Caroline J. Ketcham

Targeted Aiming Movements Are Compromised in Nonaffected Limb of Persons With Stroke

Background. Research has shown that movement impairments following stroke are typically associated with the limb contralateral to the side of the stroke. Prior studies identified ipsilateral motor declines across a variety of tasks. Objective. Two experiments were conducted to better understand the ipsilateral contributions to organization and execution of proximal upper extremity multisegment aiming movements in persons with right-hemispheric stroke. Methods. Participants performed reciprocal aiming (Experiment 1) and 2-segment aiming movements (Experiment 2) on a digitizing tablet. In both experiments, target size and/or target orientation were manipulated to examine the influence of accuracy constraints on the planning and organization of movements. Results. Kinematic measures, submovement analysis, and harmonicity measures were included in this study. Declines in organization and execution of multisegment movements were found to contribute to performance decrements and slowing in stroke patients. Furthermore, stroke patients were unable to efficiently plan multisegment movements as one functional unit, resulting in discrete movements. Conclusions . Results suggest the importance of considering ipsilateral contributions to the control and organization of targeted aiming movements as well as implications for rehabilitation and recovery.

Single-task and dual-task gait among collegiate athletes of different sport classifications: Implications for concussion management.

Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.

Evidence of a conservative gait strategy in athletes with a history of concussions

Background A history of 3 or more concussions is frequently associated with numerous short- and long-term neuropathologies. Impairments in postural control are a known acute consequence of concussion; however, limited evidence exists on the effects of multiple concussions on gait. The purpose of this study was to assess gait stepping characteristics in collegiate aged student-athletes based on concussion history. Methods There were 63 participants divided into 3 even groups based on concussion history: ≥3 concussions, 1–2 concussions, and 0 concussion. All participants completed 10 trials of gait on a 4.9 m instrumented walkway. The dependent variables of interest included both gait stepping characteristics (step velocity, length, and width, double support time, and the percentage of the gait cycle in stance) and coefficient of variability (CoV) measures (step length, time, and width). The gait stepping characteristics were compared first with a MANOVA with follow-up 1-way ANOVAs and Tukey post hoc tests as appropriate. The CoV measures were compared with 1-way ANOVAs and Tukey post hoc tests. Results There were main effects for group for step velocity, length, width, and double support time. Overall, the 0 concussion group displayed typical healthy young gait parameters and performed significantly better than either concussion group. The 0 concussion group had a significantly greater step length CoV, but there were no differences in the step time or width CoV. Conclusion This finding provides evidence of subtle impairments in postural control during gait among individuals with prior history of concussion which could be an early indicator of future neurological deficiencies. The limited difference in the variability measures is consistent with prior static stance studies and could suggest the individuals constrain their motor systems to reduce variability. Taken together, these findings suggest a conservative gait strategy which is adopted by individuals with a history of concussions.

Concussion Baseline Testing: Preexisting Factors, Symptoms, and Neurocognitive Performance

CONTEXT Neurocognitive test scores are often considered an important aspect of concussion management. To best use these data, clinicians must understand potential factors that may influence baseline performance on these tests. OBJECTIVE To determine preexisting factors that may influence performance on the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). DESIGN Cross-sectional study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 486 National Collegiate Athletic Association Division I collegiate student-athletes. MAIN OUTCOME MEASURE(S) To determine neurocognitive functioning and total symptom score at baseline, ImPACT was administered. Outcomes were verbal memory, visual memory, visual motor speed, reaction time, and total symptom score. A self-report demographic section at the beginning of ImPACT was used to gather information concerning previous treatment for headaches, migraines, and psychiatric conditions; diagnosis of attention-deficit/hyperactivity disorder; and exposure to previous strenuous exercise. We conducted multivariate analyses of variance to determine if the ImPACT composite and total symptom scores differed according to preexisting factors (P < .0083). RESULTS Sex showed an effect on verbal memory (P = .001), visual motor speed (P < .001), and reaction time (P = .006), with women performing better than men. A previous diagnosis of attention-deficit/hyperactivity disorder affected visual motor speed (P = .008). Previous treatment for headaches (P < .001), migraines (P = .001), a psychiatric condition (P < .001), or a diagnosis of attention-deficit/hyperactivity disorder (P < .001) all showed effects on the total symptom score. Strenuous exercise did not affect neurocogntive performance or total symptom score. CONCLUSIONS Based on our findings and the previous literature, we suggest that many preexisting factors influence baseline neurocognitive data. Baseline testing is an important aspect of concussion management. Sports medicine professionals should be cognizant of these factors when developing concussion-management protocols.

Concussion management in collegiate student-athletes: return-to-academics recommendations

Concussions in collegiate athletics can affect student-athletes both on the field and in the classroom. As policies are made to outline return-to-play decisions and timelines, this article will make the case that return-to-academics should also be included and follow a step-wise protocol. Complete cognitive rest is a cornerstone of concussion recovery and slow reintroduction to academics should precede return-to-play. The college structure allows for student-athletes to begin small doses of cognitive activity after the recommended complete cognitive rest. It is recommended that return-to-academics involves a team approach to help the student-athlete navigate the responsibilities of course work while healing from a brain injury.

Relationship between Information Processing and Postural Stability in Collegiate Division I NCAA Athletes: Does Concussion History Matter?

