Main Effect Of Condition Research Articles

Effects of Individualized Versus Traditional Power Training on Strength, Power, Jump Performances, and Body Composition in Young Male Nordic Athletes.

This study aimed to examine the effects of individualized-load power training (IPT) versus traditional moderate-load power training (TPT) on strength, power, jump performance, and body composition in elite young Nordic athletes. In a randomized crossover design, 10 young male athletes (ski jumpers, Nordic combined athletes) age 17.5 (0.6) years (biological maturity status: +3.5y postpeak height velocity) who competed on a national or international level performed 5weeks of IPT (4 × 5 repetitions at 49%-72% 1-repetiton maximum [RM]) and TPT (5 × 5 repetitions at 50%-60% 1-RM) in addition to their regular training. Testing before, between, and after both training blocks comprised the assessment of muscle strength (loaded back squat 3-RM), power (maximal loaded back squat power), jump performance (eg,drop-jump height, reactive strength index), and body composition (eg,skeletal muscle mass). Significant, large-size main effects for time were found for muscle strength (P < .01; g = 2.7), reactive strength index (P = .03; g = 1.6), and drop-jump height (P = .02; g = 1.9) irrespective of the training condition (IPT, TPT). No significant time-by-condition interactions were observed. For measures of body composition, no significant main effects of condition and time or time-by-condition interactions were found. Our findings demonstrate that short-term IPT and TPT at moderate loads in addition to regular training were equally effective in improving measures of muscle strength (loaded back squat 3-RM) and vertical-jump performance (reactive strength index, drop jump, and height) in young Nordic athletes.

The Effects of Intermittent Trunk Flexion With and Without Support on Sitting Balance in Young Adults.

Prolonged trunk flexion is known to affect passive and active stabilization of the trunk. Previous studies have evaluated changes in spinal range of motion, muscle activity and reflex behavior induced by prolonged trunk flexion, whereas the effect on sitting postural control is vastly underexplored. In this study, we compared the effects of supported and unsupported intermittent trunk flexion on center of pressure (CoP) motion during sitting on an unstable seat. Participants (n = 21; 11 males, 23.2 ± 2.0 years; 10 females, age 24.3 ± 4.0) were exposed to 1-h intermittent (60-s sets with 30 s of rest) trunk flexion (80% of the maximal range of motion) and CoP root mean square distance, velocity and frequency before and after the exposure were assessed. Contrary to our hypothesis, there were no main effects of exposure (pre. vs. post flexion protocol; p = 0.128–0.709), no main effects of condition (supported vs. unsupported; p = 0.134–0.931), and no interaction between exposure and condition (p = 0.163–0.912). Our results indicate that prolonged intermittent flexion does not induce any changes in CoP motion during a seated balance task, regardless of the presence of a trunk support during prolonged intermittent flexion. This suggests a successful compensation of decreased passive stiffness by increased reflex activity.

Non-invasive brain stimulation over the orbital prefrontal cortex maintains endurance performance in mentally fatigued swimmers

Background: Using anodal transcranial direct current stimulation (a-tDCS) on frontal brain areas might be a promising strategy to mitigates mental fatigue and maintain endurance performance swimmers. Objective: The objective was to analyze the effect of a-tDCS over the orbital prefrontal cortex (oPFC) on endurance performance of mentally fatigued female amateur swimmer. Methods: Nineteen female amateur swimmers participated in this study. In two experimental visits, the swimmers completed the 3-min all-out tethered swimming after performing a 30-min Stroop test with a-tDCS or placebo (Sham) stimulation over the left-oPFC. The brain stimulation conditions (i.e., a-tDCS and Sham) were performed in a double-blinded and counterbalanced order. Results: It was found lower critical force, mean force, force minimum, fatigue index, and aerobic impulse for Sham than a-tDCS (p < 0.05). There was no main effect of condition for peak force (p > 0.05). Conclusion: We concluded that a-tDCS applied over the left-oPFC in female amateur swimmers mentally fatigued maintained endurance performance. From a practical point of view, the use of a-tDCS should be considered to counteract harmful cognitive effects and maintain endurance performance during competitive race events.

