Comparison of Gastrocnemius Shear Wave Elastography Stiffness Over 5 Different Zones

A few studies report that shear wave elastography (SWE) is a reliable method of measuring gastrocnemius muscle stiffness. To date there are no studies assessing variance in stiffness measures at different locations on the muscle. This led us to ask whether the spot at which gastrocnemius stiffness is measured matters. PURPOSE: To determine if measurement site on the medial and lateral gastrocnemius affects SWE stiffness values. METHODS: Twelve subjects (3 men, 9 women) completed this study (Mean age is 23.0 (SD = 1.0) for men and 21.7 (SD = 2.0) for women (t p = 0.3035). Mean height (cm) is 179.5 (SD = 2.9) for men and 167.1 (SD = 7.8) for women (t p = 0.0256). Mean weight (kg) is 74.9 (SD =10.4) for men and 62.5 (SD = 9.7) for women (t p = 0.0892). Subjects wore shorts and lay prone on a treatment table with their bare feet hanging off the edge of the table. Ultrasound images to confirm borders of the medial and lateral gastrocnemius were confirmed and marked. SWE of both the Medial head (MG) and lateral head (LG) were taken with each head area divided into 4 zones (1=superior medial, 2=superior lateral, 3=inferior medial, 4= inferior lateral). A fifth zone was collected at the center of the muscle at 70% of the length of the lateral malleolus to lateral femoral epicondyle. All 5 points were assessed for SWE in both a relaxed and neutral (900) ankle joint position. Three separate elastogram frames were used to calculate muscle stiffness using both the velocity (m/s) and young’s modulus model (kPa) utilizing an overall area analysis for each. RESULTS: MG velocity and kPa values were significantly greater than LG in the relaxed and neutral positions (pCONCLUSION: MG stiffness is greater than LG regardless of position while intrinsic stiffness of MG increases more relative to LG when placed in neutral. Measurement of stiffness is best represented at the center of the muscle belly in the neutral position, but zones 2,3 and 5 produce similar stiffness values in the relaxed position

Reconstitution of dynein transport to the microtubule plus end by kinesin

Cytoplasmic dynein powers intracellular movement of cargo toward the microtubule minus end. The first step in a variety of dynein transport events is the targeting of dynein to the dynamic microtubule plus end, but the molecular mechanism underlying this spatial regulation is not understood. Here, we reconstitute dynein plus-end transport using purified proteins from S. cerevisiae and dissect the mechanism using single-molecule microscopy. We find that two proteins–homologs of Lis1 and Clip170–are sufficient to couple dynein to Kip2, a plus-end-directed kinesin. Dynein is transported to the plus end by Kip2, but is not a passive passenger, resisting its own plus-end-directed motion. Two microtubule-associated proteins, homologs of Clip170 and EB1, act as processivity factors for Kip2, helping it overcome dynein's intrinsic minus-end-directed motility. This reveals how a minimal system of proteins transports a molecular motor to the start of its track. DOI: http://dx.doi.org/10.7554/eLife.02641.00

Characterization of health care utilization in patients receiving implantable cardioverter-defibrillator therapies: An analysis of the managed ventricular pacing trial.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) are effective in terminating lethal arrhythmias, but little is known about the degree of health care utilization (HCU) after ICD therapies. OBJECTIVE: Using data from the managed ventricular pacing trial, we sought to identify the incidence and types of HCU in ICD patients after receiving ICD therapy (shocks or antitachycardia pacing [ATP]). METHODS: We analyzed HCU events (ventricular tachyarrhythmia [VTA]-related, heart failure-related, ICD implant procedure-related, ICD system-related, or other) and their association with ICD therapies (shocked ventricular tachycardia episode, ATP-terminated ventricular tachycardia episode, and inappropriately shocked episode). RESULTS: A total of 1879 HCUs occurred in 695 of 1030 subjects (80% primary prevention) and were classified as follows: 133 (7%) VTA-related, 373 (20%) heart failure-related, 97 (5%) implant procedure-related, 115 (6%) system-related, and 1160 (62%) other. Of 2113 treated VTA episodes, 1680 (80%) received ATP only and 433 (20%) received shocks. Stratifying VTA-related HCUs on the basis of the type of ICD therapy delivered, there were 25 HCUs per 100 shocked VTA episodes compared with 1 HCU per 100 ATP-terminated episodes. Inappropriate ICD shocks occurred in 8.7% of the subjects and were associated with 115 HCUs. The majority of HCUs (52%) began in the emergency department, and 66% of all HCUs resulted in hospitalization. CONCLUSION: For VTA-related HCUs, shocks are associated with a 25-fold increase in HCUs compared to VTAs treated by ATP only. Application of evidence-based strategies and automated device-based algorithms to reduce ICD shocks (higher rate cutoffs, use of ATP, and arrhythmia detection) may help reduce HCUs

