Search results for "Muscles"
showing 10 items of 616 documents
Neuromuscular, anaerobic, and aerobic performance characteristics of elite power athletes.
1984
Various aspects of neuromuscular, anaerobic, and aerobic performance capacity were investigated in four powerlifters, seven bodybuilders, and three wrestlers with a history of specific training for several years. The data (means +/- SD) showed that the three subject groups possessed similar values for maximal isometric force per unit bodyweight (50.7 +/- 9.6, 49.3 +/- 4.1, and 49.3 +/- 10.9 N/kg, respectively). However, significant (P less than 0.05) differences were observed in the times for isometric force production, so that e.g., times to produce a 30% force level were shorter for the wrestlers and bodybuilders (28.3 +/- 3.1 and 26.4 +/- 6.6 ms) than that (53.3 +/- 23.7 ms) for the powe…
Influence of lactate accumulation of EMG frequency spectrum during repeated concentric contractions
1983
One hundred and twenty consecutive maximal leg extensions at a constant angular velocity of 1.5 radians . s-1 were performed by nine physical education students. Integrated electromyographic (IEMG) activity and power spectrum density function (PSDF) of the EMG were recorded from m. vastus lateralis, vastus medialis and m. rectus femoris using bipolar surface electrodes. Muscle biopsies were obtained from m. vastus lateralis before and after exercise. Tissue samples were analyzed for muscle fiber type distribution and lactate and glycogen concentration. Muscle force and IEMG decreased in parallel over the exercise period. Thus, the IEMG/force ratio was unchanged. Mean power frequency (MPF) o…
Muscle activity patterns and spinal shrinkage in office workers using a sit–stand workstation versus a sit workstation
2016
Reducing sitting time by means of sit-stand workstations is an emerging trend, but further evidence is needed regarding their health benefits. This cross-sectional study compared work time muscle activity patterns and spinal shrinkage between office workers (aged 24-62, 58.3% female) who used either a sit-stand workstation (Sit-Stand group, n = 10) or a traditional sit workstation (Sit group, n = 14) for at least the past three months. During one typical workday, muscle inactivity and activity from quadriceps and hamstrings were monitored using electromyography shorts, and spinal shrinkage was measured using stadiometry before and after the workday. Compared with the Sit group, the Sit-Stan…
Superimposing hip extension on knee flexion evokes higher activation in biceps femoris than knee flexion alone.
2021
Hamstring muscle function during knee flexion has been linked to hamstring injury and performance. However, it is unclear whether knee flexion alone (KF) requires similar hamstring electromyography (EMG) activity pattern to simultaneous hip extension and knee flexion (HE-KF), a combination that occurs in the late swing phase of sprinting. This study examined whether HE-KF maximal voluntary isometric contraction (MVIC) evokes higher (EMG) activity in biceps femoris long head (BFlh) and semitendinosus (ST) than KF alone. Effects of shank rotation angles were also tested. Twenty-one males performed the above-mentioned MVICs while EMG activity was measured along ST and BFlh. Conditions were com…
Selective activation of shoulder, trunk, and arm muscles: A comparative analysis of different push-up variants
2015
Context The push-up is a widely used exercise for upper limb strengthening that can be performed with many variants. A comprehensive analysis of muscle activation during the ascendant phase (AP) and descendant phase (DP) in different variants could be useful for trainers and rehabilitators. Objective To obtain information on the effect of different push-up variants on the electromyography (EMG) of a large sample of upper limb muscles and to investigate the role of the trunk and abdomen muscles during the AP and DP. Design Cross-sectional study. Setting University laboratory. Patients or Other Participants Eight healthy, young volunteers without a history of upper extremity or spine injury.…
Comparison between anterolateral thigh perforator free flaps and pectoralis major pedicled flap for reconstruction in oral cancer patients-A quality …
2013
The aim of this study was to compare the differences between anterolateral thigh perforator free flaps (ALTFF) and pectoralis major myocutaneous flap (PMMF) for reconstruction in oral cancer patients. Method and Patients: who received free flap or PMMF reconstruction after ablation surgeries were eligible for the current study. The patients' demographic data, medical history, and quality of life scores(Medical Outcomes Study-Short Form-36 (MOS SF-36) and the University of Washington Quality of Life (UW-QOL) questionnaires were collected. Results: 81 of 118 questionnaires were returned (68.64%). There was signi.cant differences between two groups in the gender (P<0.005). Patients reconstruct…
Neck muscle ultrasonography of male weight-lifters, wrestlers and controls.
2007
The purpose of this cross-sectional study was to evaluate the effect of different sport training regimens on the size of the neck semispinalis capitis muscle (SECM). The cross-sectional area (CSA) and the linear dimensions of the SECM were measured bilaterally by real-time ultrasonography. Ten young Finnish elite level weight-lifters. 8 freestyle wrestlers and 10 controls (all male) participated in the study. Muscle CSA was significantly larger in wrestlers than in weight-lifters or controls (P<0.001). There was no significant difference in size between the right and left SECM in any of the subject groups, but the variation between sides (smaller vs. larger) was significantly higher in wres…
The mechanical efficiency of locomotion in men and women with special emphasis on stretch-shortening cycle exercises.
1986
The mechanical efficiency of the leg extensor musculature of men and women was examined with a special "sledge ergometer". The subjects (ten males and ten females) performed pure positive work, pure negative work and a combination of negative and positive work (stretch-shortening cycle). The mechanical efficiency of pure positive work was on average 19.8 +/- 1.2% for female subjects and 17.4 +/- 1.2% for male subjects (t = 4.12, P less than 0.001), although the work intensity was equal in both groups. The mechanical efficiency of pure negative work was slightly lower in women than in men (59.3 +/- 14.4% vs 75.6 +/- 29.3%). The mechanical efficiency of positive work (eta +) in a stretch-shor…
Does anaerobic threshold correlate with maximal lactate steady-state?
1992
The aim of this study was to compare the 'anaerobic threshold' (AnT) of subjects determined during a continuous 2-min incremental exercise test until exhaustion and the 'maximal lactate steady-state' (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects' AnT and/or 5-25% above and below it. Seventeen subjects performed an incremental exercise test and 1-5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached …
Trunk muscle activity during different variations of the supine plank exercise.
2017
BACKGROUND: Exercises providing neuromuscular challenges of the spinal muscles are desired for core stability, which is important for workers with heavy manual labour as well as people recovering from back pain.PURPOSE: This study evaluated whether using a suspended modality increases trunk muscle activity during unilateral or bilateral isometric supine planks.DESIGN: Cross-sectional.METHODS: Twenty university students participated in this cross-sectional study. Each subject performed four different conditions: bilateral stable supine plank, unilateral stable supine plank, bilateral suspended supine plank and unilateral suspended supine plank. Surface electromyography (EMG) signals were rec…