Effect of an Acute Bout of Low-, Moderate, and High-Intensity Aerobic Exercise on Immediate and Delayed Fractionated Response Time

In the present investigation, we investigated the role of three intensities of aerobic exercise (Low Intensity [LI], Moderate Intensity [MI], High Intensity [HI]) on IPC using a unique method to fractionate RPT into three components: (1) RT, which is the interval between the onset of the stimulus signal and the onset of muscle activity in the responding muscle (cognitive-decision making component), (2) movement time (MT), which is the time interval between the onset of muscle activation and completion of the required motor response, and (3) RPT, which encompasses both RT and MT. Movement time reflects more the muscular components of the stimulus-response action, whereas RT reflects the duration of all earlier stages of information processing

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Reciprocal coactivation patterns of the medial and lateral quadriceps and hamstrings during slow, medium and high speed isokinetic movements

The effect of movement velocity and fatigue on the reciprocal coactivation of the quadriceps and hamstrings was investigated through analysis of the root mean square (RMS) and the median frequency (MDF) of surface electromyography for the vastus medialis (VM), vastus lateralis (VL), medial hamstrings (MH) and biceps femoris (BF). Fourteen subjects performed six continuous isokinetic knee extension and flexion movements at 60 degrees, 180 degrees and 300 degrees s(-1), and 30 continuous movements at 300 degrees s(-1) to examine muscular fatigue patterns. Statistical analyses revealed that the RMS activity of the VM displayed greater coactivation than the VL (P\u3c0.01) and the BF displayed greater coactivation than the MH (P\u3c0.0001). There was no effect of velocity on the coactivation levels of the VM, the VL, or the MH; however, there was an effect of velocity on the coactivation levels of the BF (P\u3c0.0001). Relative to MDF activity, the MH shifted upward as velocity increased (P\u3c0.01) while the BF decreased between 180 and 300 degrees s(-1) (P\u3c0.01). Results of the muscular fatigue test indicated that the RMS activity of the VM showed a higher degree of coactivation a than the VL (P\u3c0.01) and the BF showed approximately three times the coactivation level of the Mn (P\u3c0.001). The MDF of the VL and MH shifted downward as the repetitions progressed (P\u3c0.01) with no changes for the VM or for the BF. Results of this study suggest that during isokinetic testing, both the VM and BF have significantly greater reciprocal coactivation levels when compared to the VL and MH, respectively. In addition, these results suggest that motor unit recruitment patterns of the VM and VL and the MH and BF differ with regard to the effects of velocity and fatigue. (C) 2000 Elsevier Science Ltd. All rights reserved

Analyses of isokinetic and closed chain movements for hamstring reciprocal coactivation

Context. Researchers have postulated that coactivation of the hamstrings during active knee extension assists the anterior cruciate ligament in maintaining knee joint stability by exerting an opposing force to anterior tibial translation. Objective: To compare the reciprocal coactivation of the hamstrings while performing low and high velocity isokinetic movements and two closed chain movements. Design: Within subject\u27s comparison of isokinetic and closed chain exercises. Setting: Biomechanics laboratory utilizing a Cybex norm isokinetic dynamometer and Biopac Data Collection system. Participants: 12 healthy women. Main Outcome Measures: The root mean square of the Electromyogram (rmsEMG) was used as a measure of overall muscle activity. Results: The rmsEMG for hamstring coactivation during knee extension showed significant differences between the isokinetic movements and the closed chain exercises with greater coactivation when performing the isokinetic movements. In addition, greater activity was seen at the higher isokinetic velocity and during the one legged squat. Conclusions: These results suggest isokinetic movements, particularly at high speed, can more effectively increase the coactivation activity of the hamstrings when compared to two closed chain activities

Utilization of sensory information in intellectual disabilities

This investigation evaluated the use of sensory information in maintaining stability in individuals with intellectual disabilities. Individuals with mild intellectual disabilities (MID; n = 8), Down syndrome (DS; N = 8), and without intellectual disabilities (WID; n = 8) were evaluated with computerized posturography using the Sensory Organization Test (SOT). Outcomes included an equilibrium composite score, equilibrium scores on six sensory conditions, and sensory ratios for visual, somatosensory, and vestibular systems. Participants were tested with their eyes open or closed while the visual surround, force plate, or combination of both moved to measure influence of sensory information on stability. Based on the data analysis, individuals WID utilize sensory information to a greater extent than did individuals with MID or DS, indicating that sensory information for maintaining stability is deficient among these individuals. To amend this problem and facilitate learning in individuals with intellectual disabilities, practitioners should utilize techniques that maximize variable practice activities using sensory information in different contexts

Dataset for Effects of Single-Session Practice Structure on Motor Skill Acquisition and Alpha and Beta EEG Oscillations

