The influence of Mulligan ankle taping during balance performance in subjects with unilateral chronic ankle instability

Objective: To determine whether Mulligan ankle tape influenced the performance in subjects with unilateral chronic ankle instability (CAI) during static balance; postural sway recovery patterns after hopping and dynamic tracking balance tasks.Design: A cross-sectional, within-subjects experimental study design between 4 ankle conditions (taped; untaped: injured and uninjured).Participants: 20 volunteer recreational athletes with unilateral CAI were recruited. Means and standard deviations highlighted the athletes' characteristics: age = 23 ± 1 years; height = 173.1 ± 2.4 cm; weight = 69.3±3 kg; Functional Ankle Disability Index (FADI) = 93.5 ± 5.1% and FADI Sport = 84.2 ± 9.4%.Interventions: Mulligan ankle taping.Main Outcome Measurements: Static balance (10 s); postural sway recovery patterns after a 30 s functional hop test (immediately, 30 and 60 s); dynamic tracking balance tasks (wandering, target overshoot and reaction-time).Results: Between the four conditions, static balance showed no significant differences (p = 0.792); significant changes occurred in postural sway over time (p < 0.001); no significant changes were reported for the dynamic tracking tasks. Wandering was highly correlated with reaction-time and overshooting (p < 0.01).Conclusion: Under resting and fatigued conditions, Mulligan ankle taping did not impact on the neuromuscular control during static and dynamic balance in subjects with healthy and unstable ankles.     

Altered postural sway persists after anterior cruciate ligament reconstruction and return to sport

Postural sway is defined as the movement of a body's center of mass within the base of support to maintain postural equilibrium. Deficits in postural sway are present after ACL injury; however, current evidence linking it to future injury risk is unclear. The purpose of this study was to determine if postural sway deficits persist after ACL reconstruction (ACLR). The hypothesis tested was that after ACLR, patients who return to sport (RTS) would demonstrate differences in postural sway compared to control (CTRL) subjects. Fifty-six subjects with unilateral ACLR released to RTS, and 42 uninjured CTRL subjects participated. Dynamic postural sway was assessed and 3-way (2 × 2 × 2) ANOVA was used to analyze the variables. A side × group × sex (p = 0.044) interaction in postural sway was observed. A side × group analysis also revealed an interaction (p = 0.04) however, no effect of sex was observed (p = 0.23). Analysis within the ACLR cohort showed less (p = 0.001) postural sway on the involved side (1.82 ± 0.84°) versus the uninvolved side (2.07 ± 0.96°). No side-to-side differences (p = 0.73) were observed in the CTRL group. The involved limb of subjects after ACLR demonstrated the least postural sway. In conclusion, these findings indicate that dynamic postural sway may be significantly altered in a population of athletes after ACLR and RTS compared to CTRL subjects. Further investigation is needed to determine if deficits in postural sway can be used as an effective criterion to assist in the decision to safely RTS after ACLR.     

Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament

AimTo explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls.Method70 individuals who had unilateral ACL rupture 23 ± 2.4 years ago (33 received ACL reconstructive surgery, ACL_R, and 37 had physiotherapy only, ACL_PT) and 33 uninjured matched controls (CTRL) (mean age 46 ± 5.3) stood quietly with eyes closed for 3 min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM.ResultsComparisons across conditions to CTRL revealed larger CoP-CoM-area in ACL_R (p = 0.017, CI: 10.95, 143.10), but not in ACL_PT. Mean distance between SD-peaks was greater for ACL_R (p < 0.001, CI: 1.73, 5.31) than for ACL_PT (p = 0.006, CI: 0.56, 4.12) relative to CTRL. Duration of SD-peaks was smaller for both ACL_R and ACL_PT (p < 0.001, CI: −4.04, −1.23 and −3.82, −1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL.ConclusionsACL-injured subjects demonstrated greater postural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies.     

