Relationships Between Running Biomechanics and Femoral Articular Cartilage Thickness and Composition in Anterior Cruciate Ligament Reconstruction Patients.

BACKGROUND: Although individuals with anterior cruciate ligament reconstruction (ACLR) are at high risk for posttraumatic osteoarthritis, mechanisms underlying the relationship between running and knee cartilage health remain unclear. OBJECTIVE: We aimed to investigate how 30 min of running influences femoral cartilage thickness and composition and their relationships with running biomechanics in patients with ACLR and controls. METHODS: Twenty patients with ACLR (time post-ACLR: 14.6 ± 6.1 months) and 20 matched controls participated in the study. A running session required both groups to run for 30 min at a self-selected speed. Before and after running, we measured femoral cartilage thickness via ultrasound imaging. A MRI session consisted of T2 mapping. RESULTS: The ACLR group showed longer T2 relaxation times in the medial femoral condyle at resting compared with the control group (central: 51.2 ± 16.6 vs. 34.9 ± 13.2 ms, p = 0.006; posterior: 50.2 ± 10.1 vs. 39.8 ± 7.4 ms, p = 0.006). Following the run, the ACLR group showed greater deformation in the medial femoral cartilage than the control group (0.03 ± 0.01 vs. 0.01 ± 0.01 cm, p = 0.001). Additionally, the ACLR group showed significant negative correlations between resting T2 relaxation time in the medial femoral condyle and vertical impulse (standardized regression coefficients = -0.99 and p = 0.004) during running. CONCLUSIONS: Our findings suggest that those who are between 6 and 24 months post-ACLR have degraded cartilage composition and their cartilage deforms more due to running vGRF.

Effects of Chronic Pain on Static and Dynamic Postural Control in Chronic Ankle Instability.

OBJECTIVE: To identify the effects of chronic pain levels on static and dynamic postural (DP) control in individuals with chronic ankle instability (CAI). DESIGN: Cross-sectional study. SETTING: Controlled laboratory. PARTICIPANTS: Sixty participants were divided into the following 3 groups: 20 high pain individuals with CAI (high pain), 20 low pain individuals with CAI (low pain), and 20 healthy controls (control). INDEPENDENT VARIABLES: Groups (CAI with high pain, CAI with low pain, and control) and visual conditions (eyes open and closed) for single-leg stance. MAIN OUTCOME MEASURES: Participants performed single-leg stance with eyes open and closed, the star excursion balance test, and single-leg hop to stabilization. RESULTS: The high pain group experienced worse self-reported outcomes, including Foot and Ankle Ability Measure activities of daily living and sports, than the low pain and control groups. Regardless of visual condition, both the high and low pain groups exhibited decreased static postural control in mediolateral (ML) compared with the control group. Specifically, the high pain group showed decreased static postural control in ML under closed eyes compared with the low pain and the control groups. The high pain group showed less reach distance than the control group and increased DP control in vertical and overall DP stability index compared with the low and control groups. CONCLUSIONS: Chronic pain can significantly affect both static and DP control in individuals with CAI. Therefore, clinicians should consider chronic pain as one of the factors affecting postural control in individuals with CAI.

EMG Analysis During Static Balance in Chronic Ankle Instability, Coper and Controls.

Patients with chronic ankle instability (CAI) consistently display postural control alterations, which may result from sensorimotor dysfunction. This study aimed to compare muscle activity in the lower extremity and postural control among individuals with CAI, copers and uninjured controls during a static balance test. A total of 57 physically active participants were categorized into three groups (CAI, copers and controls) and performed a single-leg balance test with two visual conditions: eyes open and eyes closed. Muscle activity in six lower extremity muscles and center of pressure (CoP) variables were recorded and analyzed. Patients with CAI exhibited greater muscle activity in the medial gastrocnemius and gluteus maximus compared to controls or copers, regardless of the visual condition. Copers displayed increased gluteus medius activity compared to controls. Additionally, all groups demonstrated increased muscle activity and CoP variables when visual feedback was disrupted. These findings suggest that patients with CAI may have less effective recruitment of motor units during static balance. On the other hand, greater muscle activity in the gluteus medius in copers may represent a coping mechanism to avoid further ankle injuries. Further research on muscle activity during dynamic postural control is warranted to explore sensorimotor alterations in patients with CAI.

