This test measures the respiratory endurance as it involves
isometric contraction of respiratory muscles to hold the breath while maintaining a constant pressure.
Age Height (yrs) (cm) [G.sub.han] [G.sub.han] [G.sub.con] [G.sub.han] Mean 22.75 23.55 173.77 175.62 [+ or -] SD 2.31 2.78 3.38 6.92 Weight Force - MVIC (kg) (kgf) [G.sub.con] [G.sub.con] [G.sub.con] Ext Fle Ext Fle Mean 78.00 73.17 20.34 10.42 17.43 11.37 [+ or -] SD 10.25 7.85 7.23 2.49 5.84 3.46 [G.sub.han] = Group of Handball Athletes; [G.sub.con] = Group of Control Subjects; MVIC = Maximum Voluntary
Isometric Contraction; Ext = Extension of the Knee at 60[degrees]; Fle = Knee Flexion at 80[degrees]
MVIC, maximum voluntary
isometric contraction. (a) 40% MVIC (biceps brachii); (b) 80% MVIC (biceps brachii); (c) 40% MVIC (rectus femoris); (d) 80% MVIC (rectus femoris).
The subject was asked to perform an
isometric contraction for five movements: hand open, power grasp, fine pinch, pronation, and supination, but this time the trial consisted of three parts (Figure 4):
For subjects with significant coherence, cortico-, intra-, and intermuscular coherence was most prominent in the beta band, which agrees with previous results demonstrating beta coherence during
isometric contractions [10, 11, 13-17, 20].
Median frequency (MDF) is an indication of muscle fatigue in the frequency domain during
isometric contraction [8].
A dynamic network involving M1-S1, SII-insular, medial insular, and cingulate cortices controls muscular activity during an
isometric contraction reaction time task.
Abbreviations: CG = control group, CI = confidence interval, EG = exercise group, MS = multiple sclerosis, MVIC = maximal voluntary
isometric contraction.
The following parameters were measured from
isometric contraction: peak of developed tension (DT, g/[mm.sup.2]), resting tension (RT, g/[mm.sup.2]), time to peak of tension (TPT, ms), maximum rate of tension development (+dT/dt, g/[mm.sup.2]/s), and maximum rate of tension decline (-dT/dt, g/[mm.sup.2]/s).
What we often don't realize is that the concentric contraction of mover muscles may be ineffective without the accompanying
isometric contraction of stabilizer muscles.
The LGP exercise realized with
isometric contraction promoted significant increase of RPP in the first set with 75% 1RM, may be by a rapid increase in both systolic pressure and diastolic pressure, which appears to be inappropriate for the amount of work produced by the contracting muscle.
Afterwards they were requested to perform an
isometric contraction of muscles against the resistance promoted by the evaluator.