Impaired postural control in children with developmental coordination disorder is related to less efficient central as well as peripheral control

BackgroundDevelopmental coordination disorder (DCD) is a neurodevelopmental impairment that affects approximately 6% of children in primary school age. Children with DCD are characterized by impaired postural control. It has yet to be determined what effect peripheral and central neuromuscular control has on their balance control.ObjectiveThe aim of this study was to investigate the underlying mechanisms to impaired postural control in children with DCD using the rambling-trembling decomposition of the center of pressure (CoP).MethodNine children with DCD (9.0 ± 0.5 years, 7 boys, 2 girls) and 10 age- and gender-matched typically developing children (TD) with normal motor proficiency (9.1 ± 0.4 years, 7 boys and 3 girls) performed 3 × 30 s bipedal standing on a force plate in six sensory conditions following the sensory organization procedure. Sway length was measured and rambling-trembling decomposition of CoP was calculated in medio-lateral (ML) and anterior-posterior (AP) direction.ResultsBoth rambling and trembling were larger for the children with DCD in AP (p = 0.031; p = 0.050) and ML direction (p = 0.025; p = 0.007), respectively.ML rambling trajectories did not differ in any conditions with fixed support surface. In ML direction children with DCD had a lower relative contribution of rambling to total sway (p = 0.013).ConclusionThis study showed that impaired postural control in children with DCD is associated with less efficient supraspinal control represented by increased rambling, but also by reduced spinal feedback control or peripheral control manifested as increased trembling.     

Reflex ankle stiffness is inversely correlated with natural body sway

We aimed to determine whether effective ankle stiffness (EAS), measured during slow unperceived perturbations of stance, is related to natural anterior–posterior body sway. Because the perturbations are not perceived, any neural component of the response to perturbation is assumed to be “reflex”, in the broad sense of an involuntary response to a stimulus. Subjects stood on a force platform for three 10-min trials. EAS was obtained from the average slope (Δτ/Δα) of the relation between ankle torque (τ) and ankle angle (α), recorded during repeated perturbations delivered at the waist by a weak spring. EAS was normalised using the subject's “load stiffness” (LS), calculated from mass (m) and height (h) above the ankle joint (m·g·h). Sway was obtained from fluctuations in ankle angle prior to perturbation. Variation in EAS and sway between subjects provided spread of data for correlation. There were no significant changes in EAS or sway across trials. All subjects had higher EAS than LS and mean EAS (1124 N m/rad) was significantly greater (p < 0.01) than mean LS (531 N m/rad). There was a strong significant inverse correlation between mean sway and mean normalised EAS (r = −0.68, p = 0.03). We conclude that the body, in response to slow unperceived perturbations, simulates an inverted pendulum with a stiffness of about twice LS and that EAS is largely generated by neural modulation of postural muscles. The inverse correlation between EAS and body sway suggests that the reflex mechanisms responding to perturbation also influence the extent of natural sway.     

Light finger contact concurrently reduces postural sway and enhances signal detection performance in children with developmental coordination disorder

The current study examined the effects of light finger touch on postural sway and signal detection performance in children with developmental coordination disorder (DCD). Children with DCD (n = 30; 18 boys, 12 girls; age = 11.87 ± 0.48 years) and typically developing children (n = 30; 14 boys, 16 girls; age = 11.73 ± 0.52 years) were recruited from schools in Pintung County, Taiwan. Participants completed a signal detection task under no finger touch (NT) and light finger touch (LT) conditions, while postural sway in both anteroposterior (AP) and mediolateral (ML) axes was recorded. In both conditions, children with DCD exhibited significantly higher levels of postural sway (p < 0.05) and lower signal detection performances (p < 0.05) than TDC. Additionally, both groups significantly reduced postural sway (p < 0.05) and enhanced signal detection performance (p < 0.05) when engaged in light finger touch compared with no finger touch. While the effect of LT on postural sway was greater among TDC relative to children with DCD (p < 0.05), the effect of LT on signal detection was greater in children with DCD compared with TDC (p < 0.05). These results suggest that light finger touch is effective in concurrently reducing postural sway and enhancing signal detection in both groups.     

