Influence of physical development on start and countermovement jump performance in adolescent sprint athletes.

Aim: The aim of the present study was to describe the effect of physical changes during adolescence on sprint start and countermovement jump (CMJ) performance.

Methods: Twenty-eight girls and 25 boys (15.0±1.

Decrease in postural sway and trunk stiffness during cognitive dual-task in nonspecific chronic low back pain patients, performance compared to healthy control subjects.

Study Design: A 2-group experimental design.

Objective: To investigate the effect of a cognitive dual-task on postural sway of pelvis and trunk during unstable sitting in nonspecific chronic patients with low back pain (CLBP) compared to healthy control subjects.

Summary Of Background Data: Higher cognitive systems as well as sensory processes contribute to postural control.

Experimentally generated footprints in sand: Analysis and consequences for the interpretation of fossil and forensic footprints.

Fossilized footprints contain information about the dynamics of gait, but their interpretation is difficult, as they are the combined result of foot anatomy, gait dynamics, and substrate properties. We explore how footprints are generated in modern humans. Sixteen healthy subjects walked on a solid surface and in a layer of fine-grained sand.

Differences in balance strategies between nonspecific chronic low back pain patients and healthy control subjects during unstable sitting.

Study Design: A 2-group experimental design.

Objective: To investigate differences in postural control strategies of pelvis and trunk movement between nonspecific chronic low back pain (CLBP) patients and healthy control subjects using 3-dimensional motion analysis.

Summary Of Background Data: Increased postural sway assessed by center of pressure displacements have been documented in patients with low back pain (LBP).

Reliability and discriminative validity of sudden ankle inversion measurements in patients with chronic ankle instability.

Background: Studies investigating peroneal muscle reaction times in chronically unstable ankle joints present conflicting results. The degree of reliability and accuracy of these measurements is unknown in patients with chronic ankle instability (CAI).

Methods: 40 patients with CAI and 30 healthy subjects were tested using a sudden ankle inversion of 50 degrees while standing on a trapdoor device.