scholarly journals Fatigue-Induced Alterations of Static and Dynamic Postural Control in Athletes With a History of Ankle Sprain

2013 ◽  
Vol 48 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Simon Steib ◽  
Astrid Zech ◽  
Christian Hentschke ◽  
Klaus Pfeifer
Keyword(s):  
Postural Control ◽  
Ankle Sprain ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Center Of Pressure ◽  
Sport Activity ◽  
Sensorimotor Control ◽  
Treadmill Running ◽  
History Of ◽  
Anterior Posterior

Context: Sensorimotor control is impaired after ankle injury and in fatigued conditions. However, little is known about fatigue-induced alterations of postural control in athletes who have experienced an ankle sprain in the past. Objective: To investigate the effect of fatiguing exercise on static and dynamic balance abilities in athletes who have successfully returned to preinjury levels of sport activity after an ankle sprain. Design: Cohort study. Setting: University sport science research laboratory. Patients or Other Participants: 30 active athletes, 14 with a previous severe ankle sprain (return to sport activity 6–36 months before study entry; no residual symptoms or subjective instability) and 16 uninjured controls. Intervention(s): Fatiguing treadmill running in 2 experimental sessions to assess dependent measures. Main Outcome Measure(s): Center-of-pressure sway velocity in single-legged stance and time to stabilization (TTS) after a unilateral jump-landing task (session 1) and maximum reach distance in the Star Excursion Balance Test (SEBT) (session 2) were assessed before and immediately after a fatiguing treadmill exercise. A 2-factorial linear mixed model was specified for each of the main outcomes, and effect sizes (ESs) were calculated as Cohen d. Results: In the unfatigued condition, between-groups differences existed only for the anterior-posterior TTS (P = .05, ES = 0.39). Group-by-fatigue interactions were found for mean SEBT (P = .03, ES = 0.43) and anterior-posterior TTS (P = .02, ES = 0.48). Prefatigue versus postfatigue SEBT and TTS differences were greater in previously injured athletes, whereas static sway velocity increased similarly in both groups. Conclusions: Fatiguing running significantly affected static and dynamic postural control in participants with a history of ankle sprain. Fatigue-induced alterations of dynamic postural control were greater in athletes with a previous ankle sprain. Thus, even after successful return to competition, ongoing deficits in sensorimotor control may contribute to the enhanced ankle reinjury risk.

A Comparison of Two Thera-Band Training Rehabilitation Protocols on Postural Control

2007 ◽  
Vol 16 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Alecia Puls ◽  
Phillip Gribble
Keyword(s):  
Postural Control ◽  
Healthy Subjects ◽  
Mixed Model ◽  
Outcome Measure ◽  
Center Of Pressure ◽  
Main Outcome Measure ◽  
Rehabilitation Protocols ◽  
Ankle Rehabilitation ◽  
Eyes Open ◽  
Anterior Posterior

Context:Thera-Band™ (TB) exercises are commonly utilized in ankle rehabilitation, but previous studies have shown inconsistent results.Objective:To compare two TB protocols among healthy subjects in improving postural control.Design:Mixed model design.Setting:Research laboratory.Participants:Thirty healthy subjects divided into a control (CON), three times/week (TB3) or five times/week (TB5) group.Intervention:Training groups completed TB quick-kick protocols for six weeks either three (TB3) or five times (TB5) per week.Main Outcome Measure:Center of pressure velocity in the anterior/posterior (COPVX) and medial/lateral (COPVY) directions.Results:There were no differences related to Group or Side. COPVX in the eyes open (EO) condition increased pre-post. COPVY decreased pre-post.Conclusion:The lack of differences between Groups and Side indicates these specific TB training protocols did not impact static postural control differently among healthy subjects.

scholarly journals Sensorimotor Connectivity is related to Static Postural Control in Older Adults with History of Lateral Ankle Sprain

2021 ◽  
Author(s):  
Katherine A. Bain ◽  
Kyle B. Kosik ◽  
Masafumi Terada ◽  
Phillip A. Gribble ◽  
Nathan F. Johnson
Keyword(s):  
Older Adults ◽  
Postural Control ◽  
Ankle Sprain ◽  
Functional Performance ◽  
Center Of Pressure ◽  
Brain Regions ◽  
Lateral Ankle Sprain ◽  
Lateral Ankle ◽  
Sensorimotor Network ◽  
History Of

