Indian Supercourse Network in Epidemiology - Development and Evaluation

There are many advantages to using locally produced health information, such as its cultural appropriateness, geographic specificity, and flexibility. The Indian Supercourse is an online repository of lectures in Epidemiology, written by authors in India, on topics of particular interest to teachers and students in India.The purpose of this dissertation is to describe the planning, development and evaluation of the Indian Supercourse Network. The Indian Supercourse Network has 6,000 faculty members in India, and more than 200 epidemiology lectures written by authors in India. Evaluation of the Indian Supercourse Network included an assessment of utilization of these educational materials in India using page views measured by web statistics analysis software. The main hypothesis compared page views from India, between the Indian Supercourse and the Main Supercourse. The results of the Wilcoxon Rank-Sum test showed that there were significantly more page views from India to the Indian Supercourse as compared to the Main Supercourse (p < 0.0001). This means that users in India prefer to use the Indian Supercourse more than the Main Supercourse. This may be because information in the Indian Supercourse is more pertinent to the epidemiology education needs of users in India. In contrast, there were significantly more page views from non-Indian countries to the Main Supercourse as compared to the Indian Supercourse (p < 0.0001). Interestingly, there was no significant difference (p = 0.0642) in total page views from all countries considered together, between the Indian Supercourse and the Main Supercourse.Public Health Significance - In India, there is a lack of an adequate system for formal epidemiology education. The Indian Supercourse has made epidemiology education available to everyone interested in learning epidemiology in India. The results of this study have shown that the Indian Supercourse is being utilized by people in India. Information contained on the Indian Supercourse website can eventually be disseminated across the digital divide via low-bandwidth methods and the postal system in India

Accuracy of recall of musculoskeletal injuries in elite military personnel: a cross-sectional study

Background Self-reported data are often used in research studies among military populations. Objective The accuracy of self-reported musculoskeletal injury data among elite military personnel was assessed for issues with recall. Design Cross-sectional study. Setting Applied research laboratory at a military installation. Participants A total of 101 subjects participated (age 28.5±5.6 years). Study participants were active duty military personnel, with no conditions that precluded them from full duty. Primary and secondary outcome measures Self-reported and medical record reviewed injuries that occurred during a 1-year period were matched by anatomic location, injury side (for extremity injuries), and injury year and type. The accuracy of recall was estimated as the per cent of medical record reviewed injuries correctly recalled in the self-report. The effect of injury anatomic location, injury type and severity and time since injury, on recall, was also assessed. Injuries were classified as recent (≤4 years since injury) or old injuries (\u3e4 years since injury). Recall proportions were compared using Fisher’s exact tests. Results A total of 374 injuries were extracted from the subjects’ medical records. Recall was generally low (12.0%) and was not different between recent and old injuries (P=0.206). Injury location did not affect recall (P=0.418). Recall was higher for traumatic fractures as compared with less severe non-fracture injuries (P values 0.001 to \u3c0.001). Recall for non-fracture injuries was higher for recent as compared with old injuries (P=0.033). This effect of time since injury on recall was not observed for fractures (P=0.522). Conclusions The results of this study highlight the importance of weighing the advantages and disadvantages of self-reported injury data before their use in research studies in military populations and the need for future research to identify modifiable factors that influence recall

THE RELATIONSHIP BETWEEN MUSCULOSKELETAL STRENGTH, PHYSIOLOGICAL CHARACTERISTICS, AND KNEE KINESTHESIA FOLLOWING FATIGUING EXERCISE