Virtual reality-based distraction on pain, performance, and anxiety during and after moderate-vigorous intensity cycling

Purpose: To determine whether increased visual perceptual load (PL) within an immersive virtual environment may help explain previously shown pain-relieving effects of virtual reality (VR) during high intensity cycling.Methods: Using a within-subjects design, participants cycled at a perceptually “hard” intensity for 10 min on three separate occasions. The first session did not use VR (i.e., no perceptual load - NPL). Subsequent sessions employed VR during cycling with either a low or high perceptual load (LPL or HPL). Quadriceps pain intensity (PI) was reported by participants throughout cycling.Results: Data were analyzed for 43 healthy participants (20 females, mean age 21 [SD 1.4]). For PI, ANOVA showed there were significant main effects of condition (F = 13.458, df =1.579, 66.334, p<0.001) and time (F = 113.045, df =1.618, 227.683, p<0.001). At every time point, t-tests revealed mean PI was significantly lower in the NPL than in the LPL condition (t(42)=4.737, p<0.001, d = 0.472) and HPL condition (t(42)=3.380, p = 0.002, d = 0.391). Dependent t-tests showed that more work (kilojoules) was performed during the LPL condition than the NPL (t(42)=2.992, p = 0.005) and HPL (t(42)=5.810, p<0.001) conditions.Conclusions: Compared to a traditional 10-minute bout of cycle ergometry (NPL), individuals who cycled in the LPL condition chose to exercise at a higher intensity despite greater PI. Those who cycled in the HPL condition did not change their exercise intensity, but did report higher PI, possibly, because of the greater mental effort/energy requirement.

Social Value Orientation Moderated the Effect of Acute Stress on Individuals' Prosocial Behaviors.

Acute stress is believed to lead to prosocial behaviors via a “tend-and-befriend” pattern of stress response. However, the results of the effect of acute stress on prosocial behavior are inconsistent. The current study explores the moderating effect of gender and social value orientation on the relationship between acute stress and individuals’ pure prosocial behaviors (i.e., pure prosociality and prosocial third-party punishment). Specifically, eighty-one participants were selected and underwent the Trier Social Stress Test (or were in the control group), followed by the third-party punishment task and the dictator game. The results showed that, in general, the main effect of condition or respiratory sinus arrhythmia (RSA) reactivity on individual prosocial behaviors was significant and did not vary between genders. Furthermore, social value orientation (i.e., prosocial or self-orientation) might moderate the impact of RSA reactivity on the amount of punishment in the third-party punishment task. That is, individuals with self-orientation exhibited more prosocial third-party punishment as RSA reactivity decreased, while the effect did not occur for individuals with prosocial orientation. Taken together, the findings of the current study provide further evidence for the “tend-and-befriend” hypothesis and highlight the underlying physical mechanisms as well as the individual dependence of the effect of psychosocial stress on individuals’ pure prosocial behaviors.

Acute mood and cardiovascular responses to moderate intensity vinyasa yoga, static yin yoga and aerobic exercise in people with depression and/or anxiety disorders: A 5-arm randomised controlled trial

IntroductionDue to the multi-composite, mind-body features of yoga, it is of interest to determine what effect exercise plays as a component of modern yoga in providing psychological and physiological health benefits, and whether benefits are enhanced with a combination of components. Furthermore, although the effects of regular, long-term yoga practice are well documented, the acute effects have received less empirical investigation. MethodA within-subjects, repeated measures randomised controlled crossover trial with five conditions was conducted (trial registration: ACTRN12620000983909). Participants (N = 41, mean age = 32 years) with Depressive and/or Anxiety Disorders completed 1) yin yoga, 2) aerobic exercise, 3) vinyasa yoga, 4) stretching (sham) control and 5) no-intervention control. Acute changes in mood and cardiovascular tone were assessed. ResultsA significant main effect of condition on mood was observed (N = 38; F4,127.193 = 7.507, p = <.001). Participants receiving yin, vinyasa, aerobic exercise and stretching achieved comparable improvements in mood symptoms compared to no-intervention control. Cardiovascular changes were observed for aerobic exercise and vinyasa yoga. No adverse events were reported. ConclusionsThe acute mood benefits of a single initial session of yoga are not significantly greater than those derived from other forms of movement. Moderate-intensity styles of yoga can provide a sufficient and equivalent acute cardiovascular exercise effect to that of traditional exercise options (i.e., cycling).