Changes in performance markers and wellbeing in elite senior professional rugby union players during a pre-season period: Analysis of the differences across training phases

ObjectivesTo assess the magnitude of change and association with variation in training load of two performance markers and wellbeing, over three pre-season training blocks, in elite rugby union athletes.DesignObservational.MethodsTwenty-two professional players (age 25 ± 5 years; training age 6 ± 5 years; body mass, 99 ± 13 kg; stature 186 ± 6 cm) participated in this study, with changes in lower (CMJ height) and upper body (bench press mean speed) neuromuscular function and self-reported wellbeing (WB) assessed during an 11-week period.ResultsThere was a small increase in CMJ height (0.27, ±0.17 – likely substantial; standardised effect size, ±95% confidence limits – magnitude-based inference) (p = 0.003), bench press speed (0.26, ±0.15 – likely substantial) (p = 0.001) and WB (0.26, ±0.12 – possibly substantial) (p < 0.0001) across the pre-season period. There was a substantial interaction in the effect of training load on these three variables across the three training phases. A two-standard deviation (2SD) change in training load was associated with: a small decrease in CMJ height during the power phase (−0.32, ±0.19 – likely substantial) (p = 0.001); a small reduction in bench press speed during the hypertrophy phase (−0.40, ±0.32 – likely substantial) (p = 0.02); and a small reduction in WB during the strength phase (−0.40, ±0.24 – very likely substantial) (p < 0.0001). The effects of changes in training load across other phases were either likely trivial, only possibly substantial, or unclear.ConclusionsThe effect of training load on performance can vary both according to the type of training stimulus being administered and based on whether upper- or lower-body outcomes are being measured.     

Circadian amplitude and homeostatic buildup rate in postural control

Postural control during quiet stance is a common everyday physical activity. Sleepiness is increasingly prevalent in our 24-h society. Yet, little research exists that quantitatively links the fluctuations in sleepiness and postural control. This study quantifies the circadian amplitude and homeostatic buildup rate in postural control. With a force plate we assessed postural control in 12 participants (21–38 years) every 2 h during 24 h of sustained wakefulness. The sway area was 1.39 ± 0.71 mm² at the circadian high around noon, and 4.02 ± 0.67 mm² at the circadian low around 6 am (a 189% change, p = 0.02). The circadian amplitude of the sway area was therefore 2.63 mm². The sway area was 1.92 ± 0.64 mm² at the start of the 24-h period and 4.42 ± 0.69 mm² at the end of the period (a 130% change, p < 0.001). The homeostatic buildup rate of sway area was 0.04 h^?1. The circadian- and homeostatic effects on sway variability, sway velocity, sway frequency and fractal dimension were smaller but still significant. This study found that the circadian amplitude and homeostatic buildup rate are quantifiable from posturographic data, and that they have significant impact on postural control. This finding is important because it means that one could apply the framework of the famous two-process model of sleep regulation (published by Borbély in 1982) to explain the previously reported sleepiness-related changes in postural control.     

Dosimetric comparison of multichannel with one single-channel vaginal cylinder for vaginal cancer treatments with high-dose-rate brachytherapy

PurposeTo compare the three-dimensional (3D) image (CT/MR)-based planning with a multichannel vaginal cylinder (MVC) to a single-channel vaginal cylinder (SVC) for the treatment of vaginal cancer.Methods and MaterialsA total of 20 consecutive patients were treated with 3D CT/MR image-based high-dose-rate (HDR) brachytherapy using an MVC. All patients received external beam radiation therapy before HDR brachytherapy. A brachytherapy dose of 20–25 Gy of more than five fractions was delivered to clinical target volume (CTV). Retrospectively, treatment plans for all patients were generated using the central channel only to mimic an SVC applicator. The SVC plans were optimized to match CTV coverage with MVC plans. Dose homogeneity index as well as bladder, rectum, sigmoid, and urethral doses were compared.ResultsThe mean D₉₀ for CTV was 74.2 Gy (range: 48.8–84.1 Gy). The mean (±standard deviation) of dose homogeneity index for MVC vs. SVC was 0.49 (±0.19) and 0.52 (±0.23), respectively (p = 0.09). Mean bladder 0.1, 1, and 2 cc doses for MVC vs. SVC were 69 vs. 71.2 Gy (p = 0.35), 61.4 vs. 63.8 Gy (p = 0.1), and 59.5 vs. 60.9 Gy (p = 0.31), respectively. Similarly, mean rectum 0.1, 1, and 2 cc doses for MVC vs. SVC were 67.2 vs. 75.4 Gy (p = 0.005), 60.0 vs. 65.6 Gy (p = 0.008), and 57.3 vs. 62.0 Gy (p = 0.015), respectively, and mean sigmoid doses were 56.3 vs. 60.5 Gy (p = 0.10), 50.9 vs. 53.1 Gy (p = 0.09), and 49.1 vs. 50.7 Gy (p = 0.10), respectively.ConclusionThe 3D CT-/MR-based plan with MVC may provide better dose distribution in the management of certain clinical situations of vaginal cancer requiring intracavitary brachytherapy, especially in minimizing potential late rectal complications.     