Fatiguing exercise may result in impaired functional joint stability and increased risk of unintentional injury. While there are several musculoskeletal and physiological characteristics related to fatigue onset, their relationship with proprioceptive changes following fatigue has not been examined. The purpose of this study was to establish the relationship between musculoskeletal and physiological characteristics and changes in proprioception, measured by threshold to detect passive motion (TTDPM), following fatiguing exercise. Twenty, physically active females participated (age: 28.65 ± 5.6 years, height: 165.6 ± 4.3 cm, weight: 61.8 ± 8.0 kg, BMI: 22.5± 2.3 kg/m2, BF: 23.3 ± 5.4%). During Visit 1, subjects completed an exercise history and 24-hour dietary questionnaire, and body composition, TTDPM familiarization, isokinetic knee strength, and maximal oxygen uptake/lactate threshold assessments. During Visit 2, subjects completed TTDPM and isometric knee strength testing prior to and following a fatiguing exercise protocol. Wilcoxon signed rank tests determined TTDPM and isometric knee strength changes from pre- to post- fatigue. Spearman’s rho correlation coefficients determined the relationship between strength and physiological variables with pre- to post-fatigue changes in TTDPM and with pre-fatigue and post-fatigue TTDPM in extension and flexion (α=0.05). No significant differences were demonstrated from pre-fatigue to post-fatigue TTDPM despite a significant decrease in isometric knee flexion strength (P<0.01) and flexion/extension ratio (P<0.05) following fatigue. No significant correlations were observed between strength or physiological variables and changes in TTDPM from pre- to post-fatigue in extension or flexion. Flexion/extension ratio was significantly correlated with pre-fatigue TTDPM in extension (r=-0.231, P<0.05). Peak oxygen uptake was significantly correlated with pre-fatigue (r=-0.500, P<0.01) and post-fatigue (r=-0.520, P<0.05) TTDPM in extension. No significant relationships were demonstrated between musculoskeletal and physiological characteristics and changes in TTDPM following fatigue. The results suggest that highly trained individuals may have better proprioception, and that the high fitness level of subjects in this investigation may have contributed to absence of TTDPM deficits following fatigue despite reaching a high level of perceptual and physiological fatigue. Future studies should consider various subject populations, other musculoskeletal strength characteristics, and different modalities of proprioception to determine the most important contributions to proprioceptive changes following fatigue

Comparison and Correlation of Dynamic Postural Stability Indices Obtained during Different Dynamic Landing Tasks and Footwear Conditions

Objectives: To compare the dynamic postural stability indices (DPSI) from two different landing protocols with normalized jump distance (NDP) and jump height (RWDP) and footwear conditions (barefoot and shod).Design: Cross-sectional.Setting: Research laboratory.Participants: Twenty-five physically active adults (13 males/12 females, age: 22.1±4.2yrs, height: 178.3±11.1cm, weight: 75.6±19.4kg).Main Outcome Measures: Subjects jumped off two feet and landed with their preferred foot on a force-plate. From the ground reaction forces, the DPSI scores in the anterior-posterior, medial-lateral, and vertical directions, and the cumulative scores (DPSI) were calculated under two protocols and footwear conditions. Based on normality of data distribution, paired t-tests/Wilcoxon signed rank tests and Pearson/Spearman correlation coefficients were used to compare, and measure the relationship between the two protocols under two footwear conditions (p&lt;0.05).Results: There were mixed results for DPSI scores when comparing the two protocols. There were significant differences (p=0.001–0.039) and positive correlations (r=0.660–0.870, p&lt;0.001) on the DPSI scores between footwear conditions during the NDP protocol while the RWDP showed no significant differences.Conclusions: Different protocols and footwear conditions may impact DPSI scores. Therefore, a standardized protocol and footwear condition should be established for future studies examining dynamic postural stability

THE EFFECT OF LOADED FATIGUE ON LOADED POSTURAL STABILITY

Military personnel are often required to carry heavy loads for long distances over unpredictable terrain. Additional load carriage, in conjunction with fatigue, has the potential to influence postural control mechanisms which may in turn increase injury risk. The purpose of this study was to determine if a loaded incremental march to fatigue negatively influences loaded postural stability. Loaded postural stability was measured using the NeuroCom Sensory Organization Test (SOT) and kinetic force plate variables (vertical ground reaction forces: SDvGRF, and TotSway) before and after a loaded incremental march to fatigue in 23 physically active men and women (age: 24.1 4.0 years, height: 172.3 11.1 cm, weight: 162.2 38.2 lbs) while subjects were adorned with a weighted vest equating to 30% of their body weight. The SOT consisted of six conditions (C1-C6) aimed to perturb the sensorimotor system, which were performed before and after a loaded fatigue protocol. C1, C2 and C3 challenged the somatosensory system, C4 challenged the visual system, while C5 and C6 challenged the vestibular system. Fatigue was induced with a treadmill march at 4mph with increasing grades of 2% every three minutes until volitional fatigue. After testing for normality, paired sample t-tests or Wilcoxon signed rank tests were conducted to assess pre- to post-fatigue differences. Significant reductions in SOT scores were found in overall composite scores (pre: 82.8 4.7, post: 81.6 5.2, p = 0.010), SDvGRF of C1 (pre: 1.3 0.5, post: 2.0 0.9, p < 0.001), C2 (pre: 1.4 0.6, post: 1.9 1.2, p < 0.001), C3 (pre: 1.4 0.5, post: 2.1 1.8, p = 0.026), and C6 (pre: 2.5 2.2, post: 3.5 3.2, p < 0.001) and TotSway of all conditions. Results suggest that significant changes in loaded postural stability were caused by loaded fatigue. Findings could aid in future postural stability screenings, load carriage training and strategies for injury prevention in the military

