Context: Determination of return to play (RTP) after sport-related concussion (SRC) is critical given the potential consequences of premature RTP. Current RTP guidelines may not identify persistent exercise-induced neurocognitive deficits in asymptomatic athletes after SRC. Therefore, postexercise neurocognitive testing has been recommended to further inform RTP determination. To implement this recommendation, the effect of exercise on neurocognitive function in healthy athletes should be understood. Objective: To examine the acute effects of a high-intensity intermittent-exercise protocol (HIIP) on neurocognitive function assessed by the Symbol Digits Modality Test (SDMT) and Stroop Interference Test. Design: Cohort study. Setting: University laboratory. Participants 40 healthy male athletes (age 21.25 ± 1.29 y, education 16.95 ± 1.37 y). Intervention: Each participant completed the SDMT and Stroop Interference Test at baseline and after random allocation to a condition (HIIP vs control). A mixed between-within-subjects ANOVA assessed time- (pre- vs postcondition) -by-condition interaction effects. Main Outcome Measures: SDMT and Stroop Interference Test scores. Results: There was a significant time-by-condition interaction effect (P < .001, η 2 = .364) for the Stroop Interference Test scores, indicating that the HIIP group scored significantly lower (56.05 ± 9.34) postcondition than the control group (66.39 ± 19.6). There was no significant time-by-condition effect (P = .997, η 2 < .001) for the SDMT, indicating that there was no difference between SDMT scores for the HIIP and control groups (59.95 ± 10.7 vs 58.56 ± 14.02). Conclusions: In healthy athletes, the HIIP results in a reduction in neurocognitive function as assessed by the Stroop Interference Test, with no effect on function as assessed by the SDMT. Testing should also be considered after high-intensity exercise in determining RTP decisions for athletes after SRC in conjunction with the existing recommended RTP protocol. These results may provide an initial reference point for future research investigating the effects of an HIIP on the neurocognitive function of athletes recovering from SRC.
Enda F. Whyte, Nicola Gibbons, Grainne Kerr, and Kieran A. Moran
Siobhán O’Connor, Noel McCaffrey, Enda F. Whyte, Michael Fop, Brendan Murphy, and Kieran A. Moran
Context: Hamstring injuries are a leading cause of injury in Gaelic games. Hamstring flexibility as a risk factor for hamstring injury has not yet been examined prospectively in Gaelic games. Objective: To examine whether hamstring flexibility, using the modified active knee extension (AKE) test, and previous injury are risk factors for hamstring injury in Gaelic players and to generate population-specific AKE cutoff points. Design: Prospective cohort study. Setting: School and colleges. Patients (or Other Participants): Adolescent and collegiate Gaelic footballers and hurlers (n = 570). Intervention(s): The modified AKE test was completed at preseason, and hamstring injuries were assessed over the course of one season. Any previous hamstring injuries were noted in those who presented with a hamstring injury. Main Outcome Measures: Bilateral AKE scores and between-leg asymmetries were recorded. Receiver operating characteristic curves were implemented to generate cutoff points specific to Gaelic players. Univariate and backward stepwise logistic regression analyses were completed to predict hamstring injuries, hamstring injuries on the dominant leg, and hamstring injuries on the nondominant leg. Results: Mean flexibility of 64.2° (12.3°) and 64.1° (12.4°) was noted on the dominant and nondominant leg, respectively. Receiver operating characteristic curves generated a cutoff point of < 65° in the AKE on the nondominant leg only. When controlled for age, AKE on the nondominant leg was the only predictor variable left in the multivariate model (odds ratio = 1.03) and significantly predicted hamstring injury (χ2 = 9.20, P = .01). However, the sensitivity was 0% and predicted the same amount of cases as the null model. It was not possible to generate a significant model for hamstring injuries on the dominant leg (P > .05), and no variables generated a P value < .20 in the univariate analysis on the nondominant leg. Conclusions: Poor flexibility noted in the AKE test during preseason screening and previous injury were unable to predict those at risk of sustaining a hamstring strain in Gaelic games with adequate sensitivity.
Shane J. Gore, Brendan M. Marshall, Andrew D. Franklyn-Miller, Eanna C. Falvey, and Kieran A. Moran
When reporting a subject’s mean movement pattern, it is important to ensure that reported values are representative of the subject’s typical movement. While previous studies have used the mean of 3 trials, scientific justification of this number is lacking. One approach is to determine statistically how many trials are required to achieve a representative mean. This study compared 4 methods of calculating the number of trials required in a hopping movement to achieve a representative mean. Fifteen males completed 15 trials of a lateral hurdle hop. Range of motion at the trunk, pelvis, hip, knee, and ankle, in addition to peak moments for the latter 3 joints were examined. The number of trials required was computed using a peak intraclass correlation coefficient method, sequential analysis with a bandwidth of acceptable variance in the mean, and a novel method based on the standard error of measurement (SEMind). The number of trials required across all variables ranged from 2 to 12 depending on method, joint, and anatomical plane. The authors advocate the SEMind method as it demonstrated fewer limitations than the other methods. Using the SEMind, the required number of trials for a representative mean during the lateral hurdle hop is 6.
Brendan M. Marshall, Andrew D. Franklyn-Miller, Kieran A. Moran, Enda A. King, Siobhán C. Strike, and Éanna C Falvey
Chronic athletic groin pain (AGP) is common in field sports and has been associated with abnormal movement control and loading of the hip and pelvis during play. A single-leg squat (SLS) is commonly used by clinicians to assess movement control, but whether it can provide insight into control during more dynamic sporting movements in AGP patients is unclear.
To determine the relationships between biomechanical measures in an SLS and the same measures in a single-leg drop landing, single-leg hurdle hop, and a cutting maneuver in AGP patients.
40 recreational field-sports players diagnosed with AGP.
A biomechanical analysis of each individual’s SLS, drop landing, hurdle hop, and cut was undertaken.
Main Outcome Measures:
Hip, knee, and pelvis angular displacement and hip and knee peak moments. Pearson product–moment correlations were used to examine relationships between SLS measures and equivalent measures in the other movements.
There were no significant correlations between any hip or pelvis measure in the SLS with the same measures in the drop landing, hurdle hop, or cut (r = .03–.43, P > .05). Knee frontal- and transverse-plane angular displacement were related in the SLS and drop landing only, while knee moments were related in the SLS, drop-landing, and hurdle hop (r = .50–.67, P < .05).
For AGP patients, an SLS did not provide meaningful insight into hip and pelvis control or loading during sporting movements that are associated with injury development. The usefulness of an SLS test in the assessment of movement control and loading in AGP patients is thus limited. The SLS provided moderate insight into knee control while landing and therefore may be of use in the examination of knee-injury risk.