Effect of varied dorsiflexion range of motion on landing biomechanics in chronic ankle instability.

BACKGROUND: Limited dorsiflexion range of motion (DFROM) is a risk factor for lateral ankle sprain. However, varied DFROM exists within the chronic ankle instability (CAI) population, and how the variability may influence altered movement patterns during landing is unclear. OBJECTIVE: The purpose of this study was to identify different movement strategies during maximal jump landing/cutting among CAI patients classified by varied DFROM. METHODS: One hundred CAI subjects were classified into 3 subgroups based on their DFROM, measured by the weight-bearing lunge test: a Hypo- (≤40°), Normal- (40-50°), and Hyper-DFROM group (≥50°). Participants completed five trials of maximal jump landing/cutting. Lower extremity joint angles and EMG activation of seven muscles were collected from initial contact to toe-off. Functional analyses of variance were used to evaluate between-group differences for these outcome variables. RESULTS: Hypo-DFROM group (14M, 10F) displayed the reduced ankle dorsiflexion and inversion angles with increased hip flexion angle as a compensatory kinematic chain movement strategy. In addition, motion restrictions of the ankle are associated with altered muscle activation in both distal and proximal muscles during landing/cutting. Normal-DFROM (25M, 30F) and Hyper-DFROM (11M, 10F) groups also have different movement strategies including greater inversion angle and less EMG activation, which could contribute to further ankle injuries. CONCLUSIONS: Our data suggest that limited DFROM negatively affects the ankle joint during demanding movement within the CAI population. These movement patterns in CAI patients with pathomechanical deficits could contribute to further ankle sprains.

Effects of balance training with stroboscopic glasses on postural control in chronic ankle instability patients.

Individuals with chronic ankle instability (CAI) are believed to rely more on visual information during postural control due to impaired proprioceptive function, which may increase the risk of injury when their vision is limited during sports activities. OBJECTIVES: To compare (1) the effects of balance training with and without stroboscopic glasses on postural control and (2) the effects of the training on visual reliance in patients with CAI. DESIGN: A randomized controlled clinical trial. METHODS: Twenty-eight CAI patients were equally assigned to one of 2 groups: strobe or control group. The strobe group wore stroboscopic glasses during a 4-week balance training. Static postural control, a single-leg hop balance test calculated by Dynamic Postural Stability Index (DPSI), and the Y-Balance test (YBT) were measured. During the tests, there were different visual conditions: eyes-open (EO), eyes-closed (EC), and strobe vision (SV). Romberg ratios were then calculated as SV/EO, and EC/EO and used for statistical analysis. RESULTS: The strobe group showed a higher pretest-posttest difference in velocity in the medial-lateral direction and vertical stability index under SV compared with the control group (p < .05). The strobe group showed higher differences in EC/EO for velocity in the medial-lateral and anterior-posterior directions, and 95% confidence ellipse area (p < .05), and in SV/EO for velocity in the medial-lateral, 95% confidence ellipse area, and YBT-anterior direction (p < .05). CONCLUSION: The 4-week balance training with stroboscopic glasses appeared to be effective in improving postural control and altering visual reliance in patients with CAI.

A Review of the Relationships Between Knee Pain and Movement Neuromechanics.

