Context: Gait termination time (GTT) has been used to predict falls in older adults but has not been explored in the sport rehabilitation setting. The incorporation of a concurrent cognitive task as a complex measure of gait in this clinical population could lead to better health-related outcomes. Objective: To compare the effect of planned and unplanned gait termination with and without a concurrent cognitive task on reaction time (RT), gait velocity, and GTT. Design: Cross-sectional. Setting: Laboratory. Participants: Twenty young adults (females 60.0%, age 20.1 [0.9] y, height 169.5 [8.8] cm, mass 67.4 [10.8] kg). Intervention: Participants completed 6 planned and 6 unplanned gait termination trials on an instrumented gait mat with and without a cognitive task. Main Outcome Measures: The authors measured RT (s), gait velocity (m/s), GTT (s), and normalized GTT (s2/m). A 2 (motor) × 2 (cognitive) repeated-measures analysis of variance (α = .05) was used; significant interaction effects were explored using Bonferroni-corrected t tests (α < .008). Results: Participants walked more slowly during dual-task trials compared with single-task trials (F 1,19 = 4.401, P = .050). Participants walked significantly more slowly with a cognitive task during planned (P < .001, mean difference = −0.184 m/s, 95% CI, −0.256 to −0.111) and unplanned (P = .001, mean difference = −0.111 m/s, 95% CI, −0.173 to −0.050) gait termination. Participants walked significantly more slowly (P < .001, mean difference = −0.142 m/s, 95% CI, −0.210 to −0.075) when performing the most difficult task, unplanned termination with a cognitive task, than when performing the least difficult task, planned termination with no cognitive task. We observed a cognitive task main effect such that adding a cognitive task increased RT (F 1,19 = 16.375, P = .001, mean difference = −0.118 s, 95% CI, −0.178 to −0.057) and slowed normalized GTT (F 1,19 = 5.655, P = .028, mean difference = −0.167 s2/m, 95% CI, −0.314 to −0.020). Conclusions: Overall, participants displayed more conservative gait strategies and slower RT, normalized GTT, and gait velocity as task difficulty increased. More investigation is needed to truly understand the clinical meaningfulness of these measures in athletic injuries.
Rachel S. Johnson, Kendall H. Scott, and Robert C. Lynall
Robert C. Lynall, Rachel S. Johnson, Landon B. Lempke, and Julianne D. Schmidt
Context: Reaction time is commonly assessed postconcussion through a computerized neurocognitive battery. Although this measure is sensitive to postconcussion deficits, it is not clear if computerized reaction time reflects the dynamic reaction time necessary to compete effectively and safely during sporting activities. Functional reaction time assessments may be useful postconcussion, but reliability must be determined before clinical implementation. Objective: To determine the test–retest reliability of a functional reaction time assessment battery and to determine if reaction time improved between sessions. Design: Cohort. Setting: Laboratory. Participants: Forty-one participants (21 men and 20 women) completed 2 time points. Participants, on average, were 22.5 (2.1) years old, 72.5 (11.9) cm tall, had a mass of 71.0 (13.7) kg, and were mostly right leg and hand dominant (92.7%). Interventions: Participants completed 2 clinical reaction time tests (computerized Stroop and drop stick) and 5 functional reaction time tests (gait, jump landing, single-leg hop, anticipated cut, and unanticipated cut) across 2 sessions. Drop stick and functional reaction time assessments were performed in single (motor task only) and dual task (motor task with cognitive task). Main Outcome Measures: Reaction time (in seconds) was calculated during all assessments. Test–retest reliability was determined using 2-way mixed-effects intraclass correlation coefficients (3, k). Paired samples t tests compared mean reaction time between sessions. Results: Test–retest reliability was moderate to excellent for all reaction time outcomes (intraclass correlation coefficients [3, k] range = .766–.925). Several statistically significant between-session mean differences were observed, but effect sizes were negligible to small (d range = 0.05–0.44). Conclusions: The functional reaction time assessment battery displayed similar reliability to the standard computerized reaction time assessment battery and may provide important postinjury information, but more research is needed to determine clinical utility.
Landon B. Lempke, Jeonghoon Oh, Rachel S. Johnson, Julianne D. Schmidt, and Robert C. Lynall
Context: Laboratory-based movement assessments are commonly performed without cognitive stimuli (ie, single-task) despite the simultaneous cognitive processing and movement (ie, dual task) demands required during sport. Cognitive loading may critically alter human movement and be an important consideration for truly assessing functional movement and understanding injury risk in the laboratory, but limited investigations exist. Objective: To comprehensively examine and compare kinematics and kinetics between single- and dual-task functional movement among healthy participants while controlling for sex. Design: Cross-sectional study. Setting: Laboratory. Patients (or Other Participants): Forty-one healthy, physically active participants (49% female; 22.5 ± 2.1 y; 172.5 ± 11.9 cm; 71.0 ± 13.7 kg) enrolled in and completed the study. Intervention(s): All participants completed the functional movement protocol under single- and dual-task (subtracting by 6s or 7s) conditions in a randomized order. Participants jumped forward from a 30-cm tall box and performed (1) maximum vertical jump landings and (2) dominant and (3) nondominant leg, single-leg 45° cuts after landing. Main Outcome Measures: The authors used mixed-model analysis of variances (α = .05) to compare peak hip, knee, and ankle joint angles (degrees) and moments (N·m/BW) in the sagittal and frontal planes, and peak vertical ground reaction force (N/BW) and vertical impulse (Ns/BW) between cognitive conditions and sex. Results: Dual-task resulted in greater peak vertical ground reaction force compared with single-task during jump landing (mean difference = 0.06 N/BW; 95% confidence interval [CI], 0.01 to 0.12; P = .025) but less force during dominant leg cutting (mean difference = −0.08 N/BW; 95% CI, −0.14 to −0.02; P = .015). Less hip-flexion torque occurred during dual task than single task (mean difference = −0.09 N/BW; 95% CI, −0.17 to −0.02). No other outcomes were different between single and dual task (P ≥ .053). Conclusions: Slight, but potentially important, kinematic and kinetic differences were observed between single- and dual-task that may have implications for functional movement assessments and injury risk research. More research examining how various cognitive and movement tasks interact to alter functional movement among pathological populations is warranted before clinical implementation.