A Novel Perspective on the Proactive and Reactive Controls of Executive Function in Chronic Stroke Patients.

ObjectivesTo investigate the proactive and reactive control process when executing a complex task in patients with stroke. Proactive control is the preparatory process before the target stimulus, whereas reactive control is an imperative resolution of interference after the target stimulus.MethodsIn total, 17 patients with chronic stroke and 17 healthy individuals were recruited. The proactive and reactive control of executive function was assessed by the task-switching paradigm and the AX version of the Continuous Performance Task (AX-CPT). The general executive function was assessed by Color Trial Test (CTT) and Stroop Test. The behavioral data of the task-switching paradigm were analyzed by a three-way repeated-measures ANOVA, and the AX-CPT data were analyzed by two-way repeated-measures ANOVA.ResultsFor efficiency scores in the task-switching paradigm, trial (repeat vs. switch) × group (stroke or control group) interaction effect was significant. Post-hoc analysis on trial × group effect showed a significant between-trial difference in accuracy rates in the repeat trial in the control group regardless of 100 or 50% validity. For the AX-CPT, the main effects of condition and group on response time were statistically significant. The interaction effect of condition (AY or BX) × group (stroke or control group) was also significant. Post-hoc analysis for condition × group indicated that the stroke group had a significantly longer response time in the BX condition than the control group and longer completion time in CTT2 and larger word interference for completion time in the Stroop test than the control cohort.ConclusionsPost-stroke survivors showed deficits in the performance of proactive control but not in the performance of reactive control. Deficits in proactive control may be related to the impairment of working memory. Interventions that focus on proactive control may result in improved clinical outcomes.

Effects of short sleep duration on hemodynamic and psychological responses under long working hours in healthy middle-aged men: an experimental study.

This study examined the effects of short sleep duration (SSD) on hemodynamic and psychological responses under long working hours (LWH) in a laboratory experiment. Sixteen subjects participated in a crossover design experiment consisting of two conditions: normal (7-hours) sleep and short (5-hours) sleep. In each condition, participants engaged in simulated LWH (13 hours a day), comprising 12 task sessions. Hemodynamic and psychological responses were measured in each session. Results showed that there were significant main effects of condition and session but no interaction for hemodynamic and psychological responses. Systolic blood pressure and fatigue were higher in the later sessions than the first one. Stroke volume, sleepiness, fatigue, and stress were higher in the 5-hour than the 7-hour sleep condition (all p<0.05). These results suggest that although the combined effect of LWH and SSD was not significant, both LWH and SSD caused a hemodynamic and psychological burden.

Muscle growth adaptations to high-load training and low-load training with blood flow restriction in calf muscles.

To compare muscle growth adaptations between traditional high-load training and low-load training with blood flow restriction (BFR) in the calf muscles over 6 weeks. 27 trained individuals performed calf exercise in both legs for 6weeks. Each leg was randomly assigned to one of the two conditions: (1) Traditional (70% of 1RM) training (TRAD); and (2) Low-load (30% of 1RM) training with BFR. In addition, subjects performed standing calf raises with or without BFR. Measures were taken pre- and post-intervention. For the posterior muscle site, there was no condition (BFR vs. TRAD)×time (pre vs. post) interaction (p = 0.15). In addition, there was no main effect for condition (p = 0.83) or time (p = 0.20). For the lateral muscle site, there was no condition×time interaction (p = 0.47). In addition, there was no main effect for condition (p = 0.10) or time (p = 0.57). For the medial muscle site, there was no condition×time interaction (p = 0.60). In addition, there was no main effect for condition (p = 0.44) or time (p = 0.72). For RPE, there was no condition×time interaction. However, there was a main effect for condition (p < 0.05) with BFR having higher RPE. For discomfort, there was no condition×time interaction. However, there was a main effect for condition (p < 0.001) with the BFR condition displaying higher discomfort. No muscle growth was detected in the calf musculature. BFR was not more effective at eliciting muscle hypertrophy compared to traditional training. However, it was accompanied with higher exertion and discomfort.

