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Women’s College Volleyball Players Exhibit Asymmetries During Double-Leg Jump Landing Tasks

Jeffrey B. Taylor, Anh-Dung Nguyen, Audrey E. Westbrook, Abigail Trzeciak, and Kevin R. Ford

Context: Women’s volleyball requires frequent and repetitive jumping that when performed with altered biomechanics, including kinematic or kinetic asymmetry, may place the athlete at high risk for injury. This study identified and analyzed lower-extremity biomechanical asymmetries in college women’s volleyball players during standard and sport-specific double-leg landing tasks. Design: Cross-sectional laboratory study. Methods: Eighteen female college volleyball players were analyzed using standard 3D motion capture techniques during a drop vertical jump and an unanticipated lateral reactive jump task. Repeated-measures multivariate analysis of variance identified asymmetries in kinematic and kinetic variables of each task. Results: Average symmetry indices ranged from 9.3% to 31.3% during the drop vertical jump and 11.9% to 25.6% during the reactive jump task. During the drop vertical jump, the dominant limb exhibited lower knee abduction moments (P = .03), ankle dorsiflexion moments (P = .02), ankle eversion moments (P = .003) and vertical ground reaction forces (P = .03), and greater ankle inversion moments (P = .001). Both kinematic (λ = 0.27, P = .03) and kinetic (λ = 0.12, P = .008) asymmetries were identified during the reactive jump task. The dominant limb exhibited greater peak knee flexion (P = .003) and ankle dorsiflexion (P = .02) angles, and greater ankle dorsiflexion (P = .005) and inversion (P = .03) moments than the nondominant limb. Conclusions: These asymmetries observed during double-leg landing tasks may predispose volleyball athletes to unilaterally higher ground reaction or muscle forces and ultimately a greater risk of injury during landing.

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Erratum. The Single Hop for Distance Test: Reviewing the Methodology to Measure Maximum and Repeated Performance

Human Kinetics, Inc.

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Association Between Knee Extension Strength at 3 and 6 Months After Anterior Cruciate Ligament Reconstruction

Sho Mitomo, Junya Aizawa, Kenji Hirohata, Shunsuke Ohji, Takehiro Ohmi, Toshiyuki Ohara, Hideyuki Koga, and Kazuyoshi Yagishita

Context: Deficits in knee extension strength after anterior cruciate ligament reconstruction have been a major problem. The inadequate recovery of the knee extension strength of surgical limb reportedly delays return to sports and increases reinjury risk. Accordingly, the early detection of knee extension strength deficits after reconstruction may help plan early interventions to manage impairment. This study aimed to clarify the association between knee extension strength at 3 and 6 months after anterior cruciate ligament reconstruction. Design: Retrospective study. Methods: Fifty patients who underwent primary anterior cruciate ligament reconstruction using hamstring grafts were included. At 3 months postoperatively, the limb symmetry index (LSI) of isokinetic knee extension strength (IKE) at 60°/s, degree of swelling, passive range of motion of knee flexion and extension, and anterior leg reach distance were measured. At 6 months postoperatively, the LSI of IKE was measured at 60°/s, which was used as the main outcome. A correlation analysis was performed with the LSI of IKE at 6 months postoperatively as the dependent variable and the LSI of IKE at 3 months postoperatively as the independent variable. Subsequently, a multiple regression analysis was performed, with LSI of IKE at 6 months postoperatively as the dependent variable; LSI of IKE at 3 months postoperatively as the independent variable; and other variables, demographic information, and surgical data as covariates. Results: The correlation analysis revealed that the LSIs of IKE at 3 and 6 months postoperatively were correlated (r = .535, P < .001). In the multiple regression analysis, the LSI of IKE at 3 months postoperatively was significantly associated with that at 6 months postoperatively, even when other variables were included as covariates (R 2 = .349, P = .004). Conclusion: Asymmetry of knee extension strength at 3 months postoperatively could be more useful than other variables related to knee strength in predicting the asymmetry of knee extension strength at 6 months postoperatively.