Cognitive loading-induced sway alterations are similar in those with chronic ankle instability and uninjured controls

Performing a cognitive task while balancing can result in either increased or decreased sway depending on the nature of the cognitive task, and is commonly used in pathologic populations to evaluate postural performance. A total of 39 participants were recruited into two groups: uninjured controls (n = 20, age: 21.9 ± 2.1 years, height: 175.0 ± 11.2 cm, mass: 71.3 ± 14.9 kg) and chronic ankle instability (n = 19, age: 22.1 ± 5.6 years, height: 169.7 ± 7.7 cm, mass: 72.9 ± 17.3 kg). Participants were asked to perform one of three cognitive tasks while maintaining single limb balance. Cognitive tasks included backwards counting by 3 (BC), the manikin test (MAN), and random number generation (RNG). Time-to-boundary minima, mean, and standard deviations were calculated and compared between groups as pre to post change scores. Effect sizes and 95% confidence intervals were also calculated to test for group differences and the effect of task performance on sway. No significant main effects of Group or Group by Task interactions were identified (p > 0.05). However, a significant multivariate main effect of Task was identified in BC (p = 0.001, F(6, 32) = 4.804) and RNG (p < 0.001, F(6, 32) = 6.233) but not for MAN (p = 0.117). The results suggest that those with chronic ankle instability and uninjured controls have similar postural–suprapostural interactions across multiple cognitive task domains. Both the BC and RNG tasks resulted in less sway for all participants. Our results suggest that dual-task interference in the CAI population may not be present as previous research would suggest.     

The relationship between hip rotation range of movement and low back pain prevalence in amateur golfers: An observational study

ObjectiveTo investigate whether amateur golfers with self-reported low back pain have reduced hip rotation compared to asymptomatic controls.DesignObservational case-control study.SettingData collection took place at 2 amateur golf clubs in southern England.ParticipantsOn initial contact, all participants completed a screening questionnaire used to allocate participants into LBP (n = 28) and control groups (n = 36). LBP group were found to be heavier than controls (t = 2.242, 95% CI 0.763–13.332) but were matched for age, height, handedness, handicap, rounds played per week and years of play.Main outcome measuresPrimary outcome measures were lead and non-lead hip medial and lateral rotation in 0° of flexion as measured by inclinometer. Secondary measures included inter and intra-rater reliability.ResultsThe LBP group had significantly reduced lead hip passive (LBP 21.14 ± 10.17°; controls 31.06 ± 8.06°, t = ?4.228, 95% CI ?14.621–?5.205) and lead hip active medial rotation (LBP 21.46 ± 10.01; controls 28.06 ± 7.49°, t = ?2.908, 95% CI ?11.147–?2.036) compared to controls. No between group differences were found in non-lead hips or any passive or active lateral rotation measures.ConclusionAlthough there is lack of causality between LBP and hip rotation, the deficit in lead leg medial hip rotation in amateur golfers who suffer LBP may be relevant for screening or treatment selection.     

Malignant breast tumours: Correlation of apparent diffusion coefficient values using diffusion-weighted images and dynamic contrast-enhancement ratio with histologic grading