CONTEXT: Knee injury and disease are common, debilitating, and expensive. Pain is a chief symptom of knee injury and disease and likely contributes to arthrogenic muscle inhibition. Joint pain alters isolated motor function, muscular strength, and movement biomechanics. Because knee pain influences biomechanics, it likely also influences long-term knee joint health. OBJECTIVE: The purpose of this article is 2-fold: (1) review effects of knee pain on lower-extremity muscular activation and corresponding biomechanics and (2) consider potential implications of neuromechanical alterations associated with knee pain for long-term knee joint health. Experimental knee pain is emphasized because it has been used to mimic clinical knee pain and clarify independent effects of knee pain. Three common sources of clinical knee pain are also discussed: patellofemoral pain, anterior cruciate ligament injury and reconstruction, and knee osteoarthritis. DATA SOURCES: The PubMed, Web of Science, and SPORTDiscus databases were searched for articles relating to the purpose of this article. CONCLUSION: Researchers have consistently reported that knee pain alters neuromuscular activation, often in the form of inhibition that likely occurs via voluntary and involuntary neural pathways. The effects of knee pain on quadriceps activation have been studied extensively. Knee pain decreases voluntary and involuntary quadriceps activation and strength and alters the biomechanics of various movement tasks. If allowed to persist, these neuromechanical alterations might change the response of articular cartilage to joint loads during movement and detrimentally affect long-term knee joint health. Physical rehabilitation professionals should consider neuromechanical effects of knee pain when treating knee injury and disease. Resolution of joint pain can likely help to restore normal movement neuromechanics and potentially improve long-term knee joint health and should be a top priority.

Acute effect of whole-body vibration on electromechanical delay and vertical jump performance.

OBJECTIVES: To determine if a change in vertical jump performance from acute whole-body vibration can be explained by indirectly assessing spindle sensitivity from electromechanical delay. METHODS: Using a counter-balanced design, twenty college-aged participants performed whole-body vibration (WBV) and control treatments. WBV included 10 intervals (26 Hz, 3.6 mm) of 60 s in a half-squat followed by 60 s of rest. After 5 intervals, participants rested for 6-minutes before commencing the final 5 intervals. For the control, the exact same protocol of whole-body vibration was performed but without vibration. Electromechanical delay and vertical jump were assessed at baseline, during the 6-minute rest period and immediately after whole-body vibration and control. RESULTS: There were no differences between treatments, for both electromechanical delay (F(2, 38)=1.385, p=0.263) and vertical jump (F(2, 38)=0.040, p<0.96). Whole-body vibration had no effect on vertical jump performance. CONCLUSION: The current whole-body vibration protocol is not effective for acute vertical jump or electromechanical delay enhancement. Also, since there was no effect on electromechanical delay, this suggests that whole-body vibration did not enhance muscle spindle sensitivity for the parameters examined.

Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task.

CONTEXT: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. OBJECTIVE: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. DESIGN: Cross-sectional design. SETTING: Biomechanics laboratory. PARTICIPANTS: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. INTERVENTION: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. MAIN OUTCOME MEASURES: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. RESULTS: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. CONCLUSIONS: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.

Variation in zoobenthic blue carbon in the Arctic's Barents Sea shelf sediments.

The flow of carbon from atmosphere to sediment fauna and sediments reduces atmospheric CO2, which in turn reduces warming. Here, during the Changing Arctic Ocean Seafloor programme, we use comparable methods to those used in the Antarctic (vertical, calibrated camera drops and trawl-collected specimens) to calculate the standing stock of zoobenthic carbon throughout the Barents Sea. The highest numbers of morphotypes, functional groups and individuals were found in the northernmost sites (80-81.3° N, 29-30° E). Ordination (non-metric multidimensional scaling) suggested a cline of faunal transition from south to north. The functional group dominance differed across all six sites, despite all being apparently similar muds. Of the environmental variables we measured, only water current speed could significantly explain any of our spatial carbon differences. We found no obvious relationship with sea ice loss and thus no evidence of Arctic blue carbon-climate feedback. Blue carbon in the Barents Sea can be comparable with the highest levels in Antarctic shelf sediments. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

Delivering personalized medicine in retinal care: from artificial intelligence algorithms to clinical application.

