3D Biomechanics of Rugby Tackle Techniques to Inform Future Rugby Research Practice: a Systematic Review.

BACKGROUND: The tackle is the most common in-play event in rugby union and rugby league (the rugby codes). It is also associated with the greatest propensity for injury and thus accounts for the most injuries in the sport. It is therefore of critical importance to accurately quantify how tackle technique alters injury risk using gold-standard methodology of three-dimensional motion (3D) capture. OBJECTIVE: To examine the 3D motion capture methodology of rugby-style tackle techniques to provide recommendations to inform practice for future rugby code research and advance the knowledge of this field. STUDY DESIGN: Systematic review. METHODS: Articles published in English language, up to May 2020, were retrieved via nine online databases. All cross-sectional, correlational, observational, and cohort study designs using 3D motion capture of tackle techniques in rugby code players met inclusion criteria for this review. A qualitative synthesis using thematic analysis was pre-specified to identify five key themes. RESULTS: Seven articles met eligibility criteria. Participant demographic information (theme one) involved a total of 92 rugby union players, ranging in skill level and playing experience. Experimental task design information (theme two) included one-on-one, front-on (n=5) or side-on (n=1) contact between a tackler and a ball carrier, or a tackler impacting a tackle bag or bump pad (n=3). 3D data collection (theme three) reported differing sampling frequencies and marker sets. 3D data reduction and analysis (theme four) procedures could be mostly replicated, but the definitions of temporal events, joint modelling and filtering varied between studies. Findings of the studies (theme five) showed that the one-on-one tackle technique can be altered (n=5) when tackle height, leg drive and/or tackle speed is modified. A study reported tackle coaching intervention. CONCLUSIONS: This is the first review to evaluate 3D motion capture of rugby-style tackle technique research. A research framework was identified: (i) participant demographic information, (ii) experimental task design information, (iii) 3D motion capture data specifications, and (iv) 3D data reduction and analysis. Adherence of future 3D tackling research to these framework principles will provide critical scientific evidence to better inform injury reduction and performance practices in the rugby codes. TRIAL REGISTRATION: The review was registered with PROSPERO (registration number CRD42018092312 ).

Opioid Consumption Following Foot and Ankle Surgery.

Background Orthopedic surgeons frequently prescribe pain medications during the postoperative period. The efficacy of these medications at alleviating pain after foot/ankle surgery and the quantity of medication required (and conversely, leftover) are unknown. METHODS: Patients undergoing foot/ankle surgery during a 3-month period who met inclusion criteria were surveyed at their first postoperative visit. Information collected included gender, number of prescribed pills remaining, satisfaction with pain control, and willingness to surrender leftover opioids to a Drug Enforcement Administration (DEA) disposal center. Additional data, including utilization of a perioperative nerve block and type (bony versus nonbony) and anatomic region of procedure, were collected through review of the medical record. All data were analyzed in a retrospective fashion. A total of 171 patients with a mean age of 53.1 ± 15.5 years (range, 18-81 years) were included in the study. RESULTS: The mean number of opioids taken was 27.2 ± 17.5 pills (range, 0-70). The mean number of short-acting opioids and long-acting opioids taken was 21.4 ± 14.8 and 9.2 ± 5.0 pills, respectively. Most (73.5%) patients were satisfied with their pain control. Patients who underwent ankle/hindfoot surgery took more long-acting opioids on average than others ( P = .047). There was not a significant difference in opioid usage between bony and nonbony procedures. Of those with leftover opioids, 63% were willing to surrender them to a DEA disposal center. Patients willing to surrender leftover medications had both more short-acting ( P < .001) and long-acting ( P = .015) opioids leftover than those not willing to surrender them. CONCLUSION: Most patients undergoing foot/ankle surgery had opioids leftover at the first postoperative visit, and most were willing to surrender them. We can adequately treat patients' pain and decrease the number of opioid pills available in the community by decreasing the number of pills prescribed and encouraging disposal of leftovers. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Class XI Myosins Move Specific Organelles in Pollen Tubes and Are Required for Normal Fertility and Pollen Tube Growth in Arabidopsis.

Pollen tube growth is an essential aspect of plant reproduction because it is the mechanism through which nonmotile sperm cells are delivered to ovules, thus allowing fertilization to occur. A pollen tube is a single cell that only grows at the tip, and this tip growth has been shown to depend on actin filaments. It is generally assumed that myosin-driven movements along these actin filaments are required to sustain the high growth rates of pollen tubes. We tested this conjecture by examining seed set, pollen fitness, and pollen tube growth for knockout mutants of five of the six myosin XI genes expressed in pollen of Arabidopsis (Arabidopsis thaliana). Single mutants had little or no reduction in overall fertility, whereas double mutants of highly similar pollen myosins had greater defects in pollen tube growth. In particular, myo11c1 myo11c2 pollen tubes grew more slowly than wild-type pollen tubes, which resulted in reduced fitness compared with the wild type and a drastic reduction in seed set. Golgi stack and peroxisome movements were also significantly reduced, and actin filaments were less organized in myo11c1 myo11c2 pollen tubes. Interestingly, the movement of yellow fluorescent protein-RabA4d-labeled vesicles and their accumulation at pollen tube tips were not affected in the myo11c1 myo11c2 double mutant, demonstrating functional specialization among myosin isoforms. We conclude that class XI myosins are required for organelle motility, actin organization, and optimal growth of pollen tubes.

