Thin, soft, and elastic electronics with physical properties well matched to the epidermis can be conformally and robustly integrated with the skin. Materials and optimized designs for such devices are presented for surface electromyography (sEMG). The findings enable sEMG from wide ranging areas of the body. The measurements have quality sufficient for advanced forms of human-machine interface.

Materials and Optimized Designs for Human‐Machine Interfaces Via Epidermal Electronics

A method for positioning electrodes during surface EMG recordings in lower limb muscles.

The proper design and implementation of a study as well as a balanced and well-supported evaluation and interpretation of its main findings are of crucial importance when reporting and disseminating research Also accountability, funding acknowledgement and adequately declaring any conflict of interest play a major role in science Since the Muscles, Ligaments and Tendons Journal (MLTJ) is committed to the highest scientific and ethical standards, we encourage all Authors to take into account and to comply, as much as possible, to the contents and issues discussed in this official editorial This could be useful for improving the quality of the manuscripts, as well as to stimulate interest and debate and to promote constructive change, reflecting upon uses and misuses within our disciplines belonging to the field of "Clinical and Sport - Science Research"

/pdf/muscles-ligaments-and-tendons-journal-basic-principles-and-3zvvnsc2uk.pdf

Muscles, Ligaments and Tendons Journal - Basic principles and recommendations in clinical and field Science Research: 2016 Update.

Aim: Many studies have been performed on the methodological qualities of the (modified) Ashworth Scale but overall these studies seem inconclusive. The aim of this study was to investigate the construct validity and inter-rater reliability of the Ashworth Scale (AS) for the assessment of spasticity in the upper and lower extremities. -
Method: A cross-sectional study on spasticity in the elbow flexors (part 1) and knee extensors (part 2) was carried out. In both parts AS was assessed while muscle activity and resistance were recorded simultaneously in patients with upper motor neuron syndrome. Each patient was measured by three raters. - 
Results: 30 patients participated, 19 in each part of the study. For elbow flexor muscles, AS was not significantly associated with electromyographic parameters, except for rater 2 (rho = 0.66, p<0.01). A significant moderate association was found with resistance (0.54≤ rho ≤0.61, p<0.05). For knee extensors, AS scores were moderately associated with muscle activity (0.56≤ rho ≤0.66, p<0.05) and also with resistance (0.55≤ rho ≤0.87, p<0.05). The intraclass correlation coefficient for absolute agreement was 0.58 for elbow flexors and 0.63 for knee extensors. In linear mixed model analysis, the factor rater appeared to be highly associated with AS. - 
Conclusion: The validity and reliability of the AS is insufficient to be used as a measure of spasticity.

https://jnnp.bmj.com/content/jnnp/81/1/46.full.pdf

Stop using the Ashworth Scale for the assessment of spasticity

Humans run faster by increasing a combination of stride length and stride frequency. In slow and medium-paced running, stride length is increased by exerting larger support forces during ground contact, whereas in fast running and sprinting, stride frequency is increased by swinging the legs more rapidly through the air. Many studies have investigated the mechanics of human running, yet little is known about how the individual leg muscles accelerate the joints and centre of mass during this task. The aim of this study was to describe and explain the synergistic actions of the individual leg muscles over a wide range of running speeds, from slow running to maximal sprinting. Experimental gait data from nine subjects were combined with a detailed computer model of the musculoskeletal system to determine the forces developed by the leg muscles at different running speeds. For speeds up to 7 m s(-1), the ankle plantarflexors, soleus and gastrocnemius, contributed most significantly to vertical support forces and hence increases in stride length. At speeds greater than 7 m s(-1), these muscles shortened at relatively high velocities and had less time to generate the forces needed for support. Thus, above 7 m s(-1), the strategy used to increase running speed shifted to the goal of increasing stride frequency. The hip muscles, primarily the iliopsoas, gluteus maximus and hamstrings, achieved this goal by accelerating the hip and knee joints more vigorously during swing. These findings provide insight into the strategies used by the leg muscles to maximise running performance and have implications for the design of athletic training programs.

/pdf/muscular-strategy-shift-in-human-running-dependence-of-5gdprpjhvo.pdf

Bart Freriks

Papers

Development of recommendations for SEMG sensors and sensor placement procedures.