A novel time-based surface EMG measure for quantifying hypertonia in paretic arm muscles during daily activities after hemiparetic stroke

After stroke, paretic arm muscles are constantly exposed to abnormal neural drive from the injured brain. As such, hypertonia, broadly defined as an increase in muscle tone, is prevalent especially in distal muscles, which impairs daily function or in long-term leads to a flexed resting posture in the wrist and fingers. However, there currently is no quantitative measure that can reliably track how hypertonia is expressed on daily basis. In this study, we propose a novel time-based surface electromyography (sEMG) measure that can overcome the limitations of the coarse clinical scales often measured in functionally irrelevant context and the magnitude-based sEMG measures that suffer from signal non-stationarity. We postulated that the key to robust quantification of hypertonia is to capture the true baseline in sEMG for each measurement session, by which we can define the relative duration of activity over a short time segment continuously tracked in a sliding window fashion. We validate that the proposed measure of sEMG active duration is robust across parameter choices (e.g., sampling rate, window length, threshold criteria), robust against typical noise sources present in paretic muscles (e.g., low signal-to-noise ratio, sporadic motor unit action potentials), and reliable across measurements (e.g., sensors, trials, and days), while providing a continuum of scale over the full magnitude range for each session. Furthermore, sEMG active duration could well characterize the clinically observed differences in hypertonia expressed across different muscles and impairment levels. The proposed measure can be used for continuous and quantitative monitoring of hypertonia during activities of daily living while at home, which will allow for the study of the practical effect of pharmacological and/or physical interventions that try to combat its presence.

EXPRESS: Getting a Handle on Sales: Shopping Carts Affect Purchasing by Activating Arm Muscles

This research demonstrates that the physical properties of shopping carts influence purchasing and spending. Prior research on ergonomics indicates that standard shopping carts, which are pushed via a horizontal handlebar, are likely to activate arm extensor muscles. Prior research on arm muscle activation, in turn, suggests that arm extensor activation may elicit less purchasing than arm flexor activation. The authors thus deduce that standard shopping carts may be suboptimal for stimulating purchases. The authors predicted that shopping carts with parallel handles (i.e., like a wheelbarrow or “walker”) would instead activate the flexor muscles and thus increase purchasing. An electromyography (EMG) study revealed that both horizontal and vertical handles more strongly activate the extensor muscles of the upper arm (triceps), whereas parallel handles more strongly activate the flexor muscles (biceps). In a field experiment, parallel-handle shopping carts significantly and substantially increased sales across a broad range of categories, including both vice and virtue products. Finally, in a simulated shopping experiment, parallel handles increased purchasing and spending beyond both horizontal and vertical handles. These results were not attributable to the novelty of the shopping cart itself, participants’ mood, or purely ergonomic factors.

High resolution breakpoint junction mapping of proximally extended D4Z4 deletions in FSHD1 reveals evidence for a founder effect.

Facioscapulohumeral muscular dystrophy (FSHD) is an inherited myopathy clinically characterized by weakness in the facial, shoulder girdle and upper arm muscles. FSHD is caused by chromatin relaxation of the D4Z4 macrosatellite repeat, mostly by a repeat contraction, facilitating ectopic expression of DUX4 in skeletal muscle. Genetic diagnosis for FSHD is generally based on the sizing and haplotyping of the D4Z4 repeat on chromosome 4 by Southern blotting, molecular combing or single-molecule optical mapping, which is usually straight forward but can be complicated by atypical rearrangements of the D4Z4 repeat. One of these rearrangements is a D4Z4 proximally-extended deletion (DPED) allele, where not only the D4Z4 repeat is partially deleted, but also sequences immediately proximal to the repeat are lost, which can impede accurate diagnosis in all genetic methods. Previously, we identified several DPED alleles in FSHD and estimated the size of the proximal deletions by a complex pulsed-field gel electrophoresis and Southern blot strategy. Here, using next generation sequencing, we have defined the breakpoint junctions of these DPED alleles at the base pair resolution in 12 FSHD families and 4 control individuals facilitating a PCR-based diagnosis of these DPED alleles. Our results show that half of the DPED alleles are derivates of an ancient founder allele. For some DPED alleles we found that genetic elements are deleted such as DUX4c, FRG2, DBE-T and myogenic enhancers necessitating re-evaluation of their role in FSHD pathogenesis.

Difference in racket head trajectory and muscle activity between the standard volley and the drop volley in tennis

Among tennis coaches and players, the standard volley and drop volley are considered basically similar, but muscles need to be relaxed (deactivation) just at the moment of impact when hitting the drop volley. However, this is not evidence-based. The aim of this study was to clarify racket head trajectory and muscle activity during the drop volley and to compare them with those of the standard volley. We hypothesized that 1) the racket head would move less forward for the drop volley than for the standard volley and 2) the wrist and elbow muscles be relaxed for the drop volley at the time of ball impact. Eleven male college students with sufficient tennis experience volunteered to participate in this study. Wireless EMG sensors recorded activation of the four arm muscles. Each subject performed the standard volley or the drop volley with both a forehand and a backhand from a position near the net. Four high speed video cameras (300 Hz) were set up on the court to measure ball speed and racket head trajectory. Returned ball speed of the drop volley was significantly lower than that of the standard volley (p < 0.05). The racket head moved less forward than in the standard volley, supporting the first hypothesis. Muscle activity of the drop volley, just before and after ball impact for both the forehand and backhand, was lower than that of the standard volley. However, the activity was in the form of a gradual increase as impact time approached, rather than a sudden deactivation (relaxation), which did not support the second hypothesis. For the drop volley, lower muscle activity in the forearm enabled a softer grip and thus allowed a “flip” movement of the racket to diminish the speed of the returned ball.