Acute Stretching Effect on Hamstring Muscle Stiffness using Elastography

Having first been introduced in the 1990s, shear wave elastography (SWE) has more recently been used to investigate intrinsic muscle stiffness. While studies have shown SWE to be an effective way of determining muscle stiffness, few have been conducted to measure the effects of stretching on the hamstring muscles. PURPOSE: to determine if there is a measurable difference of hamstring muscle stiffness with acute stretching using ultrasound elastography. METHODS: 16 subjects participated in this study (11 men and 5 women). Mean age 23.4 ± 2.6yrs for men and 21.2 ±1.5 for women. Mean height (cm) is 180.3± 4.7 for men and 172.7±2.5 for women. Mean weight (kg) is 76.8±9.7 for men and 70.0±14.9 for women. Participants lay supine and positioned to 90° hip and 90° knee flexion. Each participant came in for two sessions that consisted of (1) static stretching and (2) PNF stretching protocols. Maximum ROM of the knee joint, force, and muscle stiffness of the biceps femoris (BF), semimembranosus (SM) and semitendinosus (ST) were recorded both before and 1 minute after stretching. RESULTS: After accounting for age, weight and height, there was no significant difference between the use of static and PNF stretching techniques on either velocity (p= 0.4805) or kPa (p=0.5423) stiffness values. Both static and PNF stretching resulted in significant reductions in both velocity and kPa stiffness (pCONCLUSION: Stiffness as measured using SWE decreases following an acute stretching session for both static and PNF stretching techniques. This suggests alterations to intrinsic muscle characteristics beyond just “stretch tolerance” as suggested in previous literature. Changes in both ROM and force also support this claim. Further research on retention of decreased stiffness are needed as acute stretching has previously been shown to be temporary. Longer term stretching studies to determine if intrinsic muscle stiffness changes models plastic deformation are also needed and may help better elucidate duration and stretch technique differences

Massage Gun Use at a Lower Frequency Does Not Alter Blood Flow

Data has shown that whole body vibration can affect blood flow velocity in arteries and improves cutaneous blood flow. However, there is very limited information available on therapeutic localized vibration. Massage guns have become very popular with little to no research validating their efficacy. It is currently unknown if massages guns can affect arterial blood flow. PURPOSE: To determine if massage gun treatment at 30Hz improves and retains blood flow in the popliteal artery as compared to a control condition. METHODS: There were 12 participants in this study (8 males and 4 females). The mean age was 22.7±1.6 yrs, the mean height was 181.1± 11.8 cm, and the mean weight was 78.2±16.2 kg. Participants wore shorts that allowed us to access their popliteal artery using ultrasound imaging. Participants wore electrodes to control the measurement of blood flow from widest artery diameter. Participants lay prone with a foam roller under their ankles to slightly elevate their feet. After ten minutes of rest, ultrasound imaging was used to find the participant’s popliteal artery behind the knee and took two baseline measurements. We measured the mean velocity of blood flow (TAmean) and volume flow (VolF). We measured subjects on 4 different days (30Hz at 5 minutes, 30Hz 10 minutes, Control 5 minutes, Control 10 minutes). Measurements of TAmean and VolF were measured at multiple time points after treatment. RESULTS: A two-factor repeated measures analysis was performed. Each subject was measured under all levels of condition (1=30hz 5 min, 4=Control 5 mi, 5=30hz 10 min, 8=Control 10 min) and time (baseline, post, post1-5, 7, 9, 11, 13, 15, 17, 19). TA mean is significantly greater in 30Hz versus control (p=0.0349). TAmean varies across time, and the effect of the condition on TAmean is related to time (p=0.0104). There is not a significant difference in flow between 30Hz and control (p=0.2425). Blood flow varies across time (pCONCLUSION: Use of a massage gun at a lower frequency setting of 30Hz may cause slight increases in velocity but does not increase mean blood flow as compared to control. Lower frequency settings on massage guns may not be benefit blood flow in the massaged muscle group

