Mild head injury (MHI) represents one of the most challenging neurological pathologies occurring during athletic participation. Athletic trainers and sports medicine personnel are often faced with decisions about the severity of head injury and the timing of an athlete's return to play following MHI. Returning an athlete to competition following MHI too early can be a catastrophic mistake. This case study involves a 20-year-old collegiate football player who sustained three mild head injuries during one season. The case study demonstrates how objective measures of balance and cognition can be used when making decisions about returning an athlete to play following MHI. These measures can be used to supplement the subjective guidelines proposed by many physicians.
Bryan L. Riemann and Kevin M. Guskiewicz
Michael J. Axe, Katherine Linsay and Lynn Snyder-Mackler
The purpose of this study was to determine whether there was a relationship between knee hyperextension and intra-articular pathology in 100 consecutive patients whose sole ligament injury was an arthroscopically confirmed anterior cruciate ligament (ACL) rupture. Hyperextension of both knees was measured using a supine heel-height measurement of high reliability. There was more articular damage to the total joint, lateral joint, and lateral meniscus in patients who hyperextended than in those who did not. There was more articular damage to the total joint and medial joint in patients who were chronically ACL deficient than in those who were acutely or subacutely ACL deficient. The results demonstrate that individuals with ACL injuries whose knees hyperextend 3 cm or more sustain significantly more joint damage at the time of injury than in those whose knees hyperextend less than 3 cm. This study further defines the role of knee hyperextension in ACL injuries and offers a useful and reliable means of measuring knee hyperextension.
Liria Akie Okai and André Fabio Kohn
Surprisingly little attention has been devoted to the role played by the intrinsic muscles of the human foot. The aim of this study was to quantify the capabilities of the flexor digitorum brevis (FDB) muscle to contribute to upright postural control. The approaches consisted of analysis of the effects of FDB contraction elicited by external electrical stimulation and quantification of the magnitude of FDB torque generation. The results showed the FDB can produce significant changes in static posture by itself as shown by changes in the center of pressure. Moreover, the FDB contribution to counterbalance the gravity’s toppling force was estimated at around 14.5% of the total required active torque at the ankle to keep the subject from falling. A posteriori functional analysis during horizontal perturbations showed high and self-sustained activity of FDB. These results demonstrated that the FDB has a significant capability of contributing to postural control.
Dobromir G. Dotov and Till D. Frank
A novel method for the analysis of repetitive limb behavior oscillation is presented. It is based on a model used to account for self-sustained limit cycles that involve energy pumping compensating for dissipative processes. The experiment involved a uni-manual pendulum swinging task paced at five frequencies. The median frequency corresponded to the resonant one for the chosen pendulum and hand parameters. We applied the model-based analysis to explore the relationship between behavioral observables and model parameters not available from previous methods. Oscillation amplitude and energy, and motor variability were the behavioral observables we focused on while energy pumping, attractor strength, and noise amplitude were the model parameters. As expected, energy pumping was found to increase with pacing frequency. Noise amplitude did not change and stability decreased.
Gretchen A. Schlabach
The profession of athletic training has not identified and explicitly articulated shared professional values (PV). Shared PV are the seeds of professionalism, and deeply rooted motivators of professional action which support the social contract through self-regulation. The purpose of this exploratory study was to: (1) discover shared PV in athletic training, (2) examine how important PV are to the National Athletic Trainers’ Association (NATA) membership, and (3) how important is it for our association to explicitly articulate professional values. This study found that truth/honesty, integrity, and respect are significant athletic training PV. PV are important (96.8%), and it is important for the association to explicitly articulate PV (96.5%). The declaration of shared PV will promote values-based behaviors and internally motivate a duty to uphold the legal, ethical, and regulatory standards of the profession. Dedication to our professional responsibilities will sustain the social contract and encourage public trust.