Abstract Context: The Sensorimotor Network (SMN) is often overlooked when determining relationships between postural control and sensorimotor function. SMN functional connectivity (FC) represents the temporal synchrony of functionally linked but spatially divergent brain regions. This study aimed to determine the relationship between SMN-FC and static postural control in older adults with a history of lateral ankle sprain (LAS). Methods Data were analyzed from twenty older adults (mean age = 67.0±4.3yrs; 13 females) with a history of LAS. The SMN was identified from resting-state MRI data. Bilateral thalamic and post-central gyri regions of interest were identified. Balance was assessed for the involved and non-involved limbs via center of pressure velocity (COPV) in the medial-lateral (ML) and anterior-posterior (AP) directions. Results Contralateral SMN-FC was significantly associated with COPV_ML (r = -0.468, P = .05) and COPV_AP (r = -0.530, P = .02) in the non-involved limb. No significant association was observed between involved limb balance and contralateral SMN-FC (COPV_ML: r= -0.081, P = .75; COPV_AP: r = 0.136, P = .60). Conclusion Findings suggest a dissociation between SMN-FC and balance in older adults with a history of LAS. The sensorimotor system’s ability to communicate with itself after injury may have an impact on functional performance, such as balance.

scholarly journals On the givenness of OV word order: a (re)examination of OV/VO variation in Old English

2018 ◽  
Vol 24 (1) ◽  
pp. 1-22
Author(s):  
TARA STRUIK ◽  
ANS VAN KEMENADE
Keyword(s):  
Word Order ◽  
Information Structure ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Multinomial Regression ◽  
Corpus Study ◽  
History Of ◽  
The Given ◽  
New Hypothesis ◽  
Multinomial Regression Analysis

OV/VO variation in the history of English has been a long-debated issue. Where earlier approaches were concerned with the grammatical status of the variation (see van Kemenade 1987; Pintzuk 1999 and many others), the debate has shifted more recently to explaining the variation from a pragmatic perspective (see Bech 2001; Taylor & Pintzuk 2012a), focusing on the given-before-new hypothesis (Gundel 1988) and its consequences for OV/VO. While the work by Taylor & Pintzuk (2012a) focuses specifically on the newness of VO orders, the present study is particularly concerned with the givenness of OV word order. It is hypothesized that OV orders are the result of leftward movement from VO orders, triggered by givenness. A corpus study on a database of subclauses with two verbs and a direct object, collected from the YCOE (Taylor et al.2003) corpus, and subsequent multinomial regression analysis within a generalized linear mixed model shows that OV word order is reserved for given objects, while VO objects are much more mixed in terms of information structure. We argue that these results are more in line with an analysis which derives all occurring word orders from a VO base than an analysis which proposes the opposite.

scholarly journals Effect of sleep deprivation on diurnal variation of vertical perception and postural control

2018 ◽  
Vol 125 (1) ◽  
pp. 167-174 ◽  
Author(s):  
T. Martin ◽  
A. Gauthier ◽  
Z. Ying ◽  
N. Benguigui ◽  
S. Moussay ◽  
...  
Keyword(s):  
Postural Control ◽  
Sleep Deprivation ◽  
Diurnal Variation ◽  
Linear Mixed Model ◽  
Center Of Pressure ◽  
Time Of Day ◽  
Mean Deviation ◽  
Oral Temperature ◽  
Total Sleep Deprivation ◽  
Control Capability