Use of ultrasound guidance for central venous catheter placement: survey from the American Board of Emergency Medicine Longitudinal Study of Emergency Physicians.

OBJECTIVES: The objective was to survey practicing emergency physicians (EPs) across the United States regarding the frequency of using ultrasound (US) guidance in central venous catheter (CVC) placement and, secondarily, to determine factors associated with the use or barriers to the use of US guidance. METHODS: This was a cross-sectional survey mailed to presumed practicing EPs as part of the American Board of Emergency Medicine (ABEM)'s longitudinal study of EPs. The selection process used stratified, random sampling of cohorts thought to represent four different stages within the development of the specialty of emergency medicine (EM). Multivariable logistic regression was used to identify independent factors associated with both high comfort using US guidance and high-percentage usage of US guidance. RESULTS: The survey was mailed to 1,165 subjects, and the response rate was 79%. The median number of years of practice was 20 (interquartile range [IQR]=7 to 28 years). As their primary practice setting, 64% work in private or community hospitals, 60% received training in US-guided vascular access, and 44% never use US guidance in placing CVCs. Barriers differed in those who never use US and those who sometimes or always used US guidance. In those who never use US, top barriers were insufficient training (67%) and lack of equipment (25%). In those who use US, top barriers were the perceptions that US was too time-consuming (27%) and that the preferred site was not amenable to US (24%). Independent factors associated with high comfort and high-percentage use of US guidance were training in US-guided vascular access (adjusted odds ratio=5.1 [high comfort]; 95% confidence interval [CI]=2.6 to 10.1; adjusted odds ratio 11.1=(high percentage); 95% CI=5.0 to 24.8) and being a recent residency graduate. CONCLUSIONS: Among EPs, the translation of evidence to clinical practice regarding the benefits of US guidance for CVC placement is poor and still faces many barriers. Training and education are potentially the best ways to overcome such barriers.

E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction.

OBJECTIVES: Rapid assessment of left ventricular ejection fraction (LVEF) may be critical among emergency department (ED) patients. This study examined the predictive relationship between ED physician performed bedside mitral-valve E-point septal separation (EPSS) measurements to the quantitative, calculated LVEF. We further evaluated the relationship between ED physician visual estimates of global cardiac function (GCF) and calculated LVEF values. METHODS: A prospective observational study was conducted on a sequential convenience sample of patients receiving comprehensive transthoracic echocardiography (TTE). Three ED ultrasound fellows performed bedside ultrasound examinations to obtain both EPSS measurements and subjective visual GCF estimates. A linear regression analysis was conducted to examine the relation of EPSS to the calculated LVEF from the comprehensive TTE. Agreement (modified Cohen κ) between ED ultrasound fellow GCF estimates and the calculated LVEF was also assessed. RESULTS: Linear regression analyses revealed a significant correlation (r=0.73, P<.001) between bedside EPSS and the calculated LVEF. The sensitivity and specificity of an EPSS measurement of greater than 7 mm for severe systolic dysfunction (LVEF≤30%) were 100.0% (95% confidence interval, 62.9-100.0) and 51.6% (95% confidence interval, 38.6-64.5), respectively. Subjective estimates of GCF were moderately correlated with calculated LVEF (Cohen κ=0.58). CONCLUSIONS: Measurements of EPSS by ED physicians were significantly associated with the calculated measurements of LVEF from comprehensive TTE. Subjective visual estimates of GCF, however, demonstrated only moderate agreement with the calculated LVEF. An EPSS measurement greater than 7 mm was uniformly sensitive at identifying patients with severely reduced LVEF.

Direct current stimulation for spine fusion in a nicotine exposure model.

BACKGROUND CONTEXT: Decreased effectiveness in spinal fusion procedures in patients who smoke before, during, or after the operation has been noted in several clinical studies. In previous work, direct current (DC) electrical stimulation has been shown to enhance inter-transverse process fusion in a rabbit model. PURPOSE: To test the efficacy of DC stimulation on bone healing in spinal fusion in rabbits exposed to nicotine. STUDY DESIGN/SETTING: A randomized and controlled interventional study. METHODS: Thirty male New Zealand white rabbits received a single level posterolateral, inter-transverse process fusion with autologous iliac crest bone. One group (control) acted as a control without nicotine or electrical stimulation. A second group (Nic) received a continuous dose of nicotine via a transdermal patch to simulate a heavy smoker, and a third group, nicotine/stimulator group (Nic/Stim), additionally received a 100-microamp DC stimulator. The fusion masses (L5-L6) and the adjacent unfused control segment (L4-L5) were evaluated radiographically, manually, and biomechanically. RESULTS: The Nic group showed significantly higher fusion rate compared with the control group. The Nic/Stim group also demonstrated significantly higher fusion rate and X-ray trabeculation compared with the control group. However, the Nic/Stim group was not significantly higher than the Nic group in fusion rate or X-ray trabeculation. CONCLUSIONS: Nicotine significantly improved fusion rate compared with controls, and DC stimulation significantly increased X-ray trabeculation of nicotine treated rabbits compared with controls.

Osteochondral lesions of the talus.

Osteochondral lesions of the talus (OLT) are rare joint disorders. The talus is the third most common location of this disorder, following the knee and elbow joints. OLT represents 4% of all osteochondral lesions in the body. This article discusses the surgical treatment and postoperative rehabilitation of osteochondral lesions of the talus.