Extrinsic visual feedback and additional cognitive/physical demands affect single-limb balance control in individuals with ankle instability

The Effects of Cognitive Loading on Motor Behavior in Injured Individuals: A Systematic Review

BACKGROUND

Research suggests that individuals with musculoskeletal injury may have difficulty negotiating physical tasks when they are combined with cognitive loads.

OBJECTIVE

Our objective was to conduct a systematic review to understand the effects of increased cognitive demand on movement patterns among individuals with musculoskeletal injuries.

METHODS

A comprehensive search of PubMed, MEDLINE, the Cumulative Index for Nursing and Allied Health Literature (CINAHL), and SPORTDiscus was conducted to find research reports that included a population that had previously experienced an ankle, knee, or low back injury, included an uninjured control group, and assessed a dual-task paradigm.

RESULTS

Forty-five full-text research reports were assessed, of which 28 studies (six ankle injury, nine knee injury, and 13 low back pain studies) were included in the review. Included studies were assessed for methodological quality and the study design extracted for analysis including the participants, cognitive and physical tasks performed, as well as outcome measures (e.g., three-dimensional kinematics, center of pressure, etc.). All studies included were cross-sectional or case-control with methodological quality scores of 17.8 ± 2.2 out of a possible 22. Twenty-five of the 28 studies found changes in motor performance with dual-task conditions compared with single tasks. Furthermore, 54% of studies reported a significant group by task interaction effect, reporting at least one alteration in injured groups' motor performance under dual-task conditions when compared with an uninjured group.

CONCLUSION

The results of this systematic review indicate that motor performance is further impaired by placing a cognitive load on individuals in populations with musculoskeletal injury. More demanding tasks such as gait appear to be more affected in injured individuals than simple balance tasks. Future investigators may want to consider the difficulty of the tasks included as well as the impact of dual-task paradigms on rehabilitation programs.

Males with chronic ankle instability demonstrate deficits in neurocognitive function compared to control and copers

The purpose of this study was to determine if there were neurocognitive deficits among controls, copers and those with chronic ankle instability (CAI). Participants included those without history of ankle injury (n = 14), ankle sprain copers (n = 13) and patients with self-reported CAI (n = 14). They completed a battery of valid and reliable computer-based neurocognitive tests. The differences between neurocognitive domain scores were compared across the Control, Coper and CAI groups. Patients with CAI had lower composite memory, visual memory and simple attention compared to controls. In males with CAI, large differences in memory and attention were found relative to control participants. These differences may contribute to uncontrolled episodes of giving way through deficits in spatial awareness and/or an inability to identify environmental obstacles. Clinicians should explore ways to provide additional stimuli through innovative rehabilitation protocols aimed at maximizing neurocognitive abilities in patients with CAI.

Active ankle position sense and single-leg balance in runners versus non-runners

Introduction: Ankle sprain is one of the most common injuries in collegiate athletes, including runners. The purpose of the study was to examine whether runners exhibited compromised ankle stability, ankle position sense, and single-leg balance.Methods: Thirty-seven individuals (21 non-runners and 16 runners) participated in the study. To be included in the runner group, subjects were required to run greater than 150 minutes per week for the past three months. We used the Cumberland Ankle Instability Tool (CAIT) to categorize ankle stability, and we used a dual-axis electronic goniometer to examine active ankle position sense. We examined single-leg balance with the Athletic Single Leg Stability Test of the Biodex Balance System using three different protocols: 1) default setting, 2) no extrinsic visual feedback, and 3) no extrinsic feedback with a cognitive demand.Results: Runners and non-runners had similar ankle stability (CAIT = 26.88 and 26.45 respectively; p = .666). Although runners had significantly larger ankle position errors than non-runners overall (2.56° vs. 1.68°; p = .004), they had better single-leg balance than non-runners without extrinsic visual feedback (Stability Index 1.67 vs. 4.39; p < .001), even with an added cognitive loading (Stability Index 2.18 vs. 4.32; p < .001).Conclusions: For runners, having worse ankle position sense did not compromise ankle stability, nor contribute to single-leg balance deficits. Runners may have established better motor control to maintain their single-leg balance and ankle stability.