Balancing exercises on instable bases (sensorimotor training [SMT]) are often used in the rehabilitation process of an injured athlete to restore joint function. Recently it was shown that SMT was able to enhance rate of force development (RFD) in a maximal voluntary muscle contraction. The purpose of this study was to compare adaptations on strength capacity following ballistic strength traini...

The in vivo maximum voluntary torque-velocity profile for large muscle groups differs from the in vitro tetanic profile with lower than expected eccentric torques. Using sub-maximal transcutaneous electrical stimulation has given torque-velocity profiles with an eccentric torque plateau ∼1.4 times the isometric value. This is closer to, but still less than, the in vitro tetanic profiles with pl...

The aim of this study was an investigation whether the examined subjects can be classified as normal, myopathic or neuropathic, based on 4-channel surface electromyographic (SEMG) recordings of the biceps brachii muscle recorded at isometric voluntary contractions. Five different force levels were used: 10, 30, 50, 70 and 100 % of maximum voluntary contraction (MVC), with each recording lasting...

  Background: The aim of this study was to investigate muscle damage indicators and electromyography activities of quadriceps muscles at 25° of hip flexion in untrained healthy females after an eccentric exercise induced muscle fiber damage.   Methods : A total of 14 healthy females participated in this pre-experimental study. The subjects performed maximal eccentric quadriceps contractions at ...

The object of this study was to clarify whether corticospinal excitability controlling hand muscles changes concurrently with increases in the imagined contraction level of foot dorsiflexion. Twelve participants performed actual and imagined dorsiflexion of their right foot at three different EMG levels (10, 40 or 80% of the maximum voluntary contraction). During isometric actual- or imagined- ...

Babault, Nicolas, Michel Pousson, Yves Ballay, and Jacques Van Hoecke. Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. J Appl Physiol 91: 2628–2634, 2001.—Maximal and submaximal activation level of the right knee-extensor muscle group were studied during isometric and slow isokinetic muscular contractions in eight male subjects. The activation le...

Electromyographic (EMG) amplitude and mechanical tension are directly related during isometric contraction. Maximal voluntary isometric contractions are typically elicited through two different procedures; resisting a load, which is eccentric in nature, and contracting against an immovable object, which is concentric in nature. A wealth of literature exists indicating that EMG amplitude during ...

OBJECTIVE The purpose of the current study was to quantitatively examine the muscle activations of 3 common isometric core exercises (abdominal bridge, single-leg abdominal bridge, and superman) along with a newly introduced isometric exercise (flying squirrel) and determine if muscle activations differed among the exercises. DESIGN The design was a comparison study. SETTING An athletic tra...

Voluntary activation levels during lengthening, isometric, and shortening contractions (angular velocity 60 degrees/s) were investigated by using electrical stimulation of the femoral nerve (triplet, 300 Hz) superimposed on maximal efforts. Recruitment of fiber populations was investigated by using the phosphocreatine-to-creatine ratio (PCr/Cr) of single characterized muscle fibers obtained fro...

[Purpose] The purpose of this study was to perform a quantitative assessment of neuromechanical adaptation in skeletal muscles and to propose the scientific underpinnings of the acute effects induced by resistance exercise. [Subjects] The subjects in this study were 11 healthy adult men in their 20s who had no orthopedic history at the time of the study. To examine any signs of resistance exerc...