PURPOSE OF REVIEW: To review the current status of artificial intelligence systems in ophthalmology and highlight the steps required for clinical translation of artificial intelligence into personalized health care (PHC) in retinal disease. RECENT FINDINGS: Artificial intelligence systems for ophthalmological application have made rapid advances, but are yet to attain a state of technical maturity that allows their adoption into real-world settings. There remains an 'artificial intelligence chasm' in the spheres of validation, regulation, safe implementation, and demonstration of clinical impact that needs to be bridged before the full potential of artificial intelligence to deliver PHC can be realized. SUMMARY: Ophthalmology is currently in a stage between the demonstration of the potential of artificial intelligence and widespread deployment. Next stages include aggregating and curating datasets, training and validating artificial intelligence systems, establishing the regulatory framework, implementation and adoption with ongoing evaluation and model adjustment, and finally, meaningful human-artificial intelligence interaction with clinically validated tools that have demonstrated measurable impact on patient and healthcare system outcomes. Ophthalmologists should leverage the ability of artificial intelligence systems to glean insights from large volumes of multivariate data, and to interpret artificial intelligence recommendations in a clinical context. In doing so, the field will be well positioned to lead the transformation of health care in a personalized direction. VIDEO ABSTRACT: http://links.lww.com/COOP/A35.

Temperature Influence on Pseudothecia Development Stages of Venturia inaequalis in the Western Cape of South Africa.

Pseudothecia development stages of Venturia inaequalis (apple scab) were investigated in two climatically different regions in the Western Cape of South Africa. The aim was to determine the pseudothecial density (PD; pseudothecia per fertile lesion [p/f]) and ascal density (AD; asci per pseudothecium [a/p]) that contributes to defining the potential ascospore dose in a common prediction model of the apple scab infection risk. The PD and AD were compared between Elgin (EL), now considered a warm winter apple-growing region because of climate warming, and Koue Bokkeveld (KB), a cold winter region. In 2012 and 2013, scabbed apple leaves were collected during leaf-drop in KB and EL and overwintered either in their region of origin or in the other region. PD was significantly higher in scabbed leaves collected and overwintered in KB (mean, 24.11 p/f) than in leaves collected in KB and overwintered in EL (mean, 17.11 p/f; P < 0.001). PD of scabbed leaves collected and overwintered in EL (mean, 15.27 p/f) or collected in EL and overwintered in KB (mean, 16.07 p/f) did not differ significantly. Ascal density did not differ significantly in any treatment or season. We concluded that the significantly higher PD of scabbed leaves collected from the cooler region of KB and overwintered in KB compared with scabbed leaves collected in EL or KB and overwintered in EL could be caused by adaptations of V. inaequalis populations to the respective climates. This implied long-term effects of climate warming on apple scab epidemiology and management.

Whole-Body Vibration as a Warm-up Before Exercise-Induced Muscle Damage on Symptoms of Delayed-Onset Muscle Soreness in Trained Subjects.

