Context: Lower-extremity landing mechanics have been implicated as a contributing factor in knee pain and injury, yet cost-effective and clinically accessible methods for evaluating movement mechanics are limited. The identification of valid, reliable, and readily accessible technology to assess lower-extremity alignment could be an important tool for clinicians, coaches, and strength and conditioning specialists. Objective: To examine the validity and reliability of using a handheld tablet and movement-analysis application (app) for assessing lower-extremity alignment during a drop vertical-jump task. Design: Concurrent validation. Setting: Laboratory. Participants: 22 healthy college-age subjects (11 women and 11 men, mean age 21 ± 1.4 y, mean height 1.73 ± 0.12 m, mean mass 71 ± 13 kg) with no lower-extremity pathology that prevented safe landing from a drop jump. Intervention: Subjects performed 6 drop vertical jumps that were recorded simultaneously using a 3-dimensional (3D) motion-capture system and a handheld tablet. Main Outcomes Measures: Angles on the tablet were calculated using a motion-analysis app and from the 3D motion-capture system using Visual 3D. Hip and knee angles were measured and compared between both systems. Results: Significant correlations between the tablet and 3D measures for select frontal- and sagittal-plane ranges of motion and angles at maximum knee flexion (MKF) ranged from r = .48 (P = .036) for frontal-plane knee angle at MKF to r = .77 (P < .001) for knee flexion at MKF. Conclusion: Results of this study suggest that a handheld tablet and app may be a reliable method for assessing select lower-extremity joint alignments during drop vertical jumps, but this technology should not be used to measure absolute joint angles. However, sports medicine specialists could use a handheld tablet to reliably record and evaluate lower-extremity movement patterns on the field or in the clinic.
Barbara C. Belyea, Ethan Lewis, Zachary Gabor, Jill Jackson and Deborah L. King
Johanna M. Hurtubise, Cheryl Beech and Alison Macpherson
There is a lack of research on sex differences for severe injuries across a variety of sports at the collegiate level.
To compare differences in injury severity and concussion between sexes and collegiate sports.
Descriptive epidemiological study.
1,657 injuries were analyzed from collegiate teams at York University.
Data Collection and Analysis:
Injuries were assessed by a certified or student athletic therapist and were categorized based on degree of tissue and/or joint damage as either severe or nonsevere. Severe injuries included those with third degree damage, while all others were classified as nonsevere. Injury severity was compared between the sexes and across different sports using Pearson chisquare analysis. Logistic regression was used to assess the relative contribution of each covariate.
Males sustained 1,155 injuries, with 13.3% of them being severe, while females sustained only 502 injuries, 17.7% of which were severe. The odds of sustaining severe injuries among female athletes are 1.4 times the odds of male athletes (OR: 1.40, CI 1.05−1.86). Eleven percent of all female injuries were concussions—significantly more than males (χ2 = 11.03, p = .001). The odds of female athletes having a concussion are 1.9 times the odds of a male athlete (OR: 1.85, CI 1.28−2.67).
Based on our analysis, females are at an increased risk of sustaining a severe injury, particularly concussions. These findings highlight the need for future research into sex and sport-specific risk factors. This may provide information for health care professionals, coaches, and athletes for the proper prevention, on-field care, and treatment of sport injuries.
Klaus Schneider and Ronald F. Zernicke
With a validated mathematical model of the head-neck consisting of nine rigid bodies (skull, seven cervical vertebrae, and torso), we simulated head impacts to estimate the injury risk associated with soccer heading. Experimental data from head-linear accelerations during soccer heading were used to validate the nine-body head-neck model for short duration impact loading of the head. In the computer simulations, the mass ratios between head mass and impacting body mass, the velocity of the impacting body, and the impact elasticity were varied. Head-linear and angular accelerations were compared to standard head-injury tolerance levels, and the injury risk specifically related to soccer heading was estimated. Based on our choice of tolerance levels in general, our simulations showed that injury risk from angular head accelerations was greater than from linear head accelerations, and compared to frontal impacts, lateral impacts had greater angular and less linear head accelerations. During soccer heading, our simulations indicated an unacceptable injury risk caused by angular head accelerations for frontal and lateral impacts at relatively low impact velocities for children, and at medium range impact velocities for adults. For linear head accelerations, injury risk existed for frontal and lateral impacts at medium range to relatively larger impact velocities for children, while no injury risk was shown for adults throughout the entire velocity range. For injury prevention, we suggest that head-injury risk can be reduced most substantially by increasing the mass ratio between head and impacting body. In soccer with children, the mass of the impacting body has to be adjusted to the reduced head mass of a child, that is, it must be clearly communicated to parents, coaches, and youngsters to only use smaller soccer balls.
