Auditory feedback is a simple, low-cost training solution that can be used in rehabilitation, motor learning, and performance development. The use has been limited to the instruction of a single kinematic or kinetic target. The goal of this study was to determine if auditory feedback could be used to simultaneously train 2 lower-extremity parameters to perform a bodyweight back squat. A total of 42 healthy, young, recreationally active males participated in a 4-week training program to improve squat biomechanics. The Trained group (n = 22) received 4 weeks of auditory feedback. Feedback focused on knee flexion angle and center of pressure under the foot at maximum squat depth. The Control group (n = 20) performed squats without feedback. Subjects were tested pre, post, and 1 week after training. The Trained group achieved average target knee flexion angle within 1.73 (1.31) deg (P < .001) after training and 5.36 (3.29) deg (P < .01) at retention. While achieving target knee flexion angle, the Trained group maintained target center of pressure (P < .001). The Control group improved knee range of motion, but were not able to achieve both parameter targets at maximum squat depth (P < .90). Results from this study demonstrate that auditory feedback is an effective way to train 2 independent biomechanical targets simultaneously.
Rena F. Hale, Sandor Dorgo, Roger V. Gonzalez, and Jerome Hausselle
Faezeh Mohammadi Sanjani, Abbas Bahram, Moslem Bahmani, Mina Arvin, and John van der Kamp
It has been shown that texting degrades driving performance, but the extent to which this is mediated by the driver’s age and postural stability has not been addressed. Hence, the present study examined the effects of texting, sitting surface stability, and balance training in young and older adults’ driving performance. Fifteen young (mean age = 24.3 years) and 13 older (mean age = 62.8 years) participants were tested in a driving simulator with and without texting on a smartphone and while sitting on a stable or unstable surface (i.e., a plastic wobble board), before and after a 30-min sitting balance training. Analyses of variance showed that texting deteriorated driving performance but irrespective of sitting surface stability. Balance training decreased the negative effects of texting on driving, especially in older adults. Perceived workload increased when drivers were texting, and balance training reduced perceived workload. Perceived workload was higher while sitting on the unstable surface, but less so after balance training. Path analyses showed that the effects on driving performance and perceived workload were (indirectly) associated with changes in postural stability (i.e., postural sway). The study confirms that texting threatens safe driving performance by challenging postural stability, especially in older adults. The study also suggests that it is important to further investigate the role balance training can play in reducing these negative effects of texting.
Fabio Bertapelli, Stamatis Agiovlasitis, Robert W. Motl, Roberto A. Soares, Marcos M. de Barros-Filho, Wilson D. do Amaral-Junior, and Gil Guerra-Junior
The purpose of this study was to develop and cross-validate an equation for estimating percentage body fat (%BF) from body mass index and other potential independent variables among young persons with intellectual disability. Participants were 128 persons with intellectual disability (62 women; age 16–24 years) split between development (n = 98) and cross-validation (n = 30) samples. Dual-energy X-ray absorptiometry served as the reference method for %BF. An equation including 1/body mass index and sex (0 = male; 1 = female) was highly accurate in estimating %BF (p < .001; R 2 = .82; standard error of estimate = 5.22%). Mean absolute and root mean square errors were small (3.1% and 3.9%, respectively). A Bland–Altman plot indicated nearly zero mean difference between actual and predicted %BF with modest 95% confidence intervals. The prediction equation was %BF = 56.708 − (729.200 × [1/body mass index]) + (12.134 × sex). Health care professionals may use the prediction equation for monitoring %BF among young people with intellectual disability.
Chung-Ju Huang, Hsin-Yu Tu, Ming-Chun Hsueh, Yi-Hsiang Chiu, Mei-Yao Huang, and Chien-Chih Chou
This study examined the effects of acute aerobic exercise on sustained attention and discriminatory ability of children with and without learning disabilities (LD). Fifty-one children with LD and 49 typically developing children were randomly assigned to exercise or control groups. The participants in the exercise groups performed a 30-min session of moderate-intensity aerobic exercise, whereas the control groups watched a running/exercise-related video. Neuropsychological tasks, the Daueraufmerksamkeit sustained attention test, and the determination tests were assessed before and after each treatment. Exercise significantly benefited performance in sustained attention and discriminatory ability, particularly in higher accuracy rate and shorter reaction time. In addition, the LD exercise group demonstrated greater improvement than the typically developing exercise group. The findings suggest that the acute aerobic exercise influenced the sustained attention and the discriminatory function in children with LD by enhancing regulation of mental states and allocation of attentional resources.
Jaap van Dieen
Alejandro Pérez-Castilla, Ainara Jiménez-Alonso, Mar Cepero, Sergio Miras-Moreno, F. Javier Rojas, and Amador García-Ramos
This study explored the impact of different frequencies of knowledge of results (KR) on velocity performance during ballistic training. Fifteen males completed four identical sessions (three sets of six repetitions at 30% one-repetition maximum during the countermovement jump and bench press throw) with the only difference of the KR condition provided: no feedback, velocity feedback after the first half of repetitions of each set (HalfKR), velocity feedback immediately after each repetition (ImKR), and feedback of the average velocity of each set (AvgKR). When compared with the control condition, the ImKR reported the highest velocity performance (1.9–5.3%), followed by the HalfKR (1.3–3.6%) and AvgKR (0.7–4.3%). These results support the verbal provision of velocity performance feedback after every repetition to induce acute improvements in velocity performance.
Jennifer E. Meyer, Matthew J. Rivera, and Cameron J. Powden
Context: Mulligan’s Mobilization with Movement (MWM) is a common intervention used to address dorsiflexion range of motion (DFROM) impairments. However, the treatment dosage of MWMs varies within the literature. Objective: The aim of this study was to examine the effect of serial MWM application on DFROM. Design: Repeated-measures cohort. Setting: A Midwestern University and the surrounding community. Participants: A total of 18 adults (13 females; age = 29 [12.87] y; DFROM = 30.26° [4.60°]) with decrease dorsiflexion (<40°) participated. Inclusion criteria consisted of a history of ≥1 ankle sprain, ≥18 years old, no lower-extremity injury in the last 6 months, and no history of foot/ankle surgery. Intervention: Participants completed a single data collection session consisting of 10 individual sets of MWMs. Main Outcome Measures: DFROM was taken at baseline and immediately after each intervention set (post 1, post 2, … post 10). DFROM was measured with a digital inclinometer on the anterior aspect of the tibia during the weight-bearing lunge test with the knee straight and knee bent. Analysis of variances examined DFROM changes over time. Post hoc analysis evaluated sequential pairwise comparisons and changes from baseline at each time point. Results: Analysis of variance results indicated a significant time main effect for weight-bearing lunge test with knee bent (P < .001) and a nonsignificant effect for weight-bearing lunge test with knee straight (P < .924). Post hoc analysis indicated improvements in the weight-bearing lunge test with knee bent at each timepoint compared with baseline (P < .005). Post 2 improved compared with post 1 (P = .027). No other pairwise sequential comparisons were significant (P > .417). Conclusions: MWMs significantly improved acute knee bent DFROM and indicated that after 2 sets of MWMs, no further DFROM improvements were identified. Future research should investigate the lasting effects of DFROM improvements with variable MWM dosages.