Impact of Increased Load Carriage Magnitude on the Dynamic Postural Stability of Men and Women

The impact of load carriage on dynamic postural stability affects the survivability of the Warfighter by influencing performance capabilities and injury incidence. Further, sex may interact with the relationship between load carriage and dynamic postural stability to further compromise survivability. PURPOSE: To investigate the effect of load carriage magnitude on dynamic postural stability of men and women and its relationship to jumping ability. METHODS: 32 subjects (16 men, 16 women) were investigated for maximum jump height and dynamic postural stability. Dynamic postural stability was assessed by subjects jumping a horizontal distance of 40% their height over a 30cm hurdle, landing on one leg on a force plate (sample rate = 1200 Hz). 3 trials were completed for 3 load conditions: +0, +20 and +30% body weight (BW). Dynamic postural stability was determined from ground reaction force data during landings, by calculation of the dynamic postural stability index (DPSI). Maximum jump height was assessed by subjects performing 3 countermovement jumps (sample rate = 1000 Hz). Two-way repeated measures ANOVA were used to compare mean DPSI scores between sexes and conditions (α = 0.05). Pearson’s Correlation Coefficients were used to determine the relationship between jump height and change in DPSI scores between conditions (α = 0.05). RESULTS: Load condition significantly affected DPSI (F = 100.304, p = 0.001). DPSI scores increased between the 0% (0.359 ± 0.041), 20% (0.396 ± 0.034) and 30% (0.420 ± 0.028) BW load conditions. No significant effect of sex on DPSI was found (F = 0.131). No significant sex by load interaction on DPSI was found (F = 0.393). No significant correlations were found between jump height and change in DPSI scores between conditions. CONCLUSION: Increased load was found to negatively affect dynamic postural stability, most likely as a result of modifying the demands of the task. Therefore, the dynamic postural stability of men and women changes comparably in response to increased load carriage magnitude. Future research should focus on the effects of load on dynamic postural stability under higher loads and during more military-specific tasks

Drive Leg Ground Reaction Forces and Rate of Force Development Over Consecutive Windmill Softball Pitches

BACKGROUND: Windmill softball pitching is a highly skilled movement, combining whole body coordination with explosive force. Successful pitching requires sequential movement to transfer energy produced by the lower extremity to the pitching arm. Therefore, drive leg ground reaction force (GRF) and the time over which a pitcher can develop force during push off, defined as rate of force development (RFD), is essential for optimal performance. The aim of this study was to examine GRF and RFD in the drive leg during the windmill softball pitch, as well as pitch velocity, throughout a simulated game. METHODS: Fourteen softball pitchers (17.9±2.3 years, 166.4±8.7cm, 72.2±12.6kg) pitched a simulated game. Pitch velocity and anterior-posterior and vertical GRF and RFD, each normalized to body weight, were collected for each inning. Average pitch speed remained consistent across all seven innings, 49.57±0.42mph. Changes in GRF and RFD were assessed, with level of significance set as P\u3c0.05. RESULTS: A one-way repeated measures analysis of variance showed no significant differences in apGRF%BW (P=0.297), vGRF%BW (P=0.574), apRFD (BW/s) (P=0.085) and vRFD (BW/s) (P=0.059). CONCLUSIONS: Training programs can be improved with the knowledge of the magnitude and rate in which forces are developed by the drive leg during push-off of the windmill softball pitch

Quality Control of Epidemiological Lectures Online: Scientific Evaluation of Peer Review

Aim: To examine the feasibility of using peer review for the quality control of online materials. Methods: We analyzed the inter-rater agreement on the quality of epidemiological lectures online, based on the Global Health Network Supercourse lecture library. We examined the agreement among reviewers by looking at κ statistics and intraclass correlations. Seven expert reviewers examined and rated a random sample of 100 Supercourse lectures. Their reviews were compared with the reviews of the lay Supercourse reviewers. Results: Both expert and non-expert reviewers rated lectures very highly, with a mean overall score of 4 out of 5. Kappa (κ) statistic and intraclass correlations indicated that inter-rater agreement for experts and non-experts was surprisingly low (below 0.4). Conclusions: To our knowledge, this was the first time that poor inter-rater agreement was demonstrated for the Internet lectures. Future research studies need to evaluate the alternatives to the peer review system, especially for online materials