The purpose of this study was to (1) determine whether symmetry in temporal-distance (T-D) measures is accompanied by symmetry in kinetic measures during self-paced gait and (2) evaluate the effect of symmetry on gait speed in individuals with chronic stroke. A symmetry index was calculated for stance time, swing time, step length and vertical ground reaction force (GRF) for 28 individuals with...

The goals of the study were to compare data of vertical ground reaction force (GRF) parameters during level walking, stair ascent and descent on three different stair inclinations and three different age groups. Twenty healthy subjects of three age groups (young 33.7 years; middle 63.6 years; old 76.5 years) were tested during the seven test conditions with 8-10 repetitions. Vertical forces wer...

Push-ups are a common and practical exercise that is used to enhance fitness, including upper body strength or endurance. The kinetic characteristics of push-ups and its variations are yet to be quantified. Kinetic quantification is necessary to accurately evaluate the training load, and thus the nature of the training stimulus, for these exercise variations. This study assessed the peak vertic...

BACKGROUND Many methods have been proposed to assess the stability of human postural balance by using a force plate. While most of these approaches characterize postural stability by extracting features from the trajectory of the center of pressure (COP), this work develops stability measures derived from components of the ground reaction force (GRF). METHODS In comparison with previous GRF-b...

It is known that leptin, an adipocyte-derived hormone, exerts a stimulatory effect on growth hormone (GH) secretion in various animal species. However, no previous study examined in vivo whether leptin affects the secretion of GH-releasing factor (GRF), somatostatin (SRIH), and some other closely relevant neurohormones in the hypothalamus. Therefore, in this study we investigated the effects of...

PURPOSE Walking is a recommended form of exercise for the treatment of obesity, but walking may be a critical source of biomechanical loads that link obesity and musculoskeletal pathology, particularly knee osteoarthritis. We hypothesized that compared with normal-weight adults 1) obese adults would have greater absolute ground-reaction forces (GRF) during walking, but their GRF would be reduce...

INTRODUCTION The challenging nature and high incidence of trips and falls in the elderly during stair negotiation has led to numerous research studies investigating lower extremity biomechanics in older adults [1]. Stair descent has been shown to yield greater impact peak ground reaction force (GRF), and greater peak knee internal abduction moment compared to stair ascent and level-walking [2,3...

This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimise...

BACKGROUND In patients who have undergone anterior cruciate ligament (ACL) reconstruction, there is a weak correlation between subjective evaluation of knee function on questionnaires and clinical or biomechanical test results. HYPOTHESIS Patients with lower subjective knee function will demonstrate lower ground-reaction forces (GRFs) in the operated leg and greater GRF asymmetries in both ph...

We have used high-pressure freezing techniques to study exocytosis in rat anterior pituitary cells. The cells were either unstimulated or exposed to 1 nM growth hormone releasing factor (GRF) for 10 min before ultrarapid freezing. The magnitude of growth hormone (GH) release was then correlated with the number of exocytotic events observed with freeze-fracture electron microscopy. High-pressure...