OBJECTIVE To evaluate hip abductor and adductor peak torque outputs and compare their ratios between sexes. DESIGN A cross-sectional laboratory-controlled study. SETTING Participants visited a laboratory and performed an isokinetic hip abductor and adductor test. All participants performed 2 sets of 5 repetitions of concentric hip abduction and adduction in a standing position at 60 degrees...

The effects of intermittent isometric fatigue on concentric, eccentric, and isometric torque" (2013). Public Access Theses and Dissertations from the College of Education and Human Sciences. Paper 172. Fatiguing intermittent isometric (ISO) muscle actions of the leg extensors have been shown to result in a similar percent (%) decline in torque for concentric (CON), eccentric (ECC), and ISO musc...

BACKGROUND The present study examined the acute effects of a nutritional supplement intended to improve adenosine triphosphate (ATP) concentrations on vertical jump height, isometric strength of the leg extensors, leg extension endurance, and forearm flexion endurance. METHODS Twenty-four healthy men (mean age +/- SD = 23 +/- 4 yrs, stature = 181 +/- 7 cm, and body mass = 82 +/- 12 kg) volunt...

Background: Pre-activation of antagonistic muscles is used in different modalities of exercise and neuromuscular rehabilitation protocols, but its effectiveness is still controversial. Objective: To verify the impact of two different methods of pre-activation of knee antagonist muscles in the neuromuscular performance and electromyographic activity of knee extensors. Methods: Fifteen healthy me...

We determined the frequency of strength disorders in 26 athletes with a history of hamstring muscle injury and recurrent strains and discomfort. We also assessed the effectiveness of rehabilitation to correct muscle performance. After concentric and eccentric isokinetic assessment, 18 athletes were found to have strength deficits, as determined by statistically selected cutoffs of peak torque, ...

Strength deficits associated with eccentric contraction-induced muscle injury stem, in part, from impaired voltage-gated sarcoplasmic reticulum (SR) Ca(2+) release. FKBP12 is a 12-kD immunophilin known to bind to the SR Ca(2+) release channel (ryanodine receptor, RyR1) and plays an important role in excitation-contraction coupling. To assess the effects of eccentric contractions on FKBP12 conte...

The aim of this study was to investigate the reliability of fatigue indicators calculated from peak torque and total work during isokinetic speeds of 60, 90, 120 and 180° · s-1 during a hip fatigue protocol. 10 males suffering from a history of unilateral functional ankle instability and 10 male healthy controls performed 5 maximal concentric contractions on an isokinetic dynamometer. Following...

Objective. To investigate the effect of patella taping on normal subjects. This was undertaken through the examination of isokinetic quadriceps strength and functional performance (hop distance), in an attempt to clarify the mechanism behind patella tapings reported success in the patellofemoral pain syndrome (PFPS) patient population. The aim of the study is to examine the effect of patella ta...

BACKGROUND The literature reports that the eccentric muscular action produces greater force and lower myoelectric activity than the concentric muscular action, while the heart rate (HR) responses are bigger during concentric contraction. OBJECTIVES To investigate the maximum average torque (MAT), surface electromyographic (SEMG) and the heart rate (HR) responses during different types of musc...

As aerobic exercise (AE) may interfere with adaptations to resistance exercise (RE), this study explored acute and chronic responses to consecutive AE (∼45 min cycling) and RE (4 × 7 maximal knee extensions) vs. RE only. Ten men performed acute unilateral AE + RE interspersed by 15 min recovery. The contralateral leg was subjected to RE. This exercise paradigm was then implemented in a 5-wk tra...