PurposeTo evaluate the correlation of the apparent diffusion coefficient (ADC) using diffusion weighted imaging (DWI) and early/delayed enhancement (E/D) ratio using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) with histological grading in malignant breast lesions.Material and methodsThirty-one women with 34 histopathologically proved malignant breast lesions underwent MRI within 2 weeks prior to surgery. MRI examination included T1 and T2 W sequences, DWI and DCE-MRI. ADC values and E/D ratios are correlated with the histological grades.ResultsThe mean ADC of the malignant lesions was 0.85 ± 0.12 × 10^?3 mm²/s. The mean ADC values of grade I, II and III were 0.96 ± 0.12 × 10^?3 mm²/s, 0.87 ± 0.07 × 10^?3 mm²/s and 0.75 ± 0.12 × 10^?3 mm²/s, respectively. Tumours with higher grade showed significantly lower ADC value (p = 0.0001) compared with lower grade and there is an inverse correlation between ADC value and histological grade (r = ?0.62, p-value = 0.0001). The mean E/D ratio for grade I, II and III tumours were 0.98 ± 0.04, 1.01 ± 0.05 and 1.07 ± 0.08, respectively. Tumours with higher grade showed significantly higher E/D ratio (p = 0.005) compared with lower grade and there was a direct correlation between E/D ratio and histological grade (r = 0.44, p = 0.008).ConclusionDWI is a useful diagnostic parameter with significantly higher correlation with the histological grade of breast cancer than DCE MRI, which is an important factor for proper treatment selection.     

Physiological factors determining downhill vs uphill running endurance performance

ObjectivesRecent studies investigated the determinants of trail running performance (i.e., combining uphill (UR) and downhill running sections (DR)), while the possible specific physiological factors specifically determining UR vs DR performances (i.e., isolating UR and DR) remain presently unknown. This study aims to determine the cardiorespiratory responses to outdoor DR vs UR time-trial and explore the determinants of DR and UR performance in highly trained runners.DesignRandomized controlled trial.MethodsTen male highly-trained endurance athletes completed 5-km DR and UR time-trials (average grade: ±8%) and were tested for maximal oxygen uptake, lower limb extensor maximal strength, local muscle endurance, leg musculotendinous stiffness, vertical jump ability, explosivity/agility and sprint velocity. Predictors of DR and UR performance were investigated using correlation and commonality regression analyses.ResultsRunning velocity was higher in DR vs UR time-trial (20.4 ± 1.0 vs 12.0 ± 0.5 km·h^?1, p < 0.05) with similar average heart rate (95 ± 2% vs 94 ± 2% maximal heart rate; p > 0.05) despite lower average V?O₂ (85 ± 8% vs 89 ± 7% V?O_2max; p < 0.05). Velocity at V?O_2max (vV?O_2max) body mass index (BMI) and maximal extensor strength were significant predictors of UR performance (r² = 0.94) whereas vV?O_2max, leg musculotendinous stiffness and maximal extensor strength were significant predictors of DR performance (r² = 0.84).ConclusionsFive-km UR and DR running performances are both well explained by three independent predictors. If two predictors are shared between UR and DR performances (vV?O_2max and maximal strength), their relative contribution is different and, importantly, the third predictor appears very specific to the exercise modality (BMI for UR vs leg musculotendinous stiffness for DR).     

Tattoos do not affect exercise-induced localised sweat rate or sodium concentration

ObjectivesSkin tattoos have been shown to reduce localised sweat rate and increase sweat sodium concentration ([Na⁺]) when sweating is artificially stimulated. This study investigated whether similar responses are observed with exercise-induced sweating.DesignUnblinded, within-participant control, single trial.MethodsTwenty-two healthy individuals (25.1 ± 4.8 y (Mean ± SD), 14 males) with a unilateral tattoo ≥11.4 cm² in size, ≥2 months in age, and shaded ≥50% participated in this investigation. Participants undertook 20 min of intermittent cycling (4 × 5 min intervals) on a stationary ergometer in a controlled environment (24.6 ± 1.1 °C; 64 ± 6% RH). Resultant sweat was collected into absorbent patches applied at two pairs of contralateral skin sites (pair 1: Tattoo vs. Non-Tattoo; pair 2: Control 1 vs. Control 2 (both non-tattooed)), for determination of sweat rate and sweat [Na⁺]. Paired samples t-tests were used to determine differences between contralateral sites.ResultsTattoo vs. Non-Tattoo: Neither sweat rate (Mean ± SD: 0.92 ± 0.37 vs. 0.94 ± 0.43 mg·cm⁻²·min⁻¹, respectively; p = 0.693) nor sweat [Na⁺] (Median(IQR): 37(32–52) vs. 37(31–45) mM·L⁻¹, respectively; p = 0.827) differed. Control 1 vs. Control 2: Neither sweat rate (Mean±SD: 1.19 ± 0.53 vs. 1.19 ± 0.53 mg·cm⁻²·min⁻¹, respectively; p = 0.917) nor sweat [Na⁺] (Median(IQR): 29(26–41) vs. 31(25–43) mM·L⁻¹, respectively; p = 0.147) differed. The non-significant differences for sweat rate and [Na⁺] between Tattoo vs. Non-Tattoo were inside the range of the within participant variability (sweat rate CVi = 5.4%; sweat [Na⁺] CVi = 4.4%).ConclusionsSkin tattoos do not appear to alter the rate or [Na⁺] of exercise-induced sweating. The influence of skin tattoos on localised sweat responses may have previously been over-estimated.     