The aim of the study was to test the effect of total sleep deprivation on performance and time-of-day pattern of subjective visual vertical (SVV) and postural control. Nineteen healthy, young participants (4 women and 15 men 21.9 ± 1.2 yr) were engaged in two counterbalanced experimental sessions with or without total sleep deprivation. Oral temperature, Karolinska Sleepiness Scale, and visual analogic scale for fatigue, postural control, and SVV were randomly measured every 4 h, from 0600 to 2200. A linear mixed model was used to capture the effect of time of day and sleep condition as factors. A classical adjusted COSINOR function was then used to modelize this daily variation. After the control night of sleep, SVV as well as oral temperature, sleepiness, and fatigue showed significant time-of-day variation, contrasting with measures of postural control which remained stable across the day. After sleep deprivation, SVV showed no diurnal variation, but its mean deviation value increased by 29%. Postural control capability also decreased after sleep deprivation, with a higher center of pressure surface (+70.4%) and total length (+7.37%) but remained stable throughout the day. These results further confirm the negative effect of sleep loss on postural control capability. Even if a direct relationship cannot be confirmed, the disruption of SVV capacity after sleep deprivation could strongly play a role in postural control capacity changes. Sleep deprivation should be considered as a potent factor involved in balance loss and subsequent fall. NEW & NOTEWORTHY The topic of sleep deprivation and postural control is not understood, with discrepancy among results. This study described that postural control displays a stable level throughout the day and that sleep deprivation, even if it increases postural sway, does not affect this stable diurnal pattern. The modification of the perception of the vertical level after sleep deprivation could strongly play a role in the observed changes in postural control capacity.

scholarly journals Attentional demands associated with augmented visual feedback during quiet standing

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5101 ◽  
Author(s):  
Krzysztof Kręcisz ◽  
Michał Kuczyński
Keyword(s):  
Postural Control ◽  
Visual Feedback ◽  
Center Of Pressure ◽  
Quiet Standing ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Postural Control System ◽  
Power Frequency ◽  
Auditory Reaction Time ◽  
Anterior Posterior

To investigate how additional visual feedback (VFB) affects postural stability we compared 20-sec center-of-pressure (COP) recordings in two conditions: without and with the VFB. Seven healthy adult subjects performed 10 trials lasting 20 seconds in each condition. Simultaneously, during all trials the simple auditory reaction time (RT) was measured. Based on the COP data, the following sway parameters were computed: standard deviation (SD), mean speed (MV), sample entropy (SE), and mean power frequency (MPF). The RT was higher in the VFB condition (p < 0.001) indicating that this condition was attention demanding. The VFB resulted in decreased SD and increased SE in both the medial-lateral (ML) and anterior-posterior (AP) planes (p < .001). These results account for the efficacy of the VFB in stabilizing posture and in producing more irregular COP signals which may be interpreted as higher automaticity and/or larger level of noise in postural control. The MPF was higher during VFB in both planes as was the MV in the AP plane only (p < 0.001). The latter data demonstrate higher activity of postural control system that was caused by the availability of the set-point on the screen and the resulting control error which facilitated and sped up postural control.

scholarly journals Utility of the Actiheart Accelerometer for Estimating Exercise Energy Expenditure in Female Adolescent Runners

2010 ◽  
Vol 20 (6) ◽  
pp. 487-495 ◽  
Author(s):  
Jeanne F. Nichols ◽  
Hilary Aralis ◽  
Sonia Garcia Merino ◽  
Michelle T. Barrack ◽  
Lindsay Stalker-Fader ◽  
...  
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Repeated Measures ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Young Female ◽  
Female Adolescent ◽  
Treadmill Running ◽  
Exercise Energy Expenditure ◽  
Post Hoc

There is a growing need to accurately assess exercise energy expenditure (EEE) in athletic populations that may be at risk for health disorders because of an imbalance between energy intake and energy expenditure. The Actiheart combines heart rate and uniaxial accelerometry to estimate energy expenditure above rest. The authors’ purpose was to determine the utility of the Actiheart for predicting EEE in female adolescent runners (N = 39, age 15.7 ± 1.1 yr). EEE was measured by indirect calorimetry and predicted by the Actiheart during three 8-min stages of treadmill running at individualized velocities corresponding to each runner’s training, including recovery, tempo, and 5-km-race pace. Repeated-measures ANOVA with Bonferroni post hoc comparisons across the 3 running stages indicated that the Actiheart was sensitive to changes in intensity (p < .01), but accelerometer output tended to plateau at race pace. Pairwise comparisons of the mean difference between Actiheart- and criterion-measured EEE yielded values of 0.0436, 0.0539, and 0.0753 kcal · kg−1 · min−1 during recovery, tempo, and race pace, respectively (p < .0001). Bland–Altman plots indicated that the Actiheart consistently underestimated EEE except in 1 runner’s recovery bout. A linear mixed-model regression analysis with height as a covariate provided an improved EEE prediction model, with the overall standard error of the estimate for the 3 speeds reduced to 0.0101 kcal · kg−1 · min−1. Using the manufacturer’s equation that combines heart rate and uniaxial motion, the Actiheart may have limited use in accurately assessing EEE, and therefore energy availability, in young, female competitive runners.