Randomized clinical trial of a brief, scalable intervention for mental health sequelae in college students during the COVID-19 pandemic

This randomized clinical trial aimed to determine feasibility, acceptability, and initial efficacy of brief Dialectical Behavior Therapy (DBT) skills videos in reducing psychological distress among college students during the COVID-19 pandemic. Over six weeks, 153 undergraduates at a large, public American university completed pre-assessment, intervention, and post-assessment periods. During the intervention, participants were randomized to receive animated DBT skills videos for 14 successive days (n = 99) or continue assessment (n = 54). All participants received 4x daily ecological momentary assessments on affect, self-efficacy of managing emotions, and unbearableness of emotions. The study was feasible and the intervention was acceptable, as demonstrated by moderate to high compliance rates and video ratings. There were significant pre-post video reductions in negative affect and increases in positive affect. There was a significant time × condition interaction on unbearableness of emotions; control participants rated their emotions as more unbearable in the last four vs. first two weeks, whereas the intervention participants did not rate their emotions as any more unbearable. Main effects of condition on negative affect and self-efficacy were not significant. DBT skills videos may help college students avoid worsening mental health. This brief, highly scalable intervention could extend the reach of mental health treatment.

Optical flow balance perturbations alter gait kinematics and variability in chronic ankle instability patients

BackgroundIndividuals with chronic ankle instability (CAI) have known balance impairments thought to be the result of an inability to reweight sensory information. CAI patients place greater emphasis on visual information during single-limb stance than healthy controls but this evidence is based on removing visual information during static conditions. Research questionDoes perturbed optical flow effect step kinematics and variability in those with CAI differently than healthy controls? What is the relationship among ankle laxity, plantar cutaneous sensation, and susceptibility to perturbed optical flow in those with CAI? Methods17 CAI patients and 17 healthy individuals participated in a crossover experimental study. Participants walked on a treadmill at 1.25 m/s while watching a speed-matched virtual hallway with and without continuous mediolateral (ML) optical flow perturbations. Three-dimensional pelvic and foot kinematics were recorded at 100 Hz for at least 300 consecutive steps in each condition. Step width (SW) and step length (SL) values were calculated from consecutive heel positions. Gait variability was characterized as the standard deviation of step width (SWV), step length (SLV), and ML sacrum motion (SMV) across all steps performed in each condition. ResultsThe CAI group exhibited a greater change in SWV (p = 0.037), SLV (p = 0.040), and ML SMV (p = 0.047) from the perturbed to unperturbed conditions relative to the healthy controls. A condition main effect was also noted for SW (p < 0.001) and SL (p < 0.001) as ML optical flow perturbations resulted in significant changes in SW and SL relative to the normal walking condition. SignificanceWalking with ML optical flow perturbations induced greater variability changes in those with CAI relative to controls. When combined with the existing literature, this finding suggests that CAI individuals have a greater reliance on visual information in both static and dynamic (i.e. walking gait) conditions relative to healthy individuals.

Using a smartphone on the move: do visual constraints explain why we slow walking speed?

Viewing one’s smartphone whilst walking commonly leads to a slowing of walking. Slowing walking speed may occur because of the visual constraints related to reading the hand-held phone whilst in motion. We determine how walking-induced phone motion affects the ability to read on-screen information. Phone-reading performance (PRP) was assessed whilst participants walked on a treadmill at various speeds (Slow, Customary, Fast). The fastest speed was repeated, wearing an elbow brace (Braced) or with the phone mounted stationary (Fixed). An audible cue (‘text-alert’) indicated participants had 2 s to lift/view the phone and read aloud a series of digits. PRP was the number of digits read correctly. Each condition was repeated 5 times. 3D-motion analyses determined phone motion relative to the head, from which the variability in acceleration in viewing distance, and in the point of gaze in space in the up-down and right-left directions were assessed. A main effect of condition indicated PRP decreased with walking speed; particularly so for the Braced and Fixed conditions (p = 0.022). Walking condition also affected the phone’s relative motion (p < 0.001); post-hoc analysis indicated that acceleration variability for the Fast, Fixed and Braced conditions were increased compared to that for Slow and Customary speed walking (p ≤ 0.05). There was an inverse association between phone acceleration variability and PRP (p = 0.02). These findings may explain why walking speed slows when viewing a hand-held phone: at slower speeds, head motion is smoother/more regular, enabling the motion of the phone to be coupled with head motion, thus making fewer demands on the oculomotor system. Good coupling ensures that the retinal image is stable enough to allow legibility of the information presented on the screen.