Monna Arvinen-Barrow, Damien Clement, Jennifer J. Hamson-Utley, Rebecca A. Zakrajsek, Sae-Mi Lee, Cindra Kamphoff, Taru Lintunen, Brian Hemmings and Scott B. Martin
Existing theoretical frameworks and empirical research support the applicability and usefulness of integrating mental skills throughout sport injury rehabilitation.
To determine what, if any, mental skills athletes use during injury rehabilitation, and by who these skills were taught. Cross-cultural differences were also examined.
College athletes from 5 universities in the United States and a mixture of collegiate, professional, and recreational club athletes from the United Kingdom and Finland were recruited for this study.
A total of 1283 athletes from the United States, United Kingdom, and Finland, who participated in diverse sports at varying competitive levels took part in this study.
Main Outcome Measures:
As part of a larger study on athletes’ expectations of injury rehabilitation, participants were asked a series of open-ended and closed-ended questions concerning their use of mental skills during injury rehabilitation.
Over half (64.0%) of the sample reported previous experience with athletic training, while 27.0% indicated that they used mental skills during injury rehabilitation. The top 3 mental skills reported were goal setting, positive self-talk/positive thoughts, and imagery. Of those athletes that used mental skills, 71.6% indicated that they felt mental skills helped them to rehabilitate faster. A greater proportion of athletes from the United States (33.4%) reported that they used mental skills during rehabilitation compared with athletes from the United Kingdom (23.4%) and Finland (20.3%). A small portion (27.6%) of the participants indicated that their sports medicine professional had taught them how to use mental skills; only 3% were taught mental skills by a sport psychologist.
The low number of athletes who reported using mental skills during rehabilitation is discouraging, but not surprising given research findings that mental skills are underutilized by injured athletes in the 3 countries examined. More effort should be focused on educating and training athletes, coaches, and sports medicine professionals on the effectiveness of mental training in the injury rehabilitation context.
Jamie R. Skaggs, Elizabeth R. A. LaGuardia Joiner, Milo Sini, Tishya A.L. Wren, Regina P. Woon and David L. Skaggs
A commonly encountered clinical scenario in athletic training is determining what body position is best for pulmonary recovery after strenuous training. Coaches often advise athletes to put their hands behind their heads following rigorous training, but this practice has no scientific support.
The purpose of this study is to determine how arm and body position affects ventilation in high school athletes. Our hypothesis is that a position in which the athlete is bent forward with the hands on the knees maximizes ventilation.
Seventeen healthy members of a high school track team, 8 females and 9 males with a mean age of 16.3 years (range: 14.6–18.5 years), performed a maximal voluntary ventilation (MVV) test using a portable spirometer in three different positions: standing with (1) hands behind the head, (2) arms at the sides, and (3) leaning forward with hands resting on the knees.
The MVV performed with hands on knees (120.2 ± 5.9 L/min) was significantly higher than the MVV performed with hands at sides (109.3 ± 7.0 L/min; p = .004) and with hands behind head (114.1 ± 5.9 L/min; p = .03). The MVV performed with hands behind head and with arms at side did not differ significantly (p = .20).
This is the first study examining the best body position to maximize ventilation in athletes. Leaning forward and placing the hands on the knees led to a significantly greater MVV compared with standing with the arms at the side and standing with the hands behind the head.
Megan D. Granquist, Leslie Podlog, Joanna R. Engel and Aubrey Newland
Adherence to sport-injury rehabilitation protocols may be pivotal in ensuring successful rehabilitation and return-to-play outcomes.
To investigate athletic trainers' perspectives related to the degree to which rehabilitation adherence is an issue in collegiate athletic training settings, gain insight from certified athletic trainers regarding the factors contributing to rehabilitation nonadherence (underadherence and overadherence), and ascertain views on the most effective means for promoting adherence.
Crosssectional, mixed methods.
Collegiate athletic training in the United States.
Certified athletic trainers (n = 479; 234 male, 245 female).
Main Outcome Measures:
Online survey consisting of 3 questions regarding rehabilitation adherence, each followed by an open-ended comments section. Descriptive statistics were calculated for quantitative items; hierarchical content analyses were conducted for qualitative items.