An Exploration of Pre-Professional Dancers’ Beliefs of the Low Back and Dance-Specific Low Back Movements

2019 ◽  
Vol 34 (3) ◽  
pp. 141-146
Author(s):  
Danica Hendry ◽  
Leon Straker ◽  
Amity Campbell ◽  
Luke Hopper ◽  
Rhianna Tunks ◽  
...  
Keyword(s):  
Back Pain ◽  
Perceived Risk ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Low Back ◽  
Dance Movement ◽  
Lower Back ◽  
Negative Beliefs ◽  
History Of ◽  
Professional Dancers

OBJECTIVE: Low back pain (LBP) is common in dancers. A biopsychosocial model should be considered in the aetiology of LBP, including a dancer’s general beliefs of the low back and movements of the spine. This study aimed to determine pre-professional dancers’ beliefs about their lower back in general and dance-specific movements of the spine and to explore whether these beliefs were influenced by a history of disabling LBP. METHODS: 52 pre-professional female dancers (mean age 18.3 [1.4] yrs) were recruited and reported whether they had a history of disabling LBP and completed the Back Pain Attitudes Questionnaire (Back-PAQ) and a dance movement beliefs questionnaire. A linear mixed model was applied to determine the effect of a history of disabling LBP on dancers’ beliefs (p<0.05). RESULTS: 20 dancers reported a history of disabling LBP. Regardless of this LBP history, dancers held generally negative beliefs as measured by the Back-PAQ (p=0.130). A history of disabling LBP did not influence dancers’ perceived movement safety of all tasks (p=0.867), and dancers held negative beliefs towards extension activities. These beliefs were linked to the conceptions of perceived risk of damage and the need to protect the lower back. CONCLUSIONS: Dancers hold negative general beliefs around the low back and low back movements, regardless of a history of disabling LBP. Dancers perceive extension activities as more dangerous than flexion activities. These beliefs may reflect a combination of pain experience and beliefs specific to dance.

scholarly journals Utility of 5-alpha-reductase inhibitors in active surveillance for favourable risk prostate cancer

2013 ◽  
Vol 7 (11-12) ◽  
pp. 450 ◽  
Author(s):  
Andrew Chiang ◽  
Andrew Loblaw ◽  
Vibhuti Jethava ◽  
Perakaa Sethukavalan ◽  
Liying Zhang ◽  
...  
Keyword(s):  
Active Surveillance ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Specific Antigen ◽  
Reductase Inhibitors ◽  
Risk Prostate Cancer ◽  
History Of ◽  
Psa Nadir ◽  
5 Alpha Reductase Inhibitors

Introduction: This retrospective review compares prostate-specific antigen (PSA) doubling time (DT) prior to the initiation of a 5-alpha reductase inhibitor (pre-5-ARI) to after the PSA nadir (post-nadir) has been reached for patients on active surveillance for favourable risk prostate cancer.Methods: Between 1996 and 2010, a total of 100 men with a history of 5-ARI use were captured from our active surveillancedatabase. Twenty-nine patients had a sufficient number of PSA values to determine both pre-5-ARI and post-nadir DTs. PSADT was calculated using the general linear mixed-model method.Results: The median follow-up was 69.5 months. The median pre-5-ARI PSADT was 55.8 (range: 6-556.8) months, while the post-nadir value was 25.2 (range: 6-231) months (p = 0.0081). Six patients were reclassified after an average of 67.7 (range: 59-95) months, due to progression in PSADT (n = 2) or Gleason score (n = 4). The median pre-5-ARI and post-nadir DTs for this group were 42.3 (range: 32.4-91.1) and 21.1 (range: 6-44.3) months, respectively.Conclusion: 5-ARIs significantly decreased PSADT compared to prior to their initiation. This effect may be due to preferential suppression of benign tissue following PSA nadir. The resulting PSADT would then represent a more accurate depiction of the true cancer related DT. If validated with a larger cohort, 5-ARIs may enhance the utility of PSADT as a biomarker of disease progression in active surveillance.

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