Browsing by Author "Le, Daniel"

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    ItemOpen Access
    Effect of Concussion on Reaction Time and Neurocognitive Factors: Implications for Subsequent Lower Extremity Injury.
    (International journal of sports physical therapy, 2022-01) Ray, Tyler; Fleming, Daniel; Le, Daniel; Faherty, Mallory; Killelea, Carolyn; Bytomski, Jeffrey; Ray, Tracy; Lemak, Larry; Martinez, Corina; Bergeron, Michael F; Sell, Timothy

    Background

    Recent evidence has demonstrated that athletes are at greater risk for a lower extremity injury following a return-to-sport (RTS) after sport-related concussion (SRC). The reason for this is not completely clear, but it has been hypothesized that persistent deficits in neurocognitive factors may be a contributing factor.

    Hypothesis/purpose

    This study assessed simple reaction time, processing speed, attention, and concentration in a group of athletes, post-concussion upon clearance for RTS for potential deficits that may result in slower reaction time, processing speed, attention, and concentration. The researchers hypothesized that the concussion group would demonstrate worse scores on both assessments compared to a sex-, age-, and sport-matched cohort.

    Study design

    Case-controlled study.

    Methods

    Twelve participants who had suffered a SRC and eight healthy individuals who were matched to the concussed group by age, sex, and sport were evaluated. Those with a concussion had been cleared for RTS by a licensed healthcare provider. Each participant underwent neurocognitive tests that included a simple reaction time test (SRT) and the King-Devick Test (K-D). Independent t-tests were performed to compare the groups with significance set a priori at p<0.05.

    Results

    There was a significant difference (p =0.024) between groups for SRT with the concussed group demonstrating a better SRT than the control group. There were no significant differences (p =0.939) between the groups for the K-D.

    Conclusion

    With no significant differences between groups in the K-D assessment and, surprisingly, the concussed group having a better SRT compared to the healthy group, our hypothesis was not supported.

    Clinical relevance

    These specific measures, compounded with extensive post-concussion time lapse until RTS clearance, may have limited capacity in revealing potential persistent deficits in relevant neurocognitive characteristics.

    Level of evidence

    Level of Evidence 3.
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    ItemOpen Access
    Females have Lower Knee Strength and Vertical Ground Reaction Forces During Landing than Males Following Anterior Cruciate Ligament Reconstruction at the Time of Return to Sport.
    (International journal of sports physical therapy, 2022-01) Sullivan, Zachary B; Sugarman, Barrie S; Faherty, Mallory S; Killelea, Carrie; Taylor, Dean C; Le, Daniel; Toth, Alison P; Riboh, Jonathan C; Diehl, Lee H; Wittstein, Jocelyn R; Amendola, Annunziato; Sell, Timothy C

    Purpose

    There is a high rate of second anterior cruciate ligament (ACL) injury (ipsilateral graft or contralateral ACL) upon return-to-sport (RTS) following ACL reconstruction (ACLR). While a significant amount of epidemiological data exists demonstrating sex differences as risk factors for primary ACL injury, less is known about sex differences as potential risk factors for second ACL injury. The purpose of this study is to determine if there are sex-specific differences in potential risk factors for second ACL injury at the time of clearance for RTS.

    Methods

    Ten male and eight female athletes (age: 20.8 years ±6.3, height: 173.2 cm ±10.1, mass: 76.6 kg ±18.3) participated in the study following ACLR at time of RTS (mean 10.2 months). Performance in lower extremity isokinetic and isometric strength testing, static and dynamic postural stability testing, and a single leg stop-jump task was compared between the sexes.

    Results

    Normalized for body weight, males had significantly greater isokinetic knee flexion (141±14.1 Nm/kg vs. 78±27.4 Nm/kg, p=0.001) and extension strength (216±45.5 Nm/kg vs. 159±53.9 Nm/kg, p=0.013) as well as isometric flexion (21.1±6.87% body weight vs. 12.5±5.57% body weight, p=0.013) and extension (41.1±7.34% body weight vs. 27.3±11.0% body weight, p=0.016) strength compared to females. In the single-leg stop jump task, males had a greater maximum vertical ground reaction force during landing (332±85.5% vs. 259±27.4% body weight, p=0.027) compared to females.

    Conclusions

    Based on these results, there are significant differences between sexes following ACLR at the time of RTS. Lower knee flexion and extension strength may be a potential risk factor for second ACL injury among females. Alternatively, the increased maximum vertical force observed in males may be a potential risk factor of second ACL injury in males. Although these results should be interpreted with some caution, they support that rehabilitation programs in the post-ACLR population should be individualized based on the sex of the individual.

    Level of evidence

    Level 3.
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    ItemOpen Access
    Isometric Knee Strength is Greater in Individuals Who Score Higher on Psychological Readiness to Return to Sport After Primary Anterior Cruciate Ligament Reconstruction.
    (International journal of sports physical therapy, 2022-01) Sugarman, Barrie S; Sullivan, Zach B; Le, Daniel; Killelea, Carolyn; Faherty, Mallory S; Diehl, Lee H; Wittstein, Jocelyn R; Riboh, Jonathan C; Toth, Alison P; Amendola, Annunziato; Taylor, Dean C; Sell, Timothy C

    Background

    Anterior cruciate ligament (ACL) injury is extremely common among athletes. Rate of second ACL injury due to surgical graft rupture or contralateral limb ACL injury is approximately 15-32%. Psychological readiness to return to sport (RTS) may be an important predictor of successful RTS outcomes. Psychological readiness can be quantified using the ACL Return to Sport after Injury (ACL-RSI) questionnaire, with higher scores demonstrating greater psychological readiness.

    Purpose

    The purpose of this study was to investigate differences in functional performance and psychological readiness to return to sport among athletes who have undergone primary ACL reconstruction (ACLR).

    Study design

    Descriptive cohort study.

    Methods

    Eighteen athletes who had undergone primary ACLR were tested at time of RTS clearance. The cohort was divided into two groups, high score (HS) and low score (LS), based on median ACL-RSI score, and performance on static and dynamic postural stability testing, lower extremity isokinetic and isometric strength testing, and single leg hop testing was compared between the groups using an independent samples t-test.

    Results

    The median ACL-RSI score was 74.17. The average ACL-RSI score was 83.1±6.2 for the HS group and 61.8±8.0 for the LS group. High scorers on the ACL-RSI performed significantly better on isometric knee flexion as measured via handheld dynamometry (22.61% ±6.01 vs. 12.12% ±4.88, p=0.001) than the low score group.

    Conclusion

    The findings suggest that increased knee flexion strength may be important for psychological readiness to RTS after primary ACLR. Further research is indicated to explore this relationship, however, a continued emphasis on improving hamstring strength may be appropriate during rehabilitation following ACLR to positively impact psychological readiness for RTS.

    Level of evidence

    III.