FOOTBALL AS A MEANS OF PHYSICAL EDUCATION

This article discusses the effective teaching of football sports in the physical development of preschool children. Additionally, it is mentioned that, football exercises not only have a healthy effect on their healthy growth and development, but also on the leg and arm muscles of children in motion. And exercises that encourage children to move with the ball were also kept in mind.

Selectivity and excitability of upper-limb muscle activation during cervical transcutaneous spinal cord stimulation in humans

Cervical transcutaneous spinal cord stimulation (tSCS) efficacy for rehabilitation of upper-limb motor function was suggested to depend on recruitment of Ia afferents. However, selectivity and excitability of motor activation with different electrode configurations remains unclear. In this study, activation of upper-limb motor pools was examined with different cathode and anode configurations during cervical tSCS in 10 able-bodied individuals. Muscle responses were measured from six upper-limb muscles simultaneously. First, post-activation depression was confirmed with tSCS paired pulses (50 ms interval) for each cathode configuration (C6, C7, and T1 vertebral levels), with anode on the anterior neck. Selectivity and excitability of activation of the upper-limb motor pools were examined by comparing the recruitment curves (10-100 mA) of first evoked responses across muscles and cathode configurations. Our results showed that hand muscles were preferentially activated when the cathode was placed over T1 compared to the other vertebral levels, while there was no selectivity for proximal arm muscles. Furthermore, higher stimulation intensities were required to activate distal hand muscles than proximal arm muscles, suggesting different excitability thresholds between muscles. In a separate protocol, responses were compared between anode configurations (anterior neck, shoulders, iliac crests, and back), with one selected cathode configuration. The level of discomfort was also assessed. Largest muscle responses were elicited with the anode configuration over the anterior neck, while there were no differences in the discomfort. Our results therefore inform methodological considerations for electrode configuration to help optimize recruitment of Ia afferents during cervical tSCS.

USE OF KB INJECTIONS FOR 3 MONTHS AT THE PUSKESMAS BALOI PERMAI, BATAM CITY

Injectable birth control methods use medroxyprogesterone (a type of progestin) which is injected once or 3 months into the buttocks or upper arm muscles. This is very effective but can interfere with the menstrual cycle. The results of several studies conducted on injection family planning acceptors showed that the factors associated with injection contraceptive use were menstrual disorders 51.25%, 36.25% increase in body weight and an increase in blood pressure. Some of the results of studies conducted on injection contraceptive acceptors showed that factors which is associated with the use of injection contraceptives is the occurrence of menstrual disorders 51.25%, weight gain 36.25% and an increase in blood pressure 3.75% (Eiska, 2007). Method : The research objective was to determine the use of 3-month injection of family planning at the UPT Puskesmas Baloi Permai. The population of this study were mothers who used 3-month injection contraception. Sampling with purposive sampling technique. The number of samples is 98 respondents. Result :The univariate results obtained were more than half of the respondents who used 3-month injection contraception (57.1%). Conclusion : Based on the results of the research that has been carried out, it can be concluded as follows : The conclusion in this study was that 98 respondents obtained the results, namely, respondents who used injection contraceptives for 3 months with categories using as many as 92 people (93.9%

Level of Physical Condition of Women's Volleyball Athlete at BPC Club

The problem in this research is that the athletes have not had a good physical condition. The low performance of athletes has decreased from year to year. The aim of the study was to see how the Physical Condition Level of Women's Volleyball Athletes at the BPC Tanah Datar Regency club. This type of research is quantitative using descriptive methods. The population in the study amounted to 16 people. The sampling technique used purposive sampling, thus the number of samples in the study were 12 female volleyball athletes at the BPC club Tanah Datar Regency. The data analysis technique is a percentage. Research result ; (1) The aerobic endurance in the category is sufficient with an average of 23.3 ml / kg.bb / m or about 41.67%, (2) the explosive power of the arm muscles in the less category with an average of 5.5 m or about 25%, (3) The explosive power of the leg muscles that is currently owned is in the low category with an average of 63 kg-m / second or about 33.33%, (4) the agility possessed is classified as in the medium category with an average of 9 seconds or about 25%, (5) The flexibility of the waist that is owned is classified in the less category with an average of 12.08 cm or about 33.33%, thus it can be concluded that the physical condition of women's volleyball athletes is good from indicators, power endurance, leg muscle explosive power, arm muscle explosive power, agility, and flexibility, are still in the low category and need to be improved to be higher.