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Patients Experience Significant and Meaningful Changes in Self-Report of Function During the First 2 Weeks After an Ankle Sprain Injury: A Report From the Athletic Training Practice-Based Research Network

Kenneth C. Lam, Ashley N. Marshall, Brandon Holland, R. Curtis Bay, Erik A. Wikstrom, and Alison R. Snyder Valier

Context: Ankle sprains are common during sport participation and associated with long-term deficits in self-report of function. However, little is known of short-term changes in self-report of function following injury. The authors aimed to assess statistical and clinically meaningful changes in self-report of function, as measured by the Foot and Ankle Ability Measure (FAAM), during the first 2 weeks after an ankle sprain injury. Design: A retrospective analysis of electronic medical records. Methods: Eighty-eight patients, who were diagnosed with an ankle sprain injury by an athletic trainer, received usual care from an athletic trainer, and completed the FAAM during treatment at weeks 1 and 2 postinjury. The authors calculated the percentage of patients who reported clinically meaningful changes and used Wilcoxon signed-rank tests to compare differences in FAAM scores between time points. Results: Between weeks 1 and 2, significant differences were noted for the FAAM Activities of Daily Living (FAAM-ADL) (P < .001) and FAAM Sport (FAAM-Sport) (P < .001). At the patient level, 86.5% (64/74) and 85.2% (69/81) of patients reported changes that exceeded the minimal clinically important difference value for the FAAM-ADL and FAAM-Sport, respectively, between weeks 1 and 2. At week 2, 31.8% (28/88) and 47.7% (42/88) of patients reported a score below 90% on the FAAM-ADL and below 80% on the FAAM-Sport subscale, respectively. Also, 36.4% (32/88) and 25.0% (22/88) of patients reported a score of 100% on the FAAM-ADL and FAAM-Sport subscales, respectively, at week 2. Conclusions: Patients report statistically significant and meaningful improvements in self-report of function during the first 2 weeks following ankle sprain injury. However, almost half of patients still report deficits in sport function at 2 weeks postinjury. Patient-reported outcome measures such as the FAAM, can help capture the patient’s perception of function and inform patient care decisions. Research efforts should explore individual response patterns to treatment.

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Quadriceps Function and Athletic Performance in Highly Trained Female Athletes

Frederick J. Henderson, Wakana Sasakabe, Kuwano Satoshi, Norihiro Shima, and Yohei Shimokochi

Context: Quadriceps strength is considered a key contributor to performance in various athletic tasks. Yet, past research has reported conflicting results based on population, with little data available in highly trained female athletes. Design: Cross-sectional. Method: To examine how athletic performance relates to quadriceps strength and neural function, we measured the quadriceps maximum voluntary isometric contraction force (MVIC) and rate of force development over 0 to 50 ms (rate of force development [RFD]0−50ms), and various performance measures in 34 highly trained female athletes. Results: Stepwise multiple regression analysis revealed that the quadriceps variables explained 16 of 21 performance variables (R 2 = .08–.36, P ≤ .10). Squat performance related to RFD0−50ms alone (R 2 = .17–.20, P < .05; β RFD = 0.41 to 0.45, P < .05) but only MVIC explained the variance in sprinting and vertical jump performance (R 2 = .08–.34, P ≤ .10; β MVIC = −0.51 to 0.58, P ≤ .10). The broad jump model included both parameters and their interaction (R 2 = .20, P = .08; β RFD = 0.06, P = .76; β MVIC = −0.39, P = .03; β RFD×MVIC = −0.24, P = .10). Conclusion: The contribution of the quadriceps MVIC or RFD0–50ms varies in size and nature depending on the task or leg dominance. While quadriceps are significant contributors to performance, because our models leave most of the variance in performance unexplained, rehabilitation and performance professionals should refrain from interpreting peak athletic performance as a reflection of knee-extensors function in highly trained female athletes.

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Volume 31 (2022): Issue 6 (Aug 2022): Special Section: Arthrogenic Muscle Inhibition

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Does an Adjusted Kinematic Model Predict the Relative Eccentric Force During Nordic Curl?

Maressa da Rocha, Maria de C. Macedo, Geyson de L. Batista, Viviane Moura, Kariny R. Ferreira, Michelle A. Barbosa, and Alexandre C. Barbosa

This study aimed to assess the combination of video-based kinematic variables adjusted by intrinsic covariates to predict the relative eccentric force (RelF) during the Nordic curl. The participants (n = 21) performed Nordic curls (3 trials; 3-min rest) on a device measuring the eccentric force. The peaks were normalized by body weight. Kinovea software was used to track angular and linear velocity and acceleration from recorded videos. Two prediction models with multiple linear regression equations associated kinematic, anthropometric, and age variables to adjust the actual RelF. The equations obtained the predicted RelF. The actual RelF was inversely correlated with height (r = −.52), tangential (r = −.50) and centripetal accelerations (r = −.715), and angular velocity (r = −.70). The best prediction models combined angular velocity with age (F 2,18 = 15.1, P = .001, r = .792, r 2 = .627) and with height (F 2,18 = 14.5, P = .001, r = .785, r 2 = .616). No differences were observed between actual and predicted values (P = .993−.994), with good levels of agreement and consistency (intraclass correlation coefficient = .77−.78; Cronbach α = .86−.87). Bland–Altman results showed high levels of agreement and low biases. The standard error of measurement and minimal detectable change ranges were 0.46 to 0.49 N/kg and 1.28 to 1.36 N/kg, respectively. Also, the percentage of standard error of measurement was below 10% (7.92%–8.35%). The coefficient of variation analysis returned a 14.54% and 15.13% for each model, respectively. Kinematic analysis offers portability and low cost to current expensive or technical impaired dynamometry-based techniques to assess the RelF.

