Isabel de Almeida Paz, Francesca Chaida Sonda, Matias Fröhlich, João Luiz Quagliotti Durigan, and Marco Aurélio Vaz
Context: Pulsed current and kilohertz frequency alternating current are 2 types of neuromuscular electrical stimulation (NMES) currents often used by clinicians during rehabilitation. However, the low methodological quality and the different NMES parameters and protocols used in several studies might explain their inconclusive results in terms of their effects in the evoked torque and the discomfort level. In addition, the neuromuscular efficiency (ie, the NMES current type that evokes the highest torque with the lowest current intensity) has not been established yet. Therefore, our objective was to compare the evoked torque, current intensity, neuromuscular efficiency (evoked torque/current intensity ratio), and discomfort between pulsed current and kilohertz frequency alternating current in healthy people. Design: A double-blind, randomized crossover trial. Methods: Thirty healthy men (23.2 [4.5] y) participated in the study. Each participant was randomized to 4 current settings: 2 kilohertz frequency alternating currents with 2.5 kHz of carrier frequency and similar pulse duration (0.4 ms) and burst frequency (100 Hz) but with different burst duty cycles (20% and 50%) and burst durations (2 and 5 ms); and 2 pulsed currents with similar pulse frequency (100 Hz) and different pulse duration (2 and 0.4 ms). The evoked torque, current intensity at the maximal tolerated intensity, neuromuscular efficiency, and discomfort level were evaluated. Results: Both pulsed currents generated higher evoked torque than the kilohertz frequency alternating currents, despite the similar between-currents discomfort levels. The 2 ms pulsed current showed lower current intensity and higher neuromuscular efficiency compared with both alternated currents and with the 0.4 ms pulsed current. Conclusions: The higher evoked torque, higher neuromuscular efficiency, and similar discomfort of the 2 ms pulsed current compared with 2.5-kHz frequency alternating current suggests this current as the best choice for clinicians to use in NMES-based protocols.
Lawrence P. Behmer Jr., Mathew J.C. Crump, and Kelly J. Jantzen
Several computational models make predictions about the activation states of individual elements of an action sequence during planning and execution; however, the neural mechanisms of action planning are still poorly understood. Simple chaining models predict that only the first response in an action sequence should be active during planning. Conversely, some parallel activation models suggest that during planning, a serial inhibition process places the individual elements of the action into a serial order across a winner-takes-all competitive choice gradient in which earlier responses are more active, and hence likely to be selected for execution compared with later responses. We triggered transcranial magnetic stimulation pulses at 200 or 400 ms after the onset of a five-letter word, in which all but one response was planned and typed with the left hand, except for a single letter which required a right index finger response exclusively at one of five serial positions. We measured the resulting motor-evoked potentials at the right index finger as a marker for the activation state of that planned response. We observed no difference in motor-evoked potential amplitude across any serial position when a right index finger response was planned at 200 ms after the onset of the word; however, we observed a graded pattern of activation at 400 ms, with earlier positions that required a right index finger response showing greater motor-evoked potentials amplitude compared with later positions. These findings provide empirical support for competitive queuing computational models of action planning.
Brendan L. Pinto and Jack P. Callaghan
Computational approaches for movement onset detection can standardize and automate analyses to improve repeatability, accessibility, and time efficiency. With the increasing interest in assessing time-varying biomechanical signals such as force–time recordings, there remains a need to investigate the recently adopted 5 times the standard deviation (5 × SD) threshold method. In addition, other employed methods and their variations such as the reverse scanning and first derivative methods have been scarcely evaluated. The aim of this study was to compare the 5 × SD threshold method, 3 variations of the reverse scanning method, and 5 variations of the first derivative method against manually selected onsets, in the countermovement jump and squat. Limits of agreement with respect to onsets, manually selected from unfiltered data, were best for the first derivative method using a 10-Hz low-pass filter (limits of agreement: −0.02 to 0.05 s and −0.07 to 0.11 s for the countermovement jump and squat, respectively). Thus, even when the onset of unfiltered data is of primary interest, filtering before calculating the first derivative is necessary as it reduces the amplification of high frequencies. The first derivative approach is also less susceptible to inherent variation during the quiet phase prior to the onset compared to the other approaches investigated.
