Youth with intellectual disabilities (IDs) demonstrate below-criteria motor competence (MC) compared with typically developing (TD) youth. Whether differences in MC exist for youth with ID from different countries is unknown. This study examined the MC of youth with ID from Brazil (BR) and the United States (US) and compared it with norms for TD youth as established by the Bruininks–Oseretsky Test of Motor Proficiency (BOT-2). The authors measured 19 BOT-2 test items for bilateral coordination, balance, and upper limb coordination of 502 youth (BR = 252, US = 250) with ID (6–21 years). Raw scores were converted to %ceiling (percentile of highest expected scores). For all test items, no significant differences were seen between BR and US participants in %ceiling scores. Participants from both countries demonstrated equivalent to slightly below BOT-2 norms in 14 of the 19 test items, with lowest scores seen in contralateral synchronizing bilateral coordination, balancing on one leg, and ball handling.
Fabio Bertapelli, Ken Pitetti, Ruth A. Miller, Adam Jaeger, Michael Loovis, Wilson D. do Amaral-Junior, Marcos M. de Barros-Filho and Gil Guerra-Junior
Jayshree Shah, Tarushi Tanwar, Iram Iram, Mosab Aldabbas and Zubia Veqar
The objective was to investigate the electromyographic activity of the lumbar multifidus (MF) muscle and longissimus thoracis muscle, along with their activity ratio (MF longissimus thoracis ratio), during quadruped stabilization exercise performed with neutral posture and with increased lumbar lordosis in patients with chronic low back pain (CLBP). A total of 23 patients with CLBP (12 females and 11 males) were recruited based on inclusion and exclusion criterion. Each patient performed 4 exercises in random order, with surface electromyography electrodes and an electrogoniometer attached. A cross-sectional study design was used to measure the amplitude of muscle activation (as a percentage of maximum voluntary contraction) in each patient across the 2 muscles (MF and longissimus thoracis) during quadruped stabilization exercise with neutral posture and with increased lumbar lordosis. A 2-way analysis of variance was conducted, which demonstrated a statistically significant increase in the recruitment of MF with increased lumbar lordosis in patients with CLBP during quadruped exercise. An increase of 9.7% and 16.9% maximum voluntary contraction in MF electromyographic activity was observed in lumbar lordosis posture during the quadruped leg raise and quadruped leg-arm raise exercise, respectively (P < .01), when compared to the neutral posture. The increased recruitment of MF with lumbar lordosis in the quadruped position has strong implications in the assessment and management of patients with CLBP.
Angelica E. Lang, Soo Y. Kim, Stephan Milosavljevic and Clark R. Dickerson
Breast cancer survivors have known scapular kinematic alterations that may be related to the development of secondary morbidities. A measure of muscle activation would help understand the mechanisms behind potential harmful kinematics. The purpose of this study was to define muscle force strategies in breast cancer survivors. Shoulder muscle forces during 6 functional tasks were predicted for 25 breast cancer survivors (divided by impingement pain) and 25 controls using a modified Shoulder Loading Analysis Module. Maximum forces for each muscle were calculated, and 1-way analysis of variance (P < .05) was used to identify group differences. The differences between maximum predicted forces and maximum electromyography were compared with repeated-measures analysis of variance (P < .05) to evaluate the success of the model predictions. Average differences between force predictions and electromyography ranged from 7.3% to 31.6% but were within the range of previously accepted differences. Impingement related pain in breast cancer survivors is associated with increased force of select shoulder muscles. Both pectoralis major heads, upper trapezius, and supraspinatus peak forces were higher in the pain group across all tasks. These force prediction differences are also associated with potentially harmful kinematic strategies, providing a direction for possible rehabilitation strategies.
Justin A. Haegele, Chunxiao Li and Wesley J. Wilson
The purpose of this study was to examine the relationship between interpersonal/intrapersonal mindfulness, contact anxiety, and attitudes toward students with visual impairments among certified adapted physical educators. Participants included 115 certified adapted physical educators who completed a 31-item online survey, composed of a 10-item demographic questionnaire, a 14-item mindfulness in teaching scale, a four-item intergroup anxiety scale, and a three-item attitude scale. Hierarchical multiple regression analyses revealed that intrapersonal mindfulness was a negative predictor of contact anxiety (β = −0.26, p = .007) and contact anxiety negatively predicted attitudes (β = −0.22, p = .02). A mediation analysis revealed that intrapersonal mindfulness had an indirect effect on attitudes through contact anxiety, b = 0.09, SE = 0.05, 95% confidence interval [0.006, 0.22]. Collectively, both intrapersonal and interpersonal mindfulness appear to be responsible for the formation of attitudes, but with different underlying processes involved.