Although it is known that practicing a motor skill updates the associated internal model, it is still unclear as to how cortical oscillations linked with the motor skill change under differing practice schedules. The current study investigated α- and β-power changes associated with motor skill acquisition. Firstly, we investigated the behavioral effects of practice on motor learning and retention during repetitive (RP) and variable (VP) practice schedules on an anticipation timing task. Secondly, we investigated changes in cortical α (10-13 HZ) and β (15-30 Hz) event-related synchronization and dyssynchronization (ERS/ERD) under RP and VP during early (EP) and late (LP) stages of practice. To investigate the behavioral effects of practice on learning and retention, participants were pretested, post-tested at 5 min (retention), and tested twice at 30 min (one for longer retention, one for transfer to a novel velocity). Based on a 2 x 4 (Practice Group x Practice Trial Blocks) ANOVA, results indicated a significant learning effect for both group participants, with VP participants performing better on the 30 min transfer test. To investigate EEG α and β power changes, data were collected from electrode sites T7, T8, C3, C4, CP3, CP4, FCz, AFz, and Pz, and were analyzed using separate, 2 x 2 repeated measures ANOVA (Group [RP and VP] x Practice Trial Blocks [EP and LP]). Power analyses revealed (1) attenuated α ERD at T7 (cognitive/verbal rehearsal), C3 (motor cortex), CP3, CP4, and FCz (pooled data representing premotor cortices), and AFz (frontal cortex and attentional processes) during LP, with greater changes observed in PMA, T7, and AFz electrode sites in RP participants. β frequency analysis, using beta modulation depth (BMD), revealed that participants in both groups had increased BMD at premotor, motor, and frontal electrode sites at LP, with RP participants exhibiting greater changes. Results are in accordance with previous research indicating that practicing under a VP schedule leads to superior motor skill transfer than practicing under an RP schedule. Moreover, lesser changes in α ERD along and lower BMD observed in VP participants might be responsible for a more adaptable and flexible motor program, allowing for greater skill retention and transfer in individuals practicing under VP conditions

Reliability and concurrent validity of the movement assessment battery for children

Reliability and concurrent validity of the Movement Assessment Battery for Children were evaluated Nvith a sample of 106 boys and girls, distributed into four age groups: 5-6 yr. (n=20), 7-8 yr. (n=20), 9-10 yr. (n=46), and 11-12 yr. (n=20). Test-retest reliability of the Movement Assessment Battery for Children, estimated using intraclass correlation coefficients, was high across all age groups, and concurrent validity yielded moderate Pearson correlation coefficients between the Movement battery and long and short forms of the Bruininks-Oseretsky Test of Motor Proficiency. These results support the use of the Movement battery as a measure of motor ability in children, ages 5 to 12 years

A comparison of isokinetic muscle strength and power in visually impaired and sighted individuals

The purpose of this investigation was to compare the isokinetic strength characteristics of visually impaired with sighted individuals. Thirty age-matched participants who met the criteria for blind and partially sighted were matched according to age, height, and sex. Participants were evaluated on a Cybex Isokinetic dynamometer at speeds of 90 and 180 deg/sec. The main outcome measures were peak torque normalized by body weight; and power adjusted by body weight. Data was analyzed by using separate 2 x 2 x 2 x 2 (group x gender x muscle x velocity) repeated measures analyses of variance (ANOVAs). Separate ANOVAs were performed because of the relatively low number of subjects used in the investigation. Results demonstrated significant group, velocity and muscle main effects; sighted individuals had significantly greater values for peak torque and power than individuals with visual impairments. In conclusion, it appears that individuals with visual impairments are deficient in strength and power compared to sighted individuals. Interventions programs should begin early in an individual\u27s development and stress developing muscular strength and power

Alterations in torque and hamstrings agonist and antagonist activity over repeated maximum effort, reciprocal isokinetic flexion-extension movements

Examining the effects of fatigue on hamstrings\u27 functioning can provide useful information regarding their role in stabilizing the knee joint. The purpose of the present investigation was to determine the effect of fatiguing, maximum effort, reciprocal isokinetic flexion-extension movements on peak torque (PT) and average torque (AVT) of the knee flexors and extensors, and agonist and antagonist medial hamstrings (MH) and biceps femoris (BF) surface electromyography (SEMG), as measured by the root mean square amplitude (RMS) and median frequency of the frequency spectrum (MDF). Ten healthy adult female university students (age = 22.5 +/- 2.0 years) performed 32 maximal effort contractions of the quadriceps (extension) followed by maximal effort contractions of the hamstrings (flexion) at an angular velocity of 400 degrees. s(-1). Data were normalized (as a percentage) and compared to maximum voluntary contractions (MVC) at repetitions 8, 16, 24, and 32. Separate repeated measures analyses of variance were performed on data to determine changes from MVC levels. Results indicated: ( 1) there were significant declines in PT and AVT from MVC levels across repetitions tested; ( 2) when acting as agonists MH and BF displayed increased RMS across repetitions tested, except from repetition 8-to-16; ( 3) when acting as antagonists MH and BF displayed no significant differences in RMS across repetitions tested; and, ( 4) there was a steady decline in MDF across repetitions tested in both MH and BF muscles when acting as agonists and antagonists, indicating a shift in motor unit recruitment from fast-to-slow twitch units. Based on the results, it appears that the MH and BF behave in unison when acting as either agonists or antagonists but as a muscle pair, they behave differently when acting in agonist or antagonist mode. As agonists, the MH and BF displayed increased amplitude and decreased spectral frequency over the course of a fatiguing, maximum effort, reciprocal isokinetic flexion-extension test performed at 400 degrees . s(-1). However, when acting as antagonists, they displayed stable amplitude with decreasing spectral frequency