Jesús Díaz-García, Bart Roelands, Jelle Habay, Inmaculada González-Ponce, Miguel Ángel López-Gajardo, Tomás García-Calvo, and Jeroen Van Cutsem
This study aimed to assess, for the first time, how self-reported sleep, mental toughness, and reaction time are impacted by a professional padel tournament. In addition, we evaluated whether sex, age, and/or ranking play a role in this possible effect of a tournament on these variables. Twenty-three professional players (15 men, M age = 24 ± 6 years; eight women, M age = 21 ± 5 years) were evaluated on two occasions: (a) baseline, in a noncompetitive week and (b) postmeasure, the morning after an individual was eliminated from the tournament. The Pittsburgh Sleep Quality Index, the Mental Toughness Questionnaire, and the psychomotor vigilance task were used to evaluate the dependent variables. Wilcoxon tests or paired samples t tests were employed to assess the effect of participating in the tournament. To test correlations between variables, Pearson correlation coefficients (quantitative variables) or chi-square distributions (qualitative variables) were employed. Results showed that self-reported sleep (p < .01), mental toughness (p = .01), and reaction time (p = .04) were significantly impaired by the tournament. Exploring moderating variables, results showed that mental toughness did not correlate with sleep impairments (p > .05). In contrast, a nearly significant correlation between sleep impairments and higher reaction times was found (p = .066). No significant effects of age, sex, and ranking were observed. In conclusion, participating in a padel competition impairs the self-reported sleep, mental toughness, and reaction time of professional padel players. A trend toward a significant correlation between the competition-related impairment in sleep and reaction time was observed, whereas age, ranking, and sex were not found to be moderators of any of these impairments.
Utku Berberoğlu and Özlem Ülger
Background: Low back pain (LBP) is one of the top 3 diseases that may lead to disability. Current treatment guidelines define exercise as a first-line treatment for nonspecific LBP (NSLBP). There are various evidence-based exercise approaches for treating NSLBP, and many of them include motor control principles. Motor control exercises (MCEs) are better than general exercises that do not include motor control principles. Many patients find learning these exercises complex and challenging, in that MCE exercises have no standard teaching method. The researchers of this study developed multimedia instructions for an MCE program to make teaching MCE easier; thus, more effective. Methods: The participants were randomized into multimedia or standard (face-to-face) instruction groups. We applied the same treatments to both groups at the same dosage. The only differences between groups were the exercise instruction methods. The multimedia group learned MCE from multimedia videos; the control group learned MCE from a physiotherapist with face-to-face instructions. Treatment lasted 8 weeks. We evaluated patients’ exercise adherence with Exercise Adherence Rating Scale (EARS), pain with the Visual Analog Scale, and disability with Oswestry Disability Index. Evaluations were made before and after treatment. Follow-up evaluations were carried out 4 weeks after the end of treatment. Results: There was no statistically significant interaction between the group and time on pain, F 2,56 = 0.068, P = .935, partial η 2 = .002 and Oswestry Disability Index scores, F 2,56 = 0.951, P = .393, partial η 2 = .033. Also, there was no statistically significant interaction between the group and time on Exercise Adherence Rating Scale total scores F 1,20 = 2.343, P = .142, partial η 2 = .105. Conclusions: This study showed that multimedia instructions for MCE have similar effects to standard (face-to-face) instructions on pain, disability, and exercise adherence in patients with NSLBP. To our knowledge, with these results, the developed multimedia instructions became the first free, evidence-based instructions that have objective progression criteria and a Creative Commons license.
Xiaoxia Zhang, Zackary G. Kern, and Joonkoo Yun
This study aimed to examine physical activity (PA) levels and mental health status (i.e., anxiety and depression) among parents of children with autism spectrum disorder (ASD). Secondary data analysis was conducted using the 2018 National Health Interview Survey. We identified 139 parents of children with ASD and 4,470 parents of children with no disability. Their PA levels, anxiety, and depression were analyzed. Compared with parents of children with no disability, parents of children with ASD were significantly less likely to meet the PA guideline for Americans and had lower odds of vigorous PA (aOR = 0.702), strengthening PA (aOR = 0.885), and light to moderate PA (aOR = 0.994). Parents of children with ASD reported significantly higher odds of anxiety (aOR = 1.559) and depression (aOR = 1.885). This study revealed lower PA levels and higher risks of anxiety and depression in parents of children with ASD.
Jurate Pozeriene, Arūnas Emeljanovas, Vida Ostaseviciene, Kestutis Skucas, Kristina Bradauskiene, Renatas Mizeras, Ausrine Packeviciute, Kristina Venckuniene, Vaida Pokvytyte, Diana Reklaitiene, and Kwok Ng
Despite the recognized benefits of physical activity (PA) for children and adolescents with disabilities (CAWD), collective information on this is lacking in Lithuania. The purpose of this study was to investigate the current “state of the nation” PA levels of CAWD, based on the 10 indicators from the Active Healthy Kids Global Alliance Global Matrix 4.0 methodology. Scientific articles, practical reports, and published theses related to the 10 indicators from the Global Matrix 4.0 on CAWD age 6–19 years were reviewed, and data were converted to grades from A to F. (A) Strengths, Weaknesses, Opportunities, and Threats analysis was carried out to interpret the grades by four experts. Data on organized sport participation (F), school (D), community & environment (D), and government (C) were available. Data on other indicators are largely missing yet are needed for policymakers and researchers to be aware of the current state of PA among CAWD.