Magoffin, RD, Parcell, AC, Hyldahl, RD, Fellingham, GW, Hopkins, JT, and Feland, JB. Whole-body vibration as a warm-up before exercise-induced muscle damage on symptoms of delayed-onset muscle soreness in trained subjects. J Strength Cond Res 34(4): 1123-1132, 2020-There is no clear scientific evidence that whole-body vibration (WBV) used as a warm-up before performing eccentric exercise mitigates delayed-onset muscle soreness (DOMS) and speeds strength loss recovery. These benefits were observed primarily in nonresistance-trained individuals. The aim of this study was to determine whether WBV could mitigate soreness and expedite strength recovery for resistance-trained individuals when used as a warm-up before eccentric exercise. Thirty resistance-trained males completed 300 maximal eccentric contractions of the quadriceps after warming up with (WBV) or without (CON) WBV. Both CON and WBV experienced significant isometric (26.3 and 30.2%, respectively) and dynamic (50.9 and 46.4%, respectively) strength loss immediately after exercise. Isometric strength was significantly depressed after 24 hours in the CON group (8.2% p < 0.02), but not in the WBV group (5.9% p = 0.7). Isometric strength was no longer significantly depressed after 48 hours in the CON group (6.1% p < 0.07) or the WBV group (4.1% p = 0.20). Dynamic strength was significantly decreased in both the CON and WBV groups at 24 hours (17.7% p < 0.001 and 15.5% p < 0.001, respectively) and 48 hours (17.1% p < 0.01 and 13.6% p < 0.002), but only significant for the CON at 1 week after exercise (8.6% p = 0.05). Pain as measured by a visual analog scale was significant in both groups at 24 and 48 hours after exercise, but WBV experienced significantly less soreness than the CON group after 24 hours (28 vs. 46 mm p < 0.01, respectively) and 48 hours (38 vs. 50 mm p < 0.01). Pain pressure threshold increased significantly in both groups, but there was no difference between groups. These results suggest the use of WBV before eccentric exercise mildly mitigates DOMS in trained individuals. Application of WBV can function as a quick mode of warm-up before resistance training and can decrease pain perception from DOMS. This may be beneficial to athletes undergoing a heavy strength training phase where DOMS is likely.

Broadly tunable femtosecond pulses around 2.06 µm from a diode-pumped Tm3+-doped solid-state laser source.

We report on a broadly tunable diode-pumped femtosecond Tm:LuScO3 laser source around 2.06 µm. Tuning was obtained through the use of a steeply diving birefringent filter, maintaining sub-600 fs pulses over a tuning range of 2019-2110 nm. The minimum pulse duration of 240 fs was recorded at a central wavelength of 2080 nm with an average output power of 93 mW. Higher output coupling of 2% resulted in a narrower tuning range of 2070-2102 nm with generated pulses as short as 435 fs and an average output power of 119 mW at 2090 nm.

Troubleshooting Hypoxemia After Placement of an Extraglottic Airway.

The case presented here highlights the feasibility of using an extraglottic airway device as a conduit for delivering high levels of lifesaving positive end expiratory pressure (PEEP), as well as other means of combating recalcitrant hypoxia. The case also highlights the merit of an approach to the hypoxic patient with an in-situ extraglottic airway device based not only on deciding if the device is functioning to maintain a patent airway, but also, simultaneously considering the patient's physiology. A 71 year old male suffered an out-of-hospital cardiac arrest. Part of his resuscitation included placement of a dual-balloon extraglottic airway device by EMS. He was hypoxic, but the device seemed to be providing for a patent airway without an air leak. There was also a favorable end-tidal carbon dioxide waveform. The flight team chose to the leave the device in place. PEEP was up-titrated to 17 cmH20 without issue. Sigh breaths, as well as breath holds, were also able to be delivered. The patient's hypoxia improved over the course of the patient's transport, and he ultimately did well.

Macular Atrophy in the HARBOR Study for Neovascular Age-Related Macular Degeneration.

