We investigated the effect of quadriceps and hamstring muscle fatigue on anterior tibial translation and muscle reaction time in 10 healthy subjects. The six men and four women had an average age of 21.3 years and had no known pathologic knee conditions. Each patient underwent a knee examination, arthrometer measurements of tibial translation, subjective functional assessment, and an anterior t...

Fall accidents are a significant problem for the elderly, in terms of both human suffering and economic losses. Localized muscle fatigue is a potential risk factor for slip-induced falls as muscle fatigue adversely affects proprioception, movement coordination and muscle reaction times leading to postural instability and gait changes. Specifically, fatigue in ankle is associated with decline in...

BACKGROUND Muscle strength and endurance of the shoulder rotators is important for overhead throwing performance and dynamic glenohumeral stability. Baseball pitching is distinguished as an intermittent activity with explosive, high intensity muscle contractions separated by periods of rest. Rotator cuff muscle performance could acutely decrease due to fatigue associated with bouts of throwing....

PURPOSE The purpose of this study was to investigate the relationship of serum vitamin D levels with physical activity, obesity, muscle fatigue biomarkers, and total antioxidant capacity (TAC) in healthy older adults. METHODS A total of 85 healthy older subjects aged 64-96 years were recruited in this study. Based on estimated energy expenditure scores, the participants were classified into t...

Fatigue is a common symptom in a large number of medical and psychological disorders, including many rheumatologic illnesses. A frequent question for health care providers is related to whether reported fatigue is "in the mind" or "in the body"-that is, central or peripheral. If fatigue occurs at rest without any exertion, this suggests psychological or central origins. If patients relate their...

Over the past century, understanding the mechanisms underlying muscle fatigue and weakness has been the focus of much investigation. However, the dominant theory in the field, that lactic acidosis causes muscle fatigue, is unlikely to tell the whole story. Recently, dysregulation of sarcoplasmic reticulum (SR) Ca(2+) release has been associated with impaired muscle function induced by a wide ra...

cordingly, slowing of the maximum relaxation rate (MRR) of inspiratory muscles during short and sharp sniffs is considered to be an index of inspiratory muscle fatigue [5] . Sniff MRR is commonly calculated from esophageal pressure traces; however, a non-invasive and reliable measure of inspiratory muscle MRR can be obtained by measuring sniff nasal pressure [6] . This non-invasive technique ha...

[Purpose] This study investigated the variations in muscle fatigue, time to fatigue, and maximum task duration at different levels of production standard time. [Methods] Twenty subjects performed repetitive tasks at three different levels of production standard time corresponding to "normal", "hard" and "very hard". Surface electromyography was used to measure the muscle activity. [Results] The...

Purpose: The present study aimed to investigate the effect of voluntary and electrically stimulated quadriceps muscle fatigue on postural control. Methods: Sixteen healthy young males participated in this quasi-experimental study. All subjects performed two fatiguing exercises with equal intensity of isometric maximal voluntary contraction: Voluntary (VOL) and Electrical Stimulation (ES). The ...

OBJECTIVES Work-related musculoskeletal disorders in the neck and shoulder regions are common among carpet weavers. Working for prolonged hours in a static and awkward posture could result in an increased muscle activity and may lead to musculoskeletal disorders. Ergonomic workstation improvements can reduce muscle fatigue and the risk of musculoskeletal disorders. MATERIAL AND METHODS The ai...