flexibility. This study was set up to examine how movement variability changes in healthy participants during sustained bimanual reaching under controlled precision conditions, in particular with regard to movement time (MT), end-point variability, approximate entropy (ApEn), and standard deviation (SD) of
Alessia Longo and Ruud Meulenbroek
Trampas M. TenBroek, Pedro A. Rodrigues, Edward C. Frederick and Joseph Hamill
The purpose of this study was to: (1) investigate how kinematic patterns are adjusted while running in footwear with THIN, MEDIUM, and THICK midsole thicknesses and (2) determine if these patterns are adjusted over time during a sustained run in footwear of different thicknesses. Ten male heel-toe runners performed treadmill runs in specially constructed footwear (THIN, MEDIUM, and THICK midsoles) on separate days. Standard lower extremity kinematics and acceleration at the tibia and head were captured. Time epochs were created using data from every 5 minutes of the run. Repeated-measures ANOVA was used (P < .05) to determine differences across footwear and time. At touchdown, kinematics were similar for the THIN and MEDIUM conditions distal to the knee, whereas only the THIN condition was isolated above the knee. No runners displayed midfoot or forefoot strike patterns in any condition. Peak accelerations were slightly increased with THIN and MEDIUM footwear as was eversion, as well as tibial and thigh internal rotation. It appears that participants may have been anticipating, very early in their run, a suitable kinematic pattern based on both the length of the run and the footwear condition.
Teri Todd, Greg Reid and Lynn Butler-Kisber
Individuals with autism often lack motivation to engage in sustained physical activity. Three adolescents with severe autism participated in a 16-week program and each regularly completed 30 min of cycling at the end of program. This study investigated the effect of a self-regulation instructional strategy on sustained cycling, which included self-monitoring, goal setting, and self-reinforcement. Of particular interest was the development of self-efficacy during the physical activity as a mediator of goal setting. A multiple baseline changing criterion design established the effectiveness of the intervention. The results suggest that self-regulation interventions can promote sustained participation in physical activity for adolescents with severe autism.
Takeshi Hirano, Kazutoshi Kudo, Tatsuyuki Ohtsuki and Hiroshi Kinoshita
This study investigated activity of the embouchure-related orofacial muscles during pre- and postattack phases of sound production by 10 trained French-horn players. Surface electromyogram (EMG) from five selected facial muscles, and related facial skin kinematics were examined in relation to pitch and intensity of a tone produced. No difference in EMGs and facial kinematics between the two phases was found, indicating importance of appropriate formation of preattack embouchure. EMGs in all muscles during the postattack phase increased linearly with an increase in pitch, and they also increased with tone intensity without interacting with the pitch effect. Orofacial skin movement remained constant across all pitches and intensities except for lateral retraction of the lips during high-pitch tone production. Contraction of the orofacial muscles is fundamentally isometric by which tension on the lips and the cheeks is regulated for flexible sound parameter control.
Srinidhi Bellamkonda, Samantha J. Woodward, Eamon Campolettano, Ryan Gellner, Mireille E. Kelley, Derek A. Jones, Amaris Genemaras, Jonathan G. Beckwith, Richard M. Greenwald, Arthur C. Maerlender, Steven Rowson, Stefan M. Duma, Jillian E. Urban, Joel D. Stitzel and Joseph J. Crisco
understand the trends at the youth level and to gauge the cumulative effect of the head impacts that the players sustain throughout their career. Recent studies have compared head impact exposure of practice and game sessions, 13 , 21 , 22 citing specific drills as having the highest rate of high
Eric Foch and Clare E. Milner
The accessibility of running makes it a common exercise choice for individuals looking to improve their overall health. However, the likelihood that a runner will develop an overuse injury is high. Prospective studies indicate that 47% to 52% of recreational runners sustained an overuse injury that
Deborah A.M. Jehu, Nicole Paquet and Yves Lajoie
) possible improvements in obstacle clearance parameters and RT would be sustained at the 12-week follow-up in both training groups because previous work has also observed maintained improvements ( Lim & Yoon, 2014b ; Marusic et al., 2016 ). Methods Participants In total, 76 older adults were evaluated for eligibility
John Strickland and Grant Bevill
tested with replication because it sustained extensive damage during several impact conditions and went out of production after this was discovered. The total of number tests conducted was 176. Table 1 Description of Protective Headgear Used for Softball Impact Testing Type Brand Model Size NOCSAE
Joseph J. Crisco, Bethany J. Wilcox, Jason T. Machan, Thomas W. McAllister, Ann-Christine Duhaime, Stefan M. Duma, Steven Rowson, Jonathan G. Beckwith, Jeffrey J. Chu and Richard M. Greenwald
The purpose of this study was to quantify the severity of head impacts sustained by individual collegiate football players and to investigate differences between impacts sustained during practice and game sessions, as well as by player position and impact location. Head impacts (N = 184,358) were analyzed for 254 collegiate players at three collegiate institutions. In practice, the 50th and 95th percentile values for individual players were 20.0 g and 49.5 g for peak linear acceleration, 1187 rad/s2 and 3147 rad/s2 for peak rotational acceleration, and 13.4 and 29.9 for HITsp, respectively. Only the 95th percentile HITsp increased significantly in games compared with practices (8.4%, p = .0002). Player position and impact location were the largest factors associated with differences in head impacts. Running backs consistently sustained the greatest impact magnitudes. Peak linear accelerations were greatest for impacts to the top of the helmet, whereas rotational accelerations were greatest for impacts to the front and back. The findings of this study provide essential data for future investigations that aim to establish the correlations between head impact exposure, acute brain injury, and long-term cognitive deficits.
Shane R. Wurdeman, Jessie M. Huisinga, Mary Filipi and Nicholas Stergiou
Patients with multiple sclerosis (MS) have less-coordinated movements of the center of mass resulting in greater mechanical work. The purpose of this study was to quantify the work performed on the body’s center of mass by patients with MS. It was hypothesized that patients with MS would perform greater negative work during initial double support and less positive work in terminal double support. Results revealed that patients with MS perform less negative work in single support and early terminal double support and less positive work in the terminal double support period. However, summed over the entire stance phase, patients with MS and healthy controls performed similar amounts of positive and negative work on the body’s center of mass. The altered work throughout different periods in the stance phase may be indicative of a failure to capitalize on passive elastic energy mechanisms and increased reliance upon more active work generation to sustain gait.