Dietary supplementation with New Zealand blackcurrant extract enhances fat oxidation during submaximal exercise in the heat

ObjectivesThis study investigated the effect of 7 days’ supplementation with New Zealand blackcurrant extract on thermoregulation and substrate metabolism during running in the heat.DesignRandomized, double-blind, cross-over study.MethodsTwelve men and six women (mean ± SD: Age 27 ± 6 years, height 1.76 ± 0.10 m, mass 74 ± 12 kg, V̇O_2max 53.4 ± 7.0 mL kg⁻¹ min⁻¹) completed one assessment of maximal aerobic capacity and one familiarisation trial (18 °C, 40% relative humidity, RH), before ingesting 2 × 300 mg day⁻¹ capsules of CurraNZ™ (each containing 105 mg anthocyanin) or a visually matched placebo (2 × 300 mg microcrystalline cellulose M102) for 7 days (washout 14 days). On day 7 of each supplementation period, participants completed 60 min of fasted running at 65% V̇O_2max in hot ambient conditions (34 °C and 40% relative humidity).ResultsCarbohydrate oxidation was decreased in the NZBC trial [by 0.24 g min⁻¹ (95% CI: 0.21–0.27 g min^-1)] compared to placebo (p =  0.014, d = 0.46), and fat oxidation was increased in the NZBC trial [by 0.12 g min⁻¹ (95% CI: 0.10 to 0.15 g min⁻¹)], compared to placebo (p = 0.008, d = 0.57). NZBC did not influence heart rate (p = 0.963), rectal temperature (p = 0.380), skin temperature (p = 0.955), body temperature (p = 0.214) or physiological strain index (p = 0.705) during exercise.ConclusionsSeven-days intake of 600 mg NZBC extract increased fat oxidation without influencing cardiorespiratory or thermoregulatory variables during prolonged moderate intensity running in hot conditions.     

Transitioning from daytime to nighttime operations in military training has a temporary negative impact on dynamic balance and jump performance in U.S. Army Rangers

ObjectivesExplore the impact transitioning from daytime to nighttime operations has on performance in U.S. Army Rangers.MethodsFifty-four male Rangers (age 26.1 ± 4.0 years) completed the Y-Balance Test (YBT), a vertical jump assessment, and a grip strength test at three time points. Baseline testing occurred while the Rangers were on daytime operations; post-test occurred after the first night into the nighttime operation training (after full night of sleep loss), and follow-up testing occurred six days later (end of nighttime training).ResultsOn the YBT, performance was significantly worse at post-test compared to baseline during right posteromedial reach (104.1 ± 7.2 cm vs 106.5 ± 6.7 cm, p = .014), left posteromedial reach (105.4 ± 7.5 cm vs 108.5 ± 6.6 cm, p = .003), right composite score (274.8 ± 19.3 cm vs 279.7 ± 18.1 cm, p = .043), left composite score (277.9 ± 18.1 cm vs 283.3 ± 16.7 cm, p = .016), and leg asymmetry was significantly worse in the posterolateral direction (4.8 ± 4.0 cm vs 3.7 ± 3.1 cm, p = .030) and the anterior direction (5.0 ± 4.0 cm vs 3.6 ± 2.6 cm, p = .040). The average vertical jump height was significantly lower at post-test compared to baseline (20.6 ± 3.4 in vs 21.8 ± 3.0 in, p = .004). Baseline performance on YBT and vertical jump did not differ from follow-up.ConclusionsArmy Rangers experienced an immediate, but temporary, drop in dynamic balance and vertical jump performance when transitioning from daytime to nighttime operations. When feasible, Rangers should consider adjusting their sleep cycles prior to anticipating nighttime operations in order to maintain their performance levels. Investigating strategies that may limit impairments during this transition is warranted.     