Most (98.3%) participants reported poor rehabilitation adherence to be a problem (1.7% = no problem, 29.2% = minor problem, 49.7% = problem, 19.4% = major problem), while most (98.96%) participants reported that they had athletes who exhibited poor rehabilitation adherence (1% = never, 71.4% = occasionally, 22.5% = often, 5% = always). In addition, the majority (97.91%) of participants reported that overadherence (eg, doing too much, failing to comply with activity restrictions, etc) was at least an occasional occurrence (2.1% = never, 69.3% = occasionally, 26.3% = often, 1.9% = always). Hierarchical content analyses regarding the constructs of poor adherence and overadherence revealed 4 major themes: the motivation to adhere, the development of good athletic trainer–athlete rapport and effective communication, athletic trainers' perception of the coaches' role in fostering adherence, and the influence of injury- or individual- (eg, injury severity, sport type, gender) specific characteristics on rehabilitation adherence.
These results suggest that participants believe that underadherence (and to a lesser extent overadherence) is a frequent occurrence in collegiate athletic training settings. Strategies for enhancing rehabilitation adherence rates and preventing overadherence may therefore be important for optimizing rehabilitation outcomes.
David F. Stodden, Glenn S. Fleisig, Scott P. McLean, Stephen L. Lyman and James R. Andrews
Generating consistent maximum ball velocity is an important factor for a baseball pitcher’s success. While previous investigations have focused on the role of the upper and lower extremities, little attention has been given to the trunk. In this study it was hypothesized that variations in pelvis and upper torso kinematics within individual pitchers would be significantly associated with variations in pitched ball velocity. Nineteen elite baseball pitchers were analyzed using 3-D high-speed motion analysis. For inclusion in this study, each pitcher demonstrated a variation in ball velocity of at least 1.8 m/s (range: 1.8–3.5 m/s) during his 10 fastball pitch trials. A mixed-model analysis was used to determine the relationship between 12 pelvis and upper torso kinematic variables and pitched ball velocity. Results indicated that five variables were associated with variations in ball velocity within individual pitchers: pelvis orientation at maximum external rotation of the throwing shoulder (p = .026), pelvis orientation at ball release (p = .044), upper torso orientation at maximum external rotation of the throwing shoulder (p = .007), average pelvis velocity during arm cocking (p = .024), and average upper torso velocity during arm acceleration (p = .035). As ball velocity increased, pitchers showed an increase in pelvis orientation and upper torso orientation at the instant of maximal external rotation of the throwing shoulder. In addition, average pelvis velocity during arm cocking and average upper torso velocity during arm acceleration increased as ball velocity increased. From a practical perspective, the athlete should be coached to strive for proper trunk rotation during arm cocking as well as strength and flexibility in order to generate angular velocity within the trunk for maximum ball velocity.
Inne Aerts, Elke Cumps, Evert Verhagen, Bram Wuyts, Sam Van De Gucht and Romain Meeusen
In jump-landing sports, the injury mechanism that most frequently results in an injury is the jump-landing movement. Influencing the movement patterns and biomechanical predisposing factors are supposed to decrease injury occurrence.
To evaluate the influence of a 3-mo coach-supervised jump-landing prevention program on jump-landing technique using the jump-landing scoring (JLS) system.
Randomized controlled trial.
116 athletes age 15–41 y, with 63 athletes in the control group and 53 athletes in the intervention group. Intervention: The intervention program in this randomized control trial was administered at the start of the basketball season 2010–11. The jump-landing training program, supervised by the athletic trainers, was performed for a period of 3 mo.
Main Outcome Measures:
The jump-landing technique was determined by registering the jump-landing technique of all athletes with the JLS system, pre- and postintervention.
After the prevention program, the athletes of the male and female intervention groups landed with a significantly less erect position than those in the control groups (P < .05). This was presented by a significant improvement in maximal hip flexion, maximal knee flexion, hip active range of motion, and knee active range of motion. Another important finding was that postintervention, knee valgus during landing diminished significantly (P < .05) in the female intervention group compared with their control group. Furthermore, the male intervention group significantly improved (P < .05) the scores of the JLS system from pre- to postintervention.
Malalignments such as valgus position and insufficient knee flexion and hip flexion, previously identified as possible risk factors for lower-extremity injuries, improved significantly after the completion of the prevention program. The JLS system can help in identifying these malalignments.
Level of Evidence:
Therapy, prevention, level 1b.
Jay Johnson, Michelle D. Guerrero, Margery Holman, Jessica W. Chin and Mary Anne Signer-Kroeker
sent via emails to the athletic directors of each institution. Following this, members of the research team sent emails to the head coaches of sport teams across Canada, which were then forwarded to each athlete by the head coaches. The emails sent to each athlete contained a link to the anonymous
Hannah Butler-Coyne, Vaithehy Shanmuganathan-Felton and Jamie Taylor
sports initiated a number of changes ranging from 24 hour telephone helplines for athletes, increased access to counseling and mental health support services for players/athletes, specific mental health training for staff and training inclusion within coaching qualifications ( Mind, 2014 ). Although a