Fatigue Affects the Interpolated Twitch Technique When Assessed Using Electrically-Induced Contractions in Human and Rat Muscles
The interpolated twitch technique (ITT) is the gold standard to assess voluntary activation and central fatigue. Yet, its validity has been questioned. Here we studied how peripheral fatigue can affect the ITT. Repeated contractions at submaximal frequencies were produced by supramaximal electrical stimulations of the human adductor pollicis muscle in vivo and of isolated rat soleus fiber bundles; an extra stimulation pulse was given during contractions to induce a superimposed twitch. Human muscles fatigued by repeated 30-Hz stimulation trains (3 s on-1 s off) showed an ~80% reduction in the superimposed twitch force accompanied by a severely reduced EMG response (M-wave amplitude), which implies action potential failure. Subsequent experiments combined a less intense stimulation protocol (1.5 s on-3 s off) with ischemia to cause muscle fatigue, but which preserved M-wave amplitude. However, the superimposed twitch force still decreased markedly more than the potentiated twitch force; with ITT this would reflect increased "voluntary activation." In contrast, the superimposed twitch force was relatively spared when a similar protocol was performed in rat soleus bundles. Force relaxation was slowed by >150% in fatigued human muscles, whereas it was unchanged in rat soleus bundles. Accordingly, results similar to those in the human muscle were obtained when relaxation was slowed by cooling the rat soleus muscles. In conclusion, our data demonstrate that muscle fatigue can confound the quantification of central fatigue using the ITT
Use of the track structure approach in TEM
10.1016/S0304-3991(00)00019-XUltramicroscopy833-4261-264ULTR
Impact parameters and intraband scattering in electron diffraction from thin foils
10.1088/0953-8984/7/4/011Journal of Physics: Condensed Matter74803-80
Interband scattering of channelled electrons suffering high energy losses
Philosophical Magazine Letters742113-118PMLE
Displacement damage in supported YBa2Cu3O7-x thin films and finite-element simulations
10.1088/0953-2048/8/7/004Superconductor Science and Technology87507-512SUST
Analysis of coatings which inhibit epoxy bleeding in electronic packaging
Journal of Materials Science: Materials in Electronics8273-7
Hot isostatically pressed Bi2Sr2Ca2Cu3O10 coils made with novel precursors
Journal of Materials Science Letters155439-441JMSL
Orientation anomalies in plating thickness measurements from advanced packaging substrates
10.1088/0268-1242/11/3/026Semiconductor Science and Technology113437-442SSTE
A critical condition in Fresnel diffraction used for ultra-high resolution lithographic printing
10.1088/0022-3727/33/17/307Journal of Physics D: Applied Physics33172133-2141JPAP