Jason P. Mihalik
Column-editor : Richard DeMont
Jason P. Mihalik, Luv Kohli, and Mary C. Whitton
Virtual reality environments may allow researchers to investigate functional balance performance without risks associated with testing in the real world.
To investigate the effects of the mass of a head-mounted display (HMD) on balance performance.
Virtual reality laboratory.
20 healthy college students.
Balance Error Scoring System (BESS) with a tracker-only headband and again with tracker plus HMD was performed.
Main Outcome Measures:
BESS error scores, elliptical sway area, and center of pressure travel distance were recorded.
No effect of the HMD mass on balance performance was observed. A significant stance by surface interaction was present but was negated when the HMD conditions were included in the model.
The mass of a HMD has not been proven to adversely affect balance performance. These data suggest the HMD mass is not a contraindication to the use of immersive virtual environments in future concussion research involving balance.
Luke M. Ross, Johna K. Register-Mihalik, Jason P. Mihalik, Karen L. McCulloch, William E. Prentice, Edgar W. Shields, and Kevin M. Guskiewicz
Recent evidence has revealed deficiencies in the ability to divide attention after concussion.
To examine the effects of a single vs a dual task on cognition and balance in healthy subjects and to examine reliability of 2 dual-task paradigms while examining the overall feasibility of the tasks.
Pretest–posttest experimental design.
Sports medicine research laboratory.
30 healthy, recreationally active college students.
Subjects performed balance and cognitive tasks under the single- and dual-task conditions during 2 test sessions 14 d apart.
Main Outcome Measures:
The procedural reaction-time (PRT) test of the Automated Neuropsychological Assessment Metrics (eyes-closed tasks) and an adapted Procedural Auditory Task (PAT; eyes-open tasks) were used to assess cognition. The NeuroCom Sensory Organization Test (SOT) and the Balance Error Scoring System (BESS) were used to assess balance performance. Five 2-way, within-subject ANOVAs and a paired-samples t test were used to analyze the data. ICCs were used to assess reliability across 2 test sessions.
On the SOT, performance significantly improved between test sessions (F 1,29 = 35.695, P < .001) and from the single to the dual task (F 1,29 = 9.604, P = .004). On the PRT, performance significantly improved between test sessions (F 1,29 = 57.252, P < .001) and from the single to the dual task (F 1,29 = 7.673, P = .010). No differences were seen on the BESS and the PAT. Reliability across test sessions ranged from moderate to poor for outcome measure.
The BESS appears to be a more reliable and functional tool in dual-task conditions as a result of its increased reliability and clinical applicability. In addition, the BESS is more readily available to clinicians than the SOT.
Elizabeth F. Teel, Stephen W. Marshall, L. Gregory Appelbaum, Claudio L. Battaglini, Kevin A. Carneiro, Kevin M. Guskiewicz, Johna K. Register-Mihalik, and Jason P. Mihalik
Context: Concussion management is moving from passive rest strategies to active interventions, including aerobic exercise therapy. Little information is available regarding the feasibility and adherence of these programs. Objectives: To determine whether an aerobic exercise training program intended for rehabilitation in people with concussion is feasible. Healthy, nonconcussed subjects were studied in this phase 1 trial. Design: Phase 1 parallel-group, randomized controlled trial in a sample of healthy (nonconcussed), recreationally active university students. Setting: Laboratory. Patients: 40 healthy university students. Methods: Participants were equally randomized to acute concussion therapy intervention (ACTIVE) training or nontraining groups. All participants completed maximal cardiopulmonary exercise tests on a stationary cycle ergometer at 2 test sessions approximately 14 days apart. During this 2-week study period, ACTIVE training participants completed six 30-minute cycling sessions, progressing from 60% to 80% of the participant’s individualized maximal oxygen consumption. A subset of participants (NACTIVE = 12, Nnontraining = 11) wore physical activity monitors throughout the 2-week study period. Main Outcomes Measures: Study protocol and randomization effectiveness, exercise safety and adherence, and progressive intensity of the ACTIVE training procedures. Results: No adverse events occurred during any exercise sessions. Twelve ACTIVE training participants (60%) completed all training sessions, and every participant completed at least 4 sessions. Heart rate increased throughout the training period (P < .001), but symptom changes and training adherence remained stable despite the progressively increasing workload. ACTIVE training participants completed approximately 30 additional minutes of physical activity on training sessions days, although that was not statistically significant (P = .20). Conclusions: University-aged students were adherent to the ACTIVE training protocol. Future research should investigate the safety and feasibility of aerobic training programs in acutely concussed individuals to determine their appropriateness as a clinical rehabilitation strategy.
Johna K. Register, Jason P. Mihalik, Christopher J. Hirth, and Thomas E. Brickner
Column-editor : Joseph J. Piccininni
Jason P. Mihalik, Elizabeth F. Teel, Robert C. Lynall, and Erin B. Wasserman
In equipment-heavy sports, there is a growing need to evaluate players in the condition in which they participate. However, the psychometric properties of the Balance Error Scoring System (BESS) while wearing skates remains unknown. Seventy-four adolescent male hockey players completed the BESS with and without skates. A subset was reevaluated at the conclusion of the season. The BESS while wearing skates resulted in a mean of 15 more total errors than the traditional administration (t73 = 14.94, p < .001; ES = 1.95) and demonstrated low test-retest reliability. The BESS should be administered in the traditional manner (without skates).