Background: Concussions have been associated with deficits in balance and postural stability. Subjects sustaining mild to moderate head injuries showed an increase in inhibition of the primary motor cortex which has been associated with sensorimotor organization and movement execution changes. Purpose: The purpose of this study was to examine the relationship between postural stability and information processing in collegiate athletes with and without a history of concussion. Methods: One-hundred and sixty-five Division I student-athletes completed balance and neurocognitive baseline testing. Thirty-four had a previous history of concussion. Postural sway and spatio-temporal characteristics of center of pressure were measured under four conditions: eyes open firm surface, eyes closed firm surface, eyes open foam surface, eyes closed foam surface. Information processing data came from two composite scores from a neurocognitive assessment tool and from a somatosensory stimulation test. Results: Results showed that student-athletes with a history of concussions, although healthy at the time of testing, had differences in postural control compared to student-athletes without a history of concussion. While sway index scores were not significantly different, spatio-temporal measures showed larger displacements in CoP in previously concussed student-athletes. Reaction times and visual motor speeds were significantly correlated with sway index scores suggesting that processing time does influence balance control in all participants. Conclusion: Sustained balance control differences in previously concussed student-athletes may have implications for compensation strategies and risk of additional injuries.

Identifying Leading Joint Strategies in a Bimanual Coordination Task: Does Coordination Stability Depend on Leading Joint Strategy?

ABSTRACT The authors sought to determine if principles of the Leading Joint Hypothesis, when applied to a multijoint, bimanual coordination task, could provide insight into the contribution of intralimb dynamics to interlimb coordination. Participants repetitively traced ellipse templates with an isodirectional motion of the end effectors (both hands moving counterclockwise [CCW]) at two cycling frequencies. Ellipse templates were oriented either tilted right or tilted left, yielding a total of 4 left arm–right arm leading-joint combinations. Analysis of torque sign and impulse data indicated that the 4 ellipse-tracing conditions resulted in 4 distinct left arm–right arm leading-joint combinations: 2 conditions with similar leading joints and 2 conditions with different leading joints. Isodirectional CCW ellipse tracing was more stable when produced with similar leading joints compared with when produced with different leading joints. The authors discuss results within the context of intralimb control contributions to the stability of interlimb coordination patterns.

Genetics Influence Neurocognitive Performance at Baseline but Not Concussion History in Collegiate Student-athletes

Objective: This study investigates 4 single-nucleotide polymorphisms [Apolipoprotein E (APOE), APOE promoter, catechol-O-methyl transferase (COMT), and dopamine D2 receptor] that have been implicated in concussion susceptibility and/or cognitive ability in collegiate student-athletes. Design: Cross-sectional study. Setting: Neuroscience laboratory at Elon University. Participants: Two hundred fifty division I collegiate student-athletes (66 women, 184 men) from various sports. Intervention: All participants completed Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) testing at baseline concussion testing and had a buccal swab taken for DNA for genotyping. Main Outcome Measures: Self-reported history of concussions and neurocognitive performance were taken from ImPACT. Results: Individuals carrying an &egr;4 allele in their APOE gene had a significantly slower reaction time (P = 0.001). Individuals homozygous for the Val allele of the COMT gene showed significantly worse impulse control scores (P = 0.014). None of the genotypes were able to predict self-reported concussion history in collegiate student-athletes. Conclusions: These results indicate that certain genotypes may influence performance on cognitive testing at baseline and that the APOE genotypes may not influence concussion susceptibility as suggested by past studies.

The Effect of a Summer Camp Intervention on the Nutrition Knowledge and Dietary Behavior of Adolescent Girls

The purpose of this study was to design a rewards-based nutrition intervention program to improve knowledge and dietary behaviors of adolescent girls. Our participants consisted of eight girls ages 11 to 13 years. Nutritional knowledge was assessed before and after intervention program through a “Jeopardy” style quiz game and posttest questionnaires. Participants were also interviewed throughout the week about typical dietary behaviors, daily physical activity, and self-esteem. Educational activities took place for 2 to 3 hours each day and included a grocery store scavenger hunt, healthy baking demonstrations, and relay races. Participants received bracelets and charms as rewards for participation in activities. Nutritional knowledge increased for six out of eight participants, although the overall increase was not found to be statistically significant (p = .20). Significant correlations were found between measures including dietary behavior (soda consumption per week and perceived importance of body weight: r = −.827, p = .01), self-esteem (weight and endurance: r = .801, p = .03), and fitness levels (weight and curl-ups completed in 30 seconds: r = −.729, p = .04). This study shows promising evidence that this nutrition education intervention could be effective at increasing nutrition knowledge, thus potentially affecting future dietary behaviors of adolescent girls.

Healthy Living Interventions in a Residential Girl Scout Camp

Lifestyle habits developed in childhood often carry over into adulthood and that developing healthy habits at a young age can help prevent weight-related health problems later in life. The purpose of this study was to develop and implement an interventional curriculum based on nutrition, physical activity, and self-concept in adolescent girls to promote the development of healthy lifestyle habits. Ten girls between 11 and 14 years old (n = 12.5 ± 0.97) were recruited to participate in a five-day Girl Scout camp. Physical parameters were measured and each participant filled out a questionnaire regarding eating habits, nutritional knowledge, physical activity, and self-concept. Educational curriculum and activities corresponding to the above domains were incorporated into each day. Participants were guided in setting goals for healthy lifestyle changes over the coming months and provided with journals to track their progress. It was found that 60% of participants had a Body Mass Index (BMI) above the 85th percentile. All participants scored positive in self-concept, but a negative correlation was found between BMI percentile and selfconcept. Notable relationships were found between variables of nutrition, physical activity, and self-concept. Results suggested that the participants were of an important age range during which self-concept was still positive and was beginning to be shaped, indicating adolescence as a good time to intervene and influence positive self-concept through understanding the relationship of nutrition and physical activity on health.