Enhancement of Countermovement Jump Performance Using a Heavy Load with Velocity-Loss Repetition Control in Female Volleyball Players.

Although velocity control in resistance training is widely studied, its utilization in eliciting post-activation performance enhancement (PAPE) responses receives little attention. Therefore, this study aimed to evaluate the effectiveness of heavy-loaded barbell squats (BS) with velocity loss control conditioning activity (CA) on PAPE in subsequent countermovement jump (CMJ) performance. Sixteen resistance-trained female volleyball players participated in this study (age: 24 ± 5 yrs.; body mass: 63.5 ± 5.2 kg; height: 170 ± 6 cm; relative BS one-repetition maximum (1RM): 1.45 ± 0.19 kg/body mass). Each participant performed two different conditions: a set of the BS at 80% 1 RM with repetitions performed until a mean velocity loss of 10% as the CA or a control condition without CA (CNTRL). To assess changes in jump height (JH) and relative mean power output (MP), the CMJ was performed 5 min before and throughout the 10 min after the CA. The two-way analysis of variance with repeated measures showed a significant main effect of condition (p = 0.008; η2 = 0.387) and time (p < 0.0001; η2 = 0.257) for JH. The post hoc test showed a significant decrease in the 10th min in comparison to the value from baseline (p < 0.006) for the CNTRL condition. For the MP, a significant interaction (p = 0.045; η2 = 0.138) was found. The post hoc test showed a significant decrease in the 10th min in comparison to the values from baseline (p < 0.006) for the CNTRL condition. No significant differences were found between all of the time points and the baseline value for the CA condition. The CA used in the current study fails to enhance subsequent countermovement jump performance in female volleyball players. However, the individual analysis showed that 9 out of the 16 participants (56%) responded positively to the applied CA, suggesting that the PAPE effect may be individually dependent and should be carefully verified before implementation in a training program.

Effects of Capsiate Supplementation on Maximal Voluntary Contraction in Healthy Men.

This study aimed to investigate the effects of acute capsaicin analog (Capsiate - CAP) supplementation on maximal voluntary isometric contraction (MVIC) performance in healthy young men. Thirteen subjects (25.2±3.2 yrs) participated in the present study. In two different days separated by one week, the subjects ingested capsiate (12 mg) or placebo (starch: 12 mg) 45 minutes before a MVIC test. The MVIC test consisted of five 10-second knee extension maximal isometric contractions with 45 seconds of recovery between efforts. The peak force, mean force, minimum force, fatigue index, and area under the curve of each contraction were calculated. Main condition effect was found, with higher values of peak force (+4.83%, F=6.867, p=0.02), fatigue index (+8.96%, F=5.228, p=0.041), and area under the curve (+4.19%, F=4.774, p=0.04) for CAP compared to placebo, however, no interaction effect was found for any variable (F=0.090 to 1.356, p≥0.276). In summary, healthy young men produced higher maximal isometric force and delayed fatigue in the CAP condition compared to placebo condition (condition effect) but without significant difference between each effort.

Psychophysiological effects of slow-paced breathing at six cycles per minute with or without heart rate variability biofeedback.