Improving child survival through a district management strengthening and community empowerment intervention: early implementation experiences from Uganda.

BACKGROUND: The Community and District Empowerment for Scale-up (CODES) project pioneered the implementation of a comprehensive district management and community empowerment intervention in five districts in Uganda. In order to improve effective coverage and quality of child survival interventions CODES combines UNICEF tools designed to systematize priority setting, allocation of resources and problem solving with Community dialogues based on Citizen Report Cards and U-Reports used to engage and empower communities in monitoring health service provision and to demand for quality services. This paper presents early implementation experiences in five pilot districts and lessons learnt during the first 2 years of implementation. METHODS: This qualitative study was comprised of 38 in-depth interviews with members of the District Health Teams (DHTs) and two implementing partners. These were supplemented by observations during implementation and documents review. Thematic analysis was used to distill early implementation experiences and lessons learnt from the process. RESULTS: All five districts health teams with support from the implementing partners were able to adopt the UNICEF tools and to develop district health operational work plans that were evidence-based. Members of the DHTs described the approach introduced by the CODES project as a more systematic planning process and very much appreciated it. Districts were also able to implement some of the priority activities included in their work plans but limited financial resources and fiscal decision space constrained the implementation of some activities that were prioritized. Community dialogues based on Citizen Report Cards (CRC) increased community awareness of available health care services, their utilization and led to discussions on service delivery, barriers to service utilization and processes for improvement. Community dialogues were also instrumental in bringing together service users, providers and leaders to discuss problems and find solutions. The dialogues however are more likely to be sustainable if embedded in existing community structures and conducted by district based facilitators. U report as a community feedback mechanism registered a low response rate. CONCLUSION: The UNICEF tools were adopted at district level and generally well perceived by the DHTs. The limited resources and fiscal decision space however can hinder implementation of prioritized activities. Community dialogues based on CRCs can bring service providers and the community together but need to be embedded in existing community structures for sustainability

Effect of Localized Vibration Using Massage Gun at 40hz and 50hz on Blood Flow

Data has shown that whole body vibration can positively affect blood flow, however, there are very few studies on the effect of localized therapeutic vibration on arterial blood flow. Occupational studies looking at localized vibration effects on skin blood flow normally include high frequency settings. In the last few years, massage guns have become popular, but they operate at lower frequencies. Currently, there is no data on the effects of localized vibration from massage guns on arterial blood flow. PURPOSE: To compare the effects of two different frequencies of localized vibration on blood flow in the popliteal artery. METHODS: 12 subjects participated in this study (8 males and 4 females). Mean age was 22.7±1.6 years; mean height was 181.1±11.8 cm; mean weight was 78.2±16.2 kg. Participants wore shorts to give access to the popliteal artery. Participants were hooked to ECG leads to control measurement of artery diameter and then laid on a treatment table in a prone position with a foam roller under their ankles. Once at resting heart rate, baseline blood flow readings were taken using ultrasound, which measured TA Mean and Volume Flow. The participants were then randomly given a 5-minute treatment of control with no vibration or vibration at 40hz or 50hz. Blood flow readings were taken immediately post-treatment and then every minute for 5 minutes after. RESULTS: A two-factor repeated measures analysis was performed. Each subject was measured under all levels of condition (Control 5 min, 40hz 5 min, and 50hz 5 min) and time (baseline, post, post1-5). TA Mean and Volume Flow for both 40hz and 50hz were significantly greater than control (p=0.0020 and p=0.0110 respectively). The effect of time was significant (