This study determined the effects of a short period of knee isometric training on the quadriceps muscles accessible to surface electromyography (EMG). For this purpose, a training (n = 9) and a control (n = 7) group were tested on five identical occasions at 1 week intervals during 4 weeks. The training group exercised three times a week by making isometric knee extensions at 80% of the maximal voluntary contraction (MVC). During the test sessions, maximal and submaximal torque and associated activations of the rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles were analysed. As a result of training, differences between MVC values of the two groups were highly significant (P<0.001), whereas only RF-EMG showed significant differences (P<0.05). The VL and VM did not present any significant changes in maximal activation. The EMG torque relationships were analysed individually before and after the training period. For the control subjects, EMG-torque relationships did not present significant changes while for the training group, these relationships showed a significant increase in RF, VL, and VM maximal activation in 6, 6 and 4 subjects, respectively, and a significant decrease in 1, 2 and 5 subjects, respectively. In almost all cases, a significant downward shift of the relationship was observed. This study confirmed that the parts of the quadriceps muscle tested present different adaptation capacities and demonstrate inter-individual variability in the strategies used to enhance muscle strength. In conclusion, to analyse the neural effects resulting from training in a large and compartmentalized muscle like the quadriceps femoris, it is desirable to take into account each muscle independently. Moreover, we suggest that overall results obtained from the experiment population should be completed by an analysis on individuals.

In order to compare the Maximal Aerobic Speed (MAS) evaluated with different methods, eleven male physical education students (22.2 +/- 3.0 years) were submitted to a maximal treadmill protocol and to the Université de Montréal Track Test (UMTT). Four methods were used to calculate MAS. After treadmill measurement of VO2max, MAS was calculated (MAS_calc) by the following formula: MAS_calc = (VO2max - 0.083)/C, where VO2max is the maximal oxygen uptake (ml.kg-1.s-1) and C the energy cost of running (ml.kg-1.m-1). The extrapolated MAS (MAS_ex) was obtained from the measured VO2max and by extrapolation of the VO2 versus speed relationship. The MAS for treadmill measurement (MAS_tr) and for UMTT (MAS_UMTT) were the velocities at the last completed stages. The average MAS_calc (4.71 +/- 0.48 m.s-1), MAS_ex (4.62 +/- 0.48 m.s-1), MAS-tr (4.75 +/- 0.57 m.s-1) and MAS_UMTT (4.64 +/- 0.35 m.s-1) were not significantly different and were significantly correlated, between 0.85 (MAS_ex vs MAS_UMTT) and 0.99 (MAS_calc vs MAS_tr), with p < 0.001 in both cases. MAS measurements were significantly correlated to measured VO2max but independent of C.

The measurement of maximal aerobic speed (MAS) and the prediction of maximal oxygen uptake (VO2 max) by means of field tests were carried out on 17 students studying physical education. The subjects underwent a continuous multi-stage track test (Léger and Boucher, 1980), shuttle test (Léger et al., 1984) and VO2 max measurement on a treadmill. The VO2 max values estimated using the track test (56.8 +/- 5.8 ml kg-1 min-1) were not significantly different from the values measured in the treadmill test (56.8 +/- 7.1 ml kg-1 min-1), but were higher than those estimated using the shuttle test (51.1 +/- 5.9 ml kg-1 min-1). The maximal nature of the tests was checked by measurement of heart rate and lactate concentration, taken within 2 min post-test. The means of the MAS observed in the track test (15.8 +/- 1.9 km h-1) and in the treadmill test (15.9 +/- 2.6 km h-1) were not significantly different (P > 0.10). The mean of the shuttle test MAS (13.1 +/- 1 km h-1) was significantly lower (P < 0.01) than those of the other tests. However, the MAS of the shuttle test and track test are linked. The equation for linear regression between MAS values in these two tests is MAStrack = 1.81 x MASshuttle -7.86 (r = 0.91), allowing estimation of one of these MAS values when the other is known. Thus these values may be used within diversified training.

The MTP was effective in reducing back pain intensity, functional disability, symptoms of anxiety and depression and in improving quality of life, flexibility and isometric muscle endurance time. It was possible to propose the MTP to both men and women. A network organization effectively contributes to the harmonization of evaluation methods and brings coherence to the treatment of CLBP patients.

No abstract