Richelle M. Williams, Rachel S. Johnson, Alison R. Snyder Valier, R. Curtis Bay, and Tamara C. Valovich McLeod
Context: Concussions are shown to hinder multiple health dimensions, including health-related quality of life (HRQOL), suggesting a need for a whole-person approach to assessment and treatment. Patient-reported outcome measures are one method to gather the patient’s perspective regarding their HRQOL. Objective: To evaluate perceived HRQOL using the Patient-Reported Outcomes Measurement Information System Pediatric-25 subscale in patients throughout concussion recovery. Design: Prospective cohort, descriptive survey. Setting: There were 9 high school athletic training facilities. Participants: A total of 70 patients with diagnosed concussions (51 males, 7 females, 12 unreported; age = 15.7 [0.9] y, height = 174.6 [8.4] cm, mass = 72.8 [14.8] kg, grade = 10.0 [0.9] level). Interventions: Patient-Reported Outcomes Measurement Information System Pediatric-25 was administered at 3 days, 10 days postconcussion, and return to play (RTP). Main Outcome Measures: Patient-Reported Outcomes Measurement Information System Pediatric-25 subscale T scores and self-reported concussion history (yes/no). Results: A total of 70 patients completed the study. For the Pediatric-25 subscales, the severity of problems associated with Physical Function Mobility, Anxiety, Depression, Fatigue, and Pain Interference were highest 3 days postconcussion, decreasing at 10 days and RTP (all p < .05). No differences were found between days 3 and 10 for Peer Relationship scores, but improvements were identified at RTP (p < .05). Pediatric-25 subscale scores at the 3 measurements were not statistically associated with concussion history (all p > .05). Ceiling and floor effects were present in all subscales throughout each timepoint, except for Physical Function Mobility (14.7%), and pain interference (11.8%) at day 3 postinjury. Conclusions: Patients who had suffered a concussion improved from day 3 through RTP on multiple health domains as demonstrated through the Pediatric-25 subscales. These findings highlight the need for health care professionals to serially monitor HRQOL and social factors that may affect the patient postconcussion as part of a multifactorial assessment. Ceiling effects in high functioning adolescent athletes were present; thus, efforts should be made to identify appropriate scales for use in managing recovery in athletic populations.
Courtney D. Hall, Carolyn K. Clevenger, Rachel A. Wolf, James S. Lin, Theodore M. Johnson II, and Steven L. Wolf
The use of low-cost interactive game technology for balance rehabilitation has become more popular recently, with generally good outcomes. Very little research has been undertaken to determine whether this technology is appropriate for balance assessment. The Wii balance board has good reliability and is comparable to a research-grade force plate; however, recent studies examining the relationship between Wii Fit games and measures of balance and mobility demonstrate conflicting findings. This study found that the Wii Fit was feasible for community-dwelling older women to safely use the balance board and quickly learn the Wii Fit games. The Ski Slalom game scores were strongly correlated with several balance and mobility measures, whereas Table Tilt game scores were not. Based on these findings, the Ski Slalom game may have utility in the evaluation of balance problems in community-dwelling older adults.
Rachel S. Johnson, Mia K. Provenzano, Larynn M. Shumaker, Tamara C. Valovich McLeod, and Cailee E. Welch Bacon
It is hypothesized that cognitive activity following a concussion may potentially hinder patient recovery. While the recommendation of cognitive rest is often maintained and rationalized, a causal relationship between cognitive activity and symptom duration has yet to be established.
Does the implementation of cognitive rest as part of the postconcussion management plan reduce the number of days until the concussed adolescent patient is symptom free compared to a postconcussion management plan that does not incorporate cognitive rest?
Summary of Key Findings:
A thorough literature search returned 7 possible studies; 5 studies met the inclusion criteria and were included. Three studies indicated that increased cognitive activity is associated with longer recovery from a concussion, and, therefore, supported the use of cognitive rest. One study indicated that the recommendation for cognitive rest was not significantly associated with time to concussion symptom resolution. One study indicated that strict rest, defined as 5 days of no school, work, or physical activity; might prolong symptom duration.
Clinical Bottom Line:
There is moderate evidence to support the prescription of moderate cognitive rest for concussed patients. Clinicians who intend on implementing cognitive rest in their concussion protocols should be aware of inconsistencies and be open-minded to alternative treatment progressions while taking into consideration each individual patient and maintaining adequate patient-centered care principles.
Strength of Recommendation:
Grade B evidence exists that prescription of moderate cognitive rest for concussed patients may be beneficial as a supplement to physical rest as treatment for symptom reduction in adolescents.