PURPOSE: To evaluate macular atrophy (MA) presence in the 24-month HARBOR study (NCT00891735) for neovascular age-related macular degeneration (AMD). DESIGN: Post hoc analysis of a phase 3 multicenter, prospective, randomized, double-masked, active treatment-controlled clinical trial. PARTICIPANTS: Evaluable subjects (N = 1095) with subfoveal choroidal neovascularization (CNV) secondary to neovascular AMD treated with ranibizumab 0.5 mg or 2.0 mg monthly or pro re nata (PRN). METHODS: Fluorescein angiograms (FAs) and color fundus photographs at baseline and months 3, 12, and 24 were retrospectively graded by masked graders for MA: well-defined areas of depigmentation with increased choroidal vessel visibility, diameter ≥250 µm, corresponding to flat areas of well-demarcated staining on FA, excluding atrophy associated with retinal pigment epithelium tears. Atrophy immediately within, adjacent, and nonadjacent to CNV lesions was included. MAIN OUTCOME MEASURES: Macular atrophy incidence, best-corrected visual acuity (BCVA). RESULTS: At baseline, MA was detected in 11.2% (123/1095) of study eyes. At month 24, 29.4% (229/778) of eyes without baseline atrophy had detectable MA. Eyes with and without baseline MA had significant mean BCVA gains from baseline at month 24 (letters [95% confidence interval]: +6.7 [4.1-9.3]; +9.1 [8.0-10.2], respectively). Among eyes with and without MA at month 24, mean month 24 BCVA was 62.0 [60.3-63.7] and 64.7 [63.2-66.3] letters, respectively. Baseline risk factors for month 24 MA presence included intraretinal cysts (hazard ratio [HR], 2.45 [1.76-3.42]) and fellow eye atrophy (HR, 2.02 [1.42-2.87]); subretinal fluid was associated with a lower MA risk (HR, 0.50 [0.33-0.74]). Ranibizumab dose was not associated with MA development. Monthly versus PRN treatment trended toward an association with MA (HR, 1.29 [0.99-1.68]), but was not statistically significant. CONCLUSIONS: New MA was detected in 29% of study eyes after 24 months of treatment. Clinically significant BCVA gains were achieved with MA present over 24 months. Baseline subretinal fluid absence, intraretinal cyst presence, and fellow eye atrophy presence were associated with month 24 MA presence. With existing data, the benefits of ranibizumab for neovascular AMD outweighed the risk of MA development over 24 months in HARBOR, although outcomes >2 years were not evaluated.

Diode-pumped femtosecond Tm3+-doped LuScO3 laser near 2.1 µm.

We report on the first demonstration, to the best of our knowledge, of a diode-pumped Tm:LuScO3 laser. Efficient and broadly tunable continuous wave operation in the 1973-2141 nm region and femtosecond mode-locking through the use of an ion-implanted InGaAsSb quantum-well-based semiconductor saturable absorber mirror are realized. When mode-locked, near-transform-limited pulses as short as 170 fs were generated at 2093 nm with an average output power of 113 mW and a pulse repetition frequency of 115.2 MHz. Tunable picosecond pulse generation was demonstrated in the 2074-2104 nm spectral range.

1.9 µm waveguide laser fabricated by ultrafast laser inscription in Tm:Lu2O3 ceramic.

The ultrafast laser inscription technique has been used to fabricate channel waveguides in Tm3+-doped Lu2O3 ceramic gain medium for the first time to our knowledge. Laser operation has been demonstrated using a monolithic microchip cavity with a continuous-wave Ti:sapphire pump source at 796 nm. The maximum output power achieved from the Tm:Lu2O3 waveguide laser was 81 mW at 1942 nm. A maximum slope efficiency of 9.5% was measured with the laser thresholds observed to be in the range of 50-200 mW of absorbed pump power. Propagation losses for this waveguide structure are calculated to be 0.7 dB⋅cm-1 ± 0.3 dB⋅cm-1 at the lasing wavelength.

Scanning holographic optical tweezers.

The aim of this Letter is to introduce a new optical tweezers approach, called scanning holographic optical tweezers (SHOT), which drastically increases the working area (WA) of the holographic-optical tweezers (HOT) approach, while maintaining tightly focused laser traps. A 12-fold increase in the WA is demonstrated. The SHOT approach achieves its utility by combining the large WA of the scanning optical tweezers (SOT) approach with the flexibility of the HOT approach for simultaneously moving differently structured optical traps in and out of the focal plane. This Letter also demonstrates a new heuristic control algorithm for combining the functionality of the SOT and HOT approaches to efficiently allocate the available laser power among a large number of traps. The proposed approach shows promise for substantially increasing the number of particles that can be handled simultaneously, which would enable optical tweezers additive fabrication technologies to rapidly assemble microgranular materials and structures in reasonable build times.