Rachel S. Johnson, Kendall H. Scott and Robert C. Lynall
Context: Gait termination time (GTT) has been used to predict falls in older adults but has not been explored in the sport rehabilitation setting. The incorporation of a concurrent cognitive task as a complex measure of gait in this clinical population could lead to better health-related outcomes. Objective: To compare the effect of planned and unplanned gait termination with and without a concurrent cognitive task on reaction time (RT), gait velocity, and GTT. Design: Cross-sectional. Setting: Laboratory. Participants: Twenty young adults (females 60.0%, age 20.1 [0.9] y, height 169.5 [8.8] cm, mass 67.4 [10.8] kg). Intervention: Participants completed 6 planned and 6 unplanned gait termination trials on an instrumented gait mat with and without a cognitive task. Main Outcome Measures: The authors measured RT (s), gait velocity (m/s), GTT (s), and normalized GTT (s2/m). A 2 (motor) × 2 (cognitive) repeated-measures analysis of variance (α = .05) was used; significant interaction effects were explored using Bonferroni-corrected t tests (α < .008). Results: Participants walked more slowly during dual-task trials compared with single-task trials (F 1,19 = 4.401, P = .050). Participants walked significantly more slowly with a cognitive task during planned (P < .001, mean difference = −0.184 m/s, 95% CI, −0.256 to −0.111) and unplanned (P = .001, mean difference = −0.111 m/s, 95% CI, −0.173 to −0.050) gait termination. Participants walked significantly more slowly (P < .001, mean difference = −0.142 m/s, 95% CI, −0.210 to −0.075) when performing the most difficult task, unplanned termination with a cognitive task, than when performing the least difficult task, planned termination with no cognitive task. We observed a cognitive task main effect such that adding a cognitive task increased RT (F 1,19 = 16.375, P = .001, mean difference = −0.118 s, 95% CI, −0.178 to −0.057) and slowed normalized GTT (F 1,19 = 5.655, P = .028, mean difference = −0.167 s2/m, 95% CI, −0.314 to −0.020). Conclusions: Overall, participants displayed more conservative gait strategies and slower RT, normalized GTT, and gait velocity as task difficulty increased. More investigation is needed to truly understand the clinical meaningfulness of these measures in athletic injuries.
Irineu Loturco, Michael R. McGuigan, Valter P. Reis, Sileno Santos, Javier Yanci, Lucas A. Pereira and Ciro Winckler
This study aimed to investigate the association between the optimum power load in the bench press (BP), shoulder press (SP), and prone bench pull (PBP) exercises and acceleration (ACC) and speed performances in 11 National Team wheelchair basketball (WB) players with similar levels of disability. All athletes were previously familiarized with the testing procedures that were performed on the same day during the competitive period of the season. First, athletes performed a wheelchair 20-m sprint assessment and, subsequently, a maximum power load test to determine the mean propulsive power (MPP) in the BP, SP, and PBP. A Pearson product–moment correlation was used to examine the relationships between sprint velocity (VEL), ACC, and the MPP in the three exercises. The significance level was set as p < .05. Large to very large significant associations were observed between VEL and ACC and the MPP in the BP, SP, and PBP exercises (r varying from .60 to .77; p < .05). The results reveal that WB players who produce more power in these three exercises are also able to accelerate faster and achieve higher speeds over short distances. Given the key importance of high and successive ACCs during wheelchair game-related maneuvers, it is recommended that coaches frequently assess the optimum power load in BP, SP, and PBP in WB players, even during their regular training sessions.