Michael J. Cools, Weston T. Northam, Michael Boyd, Andrew Alexander, Jason P. Mihalik, Kevin M. Guskiewicz, and Kevin A. Carneiro
Primary care providers (PCPs) are evaluating increasing numbers of concussions, but it is unknown how often they are documenting concussion-specific history and physical examination findings vital for this process. This study reviews clinical documentation to determine how PCPs are evaluating concussed patients. PCPs often did not document important aspects of concussion history, including dizziness (48%), nausea (48%), vision changes (54%), cognitive complaints (54%), emotional changes (83%), sleep difficulties (84%), and neck pain (87%). Additionally, they often did not document important aspects of a concussion physical examination, including detailed neurologic examination (73%), clinical cognitive assessment (87%), balance testing (59%), and neck evaluation (54%). Omitting these parts of the history and physical examination could result in a premature return to play.
Lilly H. VanDeMark, Christina B. Vander Vegt, Cassie B. Ford, Jason P. Mihalik, and Erik A. Wikstrom
Context: Prophylactic and rehabilitative balance training is needed to maximize postural control and develop appropriate sensory organization strategies. Partially occluding vision during functional exercise may promote appropriate sensory organization strategies, but little is known about the influence of partially occluded vision on postural control in those with and without a history of musculoskeletal injury. Objective: To determine the effect of increasing levels of visual occlusion on postural control in a heterogeneous sample of those with and without chronic ankle instability (CAI). The secondary objective was to explore postural control responses to increasing levels of visual occlusion among those with unilateral and bilateral CAI relative to uninjured controls. Design: Cross-sectional. Setting: Sports medicine research laboratory. Patients or Other Participants: Twenty-five participants with unilateral CAI, 10 with bilateral CAI, and 16 participants with no history of lower extremity injury. Main Outcome Measures: All participants completed four 3-minute postural control assessments in double-limb stance under the following 4 visual conditions: (1) eyes open, (2) low occlusion, (3) high occlusion, and (4) eyes closed. Low- and high-occlusion conditions were produced using stroboscopic eyewear. Postural control outcomes included time-to-boundary minima means in the anteroposterior (TTB-AP) and mediolateral directions (TTB-ML). Repeated-measures analysis of variances tested the effects of visual condition on TTB-AP and TTB-ML. Results: Postural control under the eyes-open condition was significantly better (ie, higher) than the limited visual occlusion and eyes-closed conditions (P < .001) for TTB-AP and TTB-ML. For TTB-AP only, partially occluded vision resulted in better postural control than the eyes-closed condition (P ≤ .003). Conclusions: Partial and complete visual occlusion impaired postural control during dual-limb stance in a heterogeneous sample of those with and without CAI. Stroboscopic eyewear appears to induce postural control impairments to the same extent as complete visual occlusion in the mediolateral direction.
J.D. DeFreese, Michael J. Baum, Julianne D. Schmidt, Benjamin M. Goerger, Nikki Barczak, Kevin M. Guskiewicz, and Jason P. Mihalik
Context: Concussion baseline testing helps injury evaluation by allowing postinjury comparisons to preinjury measures. To facilitate best practice, common neurocognitive, balance, and symptom report metrics used in concussion baseline testing merit examination relative to participant life stressors. Objective: The purpose of this study was to determine if life stressors are associated with college athlete neurocognitive function, postural control, and symptom scores at preseason baseline assessment. Design: All study variables were collected in a single laboratory session where athletes completed valid and reliable psychometrics as well as a computerized neurocognitive and balance assessments. Setting: Sports medicine research center on an American university campus. Participants: A convenience sample of 123 college student-athletes: 47 females (age = 18.9 [4.3] y) and 76 males (age = 19.4 [1.6] y). Main Outcome Measures: Participants were categorized into low, moderate, or high life stressors groups using scores from the Social Readjustment Rating Scale-Revised. Dependent variables included outcomes from the CNS Vitals Signs test, the Sensory Organization Test, and the graded symptom checklist indexing neurocognition, balance, and symptom severity, respectfully. Results: One-way analysis of variance revealed that the moderate life stressors group performed significantly worse than the low life stressors group on the baseline verbal memory domain of the CNS Vital Signs (F 2,119 = 3.28; P = .04) only. Conclusion: In the current college athlete sample, few baseline concussion assessment variables were found to be significantly associated with life stressors. Considering the clinical significance of these variables, psychological life stressors may not be a confounding factor in concussion evaluation.
Maria K. Talarico, Robert C. Lynall, Timothy C. Mauntel, Erin B. Wasserman, Darin A. Padua, and Jason P. Mihalik
Although single-leg squats are a common dynamic balance clinical assessment, little is known about the relationship between parameters that influence squat movement and postural control performance. The objective of this study was to determine the relationships between squat parameters (speed and depth) and postural control under single task and dual task. A total of 30 healthy college students performed single-leg squats under single task and dual task with Stroop. Random-intercepts generalized linear mixed models determined the effect of squat parameters on center of pressure (CoP) parameters. For each 1-cm·s−1 increase in squat speed, sway range (mediolateral: β = −0.03; anteroposterior: β = −0.05) and area (β = −0.25) decreased, whereas sway speed (mediolateral: β = 0.05; anteroposterior: β = 0.29; total: β = 0.29) increased. For each 1-cm increase in squat depth, sway range (mediolateral: β = 0.05; anteroposterior: β = 0.20) and area (β = 0.72) increased, whereas sway speed (anteroposterior: β = −0.14; total: β = −0.14) decreased. Compared with single task, the association between total and anteroposterior sway speed and squat speed was stronger under dual task. Clinicians and researchers should consider monitoring squat speed and depth when assessing dynamic balance during single-leg squats, as these parameters influence postural control, especially under dual task.