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.
Alejandro Pérez-Castilla, Ainara Jiménez-Alonso, Mar Cepero, Sergio Miras-Moreno, F. Javier Rojas and Amador García-Ramos
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.
Daniel Viggiani, Erin M. Mannen, Erika Nelson-Wong, Alexander Wong, Gary Ghiselli, Kevin B. Shelburne, Bradley S. Davidson and Jack P. Callaghan
People developing transient low back pain during standing have altered control of their spine and hips during standing tasks, but the transfer of these responses to other tasks has not been assessed. This study used video fluoroscopy to assess lumbar spine intervertebral kinematics of people who do and do not develop standing-induced low back pain during a seated chair-tilting task. A total of 9 females and 8 males were categorized as pain developers (5 females and 3 males) or nonpain developers (4 females and 5 males) using a 2-hour standing exposure; pain developers reported transient low back pain and nonpain developers did not. Participants were imaged with sagittal plane fluoroscopy at 25 Hz while cyclically tilting their pelvises anteriorly and posteriorly on an unstable chair. Intervertebral angles, relative contributions, and anterior–posterior translations were measured for the L3/L4, L4/L5, and L5/S1 joints and compared between sexes, pain groups, joints, and tilting directions. Female pain developers experienced more extension in their L5/S1 joints in both tilting directions compared with female nonpain developers, a finding not present in males. The specificity in intervertebral kinematics to sex-pain group combinations suggests that these subgroups of pain developers and nonpain developers may implement different control strategies.
Byungmo Ku, Megan MacDonald, Bridget Hatfield and Kathy Gunter
The purpose of this study was to test a modified conceptual model of the associations between parental supports and physical activity (PA) orientations and the PA behaviors of young children with developmental disabilities (DDs). In total, 135 parents of young children with DDs completed a questionnaire, which consisted of 67 questions. A pathway analysis indicated that tangible and intangible parental supports were significantly associated with PA behaviors in young children with DDs (β = 0.26, p = .01, and β = 0.24, p = .02, respectively). Tangible parental support was positively associated with parents’ PA behaviors and PA enjoyment (β = 0.22, p < .001, and β = 0.13, p = .04, respectively). Intangible parental support was positively associated with parents’ PA behaviors and PA importance (β = 0.19, p = .05, and β = 0.33, p < .001, respectively). In addition, parental PA behaviors and parents’ perceptions of their children’s motor performance were both directly associated with PA behaviors in young children with DDs. These results highlight the importance of parental support and PA orientations in relation to the PA behaviors of young children with DDs.
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
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.
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.