objective: due to the frequent use of surface electromyography as a tool for the study of muscle function, to accurately compare electromyographic data from different muscles and different subjects, it is necessary to normalize the integrated data obtained from each muscle. the most common normalization technique is the use of maximum voluntary isometric contraction (mvic) of a predetermined is...

[Purpose] Maximum voluntary isometric contraction can increase the reliability of electromyography data by controlling respiration; however, many studies that use normalization of electromyography data fail to account for this. This study aims to check changes in maximum voluntary isometric contraction based on changes in posture and respiration conditions. [Subjects and Methods] Twenty-two hea...

the purpose of this study was to estimate the torque from high‑density surface electromyography signals of biceps brachii, brachioradialis, and the medial and lateral heads of triceps brachii muscles during moderate‑to‑high isometric elbow flexion‑extension. the elbow torque was estimated in two following steps: first, surface electromyography (emg) amplitudes were estimated using principal com...

Background: The transverse abdominis (TrA) muscle is one of the most important muscles that contribute to the stability of the lumbar spine. Strengthening of trunk muscles that have a significant role in trunk stability is very important in the field of professional sport, sport medicine and rehabilitation of patient with low back pain (LBP). Identifying the exercises that can improve the stren...

proprioceptive neuromuscular facilitation (pnf) training (contraction - relaxation method), in compared to the other methods of static and dynamic stretching exercises; has higher and safer effects on enhancement of hamstring muscle's flexibility, strength and endurance. achieving the optimal combination of contraction and stretching phases in pnf training that can increase these factors of phy...

This study investigated effects of caffeine ingestion (8 mg/kg) on maximum voluntary torque (MVT) and voluntary activation of the quadriceps during isometric, concentric and eccentric contractions. Fourteen subjects ingested caffeine and placebo in a randomized, controlled, counterbalanced, double-blind crossover design. Neuromuscular tests were performed before and 1 h after oral caffeine and ...

Context. Maximal voluntary isometric contraction, a method quantitatively assessing muscle strength, has proven to be reliable, accurate and sensitive in amyotrophic lateral sclerosis. Hand-held dynamometry is less expensive and more quickly applicable than maximal voluntary isometric contraction. Objective. To investigate if hand-held dynamometry is as reliable and valid as maximal voluntary i...

The purpose of the present study was to examine the effects of 2 different work-to-rest ratios, but the same mean load, cycle time, and total duration of the exercise bout, on maximal voluntary isometric contraction torque and neuromuscular responses to fatiguing, intermittent, submaximal, isometric, forearm flexion muscle actions. Ten men performed 2 fatiguing protocols with different work-to-...