Heart rate variability (HRV) biofeedback, referring to slow-paced breathing (SPB) realized while visualizing a heart rate, HRV, and/or respiratory signal, has become an adjunct treatment for a large range of psychologic and medical conditions. However, the underlying mechanisms explaining the effectiveness of HRV biofeedback still need to be uncovered. This study aimed to disentangle the specific effects of HRV biofeedback from the effects of SPB realized alone. In total, 112 participants took part in the study. The parameters assessed were emotional (valence, arousal, and control) and perceived stress intensity as self-report variables and the root mean square of the successive differences (RMSSD) as a physiologic variable. A main effect of condition was found for emotional valence only, valence being more positive overall in the SPB-HRVB condition. A main effect of time was observed for all dependent variables. However, no main effects for the condition or time x condition interaction effects were observed. Results showed that for PRE and POST comparisons (referring, respectively, to before and after SPB), both SPB-HRVB and SPB-NoHRVB conditions resulted in a more negative emotional valence, lower emotional arousal, higher emotional control, and higher RMSSD. Future research might investigate psychophysiological differences between SPB-HRVB and SPB-NoHRVB across different time periods (e.g., long-term interventions), and in response to diverse psychophysiological stressors.

Al-Anon Intensive Referral to facilitate concerned others' participation in Al-Anon Family Groups: a randomized controlled trial.

To test the effectiveness of an intervention, Al-Anon Intensive Referral (AIR), to facilitate participation in Al-Anon Family Groups (Al-Anon). Multi-site, randomized controlled trial of AIR versus usual care (UC), with follow-up assessments at 3, 6 and 12 months. The 12-month follow-up rate was 74%. Residential alcohol use disorder (AUD) treatment programs in three US locations. Concerned others (COs) of patients in treatment for AUD. COs were mainly women (77%) who were patients' spouses (33%) or parents (25%). AIR (n = 128) consisted of four sessions over 3 months with an Al-Anon coach. UC (n = 151) was the treatment program's offer of educational sessions for COs. Primary outcome: COs' self-reports of any Al-Anon attendance (yes or no) at 3 months. number of Al-Anon meetings and the CO-patient relationship (stressors, resources). Potential predictors of outcomes examined in generalized linear mixed models were their baseline value, time, CO-patient relationship type (marital or non-marital), treatment program and condition. There was no effect of condition for the primary outcome (28% in AIR, 21% in UC; Bayes factor = 1.86). Relationship stressors at follow-ups were more severe for COs in a marital relationship with the patient than for COs in a non-marital relationship [β = 2.19, 95% confidence interval (CI) = 1.07, 3.32]. For CO-patient relationship resources at follow-ups, the main effect for condition was significant (β = 1.33, 95% CI = 0.04, 2.61). COs assigned to the AIR condition had more resources than COs who were in the UC condition. Relative to usual care, Al-Anon Intensive Referral was not associated with increases in participation of concerned others in Al-Anon, but was associated with more resources in the concerned other-patient relationship.

Tongue position variability in sustained vowels produced by healthy children and young adults with and without a semi-occluded vocal tract: A pilot study

Speech development is a process by which talkers learn, among other things, to coordinate neuromuscular activations of motor units spread across several muscles that effect articulator positioning and movement. This paper presents results from an analysis of tongue position variability during sustained vowel production. Data from two children (7 years 11 months, and 9years 7 months) and two young adults (both 20 years 7 months) are presented. Articulatory data were recorded with a 3D/4D ultrasound system, in two conditions: without a semi-occluded vocal tract (“without straw”) and with a semi-occluded vocal tract (“with straw”). Statistical analyses of tongue position variability revealed a main effect of age, with children showing greater variability than adults. There was no statistically significant main effect of condition, but the main effect of age was driven primarily by the “with straw” condition. We speculate that tongue position variability during sustained vowels may be an index of speech motor control maturity, and that the interaction between age and condition suggests children are less able than adults to rely on learned feed-forward motor programs under conditions of somatosensory perturbation, such as the presence of a straw between the lips.

Walking indoors, outdoors, and on a treadmill: Gait differences in healthy young and older adults.

