Interlimb and Intralimb Coordination of Rectus Femoris and Biceps Femoris Muscles at Different Running Speeds.

Purpose: The purpose of this study was to investigate the relationship between spatiotemporal variables and the muscle activity of the rectus femoris (RF) and biceps femoris (BF) in both legs at various running speeds.

Methods: Eighteen well-trained male athletes (age: 20.7 ± 1.

The Timing of Thigh Muscle Activity Is a Factor Limiting Performance in the Deceleration Phase of the 100-m Dash.

Purpose: We aimed to examine the timing of electromyography activity of the rectus femoris (RF) and biceps femoris (BF) in both legs, as well as spatiotemporal variables (running speed (RS), step frequency (SF), step length (SL)) between the maximal speed (Max) phase (50-70 m) and the deceleration (Dec) phase (80-100 m) of the 100-m dash.

Methods: Nine track and field athletes performed the 100-m dash with maximal effort. Spatiotemporal variables of each 10-m section were measured.

Spatiotemporal inflection points in human running: Effects of training level and athletic modality.

The effect of the different training regimes and histories on the spatiotemporal characteristics of human running was evaluated in four groups of subjects who had different histories of engagement in running-specific training; sprinters, distance runners, active athletes, and sedentary individuals. Subjects ran at a variety of velocities, ranging from slowest to fastest, over 30 trials in a random order. Group averages of maximal running velocities, ranked from fastest to slowest, were: sprinters, distance runners, active athletes, and sedentary individuals.

Timing of Rectus Femoris and Biceps Femoris Muscle Activities in Both Legs at Maximal Running Speed.

Purpose: The purpose of this study was to investigate the relationship between spatiotemporal variables of running and onset/offset timing of rectus femoris (RF) and biceps femoris (BF) muscle activities in both legs.

Methods: Eighteen male well-trained athletes (age = 20.7 ± 1.

Foot posture alteration and recovery following a full marathon run.

Prolonged running results in lowering of the foot arch and a low arch is associated with subsequent chronic injuries. Foot posture alteration and recovery following a marathon run remain unknown. Therefore, the present study aimed to evaluate foot posture alteration following a full marathon run.

Continuous change in spring-mass characteristics during a 400 m sprint.

The purpose of the present study was to utilise a spring-mass model to (1) continuously measure vertical stiffness (K(vert)) and leg stiffness (K(leg)) over an entire 400 m sprint, and (2) investigate the relationship between leg spring stiffness (K(vert) and K(vert)) and the performance characteristics of mean forward running velocity (V(forwad)), mean stride frequency (f(stride)), and mean stride length (L(stride)). Eight well-trained male athletes performed a 400 m sprint with maximal effort on an outdoor field track. K(vert) was calculated from the subjects' body mass, ground contact time and flight time at each step.

Determinants of difference in leg stiffness between endurance- and power-trained athletes.

Understanding the leg and joint stiffness during human movement would provide important information that could be utilized for evaluating sports performance and for injury prevention. In the present study, we examined the determinants of the difference in the leg stiffness between the endurance-trained and power-trained athletes. Seven distance runners and seven power-trained athletes performed in-place hopping, matching metronome beats at 3.