Angus and Charolais heifers (195 +/- 7 kg) were actively immunized against growth hormone-releasing factor (GRF) to evaluate the effect on concentrations of somatotropin (ST), insulin-like growth factor I (IGF-I), insulin (INS), growth, and onset of puberty. Primary immunizations were given at 184 +/- 7 d of age (d 0 of experiment) by injecting (s.c.) 1.5 mg of GRF-(1-29)-Gly-Gly-Cys-NH2 conjug...

The purpose of this study was to compare vertical ground reaction forces (GRF) and electromyographic activity (EMG) from peroneus longus (PL), tibialis anterior (TA) and gastrocnemius lateralis (GL) of volleyball athletes with and without functional ankle instability (FI) during landing after a blocking maneuver. Synchronized EMG and GRF from 200ms prior to impact to 200ms after impact were acq...

The aim of this study is to investigate the effect of flooring surfaces in the ground reaction forces and foot/floor friction during stroke gait. The participant was oriented to walk, in its own preferred speed, over two force plates on the following surfaces: HOV, carpet and HTV. The results of this study showed no differences between the hemiparetic and the control group when de GRF and COF w...

There remains a pressing need for a stability metric that can reliably identify fall susceptibility during walking, enabling more effective gait rehabilitation for reduced fall incidence. One available metric is the maximum margin of stability (MOS(max)), which is calculated using the body's center of mass (COM) position and velocity along with the location of the maximum center of pressure (CO...

The aim of the present study was to elucidate the adaptive and de-adaptive nature of human running on a split-belt treadmill. The degree of adaptation and de-adaptation was compared with those in walking by calculating the antero-posterior component of the ground reaction force (GRF). Adaptation to walking and running on a split-belt resulted in a prominent asymmetry in the movement pattern upo...

AIM The aim of the present study was to evaluate reactive hops under systematically modified acceleration conditions. It was hypothesized that a high preactivity of the leg extensors and phase-specific adjustments of the leg muscle activation would compensate the alterations caused by the various acceleration levels in order to maintain a high leg stiffness, thus enabling the jumper to perform ...

Background In-vitro gait simulations have great potential, allowing a systematic analysis of the foot function. However, it is important that the loading conditions are realistic i.e. physiologic ground reaction forces (GRF). In most experiments, in-vivo measured GRF can be imposed [1,2]. However in experimental designs that evaluate the effect of altered muscle forces on foot motion this is mo...

BACKGROUND Step exercise has been promoted as a low impact physical activity recommended for the improvement of cardiorespiratory and muscular fitness. This recreational activity might also be recommended to improve bone health since mechanical load plays an important role in the normal development of the skeleton. METHODS Our main purpose was to characterised 100 step sessions and to calcula...