The potential of multi-slice computed tomography based volumetry for demonstrating reverse remodeling induced by cardiac resynchronization therapy

BackgroundMulti-slice computed tomography (MSCT) was proved to provide precise cardiac volumetric assessment. Cardiac resynchronization therapy (CRT) is an effective treatment for selected patients with heart failure and reduced ejection fraction (HFREF). In HFREF patients we investigated the potential of MSCT based wall motion analysis in order to demonstrate CRT-induced reversed remodeling.MethodsBesides six patients with normal cardiac pump function serving as control group seven HFREF patients underwent contrast enhanced MSCT before and after CRT. Short cardiac axis views of the left ventricle (LV) in end-diastole (ED) and end-systole (ES) served for planimetry. Pre- and post-CRT MSCT based volumetry was compared with 2D echo. To demonstrate CRT-induced reverse remodeling, MSCT based multi-segment color-coded polar maps were introduced.ResultsWith regard to the HFREF patients pre-CRT MSCT based volumetry correlated with 2D echo data for LV-EDV (MSCT 278.3 ± 75.0 mL vs. echo 274.4 ± 85.6 mL) r = 0.380, p = 0.401, LV-ESV (MSCT 226.7 ± 75.4 mL vs. echo 220.1 ± 74.0 mL) r = 0.323, p = 0.479 and LV-EF (MSCT 20.2 ± 8.8% vs. echo 20.0 ± 11.9%) r = 0.617, p = 0.143. Post-CRT MSCT correlated well with 2D echo: LV-EDV (MSCT 218.9 ± 106.4 mL vs. echo 188.7 ± 93.1 mL) r = 0.87, p = 0.011, LV-ESV (MSCT 145 ± 71.5 mL vs. echo 125.6 ± 78 mL) r = 0.84, p = 0.018 and LV-EF (MSCT 29.6 ± 11.3 mL vs. echo 38.6 ± 14.6 mL) r = 0.89, p = 0.007. There was a significant increase of the mid-ventricular septum in terms of absolute LV wall thickening of the responders (pre 0.9 ± 2.1 mm vs. post 3.3 ± 2.2 mm; p < 0.0005).ConclusionMSCT based volumetry involving multi-segment color-coded polar maps offers wall motion analysis to demonstrate CRT-induced reverse remodeling which needs to be further validated.     

Persistent vestibular-ocular impairment following concussion in adolescents

ObjectivesThe current study investigated the role of persistent vestibular-ocular symptoms and impairment following sport-related concussion on recovery time and clinical outcomes among adolescents.DesignProspective cohort.Methods50 (F-22/M-28) adolescents aged 12–20 years completed a vestibular-ocular motor screening, neurocognitive assessment, and the Post-Concussion Symptom Scale (PCSS) at clinical assessments conducted at 0–10 and 11–21 days after concussion. Participants were assigned to: 1) persistent vestibular-ocular (PERSIST), 2) vestibular-ocular improvement (IMPROVE), or 3) no vestibular-ocular impairment (NONE) groups based on vestibular-ocular motor screening conducted during each assessment. A 3 (GROUP) X 2 (TIME) ANOVA was performed on neurocognitive and symptom scores, and a between-subjects ANOVA was performed for recovery time.Results49 subjects were identified among the PERSIST (n = 17), IMPROVE (n = 12) and NONE (n = 20) groups. There were no neurocognitive performance differences between groups at 0–10 days post-concussion, but groups differed on PCSS at 11–21 days (p = .001), with the PERSIST (29.0 ± 24.9) group reporting higher symptoms than the NONE (5.45 ± 10.0; p = .005) group. The PERSIST group took significantly longer to recover (34.9±11.6 days) than the NONE (22.9 ± 14.9 days) group (p = .03). All groups improved on verbal (p < .001) and visual memory (p = .028), visual motor speed (p = .005), and reaction time (p = .004) from 0–10 to 11–20 days following SRC and no significant group by time interactions for cognitive scores identified.ConclusionsPersistent post-concussion vestibular-ocular symptoms and impairment may influence neurocognitive performance and clinical recovery following sport-related concussion.