Although human gait is typically studied in a laboratory environment, the findings of laboratory-based gait assessments are often applied to daily life scenarios. Assessing gait in varied conditions may offer a better understanding of the influence of environment on gait performance. How do spatiotemporal gait measures differ between indoor overground walking, outdoor walking, and treadmill walking in healthy adults? Do different walking environments exaggerate age-related alterations in gait performance in older compared to young adults? 30 young (18-30yrs) and 28 older adults (60-80yrs) completed four randomized conditions at their typical, comfortable walking pace: 1) 8 m of indoor walking, 2) continuous indoor walking, 3) treadmill walking, and 4) outdoor walking on a sidewalk. Wearable inertial sensors recorded gait data and the magnitudes and variability (in standard deviations) of the following gait measures were computed: cadence, percent double support, stride length (with sample entropy), and gait velocity. Despite the lack of significant univariate interactions between group and walking condition, significant main effects for condition and group were observed in both the magnitude and variability analyses. Treadmill walking resulted in a slower gait with shorter, less variable strides (p < .001), while walking outdoors resulted in faster gait with longer strides (p < .001) compared to other walking conditions. Stride length regularity was reduced when walking outdoors compared to treadmill walking (p = .019). The results showed that the effects of walking condition on gait measures were more dramatic than participant age, and gait performance differs between walking environments in both older and younger adults. Since daily life gait encompasses both tightly controlled and unconstrained, free-living walking, researchers and clinicians should use caution when generalizing gait performance across walking conditions. Measures of gait performance typically used in laboratory gait analyses may not adequately characterize daily life gait in indoor and outdoor environments.

Walking towards a visually distracting environment does not affect gait kinematics and spatiotemporal parameters of children with cerebral palsy diplegia

Although human gait is typically studied in a laboratory environment, the findings of laboratory-based gait assessments are often applied to daily life scenarios. Assessing gait in varied conditions may offer a better understanding of the influence of environment on gait performance.How do spatiotemporal gait measures differ between indoor overground walking, outdoor walking, and treadmill walking in healthy adults? Do different walking environments exaggerate age-related alterations in gait performance in older compared to young adults?30 young (18−30yrs) and 28 older adults (60−80yrs) completed four randomized conditions at their typical, comfortable walking pace: 1) 8 m of indoor walking, 2) continuous indoor walking, 3) treadmill walking, and 4) outdoor walking on a sidewalk. Wearable inertial sensors recorded gait data and the magnitudes and variability (in standard deviations) of the following gait measures were computed: cadence, percent double support, stride length (with sample entropy), and gait velocity.Despite the lack of significant univariate interactions between group and walking condition, significant main effects for condition and group were observed in both the magnitude and variability analyses. Treadmill walking resulted in a slower gait with shorter, less variable strides (p < .001), while walking outdoors resulted in faster gait with longer strides (p < .001) compared to other walking conditions. Stride length regularity was reduced when walking outdoors compared to treadmill walking (p = .019).The results showed that the effects of walking condition on gait measures were more dramatic than participant age, and gait performance differs between walking environments in both older and younger adults. Since daily life gait encompasses both tightly controlled and unconstrained, free-living walking, researchers and clinicians should use caution when generalizing gait performance across walking conditions. Measures of gait performance typically used in laboratory gait analyses may not adequately characterize daily life gait in indoor and outdoor environments.

Tensiomyographic Responses to Warm-Up Protocols in Collegiate Male Soccer Athletes.

The mechanical properties of knee flexors and extensors in 15 collegiate male soccer players following different warm-up protocols [small-sided games (SSG), dynamic (DYN), and plyometric (PLY)] were evaluated. Tensiomyography (TMG) was used to assess contraction time (Tc), delay time (Td) and maximal displacement (Dm) of the rectus femoris (RF) and biceps femoris (BF) of both legs before and after each warm-up, while countermovement jump height variables, 20 m sprint, t-test and sit-and-reach were measured following the warm-ups. TMG was analyzed using a three-way [condition × time × leg] ANOVA, while performance variables were analyzed with a repeated measures ANOVA. Main effects of time were observed for BF-Tc (p = 0.035), RF-Td (p < 0.001), and BF-Td, (p = 0.008), and a main effect of condition was seen for RF-Tc (p = 0.038). Moreover, participants’ 20 m sprint improved following SSG (p = 0.021) compared to DYN and PLY. Sit-and-reach was greater following PLY (p = 0.021). No significant interactions were noted for the measured TMG variables. Warm-up-specific improvements were demonstrated in sprint speed and flexibility following SSG and PLY, respectively. The present study revealed changes in certain TMG measures following the warm-ups that suggest enhanced response of lower leg muscles regardless of specific activities used.