Genetic Diversity and Gene Flow of Four South African Venturia inaequalis (Apple Scab) Populations.

Venturia inaequalis isolates were collected during the 2012/13 and 2013/14 seasons from the four principal apple growing regions of South Africa, Elgin (n = 114), Koue Bokkeveld (n = 126), Lower Langkloof (n = 92), and Upper Langkloof (n = 103). Sequence analysis of the ribosomal internal transcribed spacer (ITS) gene regions and genotyping with six (2012/13) and seven (2013/14) microsatellite (SSR) markers was conducted. A subset of 12 isolates from the individual ITS haplotype groups were sequenced for the translation elongation factor-1 alpha (TEF1) and the large subunit of the RNA polymerases II (RPB1) gene regions. Four haplotypes were found for ITS, whereas all isolates were identical for the TEF1 and RPB1 gene regions. The SSR markers revealed considerable variation with an average gene diversity (H) of 0.675. Multivariate analysis (discriminant analysis of principal components [DAPC]) revealed that the two Langkloof populations clustered together with the Koue Bokkeveld population. The population from the warmer winter region, Elgin, clustered separately from the rest of the populations (ΦPT = 0.076 to 0.116; P ≤ 0.05). Estimates of gene flow showed the highest migration rate from the Koue Bokkeveld, toward the Lower Langkloof (M = 151.1), and the least migration to and from the Elgin region (average M = 42.75). Occasionally, identical genotypes (clones) were detected across seasons in the Koue Bokkeveld and Elgin area, which might contribute to overwintering conidia. From this study, it is evident that South Africa most likely has V. inaequalis subpopulations linked to diverse climatic conditions of the coastal Elgin region compared with the mountainous inland regions of the Koue Bokkeveld and the Langkloof.

Efficacy of Sensory Transcutaneous Electrical Nerve Stimulation on Perceived Pain and Gait Patterns in Individuals With Experimental Knee Pain.

OBJECTIVES: To examine the effect of experimental knee pain on perceived knee pain and gait patterns and to examine the efficacy of transcutaneous electrical nerve stimulation (TENS) on perceived knee pain and pain-induced knee gait mechanics. DESIGN: Crossover trial. SETTING: Biomechanics laboratory. PARTICIPANTS: Recreationally active, individuals without musculoskeletal pain aged 18 to 35 years (N=30). INTERVENTIONS: Thirty able-bodied individuals were assigned to either a TENS (n=15) or a placebo (n=15) group. All participants completed 3 experimental sessions in a counterbalanced order separated by 2 days: (1) hypertonic saline infusion (5% NaCl); (2) isotonic saline infusion (0.9% NaCl); and (3) control. Each group received sensory electrical stimulation or placebo treatment for 20 minutes, respectively. MAIN OUTCOME MEASURES: Perceived pain was collected every 2 minutes using a 10-cm visual analog scale (VAS) for 50 minutes and analyzed using a mixed model analysis of covariance with repeated measures. Gait analyses were performed at baseline, infusion, and treatment. Sagittal and frontal knee angles and internal net joint torque across the entire stance were analyzed using a functional data analysis approach. RESULTS: Hypertonic saline infusion increased perceived pain (4/10cm on a VAS; P<.05) and altered right knee angle (more flexion and less abduction; P<.05) and internal net joint torque (less extension and greater abduction; P<.05) across various stance phases. TENS treatment reduced perceived pain and improved right sagittal gait abnormalities as compared with placebo treatment (P<.05). CONCLUSIONS: This pain model increases perceived pain and induces compensatory gait patterns in a way that indicates potential quadriceps weakness. However, TENS treatment effectively reduces perceived pain and restores pain-induced gait abnormalities in sagittal knee mechanics.