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Adam C. Knight and Wendi H. Weimar

The purpose of this investigation was to determine the effect of different types of ankle sprains on the response latency of the peroneus longus and peroneus brevis to an inversion perturbation, as well as the time to complete the perturbation (time to maximum inversion). To create a forced inversion moment of the ankle, an outer sole with fulcrum was used to cause 25 degrees of inversion at the ankle upon landing from a 27 cm step-down task. Forty participants completed the study: 15 participants had no history of any ankle sprain, 15 participants had a history of a lateral ankle sprain, and 10 participants had a history of a high ankle sprain. There was not a significant difference between the injury groups for the latency measurements or the time to maximum inversion. These findings indicate that a previous lateral ankle sprain or high ankle sprain does not affect the latency of the peroneal muscles or the time to complete the inversion range of motion.

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Adam C. Knight and Wendi H. Weimar

Context:

The dominant and nondominant legs respond asymmetrically during landing tasks, and this difference may occur during an inversion perturbation and provide insight into the role of ankle-evertor and -invertor muscle activity.

Objective:

To determine if there is a difference in the ratio of evertor to invertor activity between the dominant and nondominant legs and outer-sole conditions when the ankle is forced into inversion.

Design:

Repeated-measures single-group design.

Setting:

University laboratory.

Participants:

15 physically active healthy volunteers with no previous history of an ankle sprain or lower extremity surgery or fracture.

Interventions:

An outer sole with fulcrum was used to cause 25° of inversion at the subtalar joint after landing from a 27-cm step-down task. Participants performed 10 fulcrum trials on both the dominant and nondominant leg.

Main Outcome Measures:

The ratio of evertor to invertor muscle activity 200 ms before and 200 ms after the inversion perturbation was measured using electromyography. This ratio was the dependent variable. Independent variables included outer-sole condition (fulcrum, flat), leg (dominant, nondominant), and time (prelanding, postlanding). The data were analyzed with separate 2-way repeated-measures ANOVA, 1 for the prelanding ratios and 1 for the postlanding ratios.

Results:

For the postlanding ratios, the fulcrum outer sole had a significantly greater (P < .05) ratio than the flat outer sole, and the nondominant leg had a significantly greater (P < .05) ratio than the dominant leg.

Conclusions:

These results indicate that a greater evertor response is produced when the ankle is forced into inversion, and a greater response is produced for the nondominant leg, which may function better during a postural-stabilizing task than the dominant leg.

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Adam C. Knight and Wendi H. Weimar

Context:

The latency of the peroneus longus in response to an inversion perturbation is a key component in the prevention of lateral ankle sprains. In addition, the dominant ankle is sprained more frequently than the nondominant ankle, but the cause of this has not been examined.

Objective:

To investigate the combination of these 2 research-supported statements, the purpose of this study was to use an inversion perturbation that replicates the mechanism of a lateral ankle sprain to determine whether there is a difference in the latency of the peroneus longus between the dominant and nondominant legs.

Design:

Repeated-measures single-group design.

Setting:

University laboratory.

Participants:

15 physically active healthy volunteers with no previous history of an ankle sprain or lower extremity surgery or fracture.

Interventions:

Outer sole with fulcrum was used to cause 25° of inversion at the subtalar joint on landing from a 27-cm step-down task. Participants performed 10 trials on both the dominant and nondominant leg.

Main Outcome Measures:

2 latency measures of the peroneus longus of both the dominant and nondominant leg, calculated as the amount of time from the moment of touchdown of the fulcrum until muscle activity exceeded 5 and 10 SD above baseline muscle activity.

Results:

The latency of the peroneus longus of the nondominant leg was significantly shorter when using both 5 SD (F 1,14 = 9.34, P = .009, d = .895) and 10 SD (F 1,14 = 18.56, P = .001, d = .920) above baseline muscle activity.

Conclusions:

This difference in latency may be a result of the different demands placed on the dominant and nondominant legs during activity and may predispose the dominant ankle to a greater number of ankle sprains than the nondominant ankle.

Open access

Adam E. Jagodinsky, Christopher Wilburn, Nick Moore, John W. Fox and Wendi H. Weimar

Context: Ankle bracing is an effective form of injury prophylaxis implemented for individuals with and without chronic ankle instability, yet mechanisms surrounding bracing efficacy remain in question. Ankle bracing has been shown to invoke biomechanical and neuromotor alterations that could influence lower-extremity coordination strategies during locomotion and contribute to bracing efficacy. Objective: The purpose of this study was to investigate the effects of ankle bracing on lower-extremity coordination and coordination dynamics during walking in healthy individuals, ankle sprain copers, and individuals with chronic ankle instability. Design: Mixed factorial design. Setting: Laboratory setting. Participants: Forty-eight recreationally active individuals (16 per group) participated in this cross-sectional study. Intervention: Participants completed 15 trials of over ground walking with and without an ankle brace. Main Outcome Measures: Coordination and coordination variability of the foot–shank, shank–thigh, and foot–thigh were assessed during stance and swing phases of the gait cycle through analysis of segment relative phase and relative phase deviation, respectively. Results: Bracing elicited more synchronous, or locked, motion of the sagittal plane foot–shank coupling throughout swing phase and early stance phase, and more asynchronous motion of remaining foot–shank and foot–thigh couplings during early swing phase. Bracing also diminished coordination variability of foot–shank, foot–thigh, and shank–thigh couplings during swing phase of the gait cycle, indicating greater pattern stability. No group differences were observed. Conclusions: Greater stability of lower-extremity coordination patterns as well as spatiotemporal locking of the foot–shank coupling during terminal swing may work to guard against malalignment at foot contact and contribute to the efficacy of ankle bracing. Ankle bracing may also act antagonistically to interventions fostering functional variability.

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Sarah Price, Richard H. Williams, Christopher Wilburn, Portia Williams, Danielle Wadsworth, Wendi Weimar, Jared Russell and Mary E. Rudisill

This article presents an overview of how faculty in the School of Kinesiology at Auburn University (AU) are working with minority-serving institutions in similar disciplines to promote diversity and inclusion. Florida A&M (FAMU) and Albany State University (ASU) are both Historically Black Colleges and Universities (HBCU), and AU is a Predominantly White Institution (PWI). Part of this initiative has been accomplished through the development of AU’s Future Scholars Summer Research Bridge Program in partnership with south-eastern HBCUs. Success has been measured as an increase in student recruitment and increased opportunities for students from underrepresented groups seeking graduate opportunities. The partnership between FAMU and AU has also provided opportunities for faculty and students to promote diversity and be more inclusive through research collaborations. These partnerships are addressing this important need to be more purposeful in our efforts of establishing greater diversity and being a more inclusive discipline.