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  • Author: Daniel Hamacher x
  • Athletic Training, Therapy, and Rehabilitation x
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Daniel Hamacher, Dennis Hamacher, Roy Müller, Lutz Schega and Astrid Zech

The aim of the current study was to evaluate the effect of a cognitive dual task on minimum toe clearance (MTC) variability while walking. In a randomized cross-over design, gait kinematics of 25 older (70 ± 6 years) and 45 younger adults (25 ± 2 years) were captured during normal walking and dual-task walking. Variability of stride time, stride length, and MTC were calculated. Differences between normal versus dual-task walking were assessed using Wilcoxon tests. Compared with normal walking, dual-task walking caused an increase in stride time variability (older adults: p < .001 and younger adults: p < .001), while the variability of MTC decreased (older adults: p = .032 and younger adults: p = .012). MTC seems to be a task-relevant gait parameter that is controlled with high priority to preserve its variability under challenging conditions.

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Cornelius John, Andreas Stotz, Julian Gmachowski, Anna Lina Rahlf, Daniel Hamacher, Karsten Hollander and Astrid Zech

Context: In some patients, ankle sprains lead to chronic symptoms like pain or muscular weakness called chronic ankle instability (CAI). External ankle supports have shown to be effective in preventing sprains and reducing recurrence, but the underlying mechanisms are unclear. As sensorimotor variables are associated with injury incidence, an influence of external ankle support on landing performance and balance seems plausible. Objective: To analyze the effects of an elastic ankle support on jump landing performance and static and dynamic balance in patients with CAI and healthy controls. Design: Crossover study. Setting: Functional tests in a laboratory setting. Patients or Other Participants: Twenty healthy students and 20 patients with CAI were included for study participation based on their scores in ankle stability and function questionnaires. Intervention: Healthy and CAI participants performed each test with and without an elastic ankle support. Main Outcome Measures: (1) Jump landing performance was measured with the Landing Error Scoring System, (2) static balance was assessed with the Balance Error Scoring System, and (3) dynamic balance was assessed using the Y Balance Test. Linear mixed models were used to analyze the effects of the elastic ankle support on sensorimotor parameters. Results: Healthy controls performed significantly better in the Landing Error Scoring System (P = .01) and Y Balance Test anterior direction (P = .01). No significant effects of elastic ankle support on Landing Error Scoring System, Balance Error Scoring System, or Y Balance Test performance were observed in the CAI or control group. There were no significant group-by-ankle support interactions. Conclusions: In the current study, the acute use of elastic ankle support was ineffective for enhancing jump landing performance, and static and dynamic balance. Further research is needed to identify the underlying mechanisms of the preventive effects of elastic ankle support.