Erika M. Pliner, April A. Dukes, Kurt E. Beschorner and Arash Mahboobin
There is a need for pedagogical techniques that increase student engagement among underrepresented groups in engineering. Relating engineering content to student interests, particularly through biomechanics applications, shows promise toward engaging a diverse group of students. This study investigates the effects of student interests on engagement and performance in 10th grade students enrolled in a summer program for students underrepresented in the science, technology, engineering, and mathematics fields. The authors assessed the effects of interest-tailored lectures on student engagement and performance in a 5-week program with bioengineering workshops, focusing on the delivery of biomechanics content. A total of 31 students received interest-tailored lectures (intervention) and 23 students received only generic lectures (control) in biomechanics. In addition, the authors assessed the effects of teaching method (lecture, classroom activities, and laboratory tours) on student engagement. The authors found interest-tailored lectures to significantly increase student engagement in lecture compared with generic lectures. Students that received interest-tailored lectures had an insignificant, but meaningful 5% increase in student performance. Students rated laboratory tours higher in engagement than other teaching methods. This study provides detailed examples that can directly assist student teaching and outreach in biomechanics. Furthermore, the pedagogical techniques in this study can be used to increase engagement of underrepresented students in engineering.
Katelyn M. Nelson, Elizabeth H.K. Daidone, Katherine M. Breedlove, Debbie A. Bradney and Thomas G. Bowman
The study objective was to determine the magnitude and frequency of head impacts in NCAA Division III soccer athletes based on player position and type of play (offense, defense, transition). Across player position, male and female soccer defenders sustained the most head impacts (males IR = 18.89, 95% CI = 16.89–20.89; females IR = 8.45, 95% CI = 7.25–9.64; IRR = 2.23, 95% CI = 1.87–2.67). The study revealed a nonstatistically significant interaction between sex, player position, and type of play for both linear (p = .42) and rotational accelerations (p = .16). Defenders sustained the majority of the head impacts in the study sample, suggesting preventative initiatives should be focused on back row players.
Rafael Gnat, Agata Dziewońska, Maciej Biały and Martyna Wieczorek
Low back pain constitutes a multidimensional problem of largely unknown origin. One of the recent theories explaining its frequent occurrence includes speculative statements on patterns of central nervous system activity associated with the control of so-called local and global muscles of the lower trunk. The objective of the study was to verify whether there is a difference in the activity of the brain during selective, voluntary contraction of the local and global abdominal muscles as assessed by functional MRI. Twenty healthy subjects participated. An experimental design was applied with repeated measurements of the blood-oxygen-level–dependent signal from the brain during voluntary contraction of the local and global abdominal muscles, performed in random order. Prior to registration, a 2-week training period was introduced, aiming to master the experimental motor tasks. The magnetic resonance imaging (MRI) data were processed using the FMRIB Software Library (Oxford, UK). Brain areas showing significant activations/deactivations were identified and averaged across all participants, and intercondition differential maps were computed. Areas of significant intercondition differences were linked to the corresponding anatomical structures and ascribed to the default mode functional brain network and to the sensorimotor network. Contraction of the local abdominal muscles elicited more pronounced activity of the brain cortex, basal ganglia, and cerebellum. This suggests that motor control of the abdominal musculature consists of two modes of brain activity and that control of the local muscles may be a more challenging task for the brain. Moreover, contraction of the local muscles elicited more distinct deactivation of the default mode network, which may have implications for diagnostics and therapy of low back pain.
Adam E. Jagodinsky, Rebecca Angles, Christopher Wilburn and Wendi H. Weimar
Current theoretical models suggest that ankle sprain copers exhibit movement adaptations contributing to the avoidance of chronic ankle instability. However, few studies have examined adaptations at the level of biomechanical motor synergies. The purpose was to examine characteristics of the support moment synergy between individuals with chronic ankle instability, copers, and healthy individuals. A total of 48 individuals participated in the study. Lower-extremity kinetics and variability in the moment of force patterns were assessed during the stance phase of walking trials. The copers exhibited reductions in the support moment during the load response and preswing phase compared with the chronic ankle instability group, as well as during the terminal stance and preswing phase compared the healthy group. The copers also exhibited reductions in the hip extensor moment and ankle plantarflexion moment compared with healthy and chronic ankle instability groups during intervals of stance phase. Variability of the support moment and knee moment was greater in the copers compared with the chronic ankle instability group. Dampening of the support moment and select joint moments exhibited by the copers may indicate an adaptive mechanism to mitigate loading perturbations on the previously injured ankle. Heightened motor variability in copers may be indicative of a more adaptable motor synergy compared with individuals with chronic ankle instability.