William A. Sparrow, Rezaul K. Begg and Suzanne Parker
Visual reaction time (RT) was measured in 10 older men (mean age, 71.1 years) and gender-matched controls (mean age, 26.3 years) when standing (single task) and when walking on a motor-driven treadmill (dual task). There were 90 quasirandomly presented trials over 15 min in each condition. Longer mean and median RTs were observed in the dual task compared to the single task. Older males had significantly slower mean and median RTs (315 and 304 ms, respectively) than the younger group (273 and 266 ms, respectively) in both task conditions. There were no age or condition effects on within-subject variability. Both groups showed a trend of increasing RT over the 90 single task trials but when walking only the younger group slowed. These novel findings demonstrate high but sustained attention by older adults when walking. It is proposed that the motor task’s attentional demands might contribute to their slower preferred walking speed.
Michael Ra, Michael Sitler, Jeff Ryan, Raymond Moyer, Paul Marchetto, John Kelly and Iris Kimura
Chondral lesions often occur in the knee as isolated defects or part of more complex injuries. Articular cartilage defects decrease the ability of the knee to sustain weight-bearing loads and may accelerate degeneration of the joint when left untreated. The purpose of this study was to determine the clinical, functional, and radiographic outcome of arthroscopic abrasion chondroplasty of the knee. The Articular Cartilage Rating System was used to assess the location, size, depth, and description of the articular lesion. The Standard Knee Evaluation Form and Cincinnati Knee Rating Scale were used to assess the clinical, functional, and radiographic outcome of the procedure. Average time to postsurgery follow-up was 46 ± 26.69 months. Within the constraints of the present study, arthroscopic abrasion chondroplasty of the knee had a favorable clinical, functional, and radiographic outcome. However, more study is needed with larger samples and longer follow-up before definitive conclusions about the efficacy of the procedure can be made.
Emmanuel Jacobs, Nathalie Roussel, Ine Van Caekenberghe, Edith Cassiers, Luc Van den Dries, Jonas Rutgeerts, Jan Gielen and Ann Hallemans
This cross-sectional study aimed at developing a biomechanical method to objectify voluntary and unpredictable movements, using an automated three-dimensional motion capture system and surface electromyography. Fourteen experienced theater performers were tested while executing the old man exercise, wherein they have to walk like an old man, building up a sustained high intensive muscular activity and tremor. Less experienced performed showed a different kinematics of movement, a slower speed of progression and more variable EMG signals at higher intensity. Female performers also differed from males in movement kinematics and muscular activity. The number of the trial only influenced the speed of progression. The performers showed results which could be well placed within the stages of learning and the degrees of freedom problem.
Lynne H. Johnston and Douglas Carroll
To examine the coping strategies used after injury and the provision of and satisfaction with social support as functions of sport involvement and stage of rehabilitation.
Complete data were available at 3 points (beginning, middle, and end of formal rehabilitation) for 93 patients, all of whom had sustained injury restricting normal functioning for at least 21 days.
Coping varied as a function of stage in rehabilitation, with patients deploying all strategies more at the beginning of rehabilitation. There was little variation in coping and social support, although those more involved in sport adopted a support-seeking coping strategy to a greater extent. Irrespective of sports-involvement status, women were more satisfied with practical and emotional support. Those who were more involved in sport were judged by their physiotherapists to be better adherents. Adoption of an emotional discharge coping strategy was negatively associated with adherence throughout rehabilitation.
Daniel S. Moran, Tomer Erlich and Yoram Epstein
Individuals in the population who are not able to sustain heat and whose body temperature will start rising earlier and at a higher rate than that of others, under the same conditions, are defined as “heat intolerant.”
The applicability of the heat tolerance test (HTT) in identifying individuals’ tolerance/intolerance to heat is presented.
HTT is performed according to the following protocol: 120 minutes exposure to 40°C and 40% relative humidity in a climatic chamber while walking on a treadmill, dressed in shorts and T-shirt, at a pace of 5 km/h and 2% elevation. Rectal temperature and heart rate are continuously monitored, and sweat rate is calculated.
Results and Conclusion:
The HTT that is based on controlled exposure to an exercise-heat stress is an applicable and an efficient tool in differentiating between a temporary and permanent state of heat susceptibility.