Association Between Protocols of the Sit-to-Stand Test and Lower Limb Muscle Force Output in Patients on Hemodialysis and Subjects Without Chronic Kidney Disease.

OBJECTIVE: To evaluate the association of three protocols of the sit-to-stand (STS) test with muscle force output of knee extension (KE) and knee flexion (KF) in patients on hemodialysis and subjects without chronic kidney disease. METHODS: This cross-sectional study included a hemodialysis group [n = 60, 59.5 (16.8) years, 55% female] and a control group [n = 60, 43.0 (11.8) years, 50% female]. The assessments were performed in 2 days, and the participants were submitted to three protocols of STS test (5-repetition STS, 10-repetition STS and 30-s STS) or muscle force output of the KE and KF evaluation by handheld dynamometer based on randomization. RESULTS: The hemodialysis group presented reduced muscle force output of the KE and KF, a longer time to perform the 5 STS and 10 STS tests, and a lower number of repetitions in the 30-s STS test. The three STS tests were associated with muscle force output of the KE in the hemodialysis group, in which the 10-repetition STS test showed the best association (R2 = 0.47; adjusted R2 = 0.42). However, the only association between the STS test and muscle force output of the KE in the control group was found in the 10-repetition STS test (R2 = 0.20; adjusted R2 = 0.13). CONCLUSIONS: The three protocols of STS tests were associated with muscle force output of the KE in patients on hemodialysis. However, the 10-repetition STS test was the best protocol to estimate the quadriceps muscle torque in these patients.

What we know so far about postural balance training: An exploratory scoping review of nomenclature and related issues.

BACKGROUND: Different terms are used to refer to postural balance training, but the ontological debate involving the concepts to pursue nomenclature consensus is unusual. OBJECTIVE: The goal of this study was to analyze how often the terms balance, neuromuscular, proprioceptive, functional and sensorimotor training/exercise are used in the literature, and to propose a conceptual critical appraisal to determine the most appropriate terminology to address postural balance exercises. METHODS: A literature search was conducted in the Scopus electronic database. Eligibility criteria: papers with the selected expressions on the title or keywords, published in English, were included. RESULTS: The most used term was balance training (471 of 1105 included papers). Europe, followed by Asia and North America, had the highest number of publications. In the 21st century, the number of publications increased considerably. However, the terms have conceptual differences and controversies regarding its use. CONCLUSION: Despite a large variety of exercise types and divergences, balance training seems to be the most suitable term, given it refers to postural equilibrium exercises.

Characterization of the mechanomyographic signal of three different muscles and at different levels of isometric contractions.

PURPOSE: Lateral (X) and longitudinal (Y) mechanical oscillations of muscle fibers that take place during muscular contraction seem to contain information additionally to the myoelectric activity, which can contribute to the interpretation of some muscle gradation force mechanisms. However, no previous study was found that had investigated the relationship between the muscle force and features associated to the mechanomyographic (MMG) signal obtained by means of a biaxial accelerometer in three different muscles. Therefore, the aim of this study was to evaluate the relationship between the force output at different load levels (20% to 100%) of the maximum voluntary isometric contraction (%MVIC) and the two signals supplied by a biaxial accelerometer and, in addition, the so-called resultant (R) acceleration signal derived from the two signals mentioned previously. Twenty seven male volunteers participated in this study. METHODS: The force output related to the right biceps brachii, soleus and gastrocnemius medialis muscles was studied by means of linear regression models fit to log-transformed of the root mean square (RMS) values of the MMG signals in X, Y, and R axes versus each %MVIC. The phase angle of R acceleration (PhaseR) and anthropometric data were also considered. RESULTS: The angular coefficient a and the antilog of y-intercept b from the log-transformed of MMG data values versus force output were able to distinguish partially motor unit strategies during isometric contractions in the three muscles studied. CONCLUSION: The findings suggest that biaxial accelerometer seems to be an interesting approach in the assessment of muscle contraction properties.

Myofascial trigger point therapy: laser therapy and dry needling.

The aim of the present review is to discuss two forms of treatment for myofascial pain: laser therapy and dry needling. Although studies have reported the deactivation of myofascial trigger points with these two methods, clinical trials demonstrating their efficacy are scarce. The literature reports greater efficacy with the use of laser over dry needling. It has been suggested that improvements in microcirculation through the administration of laser therapy may favor the supply of oxygen to the cells under conditions of hypoxia and help remove the waste products of cell metabolism, thereby breaking the vicious cycle of pain, muscle spasm and further pain. While laser therapy is the method of choice for patients with a fear of needles and healthcare professionals inexperienced with the dry needling technique, further controlled studies are still needed to prove the greater efficacy of this method.