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Angle-Specific Isokinetic Shoulder Rotational Strength Can be Reliably Assessed in Collision and Contact Athletes

Edel Fanning, Eanna Falvey, Katherine Daniels, and Ann Cools

An increased understanding of rotational strength as a potential prognostic factor for injury in contact and collision athletes may be important in planning return to sport. The aim of this study was to (1) determine the test–retest reliability of clinically relevant, angle-specific rotational and peak torque measurements in a cohort of uninjured collision and contact athletes; (2) develop a normal descriptive profile of angle-specific rotational torque measurements in the same cohort; and (3) examine the effects of direction and joint angle on shoulder rotational strength interlimb asymmetries. Twenty-three collision and contact athletes were recruited for the interday reliability substudy and 47 athletes were recruited for the remaining substudies. We used intraclass correlation coefficients with 95% confidence intervals to quantify interday reliability of all variables. We used a 2-way repeated-measures analysis of variance to analyze differences in absolute interlimb asymmetries. Interday reliability for the isokinetic strength variables was good to excellent (0.78–0.90) on the dominant side and moderate to good (0.63–0.86) on the nondominant side. Maximum angle-specific torque (as well as peak torque) can be measured reliably in internally and externally rotated positions. A normal profile of clinically relevant, angle-specific shoulder rotational torque measurements for collision and contact athletes has been established which provides a reference when assessing shoulder strength in this population.

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Epidemiology of Rink Hockey-Related Injuries

Marcos Quintana-Cepedal, Miguel Ángel Rodríguez, Irene Crespo, Miguel del Valle, and Hugo Olmedillas

Context: Determining the rate of injuries related to a certain sport is accepted as the primary step toward designing, implementing, and evaluating injury prevention programs. The aim of this study was to examine the injuries sustained by semiprofessional Spanish rink hockey players and to compare data per playing position. Design: Observational and retrospective. Methods: Athletes from 21 teams were surveyed via a self-reported questionnaire to screen for incidence, injury burden, location, tissue, and onset of injuries. Results: Overall, 101 time loss injuries were reported across 22,241 hours of exposure, giving rise to an incidence rate of 4.5/1000 hours. The main body regions injured were the hip/groin, shoulder, thigh, and head, accounting altogether for 47.5% of all injuries. Musculotendinous injuries were the most frequent, comprising 27.7% of all injuries. Incidence accounted for 3.1/1000 hours during training and 23/1000 hours during games (P < .001). A high number of injuries were caused by contact (46.5%). No differences were found for any of the variables analyzed between outfield players and goalkeepers. Conclusion: The injury incidence in rink hockey is moderate, occurring mainly due to a contact mechanism. Preventative measurements should be implemented in rink hockey with a special concern for injuries affecting the hip/groin and head.

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Comparison of Sensorimotor Integration and Skill-Related Physical Fitness Components Between College Athletes With and Without Forward Head Posture

Ibrahim Moustafa, Meeyoung Kim, and Deed E. Harrison

Objective: To evaluate sensorimotor integration and skill-related physical fitness components for participants with forward head posture (FHP) compared with strictly matched controls with normal head alignment. Material and Methods: We measured FHP, sensorimotor processing, and skill-related physical fitness variables in 50 participants with FHP and in 50 participants matched for age, gender, and body mass index with normal FHP, defined as having a craniovertebral angle >55°. Sensorimotor processing and integration variables were: (1) amplitudes of the spinal N13, (2) brainstem P14, (3) parietal N20 and P27, and (4) frontal N30 potentials. The skill-related physical fitness variables selected for the study were (1) T-test agility, (2) leg power, (3) stork static balance test, and (4) Y-balance test. Results: There was a statistically significant difference between the FHP group and control group for the sensorimotor integration variable: frontal N30 potentials (P < .05). Additionally, between-group differences were found for the sensorimotor processing variables: amplitudes of spinal N13, brainstem P14, and parietal N20, and P27 (P < .05). Statistically significant differences between groups for the skill-related physical fitness variables were also identified: T-test agility, leg power, stork static balance test, and Y-balance test (P < .05). The magnitude of the craniovertebral angle showed a correlation with all measured variables (P < .05). Conclusion: College athletes with FHP exhibited altered sensorimotor processing and integration measurements and less efficient skill-related physical fitness compared with athletes with normal sagittal head posture alignment.